U.S. patent application number 17/306525 was filed with the patent office on 2021-11-04 for catheter apparatuses for modulation of nerves in communication with pulmonary system and associated systems and methods.
The applicant listed for this patent is Medtronic Ardian Luxembourg S.a.r.l.. Invention is credited to Paul Coates.
Application Number | 20210338321 17/306525 |
Document ID | / |
Family ID | 1000005712403 |
Filed Date | 2021-11-04 |
United States Patent
Application |
20210338321 |
Kind Code |
A1 |
Coates; Paul |
November 4, 2021 |
CATHETER APPARATUSES FOR MODULATION OF NERVES IN COMMUNICATION WITH
PULMONARY SYSTEM AND ASSOCIATED SYSTEMS AND METHODS
Abstract
Devices, systems, and methods for the selective positioning of
an intravascular neuromodulation device are disclosed herein. Such
systems can include, for example, an elongated shaft and a
therapeutic assembly carried by a distal portion of the elongated
shaft. The therapeutic assembly is configured for delivery within a
blood vessel. The therapeutic assembly can include one or more
energy delivery elements configured to deliver therapeutic energy
to nerves proximate a vessel wall.
Inventors: |
Coates; Paul; (Santa Rosa,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Medtronic Ardian Luxembourg S.a.r.l. |
Luxembourg |
|
LU |
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|
Family ID: |
1000005712403 |
Appl. No.: |
17/306525 |
Filed: |
May 3, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15515977 |
Mar 30, 2017 |
11013554 |
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PCT/IB2015/002240 |
Nov 13, 2015 |
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17306525 |
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62080189 |
Nov 14, 2014 |
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62080248 |
Nov 14, 2014 |
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62082635 |
Nov 21, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 2018/0022 20130101;
A61B 2018/00404 20130101; A61B 2018/00279 20130101; A61B 2018/00255
20130101; A61B 2018/00148 20130101; A61B 2018/00375 20130101; A61B
2018/00577 20130101; A61B 2018/00351 20130101; A61B 2018/00267
20130101; A61B 18/1492 20130101; A61B 18/0206 20130101; A61B
2018/00511 20130101; A61B 2018/1407 20130101; A61B 2018/00839
20130101; A61B 2090/3966 20160201; A61B 2018/0262 20130101; G01R
5/26 20130101; A61B 2018/00434 20130101; A61B 2018/0025 20130101;
A61B 2018/00214 20130101; A61B 2218/002 20130101; A61N 2007/0026
20130101; A61B 2018/0212 20130101 |
International
Class: |
A61B 18/14 20060101
A61B018/14; A61B 18/02 20060101 A61B018/02; G01R 5/26 20060101
G01R005/26 |
Claims
1.-18. (canceled)
19. A magnetically-deformable catheter system, comprising: a
magnetic field generator configured to generate and deliver a
magnetic field; a catheter including: an elongated shaft having a
proximal portion and a distal portion, wherein the distal portion
of the elongated shaft is configured for intravascular delivery to
a vessel of a patient; and a magnetically actuatable portion
coupled to the distal portion of the elongated shaft, wherein the
magnetically actuatable portion deforms to a desired shaft
configuration when the magnetic field generator generates the
magnetic field.
20. The magnetically-deformable catheter system of claim 19,
wherein the catheter includes: an energy delivery element
positioned along the elongated shaft and configured to modulate
nerves within the vessel of the patient.
21. The magnetically-deformable catheter system of claim 19,
wherein the catheter avoids total occlusion of the vessel and
allows blood to flow through portions of the vessel.
22. The magnetically-deformable catheter system of claim 19,
wherein the magnetic field generator is a magnetic resonance
imaging system.
23. The magnetically-deformable catheter system of claim 19,
wherein the magnetic field generator is configured to deliver the
magnetic field to the magnetically actuatable portion of the
elongated shaft to deform the magnetically actuatable portion.
24. The magnetically-deformable catheter system of claim 19,
wherein the magnetic field generator is configured to be positioned
external to the patient.
25. The magnetically-deformable catheter system of claim 19,
wherein the energy delivery element is positioned at the distal
portion of the elongated shaft and is configured to delivery radio
frequency (RF) energy sufficient to ablate nerves within the vessel
of the patient.
26. The magnetically-deformable catheter system of claim 19,
wherein the vessel of the patient is a pulmonary vessel.
27. The magnetically-deformable catheter system of claim 19,
wherein the magnetically actuatable portion includes a plurality of
magnetically actuatable portions.
28. A catheter apparatus, comprising: an elongated shaft having a
proximal portion and a distal portion, wherein the distal portion
of the elongated shaft is configured for intravascular delivery to
a vessel of a patient; and a magnetically actuatable portion
coupled to the distal portion of the elongated shaft, wherein the
magnetically actuatable portion deforms to a desired shaft
configuration when a magnetic field generator generates the
magnetic field.
29. The catheter apparatus of claim 28, further comprising: an
energy delivery element positioned along the elongated shaft and
configured to modulate nerves within the vessel of the patient.
30. The catheter apparatus of claim 28, wherein the catheter
apparatus avoids total occlusion of the vessel and allows blood to
flow through portions of the vessel.
31. The catheter apparatus of claim 28, wherein the magnetic field
generator is configured to deliver the magnetic field to the
magnetically actuatable portion of the elongated shaft to deform
the magnetically actuatable portion.
32. The catheter apparatus of claim 28, wherein the magnetic field
generator is configured to be positioned external to the
patient.
33. The catheter apparatus of claim 28, wherein the energy delivery
element is positioned at the distal portion of the elongated shaft
and is configured to delivery radio frequency (RF) energy
sufficient to ablate nerves within the vessel of the patient.
34. The catheter apparatus of claim 28, wherein the vessel of the
patient is a pulmonary vessel.
35. The catheter apparatus of claim 28, wherein the magnetically
actuatable portion includes a plurality of magnetically actuatable
portions.
36. A magnetically-deformable catheter system, comprising: a
magnetic field generator configured to generate and deliver a
magnetic field and positioned external to a patient; a catheter
including: an elongated shaft having a proximal portion and a
distal portion, wherein the distal portion of the elongated shaft
is configured for intravascular delivery to a vessel of the
patient; and a magnetically actuatable portion coupled to the
distal portion of the elongated shaft, wherein the magnetically
actuatable portion deforms to a desired shaft configuration when
the magnetic field generator generates the magnetic field.
37. The magnetically-deformable catheter system of claim 36,
wherein the magnetic field generator is configured to deliver the
magnetic field to the magnetically actuatable portion of the
elongated shaft to deform the magnetically actuatable portion.
38. The magnetically-deformable catheter system of claim 36,
wherein the catheter includes: an energy delivery element that is
positioned at the distal portion of the elongated shaft and is
configured to delivery radio frequency (RF) energy sufficient to
ablate nerves within the vessel of the patient.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is a continuation application of U.S.
patent application Ser. No. 15/515,977, titled "CATHETER
APPARATUSES FOR MODULATION OF NERVES IN COMMUNICATION WITH
PULMONARY SYSTEM AND ASSOCIATED SYSTEMS AND METHODS", filed on Mar.
30, 2017, which is a National Stage Application under 35 U.S.C.
.sctn. 371 of International Application No. PCT/IB2015/002240,
titles, "CATHETER APPARATUSES FOR MODULATION OF NERVES IN
COMMUNICATION WITH THE PULMONARY SYSTEM AND ASSOCIATED SYSTEMS",
filed on Nov. 13, 2015, which claims priority to and the benefit of
U.S. Provisional Application No. 62/080,189, titled "CATHETER
APPARATUSES FOR PULMONARY ARTERY NEUROMODULATION AND ASSOCIATED
SYSTEMS AND METHODS", filed on Nov. 14, 2014, U.S. Provisional
Application No. 62/080,248, titled "METHODS AND APPARATUS FOR
TREATING PULMONARY HYPERTENSION", filed on Nov. 14, 2014, and U.S.
Provisional Application No. 62/082,635, titled "CATHETER
APPARATUSES FOR MODULATION OF NERVES IN COMMUNICATION WITH THE
PULMONARY SYSTEM AND ASSOCIATED SYSTEMS AND METHODS", filed on Nov.
21, 2014, all of which are incorporated herein by reference in
their entireties. Further, components and features of embodiments
disclosed in the applications incorporated by reference may be
combined with various components and features disclosed and claimed
in the present application.
TECHNICAL FIELD
[0002] The present technology relates generally to modulation of
nerves that communicate with the pulmonary system (e.g., pulmonary
neuromodulation or "PN") and associated systems and methods. In
particular, several embodiments are directed to radio frequency
("RF") ablation catheter apparatuses for intravascular modulation
of nerves that communicate with the pulmonary system and associated
systems and methods.
BACKGROUND
[0003] Pulmonary hypertension is an increase in blood pressure in
the pulmonary vasculature. When portions of the pulmonary
vasculature are narrowed, blocked or destroyed, it becomes harder
for blood to flow through the lungs. As a result, pressure within
the lungs increases and makes it hard for the heart to push blood
through the pulmonary arteries and into the lungs, thereby causing
the pressure in the arteries to rise. Also, because the heart is
working harder than normal, the right ventricle becomes strained
and weak, which can lead to heart failure. While there are
pharmacologic strategies to treat pulmonary hypertension, there is
no curative therapy other than lung transplantation. Thus, there is
a strong public-health need for alternative treatment
strategies.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Many aspects of the present technology can be better
understood with reference to the following drawings. The components
in the drawings are not necessarily to scale. Instead, emphasis is
placed on illustrating clearly the principles of the present
technology.
[0005] FIG. 1 is a partially-schematic view of a neuromodulation
system configured in accordance with an embodiment of the present
technology.
[0006] FIG. 2A is an enlarged side view illustrating a therapeutic
assembly of the catheter of FIG. 1 in a low-profile configuration
in accordance with an embodiment of the present technology.
[0007] FIG. 2B is a further enlarged cut-away view of a portion of
the therapeutic assembly FIG. 2A in accordance with an embodiment
of the present technology.
[0008] FIG. 2C is a cross-sectional end view taken along line 2C-2C
in FIG. 2A.
[0009] FIG. 3A1 is an illustrative cross-sectional anatomical front
view showing the advancement of the catheter shown in FIG. 1 along
an intravascular path in accordance with an embodiment of the
present technology.
[0010] FIG. 3A2 is an illustrative cross-sectional anatomical front
view showing the advancement of the catheter shown in FIG. 1 along
another intravascular path in accordance with an embodiment of the
present technology.
[0011] FIG. 3B is a side view of the therapeutic assembly shown in
FIG. 2A within the main pulmonary artery in a low-profile
configuration in accordance with an embodiment of the present
technology.
[0012] FIG. 3C is a side view of the therapeutic assembly shown in
FIG. 2A within the main pulmonary artery in a deployed
configuration in accordance with an embodiment of the present
technology.
[0013] FIG. 3D is a side view of the therapeutic assembly shown in
FIG. 2A within the left pulmonary artery in a deployed
configuration in accordance with an embodiment of the present
technology.
[0014] FIG. 3E is a side view of the therapeutic assembly shown in
FIG. 2A within the right pulmonary artery in a deployed
configuration in accordance with an embodiment of the present
technology.
[0015] FIG. 4 is a side view of a therapeutic assembly having a
single wire electrode configured in accordance with an embodiment
of the present technology.
[0016] FIGS. 5A-5B are schematic representations illustrating
rotational directions of the therapeutic assembly as noted by
opposite arrow directions.
[0017] FIG. 6 is a schematic side view of a catheter having an
inner sheath configured in accordance with an embodiment of the
present technology.
[0018] FIGS. 7 A-7B are side views of a catheter having an inner
sheath positioned within the left pulmonary artery configured in
accordance with an embodiment of the present technology.
[0019] FIG. 8 is a side view of a therapeutic assembly in a
deployed configuration having an anchoring device positioned within
the left pulmonary artery in accordance with an embodiment of the
present technology.
[0020] FIG. 9 is a side view of a therapeutic assembly in a
deployed configuration having an anchoring device positioned within
the left pulmonary artery in accordance with an embodiment of the
present technology.
[0021] FIG. 10 is a side view of a therapeutic assembly having an
anchoring device (shown in cross-section) within the right
pulmonary artery in a deployed configuration in accordance with an
embodiment of the present technology.
[0022] FIG. 11 is a side view of a therapeutic assembly having an
anchoring device within the right pulmonary artery in a deployed
configuration in accordance with an embodiment of the present
technology.
[0023] FIG. 12 is a side view of a therapeutic assembly having an
extendable shaft within the left pulmonary artery in a deployed
configuration in accordance with an embodiment of the present
technology.
[0024] FIG. 13 is a side view of a therapeutic assembly
mechanically isolated from the shaft within the right pulmonary
artery in a deployed configuration in accordance with an embodiment
of the present technology.
[0025] FIG. 14 is a side view of therapeutic assemblies in a
deployed configuration in accordance with an embodiment of the
present technology.
[0026] FIG. 15 is a side view of a therapeutic assembly having an
inflection section in a deployed configuration in accordance with
an embodiment of the present technology.
[0027] FIG. 16A is a side view of a catheter in a low-profile state
configured in accordance with an embodiment of the present
technology. A few exemplary deployed states are shown in phantom
lines for purposes of illustration.
[0028] FIG. 16B is an enlarged side view of a portion of the distal
portion of the catheter of FIG. 16A in a low-profile state
configured in accordance with an embodiment of the present
technology.
[0029] FIG. 16C is a cross-sectional end view of the shaft shown in
FIG. 16B taken along the line 16C-16C.
[0030] FIG. 17A is a perspective view of a distal portion of a
catheter in a low-profile state configured in accordance with an
embodiment of the present technology.
[0031] FIG. 17B is an isolated, enlarged view of the treatment
member of FIG. 17A configured in accordance with an embodiment of
the present technology.
[0032] FIG. 17C is a side view of the distal portion of the
catheter shown in FIG. 17A in a low-profile state configured in
accordance with an embodiment of the present technology.
[0033] FIG. 17D is a side view of the distal portion of the
catheter shown in FIG. 17A in a deployed state configured in
accordance with an embodiment of the present technology.
[0034] FIG. 18 is a schematic representation of a
magnetically-deformable catheter system configured in accordance
with an embodiment of the present technology.
[0035] FIG. 19 is a cross-sectional end view of a non-occlusive
catheter system shown deployed in a vessel and configured in
accordance with an embodiment of the present technology.
[0036] FIG. 20 is a cross-sectional end view of a non-occlusive
catheter system shown deployed in a vessel and configured in
accordance with another embodiment of the present technology.
[0037] FIG. 21A is an enlarged isometric view of a therapeutic
assembly configured in accordance with an embodiment of the present
technology.
[0038] FIG. 21B is an enlarged partially schematic view of a distal
portion of a treatment device within a blood vessel in accordance
with an embodiment of the present technology.
[0039] FIG. 22A is an enlarged isometric view of an electrode
assembly configured in accordance with another embodiment of the
present technology.
[0040] FIG. 22B is an enlarged partially schematic view of a distal
portion of a treatment device within a blood vessel in accordance
with another embodiment of the present technology.
[0041] FIG. 22C is an enlarged partially schematic view of a distal
portion of a treatment device within a blood vessel in accordance
with yet another embodiment of the present technology.
[0042] FIG. 23 is an enlarged partially schematic side view of a
distal portion of a treatment device within a blood vessel in
accordance with a further embodiment of the present technology.
[0043] FIG. 24 is an enlarged side view of a distal portion of a
treatment device within a blood vessel in accordance with yet
another embodiment of the present technology.
[0044] FIG. 25 is an enlarged side view of a distal portion of a
treatment device within a blood vessel in accordance with a further
embodiment of the present technology.
[0045] FIG. 26 is an enlarged side view of a distal portion of a
treatment device within a blood vessel in accordance with an
additional embodiment of the present technology.
[0046] FIG. 27 is a block diagram illustrating a method of
endovascularly monitoring nerve activity in accordance with an
embodiment of the present technology.
[0047] FIG. 28 is a block diagram illustrating a method of
endovascularly monitoring nerve activity in accordance with another
embodiment of the present technology.
DETAILED DESCRIPTION
[0048] The present technology is directed to neuromodulation
devices and associated systems and methods. directed to catheters
neuromodulation ("PN"). Some embodiments of the present technology,
for example, are and associated systems and methods for pulmonary
Specific details of several embodiments of the technology are
described below with reference to FIGS. 1-28. PN is the partial or
complete incapacitation or otherwise effective disruption of nerves
that communicate with the pulmonary system. For example, PN may
inhibit, reduce, and/or block neural communication along neural
fibers (i.e., efferent and/or afferent nerve fibers) innervating
the pulmonary vessels. Such incapacitation can be long-term (e.g.,
permanent or for periods of months, years, or decades) or
short-term (e.g., for periods of minutes, hours, days, or weeks).
PN is expected to efficaciously treat pulmonary hypertension.
Subjects with pulmonary hypertension generally have high blood
pressure in the lung vasculature that may lead to heart failure and
they may, for example, experience symptoms such as dyspnea
(shortness of breath), syncope, fatigue, chest pain and/or edema,
and/or other symptoms as well. PN using methods and/or devices
described herein may provide a therapeutically beneficial reduction
in one or more of these symptoms. Additionally, PN using the
methods and/or devices of the present technology may modulate the
release of circulating mediators of the nervous system (e.g., the
sympathetic nervous system) and/or neuroendocrine system, thereby
providing systemic modulation of such mediators and/or modulating
the function of specific body organs other than the lungs. For
example, the lungs produce significant quantities of catecholamines
that affect heart rate, blood pressure, blood glucose levels, etc.,
and PN using the methods and/or devices of the present technology
may increase or decrease the amount of catecholamines released from
the lungs.
[0049] The catheters, systems and methods of the present technology
may effect PN in and/or near one or more pulmonary vessels. As used
herein, "pulmonary vessel(s)" include any blood vessel that is
adjacent to and/or provides intravascular access proximate to
neural pathways that communicate with the pulmonary system. For
example, pulmonary vessels can include pulmonary veins and
pulmonary arteries, such as the main pulmonary artery ("MPA"), the
bifurcated portion of the pulmonary artery, the right pulmonary
artery ("RPA"), the left pulmonary artery ("LPA"), segmental
pulmonary arteries, and sub-segmental pulmonary arteries. Other
non-limiting examples of pulmonary vessels include the right
ventricular outflow tract, pulmonary arterioles, and/or any branch
and/or extension of any of the pulmonary vessels described above.
In some embodiments, the catheters, systems and methods of the
present technology may effect PN in and/or near one or more
pulmonary arteries (pulmonary arterial neuromodulation or "PAN").
For example, the present technology may effect neuromodulation at a
distal portion of the MP A and/or in one or more branches (e.g.,
distal branches) of the MPA. In certain embodiments, the present
technology may effect neuromodulation at or near the pulmonary
valve (e.g., to affect nerves above and/or below the pulmonary
valve).
[0050] As used herein, the terms "distal" and "proximal" define a
position or direction with respect to the treating clinician or the
clinician's control device (e.g., a handle assembly). "Distal" or
"distally" are a position distant from or in a direction away from
the clinician or clinician's control device. "Proximal" and
"proximally" are a position near or in a direction toward the
clinician or clinician's control device.
[0051] It is typically advantageous to at least generally maintain
the position of a neuromodulation unit relative to the surrounding
anatomy during a neuromodulation treatment. For example, it can be
advantageous to at least generally maintain stable contact between
a therapeutic element of a neuromodulation unit and an inner wall
of a body lumen (e.g., a blood vessel, a duct, an airway, or
another naturally occurring lumen within the human body) during a
neuromodulation treatment. In an alternative embodiment, it may be
advantageous to maintain the position of the therapeutic element at
the center of the vessel lumen or in some cases, offset from the
center of the vessel lumen by a particular distance. This can
enhance control and/or monitoring of the treatment, reduce trauma
to the body lumen, and/or have other advantages. In some cases, at
least generally maintaining the position of a neuromodulation unit
relative to the target anatomy during a neuromodulation treatment
can be challenging. For example, certain organs and/or body tissues
may move in response to respiration, cardiac contraction and
relaxation. peristaltic movement within blood vessels, and patient
movement. Such movement of organs and other tissues in a patient's
body can cause movement of a catheter shaft within a vessel or
other disadvantageous relative movement between a neuromodulation
unit connected to the shaft and the anatomy at a target site.
Moreover, it may be challenging to maintain a device at the target
site. For example, a pulmonary artery may generally be tapered,
which can make it difficult to securely deploy certain device
configurations there.
[0052] Another difficulty may exist with respect to initial
positioning of a neuromodulation unit. When a neuromodulation unit
is initially positioned at a treatment location within a pulmonary
vessel or other body lumen (e.g., a renal vessel), the position of
the neuromodulation unit may be suboptimal. For example, a catheter
and/or a sheath carrying the catheter may be insufficiently
flexible to match the curvature of anatomy near the treatment
location (e.g., the curvature of a pulmonary artery between the MPA
and the RPA and/or LPA). This may cause the catheter and/or the
sheath to enter the body lumen out of alignment with a longitudinal
dimension or other feature of the body lumen. When a
neuromodulation unit of a misaligned catheter is initially moved
into an expanded form, the neuromodulation unit may also be
misaligned with the body lumen. When a neuromodulation unit is
misaligned, one or more therapeutic elements of the neuromodulation
unit may be out of contact or in poor contact with an inner wall of
a body lumen, thereby resulting in suboptimal (or no) energy
delivery to a target site. Even when the neuromodulation unit is
sufficiently well aligned for treatment to begin, misalignment and
migration may occur later and disturb the wall contact, potentially
requiring the treatment to be aborted. Correcting misalignment of a
neuromodulation unit can be challenging when the neuromodulation
unit remains directly attached to an associated shaft trapped at a
sharp turn.
I. SELECTED EMBODIMENTS OF CATHETERS AND RELATED DEVICES
[0053] FIG. 1 is partially-schematic diagram illustrating a
pulmonary neuromodulation system 100 ("system 100") configured in
accordance with an embodiment of the present technology. The system
100 includes an intravascular catheter 110 operably coupled to an
energy source or energy generator 132 via a connector 130 (e.g., a
cable). The catheter 110 can include an elongated shaft 116 having
a proximal portion 114 and a distal portion 118. The catheter 110
also includes a handle assembly 112 at the proximal portion 114.
The catheter 110 can further include a therapeutic assembly 104
carried by or affixed to the distal portion 118 of the elongated
shaft 116, and the therapeutic assembly 104 can have one or more
energy delivery elements 106 configured to modulate nerves at or
near the treatment location. The elongated shaft 116 can be
configured to intravascularly locate the therapeutic assembly 104
at a treatment location within a pulmonary artery, renal artery, or
other blood vessel or, in a non-vascular delivery, through the
esophagus, a bronchus, or another naturally occurring body lumen of
a human patient.
[0054] The energy generator 132 can be configured to generate a
selected form and/or magnitude of energy for delivery to the
treatment site via the electrode(s) 106 of the therapeutic assembly
104. For example, the energy generator 132 can include an energy
source (not shown) configured to generate RF energy (monopolar or
bipolar), pulsed RF energy, microwave energy, optical energy,
ultrasound energy (e.g., intravascularly delivered ultrasound,
extracorporeal ultrasound, high-intensity focused ultrasound
(HIFU)), direct heat energy, chemicals, radiation (e.g., infrared,
visible, gamma), or another suitable type of energy. In some
embodiments of devices, the devices may be configured for use with
a source of cryotherapeutic energy, and/or for use with a source of
one or more chemicals (e.g., to provide the cryotherapeutic energy
and/or chemical(s) to a target site for PAN). In a particular
embodiment, the energy generator 132 includes an RF generator
operably coupled to one or more electrodes 106 of the therapeutic
assembly 104.
[0055] In some embodiments, instead of or in addition to the energy
delivery elements 106, the therapeutic assembly 104 can have ports
or other substance delivery features to produce chemically based
neuromodulation by delivering one or more chemicals. For example,
suitable chemicals include guanethidine, one or more alcohols
(e.g., ethanol), phenol, a neurotoxin (e.g., vincristine), or other
suitable agents selected to alter, damage, or disrupt nerves.
Additionally, in some embodiments the substance delivery features
can be configured to deliver one or more pain management agents
(e.g., an anesthetic agent) to the treatment site and/or one or
more substances that enhance or otherwise control energy delivered
by one or more electrodes 106 and/or effect nerve sensitivity or
activation.
[0056] Furthermore, the energy generator 132 can be configured to
control, monitor, supply, or otherwise support operation of the
catheter 110. For example, a control mechanism, such as foot pedal
144, may be connected (e.g., pneumatically connected or
electrically connected) to the energy generator 132 to allow an
operator to initiate, terminate and/or adjust various operational
characteristics of the energy generator, such as power delivery. In
some embodiments, the energy generator 132 may be configured to
provide delivery of a monopolar electric field via the electrode(s)
106. In such embodiments, one or more neutral or dispersive
electrodes 142 may be electrically connected to the energy
generator 132 and selectively positioned at a location within the
patient's body (e.g., at, near, or within the esophagus, a
bronchus, etc.) and/or attached to the exterior of the patient (not
shown). The dispersive electrode 142 can be positioned to direct
the applied electric field in a particular direction and/or towards
or away from a particular anatomical location. Also, it can be
advantageous to position the dispersive electrode such that it does
not interfere with the line of sight of the imaging device.
[0057] In some embodiments, the system 100 includes a remote
control device (not shown) that can be configured to be sterilized
to facilitate its use within a sterile field. The remote control
device can be configured to control operation of the therapeutic
assembly 104, the energy generator 132, and/or other suitable
components of the system 100. For example, the remote control
device can be configured to allow for selective activation of the
therapeutic assembly 104. In other embodiments, the remote control
device may be omitted and its functionality may be incorporated
into the handle 112 or energy generator 132.
[0058] As shown in FIG. 1, the energy generator 132 can further
include an indicator or display screen 136. The energy generator
132 can include other indicators, including one or more LEDs, a
device configured to produce an audible indication, and/or other
suitable communicative devices. In the embodiment shown in FIG. 1,
the display 136 includes a user interface configured to receive
information or instructions from a user and/or provide feedback to
the user. For example, the energy generator 132 can be configured
to provide feedback to an operator before, during, and/or after a
treatment procedure via the display 136. The feedback can be based
on output from one or more sensors (not shown) associated with the
therapeutic assembly 104 such as temperature sensor(s), impedance
sensor(s), current sensor(s), voltage sensor(s), flow sensor(s),
chemical sensor(s), ultrasound sensor(s), optical sensor(s),
pressure sensor(s) and/or other sensing or monitoring devices. In
some embodiments, the sensors can be used to monitor or detect the
presence or location of target neural structures and/or assess the
extent or efficacy of the treatment, as discussed in greater detail
below with reference to FIGS. 21-28.
[0059] The system 100 can further include a controller 146 having,
for example, memory (not shown) and processing circuitry (not
shown). The memory and storage devices are computer-readable
storage media that may be encoded with non-transitory,
computer-executable instructions such as diagnostic algorithm(s)
133, control algorithm(s) 140, and/or evaluation/feedback
algorithm(s) 138. The control algorithms 140 can be executed on a
processor (not shown) of the system 100 to control energy delivery
to the electrodes 106. In some embodiments, selection of one or
more parameters of an automated control algorithm 140 for a
particular patient may be guided by diagnostic algorithms 133 that
measure and evaluate one or more operating parameters prior to
energy delivery. The diagnostic algorithms 133 provide
patient-specific feedback to the clinician prior to activating the
electrodes 106 which can be used to select an appropriate control
algorithm 140 and/or modify the control algorithm 140 to increase
the likelihood of efficacious neuromodulation.
[0060] Although in the embodiment shown in FIG. 1 the controller
146 is incorporated into the energy generator 132, in other
embodiments the controller 146 may be an entity distinct from the
energy generator 132. For example, additionally or alternatively,
the controller 146 can be a personal computer(s), server
computer(s), handheld or laptop device(s), multiprocessor
system(s), microprocessor-based system(s), programmable consumer
electronic(s), digital camera(s), network PC(s), minicomputer(s),
mainframe computer(s), and/or any suitable computing
environment.
[0061] In some embodiments, the energy source 132 may include a
pump 150 or other suitable pressure source (e.g., a syringe)
operably coupled to an irrigation port (not shown) at the distal
portion 118 of the catheter 110. In other embodiments, the pump 150
can be a standalone device separate from the energy source 132.
Positive pressure generated by the pump 150 can be used, for
example, to push a protective agent (e.g., saline) through the
irrigation port to the treatment site. In yet other embodiments,
the catheter 110 can include an adapter (not shown) (e.g., a luer
lock) configured to be operably coupled to a syringe (not shown)
and the syringe can be used to apply pressure to the shaft 116. In
a particular embodiment, the pump 150 or other suitable pressure
source can be configured to push one or more of the aforementioned
deliverable agents through the irrigation port to the treatment
site (e.g., chemically-based neuromodulation agents, pain
management agents, energy-enhancement/control agents, agents that
affect nerve sensitivity or activation, etc.).
[0062] FIG. 2A is a side view of the therapeutic assembly 104 in a
low-profile or delivery state in accordance with an embodiment of
the present technology. A proximal region 208 of the therapeutic
assembly 104 can be carried by or affixed to the distal portion 118
of the elongated shaft 116. For example, all or a portion (e.g., a
proximal portion) of the therapeutic assembly 104 can be an
integral extension of the shaft 116. A distal region 206 of the
therapeutic assembly 104 may terminate distally with, for example,
an atraumatic, flexible curved tip 214 having an opening 212 at its
distal end. In some embodiments, the distal region 206 of the
therapeutic assembly 104 may also be configured to engage another
element of the system 100 or catheter 110.
[0063] FIG. 2B is an enlarged view of a portion of the therapeutic
assembly 104 of FIG. 2A, and FIG. 2C is a cross-sectional end view
taken along line 2C-2C in FIG. 2A. Referring to FIGS. 2A-2C
together, the therapeutic assembly 104 can include the one or more
energy delivery elements 106 carried by a helical/spiral-shaped
support structure 210. The helical/spiral support structure 210 can
have one or more turns (e.g., two turns, etc.). Examples of
suitable energy delivery elements include RF electrodes, ultrasound
transducers, cryotherapeutic cooling assemblies, and/or other
elements that deliver other types of energy. The energy delivery
elements 106, for example, can be separate band electrodes axially
spaced apart along the support structure 210 (e.g., adhesively
bonded, welded (e.g., laser bonded) or bonded by mechanical
interference to the support structure 210 at different positions
along the length of the support structure 210). In other
embodiments, the therapeutic assembly 104 may have a single energy
delivery element 106 at or near the distal portion 118 of the shaft
116.
[0064] In embodiments where the support structure includes more
than one energy delivery element, the support structure can
include, for example, between 1 and 12 energy delivery elements
(e.g., 1 element, 4 elements, 10 elements, 12 elements, etc.). In
some embodiments, the energy delivery elements can be spaced apart
along the support structure every 1 mm to 50 mm, such as every 2 mm
to every 15 mm (e.g., every 10 mm, etc.). In the deployed
configuration, the support structure and/or therapeutic assembly
can have an outer diameter between about 12 mm and about 20 mm
(e.g., between about 15 mm and about 18 mm). Additionally, the
support structure and energy delivery elements can be configured
for delivery within a guide catheter between 5 Fr and 9 Fr. In
other examples, other suitable guide catheters may be used, and
outer dimensions and/or arrangements of the catheter 110 can vary
accordingly.
[0065] In some embodiments, the energy delivery elements 106 are
formed from gold, platinum, alloys of platinum and iridium, other
metals, and/or other suitable electrically conductive materials.
The number, arrangement, shape (e.g., spiral and/or coil
electrodes) and/or composition of the energy delivery elements 106
may vary. The individual energy delivery elements 106 can be
electrically connected to the energy generator 132 by a conductor
or bifilar wire 300 (FIG. 2C) extending through a lumen 302 of the
shaft 116 and/or support structure 210. For example, the individual
energy delivery elements 106 may be welded or otherwise
electrically coupled to corresponding energy supply wires 300, and
the wires 300 can extend through the elongated shaft 116 for the
entire length of the shaft 116 such that proximal ends of the wires
300 are coupled to the handle 112 and/or to the energy generator
132.
[0066] In a particular embodiment, the catheter 110 can include an
electrical element 211 (FIG. 2A) positioned along the shaft 116
between the energy delivery elements 106 and the proximal portion
of the shaft 116. The electrical element 211 can be electrically
coupled to the energy delivery elements I 06 via their respective
bifilar wires 300. The catheter 110 can include an additional
bifilar wire (not shown) that electrically couples the electrical
element 211 and the energy generator 132. The additional bifilar
wire, for example, can extend proximally from the electrical
element 211 through the shaft 116 such that the proximal end of the
wire is coupled to the handle 112 and/or to the generator 132. In
some embodiments, the electrical element 211 can include an
analog-to-digital converter configured to receive an analog signal
from the energy generator 132 and transmit a digital signal to the
energy delivery elements 106. Use of an analog-to-digital converter
can be advantageous because, unlike analog signals, digital signals
are not susceptible to interference. In these and other
embodiments, the electrical element 211 can include a multiplexer
configured to independently transmit signals to and/or from one or
more of the energy delivery elements.
[0067] As shown in the enlarged cut-away view of FIG. 2B, the
support structure 210 can be a tube (e.g., a flexible tube) and the
therapeutic assembly 104 can include a pre-shaped control member
220 positioned within the tube. Upon deployment, the control member
220 can form at least a portion of the therapeutic assembly 104
into a deployed state (FIG. 3C-3E). For example, the control member
220 can have a pre-set configuration that gives at least a portion
of the therapeutic assembly 104 a helical/spiral configuration in
the deployed state (FIG. 3C-3E). In some embodiments, the control
member 220 includes a tubular structure comprising a Nitinol
multifilar stranded wire with a lumen 222 therethrough and sold
under the trademark HELICAL HOLLOW STRAND.RTM. (HHS), and
commercially available from Fort Wayne Metals of Fort Wayne, Ind.
The lumen 222 can define a passageway for receiving a guide wire
(not shown) that extends proximally from the opening 212 (FIG. 2A)
at the tip 214 of the therapeutic assembly 104. In other
embodiments, the control member 220 may be composed of different
materials and/or have a different configuration. For example, the
control member 220 may be formed from nickel-titanium (Nitinol),
shape memory polymers, electro-active polymers or other suitable
shape memory materials that are pre-formed or pre-shaped into the
desired deployed state. Alternatively, the control member 220 may
be formed from multiple materials such as a composite of one or
more polymers and metals.
[0068] As shown in FIG. 2C, the support structure 210 can be
configured to fit tightly against the control member 220 and/or
wires 300 to reduce space between an inner portion of the support
structure 210 and the components positioned therein. For example,
the control member 220 and the inner wall of the support structure
210 can be in intimate contact such that there is little or no
space between the control member 220 and the support structure 210.
Such an arrangement can help to reduce or prevent the formation of
wrinkles in the therapeutic assembly 104 during deployment. The
support structure 210 may be composed of one or more polymer
materials such as polyamide, polyimide, polyether block amide
copolymer sold under the trademark PEBAX.RTM., polyethylene
terephthalate ("PET"), polypropylene, aliphatic,
polycarbonate-based thermoplastic polyurethane sold under the
trademark CARBOTHANE.RTM., ELASTHANE.RTM. TPU, a polyether ether
ketone ("PEEK") polymer, or another suitable material that provides
sufficient flexibility to the support structure 210.
[0069] In some embodiments, when the therapeutic assembly 104
and/or support structure 210 is in deployed configuration, the
therapeutic assembly 104 and/or support structure 210 preferably
define a minimum width of greater than or equal to approximately
0.040''. Additionally, the support structure 210 and energy
delivery elements 106 are configured for delivery within a guide
catheter no smaller than a 5 French guide catheter. In other
examples, other suitable guide catheters may be used, and outer
dimensions and/or arrangements of the catheter 110 can vary
accordingly.
[0070] Referring to FIG. 2A, the curved tip 214 can be configured
to provide an exit (e.g., via the opening 212) for a guide wire
that directs the guide wire away from a wall of a vessel or lumen
at or near a treatment location. As a result, the curved tip 214
can facilitate alignment of the therapeutic assembly 104 in the
vessel or lumen as it expands from the delivery state shown in FIG.
2A. Furthermore, the curved tip 214 can reduce the risk of injuring
a wall of the vessel or lumen when a distal end of a guide wire is
advanced from the opening 212. The curvature of the tip 214 can be
varied depending upon the particular sizing/configuration of the
therapeutic assembly 104 and/or anatomy at a treatment location. In
some embodiments, the tip 214 may also comprise a radiopaque marker
(not shown) and/or one or more sensors (not shown) positioned
anywhere along the length of the tip 214. For example, in some
embodiments, the tip 214 can include one or more layers of material
(e.g., the same or different materials) and the radiopaque marker
can be sandwiched between two or more layers. Alternatively, the
radiopaque marker can be soldered, glued, laminated, or
mechanically locked to the exterior surface of the tip 214. In
other embodiments, the entire tip 214 or a portion of the tip 214
can be made of or include a radiopaque material and/or the tip 214
can be coated with a radiopaque material. The tip 214 can be
affixed to the distal end of the support structure 210 via
adhesive, crimping, over-molding, or other suitable techniques.
[0071] The flexible curved tip 214 can be made from a polymer
material (e.g., polyether block amide copolymer sold under the
trademark PEBAX.RTM.), a thermoplastic polyether urethane material
(sold under the trademarks ELASTHANE.RTM. or PELLETHANE.RTM.), or
other suitable materials having the desired properties, including a
selected durometer. As noted above, the tip 214 is configured to
provide an opening for the guide wire, and it is desirable that the
tip itself maintain a desired shape/configuration during operation.
Accordingly, in some embodiments, one or more additional materials
may be added to the tip material to help improve tip shape
retention. In one particular embodiment, for example, about 5 to 30
weight percent of siloxane can be blended with the tip material
(e.g., the thermoplastic polyether urethane material), and electron
beam or gamma irradiation may be used to induce crosslinking of the
materials. In other embodiments, the tip 214 may be formed from
different material(s) and/or have a different arrangement.
II. SELECTED DELIVERY EMBODIMENTS
[0072] Referring to FIGS. 3A1 and 3A2, intravascular delivery of
the therapeutic assembly 104 can include percutaneously inserting a
guide wire 115 within the vasculature at an access site and
progressing the guidewire to the MPA. Suitable access sites
include, for example, the femoral (FIG. 3A1), brachial, radial,
axillary, jugular (FIG. 3A2) or subclavian arteries or veins. The
lumen 222 (FIGS. 2B and 2C) of the shaft 116 and/or therapeutic
assembly 104 can be configured to receive a guide wire 115 in an
over-the-wire or rapid exchange configuration. As shown in FIG. 3B,
the shaft and the therapeutic assembly (in the delivery state) can
then be advanced along the guide wire 115 until at least a portion
of the therapeutic assembly 104 reaches the treatment location. As
illustrated in FIG. 3A, a section of the proximal portion 114 of
the shaft 116 can be extracorporeally positioned and manipulated by
the operator (e.g., via the actuator 128 shown in FIG. 1) to
advance the shaft through the sometimes tortuous intravascular path
and remotely manipulate the distal portion of the shaft.
[0073] Image guidance, e.g., computed tomography (CT), fluoroscopy,
intravascular ultrasound (IVUS), optical coherence tomography
(OCT), intracardiac echocardiography (ICE), or another suitable
guidance modality, or combinations thereof, may be used to aid the
clinician's positioning and manipulation of the therapeutic
assembly 104. For example, a fluoroscopy system (e.g., including a
flat-panel detector, x-ray, or c-arm) can be rotated to accurately
visualize and identify the target treatment site. In other
embodiments, the treatment site can be located using IVUS, OCT,
and/or other suitable image mapping modalities that can correlate
the target treatment site with an identifiable anatomical structure
(e.g., a spinal feature) and/or a radiopaque ruler (e.g.,
positioned under or on the patient) before delivering the catheter
110. Further, in some embodiments, image guidance components (e.g.,
IVUS, OCT) may be integrated with the catheter 110 and/or run in
parallel with the catheter 110 to provide image guidance during
positioning of the therapeutic assembly 104. For example, image
guidance components (e.g., IVUS or OCT) can be coupled to a distal
portion of the catheter 110 to provide three-dimensional images of
the vasculature proximate the target site to facilitate positioning
or deploying the therapeutic assembly 104 within the target blood
vessel.
[0074] Once the therapeutic assembly 104 is positioned at a
treatment location, such as within a pulmonary artery, the guide
wire 115 can be at least partially removed (e.g., withdrawn) from
or introduced (e.g., inserted) into the therapeutic assembly 104 to
transform or otherwise move the therapeutic assembly 104 to a
deployed configuration. FIG. 3C is a side view of the therapeutic
assembly 104 shown in FIG. 2A within the main pulmonary artery in a
deployed configuration, FIG. 3D is a side view of the therapeutic
assembly 104 within the left pulmonary artery, and FIG. 3E is a
side view of the therapeutic assembly 104 within the right
pulmonary artery in accordance with an embodiment of the present
technology. As shown in FIGS. 3B-3D, in the deployed state, at
least a portion of the therapeutic assembly 104 can be configured
to contact an inner wall of a pulmonary artery and to cause a
fully-circumferential lesion without the need for repositioning.
For example, the therapeutic assembly 104 can be configured to form
a continuous or discontinuous lesion that is fully-circumferential
within a single plane perpendicular to the longitudinal axis of the
vessel (see, for example, FIG. 22A). In other embodiments, the
therapeutic assembly 104 can be configured to form a continuous or
discontinuous lesion that wraps around the circumference of the
vessel (one or more times) along a particular length of the vessel
(e.g., generally non-circumferential at longitudinal segments of
the treatment location). In several of such embodiments, the lesion
can have a helical/spiral configuration. This can facilitate
precise and efficient treatment with a low possibility of vessel
stenosis. In other embodiments, the therapeutic assembly 104 can be
configured to form a partially-circumferential lesion or a
fully-circumferential lesion at a single longitudinal segment of
the treatment location. In some embodiments, the therapeutic
assembly 104 can be configured to cause therapeutically-effective
neuromodulation (e.g., using ultrasound energy) without contacting
a vessel wall.
[0075] As shown in FIGS. 3C-3E, in the deployed state, the
therapeutic assembly 104 defines a substantially helical/spiral
structure in contact with the pulmonary artery wall along a
helical/spiral path. One advantage of this arrangement is that
pressure from the helical/spiral structure can be applied to a
large range of radial directions without applying pressure to a
circumference of the pulmonary vessel. Thus, the
spiral/helically-shaped therapeutic assembly 104 is expected to
provide stable contact between the energy delivery elements 106 and
the pulmonary vessel wall when the wall moves in any direction.
Furthermore, pressure applied to the pulmonary vessel wall along a
helical/spiral path is less likely to stretch or distend a
circumference of a vessel that could thereby cause injury to the
vessel tissue. Still another feature of the expanded helical/spiral
structure is that it may contact the pulmonary vessel wall in a
large range of radial directions and maintain a sufficiently open
lumen in the pulmonary vessel allowing blood to flow through the
helix/spiral during therapy. In other embodiments, the therapeutic
assembly 104 can define a circular structure (see, for example,
FIG. 22A) in contact with the pulmonary artery wall along a
circular or fully-circumferential path.
[0076] In some procedures it may be necessary to adjust the
positioning of the therapeutic assembly 104 one or more times. For
example, the therapeutic assembly 104 can be used to modulate
nerves proximate the wall of the main pulmonary artery, the left
pulmonary artery, and/or the right pulmonary artery and/or any
branch or extension. Additionally, in some embodiments the
therapeutic assembly 104 may be repositioned within the same
pulmonary vessel multiple times within the same procedure. After
repositioning, the clinician may then re-activate the therapeutic
assembly 104 to modulate the nerves.
[0077] Often times it may be advantageous to modulate nerves and/or
electrical signals at two or more locations within the body. As an
example, one device may be used to modulate renal nerves, while
another device is used to modulate electrical signals in the heart.
As another example, pulmonary neuromodulation may be effected in
one location in the body, while modulation of electrical signals
may be effected in the heart (e.g., simultaneously or
sequentially). In some embodiments, modulation may result in
denervation of one or more of the treated locations. In certain
embodiments, cardiac tissue (e.g., the right atrium of the heart of
a patient) may be ablated to modulate electrical signals within the
heart (e.g., preventing abnormal electrical signals from
occurring), and one or more renal arteries of the patient may also
be ablated to modulate nerves proximate the renal artery or renal
arteries (e.g., nerves extending along the outside of the renal
artery or renal arteries). The modulation of nerves and/or
electrical signals may result in a reduction in clinical symptoms
of pulmonary hypertension. Two or more different locations in the
body may be modulated in the same procedure (at the same time or at
different times) and/or in different procedures (e.g., one taking
place immediately after the other has been completed, or days,
weeks or months after the other has been completed). Additionally,
different types of denervation may be employed in one patient.
[0078] In some methods, mechanical devices may be used, such as a
device (e.g., an implant) that modulates blood flow, creates an
anastomosis, and/or affects baroreceptors. Such devices may be used
alone (e.g., multiple of the same type of device in different
locations), in combination with each other, and/or in combination
with devices that modulate nerves and/or electrical signals.
[0079] Although the embodiments shown in FIGS. 3C-3E show a
deployed therapeutic assembly 104 in a spiral or helically-shaped
configuration, in other embodiments, the therapeutic assembly 104
and/or other portions of the therapeutic assembly 104 can have
other suitable shapes, sizes, and/or configurations (e.g., bent,
deflected, zig-zag, Malecot, etc.). Examples of other suitable
therapeutic assembly configurations, deployment configurations
and/or deployment mechanisms can be found in: U.S. application Ser.
No. 12/910,631, filed Oct. 22, 2010; U.S. application Ser. No.
13/281,361, filed Oct. 25, 2011; U.S. Provisional Application No.
61/646,218, filed May 5, 2012; U.S. Provisional Application No.
61/895,297, filed Oct. 24, 2013; PCT Application No.
PCT/US11/57754, filed Oct. 25, 2011; U.S. Pat. No. 8,888,773, filed
Mar. 11, 2013; and U.S. patent application Ser. No. 13/670,452,
filed Nov. 6, 2012. All of the foregoing references are
incorporated herein by reference in their entireties. Non-limiting
examples of devices and systems include the Symplicity Flex.TM.,
the Symplicity Spyral.TM. multielectrode RF ablation catheter, and
the Arctic Front Advance.TM. cardiac cryoablation system.
[0080] FIG. 4 shows another embodiment of a therapeutic assembly
404 comprising a support structure 410 defined by a single wire
electrode 406. For example, the support structure 410 can be a
unipolar single metal wire (e.g., Nitinol) that is pre-formed into
a helical/spiral shape. The single wire electrode 406 can have a
continuous electrically conductive surface along all or a
significant part of its length such that it forms a continuous
helical lesion around a complete or nearly complete turn of the
spiral/helix. In some embodiments, the wire electrode 406 can have
a diameter of between about 0.002 inches and about 0.010 inches
(e.g., about 0.008 inches). In other embodiments, the therapeutic
assembly 404 can include a "ground" electrode that is electrically
insulated from the spiral at a more proximal portion of the
spiral/helix (e.g., a bipolar configuration). The spiral/helix can
have a constant diameter, or in other embodiments the spiral/helix
can have a varying diameter. For example, spiral/helix can have a
diameter that tapers in a distal direction or a proximal direction.
In other embodiments, the single wire electrode has discrete
dielectric coating segments that are spaced apart from each other
to define discrete energy delivery elements between the dielectric
coating segments. The single wire electrode can be made from a
shape memory metal or other suitable material. Additionally, the
control algorithm 140 (FIG. 1) can be adjusted to account for the
increased surface area contact of the single wire electrode 406
such that sufficient ablation depths can be achieved without
charring or overheating the inner wall of the vessel.
[0081] In some embodiments, the single wire electrode 406 can be
delivered with the guide catheter (not shown) or an additional
sheath (not shown) for precise positioning and deployment. The
guide catheter (not shown) can be advanced and/or manipulated until
positioned at a desired location proximate the treatment site. The
therapeutic assembly 404 can then be inserted through the guide
catheter. In some embodiments, the therapeutic assembly 404 expands
into a helical/spiral shape immediately once exiting a distal end
of the guide catheter. In other embodiments, the single wire
electrode 406 can be tubular and transforms into a helical/spiral
shape when a guide wire (placed therethrough) is removed in a
proximal direction. In yet other embodiments, the therapeutic
assembly 404 expands into a circular shape immediately once exiting
a distal end of the guide catheter.
A. Rotation Devices and Methods
[0082] As shown in FIGS. 5A and 5B, the therapeutic assembly 104
can be configured to rotate about a longitudinal axis A when
advanced distally from the shaft 116 or retracted proximally from
the shaft 116. For example, when the therapeutic assembly 104 is
advance distally, the spiral/helical structure can be rotated in a
first direction, as shown by arrows D in FIG. 5A. Likewise, when
the therapeutic assembly 104 is retracted proximally, the
spiral/helical structure can be rotated in a second direction, as
shown by arrows D2 in FIG. 5B. Such a rotational feature can be
particularly advantageous in the pulmonary vessels, since, at least
at the MPA and proximal portions of the LPA and RPA, the pulmonary
vessels have relatively large diameters that can require a large
number of lesions to provide fully-circumferential coverage and/or
effective. treatment. To compensate for this, effective treatment
in the pulmonary vessels can often times require multiple rotations
of the therapeutic assembly 104 to reposition the therapeutic
assembly 104 and achieve such a fully circumferential lesion.
Additionally, rotation of the therapeutic assembly 104 can aid in
maneuvering the therapeutic assembly 104 through a turn in a
vessel, such as when accessing a branch or segment of a larger
vessel (e.g., accessing the LPA and RPA from the MPA).
[0083] FIG. 6 is a side view of another embodiment of a catheter
618 configured in accordance with the present technology. The
catheter 618 can include a therapeutic assembly 604 generally
similar to the previously described therapeutic assembly 104
(referenced herein with respect to FIGS. 1-4). As shown in FIG. 6,
the catheter 618 includes an inner sheath 617 slidably positioned
within a guide catheter 616 between the guide catheter 616 and the
therapeutic assembly 604. In certain vessels, contact forces
between the therapeutic assembly 604 and the vessel wall can make
it difficult to rotate the therapeutic assembly 604 distally and/or
proximally. Likewise, a catheter and/or a sheath carrying the
catheter 618 may be insufficiently flexible to match the curvature
of anatomy near the treatment location, such as the curvature of a
pulmonary artery between the MPA and the RPA and/or LPA. This may
cause the catheter and/or the sheath to enter the body lumen out of
alignment with a longitudinal axis of the body lumen. Because of
the inner sheath 617 of the present technology, the guide catheter
616 and the inner sheath 617 can rotate along a central axis
independently of one another. Moreover, the inner sheath 617 can be
sufficiently flexible to de-couple at least the therapeutic
assembly 604 (positioned within a relatively stable pulmonary
vessel) from the catheter (e.g., the guide catheter 616) positioned
within or nearer to the contracting and expanding heart. This
feature can be advantageous because, for example, when at least a
portion of the catheter and/or shaft is positioned within the
heart, the guide catheter 616 often time translates the pumping
movement of the heart to the therapeutic assembly 604. In addition,
the inner sheath 617 can also selectively position the therapeutic
assembly 604 relative to the vessel wall. For example, in some
embodiments it may be advantageous to position the therapeutic
assembly 604 at a central location within the vessel lumen before,
during, or after energy delivery.
[0084] FIGS. 7A and 7B show examples of various deployment
configurations of the catheter with the inner sheath 617. As shown
in FIG. 7A, the shaft 616 can be advanced along the MPA just
proximal to the ostium of the LPA (or RPA (not shown)). The inner
sheath 617 (containing the therapeutic assembly 604) can then be
advanced past the distal end of the shaft 616 and into the LP A for
deployment of the therapeutic assembly 604. As shown in FIG. 7B, in
some embodiments the shaft 616 can be advanced just distal of the
pulmonary valve. The inner sheath 617 can then be advanced past the
distal end of the shaft 616, past the bifurcation, and into the LPA
for deployment of the therapeutic assembly 604.
B. Anchoring Devices and Methods
[0085] The PN systems and/or therapeutic assemblies discloses
herein can include one or more anchoring devices for stabilizing
the distal portion and/or therapeutic assembly relative to the
vessel wall and/or selectively positioning the distal portion
and/or therapeutic assembly relative to the vessel wall (e.g., at a
central location within the vessel lumen, selectively offset from
the center of the vessel lumen).
[0086] FIG. 8, for example, is a side view of another embodiment of
a catheter shown in the deployed configuration within the LPA in
accordance with the present technology. The catheter can be
generally similar to the previously described catheters 110 or
(referenced herein with respect to FIGS. 1-7A). However, as shown
in FIG. 8, the catheter includes fixation members 801 (shown
schematically for illustrative purposes only) along at least a
portion of its shaft 816 and/or inner sheath 817. The fixation
members 801 can be configured to contact the inner wall of the
pulmonary vessel and stabilize the distal portion 818 and/or
therapeutic assembly 804 with respect to the pulmonary vessel. Such
stabilization can be advantageous because the pulmonary vessels
constantly move as a result of the surrounding anatomy,
particularly the contraction and relaxation of the heart, and also
the respiratory cycle. As previously discussed, the most common
intravascular approach to the pulmonary vessel involves the
positioning of at least a portion of the catheter and/or shaft
within the heart. As a result, the shaft translates the pumping
movement of the heart to the therapeutic assembly 804. The fixation
members 801 can stabilize at least the therapeutic assembly 804
within the pulmonary vessel so that movement of the catheter (e.g.,
the shaft 816) will not affect the alignment and/or contact of the
therapeutic assembly 804 and the vessel wall. In some embodiments,
the fixation members 801 can be a traumatic or non-tissue
penetrating, and in other embodiments the fixation members 801 can
be tissue-penetrating (e.g., embedded in the tissue by radial
force). The fixation members 801 can have any size or configuration
suitable to stabilize the therapeutic assembly 804 relative to the
vessel.
[0087] FIG. 9 is a side view of another embodiment of a catheter
shown in the deployed configuration within the LPA in accordance
with the present technology. The catheter can include an expandable
inner sheath 901 that, when in the deployed configuration, expands
to an outer radius generally equal to or greater than the inner
radius of the vessel at the target location (e.g., a pulmonary
vessel). As such, at least a distal end 903 of the sheath 901 can
expand to engage the vessel wall thereby exerting a radially
outward force against the vessel wall and stabilizing the sheath
901. In some embodiments, the sheath 901 can comprise an expandable
stent-like structure which is collapsed in a delivery state within
the elongated shaft 916 and expanded to a deployed state when
advanced beyond a distal end 915 of the elongated shaft 916. Once
deployed, the sheath 901 helps to mechanically isolate the
therapeutic assembly 904 from the shaft 916. The sheath 901 can
have a generally tapered shape such that the distal end 903 of the
sheath 901 has a greater diameter than a proximal end (not shown).
In some embodiments, at least a portion of the sheath 901 can
include one or more fixation members configured to engage the
vessel wall.
[0088] FIG. 10 is a side view of another embodiment of a catheter
shown in the deployed configuration within the RP A in accordance
with the present technology. The catheter can include a guide
sheath 1006 and a circumferentially grooved or threaded elongated
member 1010 slideably positioned therethrough. As shown in FIG. 10,
the elongated member 1010 can be mated with an anchor 1002. Once
deployed, the anchor 1002 can be fixed or secured to the vessel
wall by frictional force and/or fixation members (not shown) (see
FIG. 8 and accompanying description). In operation, insertion of
the catheter 1017 from its proximal end (not shown) causes the
therapeutic assembly 1004 to rotate in a distal direction while the
anchor 1002 remains relatively generally stationary. In some
embodiments (not shown), the anchor 1002 can be fixed to the guide
sheath 1006.
[0089] FIG. 11 is a side view of another embodiment of a catheter
shown in the deployed configuration within the RPA in accordance
with the present technology. The catheter can include an expandable
anchor 1101 configured to expand against at least a portion of the
vessel wall and secure the therapeutic assembly 1104 relative to
the local anatomy. For example, as shown in FIG. 11, once advanced
distally past the catheter shaft 1106, the expandable anchor 1101
can expand and exert an outward force against the vessel wall. In
particular embodiments, the anchor 1101 can engage and/or exert a
contact force in one or more branches of the pulmonary artery
simultaneously. For example, as shown in the illustrated
embodiment, the anchor 1101 can span the bifurcation of the MPA
into the LPA and/or RPA. Additionally, the anchor 1101 can have a
tapered shape in the proximal and/or distal directions, and in
other embodiments, the anchor 1101 can have a relatively uniform
cross-sectional area along its length. In yet other embodiments,
the anchor 1101 can have a main body and one or more branches (not
shown) configured to be positioned within at least a portion of the
MPA and the LPA or RPA, respectively. In some embodiments, the
expandable anchor 1101 can be a stent, balloon, self-expanding
basket or other suitable expandable or shape-changing structures or
devices.
C. Tension-Relieving Devices and Methods
[0090] FIG. 12 is a side view of another embodiment of the catheter
having a collapsible inner shaft 1201 configured in accordance with
an embodiment of the present technology. At least a proximal
portion of the therapeutic assembly 1204 can be carried by the
inner shaft 1201. As shown in FIG. 12, the inner shaft 1201 can
have a "telescoping" design that allows the inner shaft 1201 to
extend and retract freely such that proximal and distal movement of
the shaft 1216 caused by the cardiac cycle, respiration, etc. will
not pull or push the therapeutic assembly 104 out of position.
Instead such motion is absorbed by the collapsible/extendable
design of the inner shaft 1201. In some embodiments, the catheter
can include a locking and/or activation mechanism (not shown) so
that the timing and/or extent of the extension/retraction of the
inner shaft 1201 can be controlled by the clinician. In further
embodiments, the inner shaft can be corrugated along at least a
portion of length to allow extension and retraction. Likewise, in a
particular embodiment, the inner shaft 1201 can be a braided
structure having a plurality of sections with alternating
flexibility (e.g., by altering wire diameter, wire count, etc.) As
a result, the sectioned inner shaft 1201 would allow for
compression and extension with motion, thus mechanically isolating
(at least in part) the therapeutic assembly 1204 from the shaft
1216.
[0091] FIG. 13 is a side view of another embodiment of the catheter
having a therapeutic assembly 1304 mechanically isolated from the
shaft 1316 by an isolating element 1315. The isolating element 1315
can include a first portion 1303 operably connected to the
therapeutic assembly 1304, a second portion 1305 operably connected
to the shaft 1316, and a connector 1301 therebetween. The connector
1301 can have enough slack such that the position of the
therapeutic assembly 1304 with respect to the vessel in which it is
expanded is generally unaffected by movement of the shaft 1316. As
discussed above, often times during cardiac contraction and
relaxation the movement of the shaft 1316 is strong enough to pull
or push the therapeutic assembly 1304 along the pulmonary vessel.
For example, when the heart contracts, the shaft 1316 can be pulled
distally by the contracting heart muscles, thereby pulling the
therapeutic assembly 1304 distally (and likely out of position).
The isolating element 1315 of the present technology mechanically
isolates the therapeutic assembly 1304 from the catheter shaft
1316, allowing the shaft to move while the therapeutic assembly
1304 remains relatively stationary. In some embodiments, the
catheter can include a locking and/or activation mechanism 1307
operably connected to the isolating element 1315 so that the timing
of the release of the therapeutic assembly 1304 from the shaft 1316
can be controlled by the clinician. Additional devices and
deployment methods for mechanical isolation of the therapeutic
assembly from the shaft and/or catheter can be found in U.S. patent
application Ser. No. 13/836,309, filed Mar. 15, 2013, titled
"CATHETERS HAVING TETHERED NEUROMODULATION UNITS AND ASSOCIATED
DEVICES, SYSTEMS, AND METHODS," which is incorporated herein by
reference in its entirety.
[0092] In some embodiments, the therapeutic assembly and/or support
structure can be modified to relieve tension between therapeutic
assembly and the shaft. For example, as shown in FIG. 14, the
support structure 1410 can include an extended segment 1401 at a
proximal section of the helical/spiral portion 1403 of the support
structure 1410 and/or therapeutic assembly 1404. Such an extension
can provide more slack and greater flexibility at the proximal
section of the helical/spiral portion 1403. Additionally, one or
more turns (labeled (1), (2), (3) and (4) in FIG. 14) can be added
to the support structure 1410 to increase flexibility and/or the
lengthening potential of the therapeutic assembly 1404. In a
particular embodiment shown in FIG. 15, an inflection section 1501
can be included along the generally straight portion of the support
structure 1510. Similar to the features described above with
reference to FIG. 14, the inflection section 1501 can provide the
added slack to absorb the disruptive motion of the shaft 1516.
D. Additional Embodiments
[0093] FIG. 16A is a side view of a catheter apparatus 1700
("catheter 1700") configured in accordance with an embodiment of
the present technology. The catheter 1700 can include a proximal
portion 1702, a distal portion 1704, a handle assembly 1706 at the
proximal portion 1702, and an elongated shaft 1710 extending
distally from the handle assembly 1706. The distal portion 1704 of
the elongated shaft 1710 can include an actuatable portion 1716 and
one or more energy delivery elements 1712 (e.g., electrodes). For
example, as shown in FIG. 16A, the catheter 1700 can include a
single energy delivery element 1712 positioned at a distal-most
portion of the shaft 1710. In other embodiments, the catheter 1700
can include more than one energy delivery element 1712 and/or one
or more energy delivery elements 1712 can be positioned at any
location along the length of the shaft 1710.
[0094] The handle assembly 1706 can include a control 1708 that is
electrically coupled to the actuatable portion 1716 at the distal
portion 1704 of the shaft 1710. For example, the catheter 1700 can
include one or more wires (not shown in FIG. 16A) extending
distally from the handle assembly 1706 through or along the shaft
to the actuatable portion 1716. As indicated by arrow A, movement
of the actuatable portion 1716 by the control 1708 can deflect,
flex and/or bend the distal portion 1704 of the shaft 1710 to space
the energy delivery element 1712 apart from a longitudinal axis L
of the shaft 1710. Such movement by the actuatable portion 1716 can
be used, for example, to place the energy delivery element 1712 in
apposition with a vessel wall at a treatment site, as explained in
greater detail below.
[0095] FIG. 16B is an enlarged side view of a portion of the distal
portion 1716, and FIG. 16C is a cross-sectional end view of the
shaft 1710 taken along line 17C-17C in FIG. 16B. Referring to FIGS.
16A-16C together, the actuatable portion 1716 can include four
deflectable members 1714a-d (referred to collectively as
deflectable members 1714) spaced apart about the circumference of
the shaft 1710. In the embodiment shown in FIGS. 16A-16C, the
deflectable members 1714 are evenly spaced apart about the
circumference of the shaft 1710 such that each deflectable member
1714a-d corresponds to a distinct quadrant of the shaft 1710. In
other embodiments, the actuatable portion 1716 can include more or
less than four deflectable members 1714 (e.g., one deflectable
member, two deflectable members, six deflectable members, etc.)
and/or the deflectable members 1714 can have any spacing about the
shaft 1710. The deflectable members 1714 can have a length less
than the length of the shaft. In one embodiment, the deflectable
members 1714 can have a distal terminus spaced proximally of the
energy delivery element 1712 and a proximal terminus within the
distal portion 1704 of the shaft 1710. For example, the deflectable
members 1714 can have a length of about 0.5 cm to about 10 cm,
about 1 cm to about 5 cm, or more specifically about 1 cm to about
2 cm. Each of the deflectable members 1714a-d can include a wire
1718a-d running therethrough (referred to collectively as wires
1718). Each of the wires 1718a-d can extend proximally from a
proximal portion one of the corresponding deflectable members
1714a-d along the shaft 1710 to the handle 1706. The wires 1718 can
be electrically isolated from one another in the shaft 1710 (e.g.,
via separate lumens (not shown), embedding the wires in a polymer,
etc.). As such, each of the deflectable members 1714a-d can be
independently electrically controlled from the handle assembly
1706.
[0096] In operation, upon positioning the distal portion 1704 of
the shaft 1710 at a treatment site adjacent a vessel wall (not
shown), one or more of the deflectable members 1714 can be actuated
to bend the distal portion 1704 in a desired direction. For
example, selection of deflectable member 1714a (e.g., via the
control) sends a current distally along the wire 1718a to the
deflectable member 1714a, thereby causing the deflectable member
1714a to bend outwardly (see arrow Ba) and away from the
longitudinal axis of the shaft 1710. The second-fourth deflectable
members 1714b-d can be actuated in a similar fashion (see arrows
B.sub.b, B.sub.c, B.sub.d). The ability of the present technology
to independently manipulate the distal portion of the shaft
(relative to the rest of the shaft) can be advantageous, especially
in a pulmonary setting, to compensate for the pulsatile, dynamic
flow conditions present with vessels in close proximity to the
heart. Moreover, such independent control can be advantageous to
finely tune the deformation of the distal portion to position or
navigate tortuous vasculature at and near the pulmonary system.
[0097] In some embodiments, the deflectable members 1714a-d can
individually comprise a bimetallic strip including a first material
having a first coefficient of thermal expansion (CTE) positioned
adjacent a second material having a second coefficient of thermal
expansion (CTE) that is different than the first CTE. The wires
1718a-d can be positioned between the first and second materials,
and the first and second materials can be coupled to one another
along their lengths. As the current flows through the wire 1718,
the first and second materials begin to heat. Because the first and
second materials have different CTE's, the lengths of the first and
second materials will expand at different rates. As a result, the
deflectable member will bend in the direction of the material with
the lower CTE. In some embodiments, the first and second materials
can comprise platinum (linear CTE of about 9 (10.sup.-6 K.sup.-1)),
aluminum (CTE of about 22.2 (10.sup.-6 K.sup.-1)), silver (linear
CTE of about 429 (10.sup.-6 K.sup.-1)), and steel (linear CTE of
about 13 (10.sup.-6 K.sup.-1)).
[0098] Additionally, the deflectable members 1714a-d can
individually comprise a piezoelectric material (e.g., an
electrical-mechanical polymer) positioned on or adjacent a
substrate material. The piezoelectric material and the substrate
material can be coupled to one another along their lengths such
that, when current is applied to the deflectable member (e.g., via
the wire 1718), the piezoelectric material elongates while the
substrate does not, thereby bending the deflectable member.
[0099] In some embodiments, the catheter 1700 can include a
plurality of actuatable portions spaced apart along the length of
the shaft 1710. When actuated, the plurality of actuatable portions
can bend the shaft 1710 at multiple locations and/or in different
directions. In such embodiments, the number, size, shape and/or
spacing of the deflectable members can be the same or different
amongst the actuatable portions.
[0100] FIG. 17A is a perspective view of a portion of a catheter
1800 in a low-profile state configured in accordance with another
embodiment of the present technology. As shown in FIG. 17 A, the
catheter 1800 can include a shaft 1810 having a proximal portion
(not shown) and a distal portion configured to be intravascularly
positioned at a treatment site. The distal portion can include a
recessed portion 1816 and an atraumatic distal end region 1812. The
recessed portion 1816 can house a deformable member 1802. An
isolated, enlarged view of the deformable member 1802 is shown in
FIG. 17B. Referring to FIGS. 17A and 17B together, the deformable
member 1802 can comprise a first conductive member 1806 positioned
on a second conductive member 1808. The first and second members
1806, 1808 can individually comprise a metal. In some embodiments,
the first member 1806 can be a first material having a first CTE
and the second member 1808 can be a second material having a second
CTE different than the first CTE. A wire 1814 extending from a
proximal portion of the catheter 1800 (not shown) can be coupled to
the first and second conductive members 1806, 1808. For example,
the wire 1814 can be positioned between the first and second
members 1806, 1808. The first and second conductive members 1806,
1808 can be coupled to one another along their lengths. In some
embodiments, the first and second conductive members can
individually comprise platinum (linear CTE of about 9 (10.sup.-6
K.sup.-1)), aluminum (CTE of about 22.2 (10.sup.-6 K.sup.-1)),
silver (linear CTE of about 429 (10.sup.-6 K.sup.-1)), and steel
(linear CTE of about 13 (10.sup.-6 K.sup.-1)).
[0101] Referring still to FIGS. 17A-17B, the first and second
conductive members 1806, 1808 can be coated or otherwise surrounded
by an insulative material. The first conductive member 1806 can
include two energy delivery elements 1804 comprising an exposed
portion of the first conductive member 1806 (e.g., an opening in
the insulative material). In other embodiments, the deformable
member 1804 can include more or less than two energy delivery
elements (e.g., one energy delivery element, three energy delivery
elements, etc.).
[0102] FIG. 17C is a side view of the distal portion of the
catheter 1800 in a low-profile state, and FIG. 17D is a side view
of the distal portion of the catheter 1800 in a deployed state. The
sidewalls of the recessed portion 1816 are shown in phantom lines
for ease of illustration. Referring to FIGS. 17A-17D together, as
the current flows through the wire 1814, the first and second
members conductive 1806, 1808 begin to heat. Because the first and
second conductive members 1806, 1808 have different CTE's, the
lengths of the first and second conductive members 1806, 1808 will
expand at different rates. As a result, the deformable member 1802
will bend in the direction of the material with the lower CTE,
thereby projecting away from the longitudinal axis of the shaft
1810 and into apposition with the vessel wall at the treatment
site.
[0103] FIG. 18 is a schematic representation of a
magnetically-deformable catheter system 1900 configured in
accordance with an embodiment of the present technology. As shown
in FIG. 18, the catheter system 1900 can include a magnetic field
generator 1902 (e.g., a magnetic resonance imaging (Mill) system,
etc.) configured to be positioned external to the patient P and a
catheter 1904. The catheter 1904 can include an elongated shaft
1910 and a magnetically actuatable portion 1906 coupled to a distal
portion of the elongated shaft 1910. When the magnetic field
generator 1902 is activated, the magnetic field deforms the
magnetically actuatable portion 1906 of the shaft 1910 (not shown)
to achieve a desired shaft 1910 configuration.
[0104] The catheter 1904 of FIG. 18 can have a single energy
delivery element 1908 or, in other embodiments the catheter 1900
can include more than one energy delivery element 1908 positioned
along the shaft 1910. Additionally, the catheter 1900 can include
more than one magnetically actuatable portion 1906 positioned along
the shaft 1910.
[0105] When modulating the nerves from within a pulmonary vessel,
it is desirable to avoid total occlusion of the vessel since 100%
of the body's blood flows through portions of the pulmonary
vasculature (e.g., the MPA). Several of the catheters, catheter
systems, and methods of the present technology provide
non-occlusive means for effectively modulating the nerves
communicating with the pulmonary system. In other embodiments, the
catheters, catheter systems, and methods of the present technology
can provide occlusive means for effectively modulating nerves
communicating with the pulmonary system.
[0106] FIGS. 19-20 are cross-sectional views of two additional
embodiments of such nonocclusive catheters. FIG. 19 shows a
non-occlusive catheter 2000 in a deployed state positioned in a
vessel V and configured in accordance with an embodiment of the
present technology. As shown in FIG. 19, the catheter 2000 can
include an ultrasound transducer 2002 that produces sound waves
(W), a first expandable member 2004 (e.g., a balloon, a wire cage,
etc.) positioned around the ultrasound transducer 2002, and a
second expandable member 2006 (e.g., a balloon, a wire cage, etc.)
positioned adjacent the first balloon 2004. When deployed, the
first and second expandable members 2004, 2006 together position
the ultrasound transducer 2002 near the vessel wall V at a desired
distance to achieve effective neuromodulation. As shown in FIG. 19,
the diameters of the first and second expandable members 2004, 2006
can be selected such that sufficient space S remains adjacent the
catheter 2000 within the vessel V, thereby allowing blood flow
during treatment.
[0107] FIG. 20 is a cross-sectional end view of another
non-occlusive catheter 2100 in a deployed state positioned in a
vessel V and configured in accordance with an embodiment of the
present technology. As shown in FIG. 20, the catheter 2100 can
include an ultrasound transducer 2102 positioned within a
donut-shaped expandable member 2104 (e.g., a balloon, a wire cage,
etc.). During treatment, blood can flow through the opening in the
expandable member 2104. It will be appreciated that the expandable
members of the present technology can have any suitable size,
shape, and configuration. For example, in some embodiments, the
expandable members can have a helical/spiral shape in a deployed
state.
E. Nerve Monitoring Devices and Methods
[0108] Any of the pulmonary neuromodulation systems and/or
therapeutic assemblies described herein can be configured to
stimulate nerves proximate the treatment site and/or record the
resultant nerve activity. For example, several embodiments of the
pulmonary neuromodulation systems and/or therapeutic assemblies
described herein can include a nerve monitoring assembly. FIG. 21A,
for example, is an enlarged isometric view of one embodiment of a
nerve monitoring assembly 2300 (also referred to herein as
"monitoring assembly 2300") configured in accordance with the
present technology. The monitoring assembly 2300 is configured to
provide stimulation to neural fibers and/or record activity of
nerves in communication with the pulmonary system. As shown in FIG.
21A, the monitoring assembly 2300 can include a first loop
electrode or conductor 2302a and a second loop electrode or
conductor 2302b (referred to collectively as loop electrodes 2302)
electrically isolated from the first loop electrode 2302a and
positioned at a distal portion 2312 of an elongated catheter shaft
2306. In the illustrated embodiment, the two loop electrodes 2302
form a generally circular shape. However, the term "loop electrode"
as used herein should be construed broadly to include electrodes
2302 having other shapes configured to contact at least a portion
of the interior wall of a vessel. In various embodiments, the first
loop electrode 2302a can be an anode, the other loop electrode 2302
can be a cathode, and an insulated portion 2304 can electrically
isolate the anode and cathode loop electrodes 2302 from one another
and space the loop electrodes 2302 laterally apart from one
another. For example, the distal end of the first loop electrode
2302a and the proximal end of the second loop electrode 2302b can
terminate at or within a portion of the insulating portion 2304,
and the insulating portion 2304 can space apart the loop electrodes
2302. In various embodiments, the separation between the loop
electrodes 2302 (e.g., provided by the insulating portion 2304) can
be selected to enhance the signal to noise ratio for recording
nerve activity (e.g., delta fibers and/or C-fibers). For example,
the first and second loop electrodes 2302a and 2302b can be spaced
about 5 mm apart from one another for recording action potentials
from delta fibers, and may be positioned further apart from one
another for recording C-fibers.
[0109] When the first and second loop electrodes 2302a and 2302b
are configured as an anode and a cathode, the monitoring assembly
2300 can deliver bipolar stimulation to nerves proximate a target
site in a vessel (e.g., nerves that communicate with the pulmonary
system) or provide bipolar recording of nerve activity proximate
the target site. For example, a nerve monitoring device configured
in accordance with one embodiment of the present technology can
include two electrode assemblies 2300: a first electrode assembly
configured to stimulate nerves and a second electrode assembly
spaced apart from the first electrode assembly along the
vasculature and configured to measure the action potential of the
nerves resulting from the stimuli of the first electrode assembly.
Action potential is the electrical activity developed in a nerve
cell during activity (e.g., induced by a stimulus from the first
electrode assembly).
[0110] The loop electrodes 2302 can have an outer diameter at least
equal to an inner diameter of a target vessel and, in some cases,
larger (e.g., 1.5 times larger) than the inner diameter of the
target vessel.
[0111] Each loop electrode 2302 can be made from a separate shape
memory wire that defines the electrode 2302. The shape memory wire
allows the loop electrodes 2302 to be positioned in a low profile,
delivery state during intravascular delivery to the target vessel
and open transverse to the longitudinal axis of the target vessel
to an expanded or deployed state (shown in FIG. 21A). For example,
the loop electrodes 2302 can be made from nitinol wires that can
self-expand to a predefined shape upon delivery at the target
vessel. In various embodiments, the shape memory material can be
coated (e.g., sputter coated) with gold, platinum, platinum
iridium, and/or other suitable materials. The coating can be
selected to substantially optimize the impedance of the assembly
2300 and/or enhance the signal-to-noise ratio recorded by the
electrode assembly 2300. In other embodiments, the loop electrodes
2302 can be made from other suitable materials (e.g., platinum,
gold, platinum iridium, stainless steel, aluminum, etc.). The wire
thickness of each loop electrode 2302 can be sized such that the
loop electrode 2302 is stable enough to maintain its shape during
nerve monitoring, yet flexible enough to allow for intravascular
delivery in a low profile arrangement to a peripheral vessel (e.g.,
a pulmonary blood vessel).
[0112] Each loop electrode 2302 of the monitoring assembly 2300 can
have an exposed abluminal surface 2308 (e.g., an outer surface
proximate the vessel wall during nerve monitoring) to deliver
and/or receive electrical signals to neural fibers proximate to a
target vessel and an insulated abluminal or luminal surface 2310
(e.g., an inner surface facing away from the vessel wall and toward
the lumen formed by the target vessel) to reduce the likelihood
that blood flowing through the target vessel will short circuit the
loop electrodes 2302. The luminal surface 2310 may be insulated
using a coating with a high dielectric constant, strong adhesive
properties to prevent it from rubbing off during delivery,
biocompatible properties suitable for intravascular use, and/or
other suitable characteristics.
[0113] As mentioned previously, the total exposed abluminal surface
2308 of the monitoring assembly 2300 can be selected to enhance the
signal-to-noise ratio of the assembly 2300.
[0114] The monitoring assembly 2300 can be delivered
intravascularly to a treatment site before and/or after
neuromodulation. The distal portion 2312 of the shaft 2306 can be
made from various flexible polymeric materials, such as a
polyethylene block amide copolymer (e.g., PEBAX.RTM., available
from Arkema of France), high-density polyethylene (HDPE), nylon,
polyimide, and/or other suitable materials, to facilitate
navigation through tortuous vasculature. The distal portion 2312
can also include braid reinforcement comprised of polymeric
materials to improve column strength, torque, and reduce kinking. A
proximal portion (not shown) of the shaft 2306 can be more stiff
than the distal portion 2312, and can therefore transmit force to
track the shaft 2306 through the vasculature to the target site
(e.g., proximate a pulmonary blood vessel). The proximal portion
2313 can be made from PEBAX.RTM., HDPE, low-density polyethylene
(LDPE), nylon, polyimidc, nylon, nitinol, a stainless steel
hypotube, and/or other suitable materials. In various embodiments,
the distal end portion of the assembly 2300 can include an
atraumatic tip when the monitoring assembly 2300 is in the delivery
state to reduce trauma to vessel walls as the monitoring assembly
2300 advances through the vasculature and deploys at the target
site. This atraumatic tip material can be made from various soft
materials, such as PEBAX.RTM., LDPE, other polymers, and/or other
suitable materials. The distal tip can also include a radiopaque
tip marker (electrically isolated from the loop electrodes 2302) to
provide visualization of the distal tip under fluoroscopy.
[0115] Signal wires 2311 (referred to individually as a first
signal wire 2311a and a second signal wire 2311b; shown in broken
lines) can be operatively coupled to the monitoring assembly 2300
to drive nerve stimulation, record nerve activity, and/or otherwise
provide a signal to the loop electrodes 2302. The signal wires
2311, for example, can be welded, soldered, crimped, and/or
otherwise connected to the shaft 2306. A distal portion of the
first signal wire 2311a can be operably coupled to the first loop
electrode 2302a, and a distal portion of the second signal wire
2311b can be operably coupled to the second loop electrode 2302b.
The signal wires 2311 can extend through the shaft 2306 to a
proximal end of the shaft where the signal wires 2311 can be
operatively connected to a signal processing console (e.g., the
energy generator 132 of FIG. 1) suitable for nerve stimulation. In
various embodiments, for example, one or more electrode assemblies
2300 can be operatively coupled to a NIM-Response Nerve Integrity
Monitor ("NIM") made available by Medtronic Xomed of Jacksonville,
Fla., which provides intraoperative nerve monitoring capabilities
using visual and/or audible indications of nerve activity.
Additionally, in those embodiments where the catheter and/or
treatment device includes an electrical element 211 (FIG. 2A), the
signal wires 2311 can extend from the monitoring assembly 2300 to
the electrical element 211. In such embodiments, the catheter can
include an additional set of wires (not shown) that extends between
(and electrically couples) the electrical element 211 and the
energy generator 132.
[0116] FIG. 21B is an enlarged partially schematic side view of a
distal portion 2350 positioned in a blood vessel A (e.g., a
pulmonary blood vessel) and configured in accordance with an
embodiment of the present technology. The distal portion 2350 can
include a therapeutic assembly 2320 (shown schematically) and a
nerve monitoring assembly 2330. The therapeutic assembly 2320 can
include features generally similar to the features of the
therapeutic assemblies described above with reference to FIGS.
1-20. The nerve monitoring assembly 2330 can be generally similar
to the nerve monitoring assembly 2300 of FIG. 21A. In the
illustrated embodiment, the therapeutic assembly 2320 is
operatively coupled to and positioned between two electrode
assemblies (identified individually as a first electrode assembly
2300a and a second electrode assembly 2300b) which together define
the nerve monitoring assembly 2330. In other embodiments, the
therapeutic assembly 2320 and the nerve monitoring assembly 2330
may be stand-alone devices that can be delivered independently to a
target site (e.g., within the pulmonary artery). For example, in
some embodiments the second electrode assembly 2300b, the
therapeutic assembly 2320 and the first electrode assembly 2300a
are coupled to separate catheter shafts and delivered sequentially
to the target site to provide a configuration similar to that shown
in FIG. 21B. In still other embodiments, the first and second
electrode assemblies 2300a and 2300b can be integrally coupled to
one another and delivered to the target site before and/or after
neuromodulation. The distal end of the first loop electrode 2302a1
(or 2302a2) and the proximal end of the second loop electrode
2302b1 (or 2302b2) can terminate at or within a portion of the
insulating portion 2304a (or 2304b), and the insulating portion
2304a (or 2304b) can space apart the loop electrodes 2302.
[0117] The nerve monitoring assembly 2330 can be configured to
stimulate nerves in communication with the pulmonary system
proximally with the first electrode assembly 2300a and record nerve
activity distally with the second electrode assembly 2300b. The
second electrode assembly 2300b can be positioned distal to the
first electrode assembly 2300a. In further embodiments, the second
electrode assembly 2300b can be configured to provide stimulation
and the first electrode assembly 2300a can be configured to record
the resultant nerve activity.
[0118] The first and second electrode assemblies 2300a and 2300b
can be spaced far enough apart from one another such that the
signal artifact associated with the bipolar stimulation from the
first electrode assembly 2300a, which is less than that which would
be produced by monopolar stimulation, does not substantially engulf
or otherwise interfere with the signal being recorded at the second
electrode assembly 2300b. The magnitude of the signal artifact at
the second electrode assembly 2300b depends at least in part on the
conduction velocity of the nerve fibers and the spacing between the
stimulus and recording electrodes. C-fibers and delta-fibers, such
as those found in nerves, have relatively low conduction velocities
(e.g., no more than 2 m/s for C-fibers and about 3-13 m/s for delta
fibers). As such, when the second electrode assembly 2300b is
configured to record activity of nerves in communication with the
pulmonary system, the second electrode assembly 2300b can be
positioned laterally apart from the first electrode assembly 2300a
along the axis of the pulmonary vessel A to reduce the signal
artifact recorded by the second electrode assembly 2300b. In
further embodiments, at least one of the electrode assemblies 2300
can be positioned outside the pulmonary blood vessel A. For
example, in some embodiments the second electrode assembly 2300b
can be positioned in the pulmonary blood vessel A to record nerve
activity, and the first electrode assembly 2300a can be positioned
elsewhere within the vasculature that can deliver a stimulus to
nerves in communication with the pulmonary system. In still other
embodiments, the first electrode assembly 2300a can be configured
to stimulate nerves from a location outside the human body (e.g.,
at the brain stem), and the second electrode assembly 2300b can be
configured to record the resultant nerve activity at a site within
or proximate to the pulmonary blood vessel A. In additional
embodiments, the electrode assemblies 2300 can be configured to be
placed at other suitable locations for stimulating and recording
nerve activity.
[0119] In various embodiments, the first electrode assembly 2300a
can be configured to provide biphasic and bipolar stimulation. The
second loop electrode 2302b.sub.1 (i.e., the electrode closest to
the recording/second electrode assembly 2302b) can be a cathode and
the first loop electrode 2302a.sub.1 an anode. The second electrode
assembly 2300b can be configured to provide bipolar recording of
nerve activity resulting from the stimulation induced by the first
electrode assembly 2300a. As such, the first loop electrode 2302a2
can be one of an anode or a cathode, and the second loop electrode
2302b2 can be the other of the anode or the cathode. The second
electrode assembly 2300b can pick up the relatively small action
potentials associated with activity of nerves in communication with
the pulmonary system, and can be sensitive to relatively small
signals to differentiate nerve stimulation from noise. In order to
pick up the small action potentials and differentiate the nerve
activity from noise (e.g., from the signal artifact, action
potentials of proximate muscle fibers, etc.), the second electrode
assembly 2300b can be configured to record a plurality of samples
that can be averaged (e.g., using an NIM or other suitable
console). In one embodiment, for example, the second electrode
assembly 2300b can average 160 samples within 12 seconds to
identify the nerve activity. In other embodiments, more or less
samples can be averaged to identify the nerve activity.
[0120] As shown in FIG. 21B, the first and second electrode
assemblies 2300a and 2300b and the therapeutic assembly 2320 can be
attached to the distal portion 2312 of the same shaft 2306 such
that the nerve monitoring assembly 2330 and the therapeutic
assembly 2320 can be delivered as a unit to the target site. In one
embodiment, for example, the therapeutic assembly 2320 includes a
neuromodulation loop electrode that is connected between the first
and second electrode assemblies 2300a and 2300b. The first and
second electrode assemblies 2300a and 2300b can be stiffer than the
neuromodulation loop electrode such that the electrode assemblies
2300a-b stay substantially planar in the vessel A and provide
adequate contact with the arterial walls to stimulate the nerves
and record the resultant nerve activity. The neuromodulation loop
electrode may be more flexible, allowing it to be pulled into a
helix or corkscrew configuration during deployment at the target
site while the first and second electrode assemblies 2300a and
2300b stay anchored against the vessel A due to self-expansion. In
other embodiments, each electrode assembly 2300a-b and/or the
therapeutic assembly 2320 can be attached to separate shafts and
delivered independently to the target site.
[0121] In various embodiments, the nerve monitoring assembly 2330
(in conjunction with or independent of the therapeutic assembly
2320) can be delivered intravascularly to the pulmonary artery A or
other peripheral vessel via a delivery sheath (not shown). The
delivery sheath can extend along the length of the shaft 2306, and
can be made from PEBAX.RTM., nylon, HDPE, LDPE, polyimide, and/or
other suitable materials for navigating the vasculature. The
delivery sheath can cover the electrode assemblies 2300a-b such
that they are positioned in a low profile, delivery state suitable
for navigation through the vasculature. At the pulmonary vessel A,
the delivery sheath can be moved relative to the electrode
assemblies 2300a-b (e.g., the sheath can be retracted or the
electrode assemblies 2300a-b can be advanced) to expose the
electrode assemblies 2300a-b from the sheath 2300. This allows the
electrode assemblies 2300a-b to deploy (e.g., self-expand) into an
expanded state where the abluminal surfaces 2308 of the loop
electrodes 2302 contact the vessel wall. In other embodiments, the
delivery sheath is not integrated with the nerve monitoring
assembly 2330, and is advanced over a guide wire to the treatment
site via a guide catheter. In this embodiment, the delivery sheath
can be made from a soft, flexible material that allows it to
navigate tortuous vessels. Once the delivery sheath is at the
target site in the pulmonary vessel A, the electrode assemblies
2300a-b can be positioned in a proximal opening of the delivery
sheath and advanced distally to the treatment site where they can
be deployed to the expanded state by moving the delivery sheath and
the electrode assemblies 2300a-b relative to one another.
[0122] As shown in FIG. 21B, in the expanded state, the loop
electrodes 2302 of the first and second electrode assemblies 2300a
and 2300b are sized to press against or otherwise contact the
interior wall of the pulmonary vessel A. The nerve monitoring
assembly 2330 can first monitor nerve activity in real time before
neuromodulation by delivering an electrical current proximal to a
treatment site via the first electrode assembly 2300a and recording
the resultant nerve activity at the second electrode assembly
2300b. The first and second loop electrodes 2302a.sub.1 and
2302b.sub.1 of the first electrode assembly 2300a can be operably
coupled to first and second signal wires 2311a.sub.1 and
2311b.sub.1, respectively, to provide bipolar stimulation, and the
first and second loop electrodes 2302a.sub.2 and 2302b.sub.2 of the
second electrode assembly 2300b can be operably coupled to two
separate signal wires 2311a.sub.2 and 2311b.sub.2, respectively, to
provide bipolar recording, or vice versa. Since the abluminal
surface 2308 (e.g., 2308a and 2308b) of the loop electrodes 2302
are fully exposed, the first electrode assembly 2300a can deliver
stimulation to nerves positioned around the full circumference of
the pulmonary vessel A. The exposed abluminal surface 2308 also
allows the second electrode assembly 2300b to capture nerve
activity regardless of nerve orientation around the circumference
of the vessel A. The insulated luminal surface 2310 (e.g., 2310a
and 2310b) of the loop electrodes 2302 insulates the electrode
assemblies 2300 from blood flowing through the pulmonary vessel A
to avoid a short circuit between the electrode loops 2302. The
recording can be visualized using a console (e.g., an NIM) coupled
to the proximal portion (not shown) of the shaft 2306.
[0123] The therapeutic assembly 2320 can then apply an energy field
to the target site to cause electrically-induced and/or
thermally-induced partial or full denervation of the nerves in
communication with the pulmonary system (e.g., using electrodes or
cryotherapeutic devices). The nerve monitoring assembly 2330 can
again stimulate and record the nerve activity to determine whether
sufficient neuromodulation occurred. If the nerve monitoring
assembly 2330 indicates the presence of a higher level of nerve
activity than desired, the therapeutic assembly 2320 can again
apply the energy field to effectuate neuromodulation. This process
of supplying a current, recording the resultant nerve activity, and
applying neuromodulation to the treatment site can be repeated
until the desired nerve lesion is achieved. In some embodiments,
such as when the therapeutic assembly 2320 uses cryotherapeutic
cooling, the nerve monitoring assembly 2330 can also record nerve
activity during denervation. Once nerve monitoring at the treatment
site is complete, the delivery sheath can again be advanced over
the electrode assemblies 2300a-b and/or the electrode assemblies
2300a-b can be retracted into the delivery sheath, thereby moving
the electrode assemblies 2300a-b back into the delivery state for
removal from the patient.
[0124] In further embodiments, the nerve monitoring assembly 2330
can be operatively coupled to the therapeutic assembly 2320 such
that nerve monitoring and neuromodulation can run automatically as
part of a preset program. In other embodiments, the nerve
monitoring assembly 2330 is not positioned around the therapeutic
assembly 2320, but instead delivered to the treatment site
separately before and/or after neuromodulation by the therapeutic
assembly 2320.
[0125] In various embodiments, the first and second electrode
assemblies 2300a and 2300b can be delivered after neuromodulation
to confirm the desired neuromodulation has occurred. For example,
the two electrode assemblies 2300a-b can be delivered proximate the
treatment site as separate components or as an integrated unit to a
vessel (e.g., the pulmonary vessel) during the neuromodulation
procedure a short time after neuromodulation occurs (e.g., 5
minutes after neuromodulation). In other embodiments, the electrode
assemblies 2300a-b can be used to monitor nerve activity during a
separate procedure following the neuromodulation procedure (e.g.,
1, 2 or 3 days after the neuromodulation procedure).
[0126] FIG. 22A is an enlarged isometric view of an electrode
assembly 2400 configured in accordance with another embodiment of
the present technology. The electrode assembly 2400 can include
features generally similar to the assembly 2300 described above
with reference to FIGS. 21A and 21B. For example, the electrode
assembly 2400 includes a loop 2402 (e.g., a nitinol wire) at a
distal portion 2412 of an elongated shaft 2406 that is configured
to provide bipolar, biphasic nerve stimulation and/or record the
resultant nerve activity. However, the electrode assembly 2400
shown in FIG. 22A includes a plurality of electrodes 2414
(identified individually as first through sixth electrodes 2414a-f,
respectively) positioned around the circumference of the loop 2402
spaced apart and electrically insulated from one another by
insulating sections 2416. The electrodes 2414 can be made from
stainless steel, gold, platinum, platinum iridium, aluminum,
nitinol, and/or other suitable materials, and the insulation
sections 2416 can be made from a suitable dielectric material
(e.g., a high-k dielectric with strong adhesive properties). The
electrodes 2414 can be substantially coplanar with an outer surface
of the insulating sections 2416 and/or the shaft 2406, or may
project beyond the insulating sections 2416 by a distance. In
various embodiments, for example, the electrodes 2414 can extend a
radial distance from the adjacent insulating portions 2416 and
include a smoothed edge (e.g., a beveled edge) to reduce denuding
of the adjacent arterial wall. The coplanar or projecting
electrodes 2414 can facilitate contact with the arterial wall to
enhance stimulation and/or recording. In other embodiments, one or
more of the electrodes 2414 may be recessed from the insulating
portions 416.
[0127] In the illustrated embodiment, the multi-electrode loop 2402
includes six electrodes 2414a-f, which may be suitable for loops
having outer diameters of approximately 8 mm. In other embodiments,
however, the loop 2402 can include more or less electrodes 2414
(e.g., four to eight electrodes 2414) depending at least in part on
the outer diameter of the loop 2402. Each of the electrodes 2414
can be designated as a cathode, anode, or inactive by a nerve
monitoring console (e.g., an NIM and/or other suitable console)
operably coupled to the multi-electrode loop 2402 via signal wires
extending through the shaft 2406. For example, the electrodes 2414
can alternate as anodes and cathodes around the circumference of
the loop 2402 (e.g., the first, third and fifth electrodes 2414a,
2414c and 2414e can be anodes and the second, fourth and sixth
electrodes 2414b, 2414d and 2414f can be cathodes) such that the
single loop 2402 can provide bipolar stimulation or recording.
Similar to the loop electrodes 2302 described above, a luminal
surface 2410 of the multielectrode loop 2402 can also be insulated
to inhibit short circuits across the electrodes 2414 (e.g., via
blood or other conductive pathways), while an abluminal surface
2408 can remain exposed to allow the electrodes 2414 to contact a
vessel wall (e.g., the pulmonary blood vessel).
[0128] In various embodiments, the electrode assembly 2400 can
include two loops 2402 spaced laterally apart from one another
(e.g., similar to the dual loop electrode assembly 2300 shown in
FIG. 21A). This arrangement allows all the electrodes 2414 on one
multi-electrode loop 2402 to be configured as anodes, while all the
electrodes 2414 on the other multielectrode loop 2402 can be
configured as cathodes. Much like the loop electrodes 2302 shown in
FIG. 21A, the double multi-electrode loop configuration can
increase the surface area with which the electrode assembly 2400
can stimulate and/or capture nerve activity, and can therefore
enhance nerve monitoring.
[0129] FIG. 22B is an enlarged partially schematic side view of a
distal portion of a treatment device 24508 within a blood vessel A
(e.g., a pulmonary vessel) configured in accordance with another
embodiment of the present technology. The treatment device 2450B
includes features generally similar to the features of the
treatment device 2350 described above with reference to FIG. 21B.
For example, the treatment device 24508 includes a therapeutic
assembly 2420 positioned between and optionally operably coupled to
a first electrode assembly 2400a and a second electrode assembly
2400b. The first electrode assembly 2400a includes two
multi-electrode loops 2402 (identified individually as a first
multi-electrode loop 2402a and a second multi-electrode loop
2402b). In various embodiments, all the electrodes 2414 of the
first multi-electrode loop 2402a can be anodes, and all the
electrodes 2414 of the second multi-electrode loop 2402b can be
cathodes such that the first electrode assembly 2400a can provide
bipolar nerve stimulation. In the embodiment illustrated in FIG.
22B, the second electrode assembly 2400b includes one
multi-electrode loop 2402 having both anodes and cathodes spaced
around the circumference to provide bipolar recording of nerve
activity. In other embodiments, the second electrode assembly 2400b
can include two multi-electrode loops 2402 and designate one as a
cathode and the other as an anode. An insulated portion 2404 can
space the multi-electrode loops 2402a and 2402b laterally apart
from one another. In further embodiments, the first electrode
assembly 2400a and/or the second electrode assembly 2400b can
include two bare loop electrodes 2302 as shown in FIG. 21B. In
still further embodiments, the electrode assemblies 2400 can be
configured to provide monopolar nerve stimulation or recording.
[0130] FIG. 22C is an enlarged partially schematic side view of a
distal portion of a treatment device 2450C within a blood vessel A
(e.g., a pulmonary blood vessel) in accordance with yet another
embodiment of the present technology. The treatment device 2450C
includes features generally similar to the features of the
treatment device 2450B described above with reference to FIG. 22B.
For example, the treatment device 2450C includes the therapeutic
assembly 2420 positioned between the first electrode assembly 2400a
and the second electrode assembly 2400b. In the embodiment
illustrated in FIG. 22C, however, the first electrode assembly
2400a includes only one multi-electrode loop 2402 such that the
loop 2402 includes both anodes and cathodes to provide the desired
bipolar stimulation.
[0131] FIG. 23 is an enlarged partially schematic side view of a
distal portion of a treatment device 2550 within a blood vessel A
(e.g., a pulmonary blood vessel) in accordance with a further
embodiment of the present technology. The treatment device 2550
includes features generally similar to the features of the
treatment devices described above with reference to FIGS. 21B, 22B
and 22C. The treatment device 2550, for example, includes a
therapeutic assembly 2520 (shown schematically) and a nerve
monitoring assembly 2530 at a distal portion 2512 of a shaft 2506.
The therapeutic assembly 2520 is positioned between a first
electrode assembly 2500a that provides bipolar nerve stimulation
and a second electrode 2500b that provides bipolar recording of
nerve activity (collectively referred to as electrode assemblies
2500). In the illustrated embodiment, each electrode assembly 2500
includes a balloon 2532 (identified individually as a first balloon
2532a and a second balloon 2532b) having one or more conductive
portions 2534 (identified individually as a first conductive
portion 2534a and a second conductive portion 2534b) that serve as
electrodes. The conductive portions 2534 can be made from a
conductive ink that is sufficiently flexible to allow the balloons
2532 to fold into a guide catheter (not shown) during delivery and
removal of the treatment device 2550. In other embodiments, the
conductive portions 2534 can be made from other suitable materials
that attach to the balloons 2532, such as platinum iridium
wires.
[0132] In the embodiment illustrated in FIG. 23, each balloon 2532
includes two spaced apart conductive portions 2534 around at least
a portion of the circumference of the balloon 2532 such that the
conductive portions 2534 can contact the inner wall of the blood
vessel A when the balloons 2532 are inflated (e.g., as shown in
FIG. 23). The balloons 2532 can be inflated by flowing gas (e.g.,
air) or liquid (e.g., saline solution) into the balloons 2532
through one or more openings 2537 (referred to individually as a
first opening 2537a and a second opening 2537b) in a tube 2535 that
is coupled to a fluid source (not shown) at a proximal end portion
and extends through the balloons 2532 at a distal end portion.
Similar to the multi-loop electrode assemblies described above, the
two conductive portions 2534 of each balloon 2532 can be designated
as an anode and as a cathode to provide bipolar nerve stimulation
and recording. In other embodiments, at least one of the electrode
assemblies 2500 can include a dual balloon, and each balloon can
include one conductive portion 2534 such that the nerve monitoring
assembly 2530 includes three or four balloons.
[0133] In various embodiments, the therapeutic assembly 2520 can be
omitted. As such, the electrode assemblies 2500 can be
intravascularly delivered to the treatment site (e.g., at the
pulmonary vessel) to record nerve activity before neuromodulation.
The electrode assemblies 2500 can then be removed from the target
site to allow the therapeutic assembly 2520 to be delivered. After
neuromodulation, the electrode assemblies 2500 can be delivered
back to the target site to record the nerve activity. If a
sufficient nerve lesion has not been formed, the therapeutic
assembly 2520 can again be delivered to the treatment site to
deliver an energy field to ablate or otherwise modulate the nerves.
The therapeutic assembly 2520 can then be removed from the
treatment site to allow the electrode assemblies 2500 to be
delivered and monitor the resultant nerve activity. This process
can be repeated until a sufficient nerve lesion is formed at the
target site.
[0134] FIG. 24 is an enlarged side view of a distal portion of a
treatment device 2650 within a blood vessel A (e.g., a pulmonary
blood vessel) in accordance with yet another embodiment of the
present technology. The treatment device 2650 includes a number of
features generally similar to the features of the treatment devices
described above with reference to FIGS. 21B, 22B, 22C and 23. For
example, the treatment device 2650 includes an array of electrodes
(identified individually as a first electrode array 2600a and a
second electrode array 2600b, and referred to collectively as
electrode arrays 2600) proximal and distal to a neuromodulation
area 2643 (shown in broken lines). In the embodiment illustrated in
FIG. 24, the treatment device 2650 has a double balloon
configuration in which a first inflatable body or outer balloon
2640 is disposed over a second inflatable body or inner balloon
2642. The inner balloon 2642 can be configured to deliver
therapeutic neuromodulation to nerves proximate a treatment site
(e.g., a pulmonary blood vessel). For example, the inner balloon
2642 can define an expansion chamber in which a cryogenic agent
(e.g., nitrous oxide (N.sub.2O)) can expand to provide
therapeutically-effective cooling to tissue adjacent to the
inflated inner balloon 2642 (e.g., in the neuromodulation area
2643). In other embodiments, the inner balloon 2642 can be
configured to provide therapeutic neuromodulation using other
suitable means known in the art such as ultrasound (e.g., HIFU). In
further embodiments, the inner balloon 2642 may be omitted, and
energy deliver elements (e.g., electrodes) can be disposed on an
outer surface of the outer balloon 2640 to deliver RF ablation
energy and/or other forms of energy for neuromodulation.
[0135] As shown in FIG. 24, a proximal end portion of the outer
balloon 2640 can be coupled to a distal portion 2612 (also 2812,
see also FIG. 26) of an outer shaft 2606 also 2806, see also FIG.
26) and a proximal end portion of the inner balloon 2642 can be
coupled to an inner shaft 2644 that extends through the outer shaft
2606. In the illustrated embodiment, the inner shaft 2644 extends
through the outer and inner balloons 2640 and 2642 such that the
distal end portions of the outer and inner balloons 2640 and 2642
can connect thereto, and therefore the inner shaft 2644 can provide
longitudinal support along the balloons 2640 and 2642. In other
embodiments, the inner shaft 2644 can extend partially into the
balloons 2640 and 2642 or terminate proximate to the distal end of
the outer shaft 2606. The outer and inner shafts 2606 and 2644 can
define or include supply lumens fluidly coupled at proximal end
portions to one or more fluid sources and fluidly coupled at distal
end portions to the outer and inner balloons 2640 and 2642. For
example, the inner shaft 2644 can include one or more openings 2646
through which fluids (e.g., refrigerants or other cryogenic agents)
can be delivered to the inner balloon 2642 (e.g., as indicated by
the arrows) to inflate or expand the inner balloon 2642. Fluids
(e.g., saline or air) can be delivered to the outer balloon 2640
through a space or opening 2646 between the outer and inner shafts
2606 and 2644 (e.g., as indicated by the arrows) and/or by a supply
lumen spaced therebetween to inflate or expand the outer balloon
2640.
[0136] The inner balloon 2642 can have smaller dimensions than the
outer balloon 2640 such that the outer balloon 2640 expands into
full circumferential contact with the vessel wall along a length of
the vessel and the inner balloon 2642 expands to press against or
otherwise contact a segment of the inner wall of the outer balloon
2640. In the embodiment illustrated in FIG. 24, for example, the
outer and inner balloons 2640 and 2642 contact each other at an
interface extending around a full circumference of the inner
balloon 2642 spaced laterally inward of the electrode arrays 2600.
The portion of the outer balloon 2640 in contact with the inflated
inner balloon 2642 can deliver therapeutically-effective
neuromodulation (e.g., via cryotherapeutic cooling) to nerves
proximate the adjacent vessel wall. Accordingly, the double balloon
arrangement shown in FIG. 24 can deliver fully-circumferential
neuromodulation. Non-targeted tissue proximal and distal to the
contacting balloon walls is shielded or protected from
neuromodulation by an inflation medium (e.g., saline solution, air,
etc.) within the outer balloon 2640, which may effectively act as
insulation.
[0137] The outer and inner balloons 2640 and 2642 can be made from
various compliant, non-compliant, and semi-compliant balloons
materials. The outer balloon 640, for example, can be made from a
compliant balloon material (e.g., polyurethane or silicone) such
that when the outer balloon 2640 is inflated, it can press against
the inner wall of a vessel to provide stable contact therebetween.
The inner balloon 2642 can be made from semi-compliant and or
non-compliant materials (e.g., formed from polyether block amide,
nylon, etc.) to define a smaller expanded size. In other
embodiments, the outer and inner balloons 2640 and 2642 can be made
from other suitable balloon materials.
[0138] As shown in FIG. 24, the first electrode array 2600a and the
second electrode array 2600b may be located at the outer wall of
the outer balloon 2640 and positioned proximal and distal to the
neuromodulation area 2643 (i.e., the region of the outer balloon
2640 that contacts the inflated inner balloon 2642). Each electrode
array 2600 (also 2800, see also FIG. 26) can include a first
conductive portion 2634a (also 2834a, see also FIG. 26) and a
second conductive portion 2634b (also 2834b, see also FIG. 26)
(referred to collectively as conductive portions 2634 (2834)) that
extend around the circumference of the outer balloon 2640 (2840) to
define first and second electrode loops. In other embodiments, one
or both of the electrode arrays 2600 can include a single
conductive portion or strip extending around the circumference of
the outer balloon 2640. The conductive portions 2634 can be made
from a conductive ink printed on the outer wall of the outer
balloon 2640 and/or other conductive materials that can attach to
the outer balloon 2640. In operation, the first electrode array
2600a can stimulate nerves proximal to the neuromodulation area
2643 and the second electrode array 2600b can sense the resultant
stimulation, or vice versa. The first and second conductive
portions 2634 of each electrode array 2600 can be configured to
provide bipolar or monopolar stimulation and/or recording depending
upon which mode provides the highest signal response. For example,
the first electrode array 2600a can include one electrode (e.g.,
one conductive strip 2634) for monopolar stimulation and the second
electrode array 2600b can include two electrodes (e.g., two
conductive strips 2634) for bipolar recording. In other
embodiments, however, the electrode arrays 2600 may have other
arrangements and/or include different features.
[0139] The treatment device 2650 can provide nerve stimulation and
recording before, during, and/or after neuromodulation. For
example, the electrode assemblies 2600 can stimulate nerves and
record the resultant nerve activity before neuromodulation to
provide a set point against which subsequent nerve monitoring can
be compared. This information can also be used to determine the
level of power or current that must be delivered to ablate the
nerves since each patient typically has different base line levels
nerve activity. Therefore, the electrode arrays 2600 can also
provide diagnostic nerve monitoring. During the neuromodulation
procedure, the electrode arrays 2600 can monitor the reduction of
nerve signal strength to confirm the effectiveness of the
neuromodulation. For example, the electrode assemblies 2600 can
continually monitor nerve activity during neuromodulation by
interleaving stimulation pulses and recording periods. In other
embodiments, nerve monitoring periods can be spaced between
neuromodulation periods to determine whether the nerves have been
sufficiently modulated or if subsequent neuromodulation cycles are
necessary to provide the desired modulation.
[0140] FIG. 25 is an enlarged side view of a distal portion of a
treatment device 2750 within a blood vessel A (e.g., a pulmonary
blood vessel) in accordance with a further embodiment of the
present technology. The treatment device 2750 includes a number of
features generally similar to the features of the treatment device
2650 described above with reference to FIG. 24. For example, the
treatment device 2750 includes an outer balloon 2740 in fluid
communication with a first supply lumen via an opening 2746 at a
distal portion 2712 of an outer shaft 2706, and an inner balloon
2742 in fluid communication with a second supply lumen via an
opening 2746 of an inner shaft 2744. The outer balloon 2740 can be
inflated with a non-therapeutically effective fluid (e.g., air) to
press against and maintain contact with the inner vessel wall. The
inner balloon 2742 can be inflated with a cryogenic agent (e.g., a
refrigerant) and/or other fluid to contact a portion of the outer
balloon 2740 and provide neuromodulation (e.g., via cryotherapeutic
cooling or ultrasound) about the full circumference of an adjacent
vessel wall (e.g., within a neuromodulation region 2743).
[0141] The treatment device 2750 also includes first and second
electrode arrays 2700a and 2700b (referred to collectively as
electrode arrays 2700) proximal and distal to the portion at which
the inner balloon 2742 contacts the outer balloon 2740. Rather than
continuous conductive strips around the circumference of the outer
balloon 2740, however, the electrode arrays 2700 illustrated in
FIG. 25 include a plurality of point electrodes 2748 on or in an
outer wall of the outer balloon 2740. The point electrodes 2748,
for example, can be made from conductive ink printed on the outer
balloon 2740, conductive pads adhered to the outer balloon 2740,
and/or other suitable conductive features. The individual point
electrodes 2748 can be oriented about the circumference of the
outer balloon 2740 in various different patterns and provide
monopolar and/or bipolar nerve stimulation and recording before,
during and/or after neuromodulation.
[0142] FIG. 26 is an enlarged side view of a distal portion of a
treatment device 2850 within a blood vessel A (e.g., a pulmonary
blood vessel) in accordance with an additional embodiment of the
present technology. The treatment device 2850 includes several
features generally similar to the features of the treatment device
2650 described above with reference to FIG. 24. For example, the
treatment device 2850 includes first and second electrode arrays
2800a and 2800b (referred to collectively as electrode arrays 2800)
on an outer balloon 2840 and positioned proximal and distal to a
neuromodulation region 2843 provided by an inner balloon 2842. In
the embodiment illustrated in FIG. 26, the inner balloon 2842 has a
smaller outer diameter in an inflated state than that of the outer
balloon 2840 and is attached to an interior surface of the outer
balloon 2840 using an adhesive, a heat-bond and/or other types of
balloon connection. The outer balloon 2840 can be fluidly coupled
to a supply lumen defined by a shaft 2844 that delivers an
insulative medium (e.g., a heated liquid, heated gas, ambient air,
etc.) to the outer balloon 2840 via openings 2846, and the inner
balloon 2842 can be fluidly coupled to a separate supply lumen (not
shown) that delivers an inflation fluid (e.g., a cryogenic agent)
to the inner balloon 2842.
[0143] In use, the outer balloon 2840 expands into full
circumferential contact with the vessel wall to provide tissue
apposition for signal transfer to and from the vessel wall via the
electrode arrays 2800. The inner balloon 2842 is essentially
radially pulled toward only the portion of the vessel wall adjacent
to where the inner balloon 2842 is attached to the outer balloon
2840. When a cryogenic agent and/or other therapeutic medium is
introduced into the inner balloon 2842, non-targeted tissue that is
not adjacent to the inner balloon 2842 is shielded or protected
from ablation by the inflation medium located within the outer
balloon 2840. The targeted tissue adjacent to the inner balloon
2842 is ablated, resulting in a partial circumferential
neuromodulation. The inner balloon 2842 can be shaped or otherwise
configured to provide a non-continuous, helical, and/or other type
of ablation pattern.
[0144] FIG. 27 is a block diagram illustrating a method 2900A of
endovascularly monitoring nerve activity in accordance with an
embodiment of the present technology. The method 2900A can include
deploying a nerve monitoring assembly and a therapeutic assembly in
a vessel (e.g., a pulmonary blood vessel; block 2902). The nerve
monitoring assembly can include a plurality of multi-electrode
rings (e.g., similar to the multi-electrode loops 2402 described
above with reference to FIGS. 22A-22C) connected to a distal
portion of a catheter shaft. The multi-electrode rings can be made
of nitinol or other shape memory materials such that they can be
deployed by simply moving the catheter shaft and a sheath covering
the multi-electrode rings relative to one another (e.g., pulling
the sheath proximally, pushing the catheter shaft distally, etc.).
Each multi-electrode ring can include a plurality of electrodes
spaced around the circumference of the ring and communicatively
coupled to signal wires extending through the catheter shaft. The
signal wires can extend outside the body where they are operably
coupled to a signal generator and/or receiver (e.g., an NIM) to
generate stimuli and record the resultant action potential of the
proximate neural fibers.
[0145] When the therapeutic assembly is deployed, at least one and
often two or more multi-electrode rings ("distal rings") or another
distal electrode assembly can be positioned distal to the
therapeutic assembly and at least one multi-electrode ring
("proximal ring") or other proximal electrode assembly can be
positioned proximal to the therapeutic assembly. In other
embodiments, the nerve monitoring assembly can include one, two, or
more multielectrode rings on either side of the therapeutic
assembly. In further embodiments, other types of electrode arrays
can be positioned proximal and distal to the therapeutic assembly.
The therapeutic assembly, such as a single- or multi-electrode
device or a cryoballoon, can be integrated with the same catheter
shaft as the multi-electrode rings and positioned between the
proximal and distal rings. In other embodiments, the therapeutic
assembly can be attached to a separate catheter shaft and deployed
between proximal and distal multielectrode rings.
[0146] The method 2900A can further include delivering a plurality
of short, high current stimulus pulses through the electrodes on
one or both of the multi-electrode rings positioned distal to the
therapeutic assembly (block 2904), and analyzing an electrogram of
at least one of the electrodes on the proximal ring resulting from
the stimulus pulse (block 2906). For example, a signal generator
can pass a current having a magnitude of about 10-60 mA (e.g., 20
mA, 50 mA, etc.) for a pulse length of about 25-1,500 .mu.s (e.g.,
100-400 .mu.s, 1 ms, etc.) between the electrodes of the distal
rings in the delivering process 2904. The signal generator can also
control the frequency of the signal such that the signal has a
frequency of about 10-50 Hz (e.g., 20 Hz). After a predetermined
time interval, a separate electrogram can be recorded through at
least one electrode on the proximal ring. For example, a separate
electrogram can be recorded through each of the electrodes of the
proximal electrode ring. The length of the time interval between
stimulation and recording depends on the separation of the distal
and proximal rings along the length of the vessel such that the
proximal ring picks up the signal resulting from the induced
stimulus. For example, the time interval can be about 10-50 ms for
rings spaced 10-50 mm apart. In an alternative embodiment, the
delivering process (block 2904) of the method 2900A can include
delivering the short, high current stimulus pulses through at least
one of the proximal electrode rings (e.g., proximal electrode
assembly), and the analyzing process (block 2906) of the method
2900A can include analyzing an electrogram of at least one of the
electrodes of the distal electrode rings (e.g., distal electrode
assembly).
[0147] The method 2900A can further include providing
therapeutically-effective neuromodulation energy (e.g., cryogenic
cooling, RF energy, ultrasound energy, etc.) to a target site using
the therapeutic assembly (block 2908). After providing the
therapeutically-effective neuromodulation energy (block 2908), the
method 2900A includes determining whether the neuromodulation
therapeutically treated or otherwise sufficiently modulated nerves
or other neural structures proximate the treatment site (block
2910). For example, the process of determining whether the
neuromodulation therapeutically treated the nerves can include
determining whether nerves were sufficiently denervated or
otherwise disrupted to reduce, suppress, inhibit, block or
otherwise affect the afferent and/or efferent pulmonary
signals.
[0148] FIG. 28 is a block diagram illustrating a method 2900B of
endovascularly monitoring nerve activity in accordance with an
embodiment of the present technology. The method 2900B can include
deploying a nerve monitoring assembly and a therapeutic assembly in
a vessel (block 2902) and delivering short, high current signal
pulses through an electrode assembly (block 2904) as described
above with respect to the method 2900A in FIG. 27. In this
embodiment, the analyzing process (block 2906 of FIG. 27) can
optionally include recording the electrograms for each electrode on
the proximal electrode ring or other proximal electrode assembly
(block 2906-1) and signal averaging a plurality of the recorded
electrode signals (e.g., 10-100 recorded electrode signals)
resulting from a corresponding plurality of stimulus pulses to
enhance the recorded signal (block 2906-2).
[0149] The method 2900B can optionally include identifying the
nerve location proximate one or more of the electrode rings. For
example, one or more of the recorded electrode signals may include
a deflection or other change in the recorded current indicating an
action potential caused by the stimulus (e.g., identified via
signal averaging) indicating the transmission of an electrical
impulse from the stimulus pulse via adjacent nerves. Electrode
signals that include changes in current intensity correspond with
the electrodes on the proximal ring positioned proximate to nerves.
The higher the deflection or change in current intensity, the
closer the electrode is to the nerves. This information can be used
to identify electrodes on the proximal ring close to the nerves for
effective nerve stimulation or recording (block 2907-1).
Optionally, the method 2900 can include stimulating nerves via the
proximal ring and recording electro grams of the individual
electrodes at one of the distal rings to determine the location of
nerves proximate the distal rings (block 2907-2).
[0150] The method 2900B can also include providing
therapeutically-effective neuromodulation energy (e.g., cryogenic
cooling, RF energy, ultrasound energy, etc.) to a target site using
the therapeutic assembly (block 2908). In this embodiment, the
process of determining whether the neuromodulation treated the
nerves proximate the target site (block 2910 in FIG. 27) can
include repeating the nerve stimulation (block 2904) and analyzing
processes (block 2906) discussed above to assess whether the
neuromodulation caused any changes in the nerve activity (block
2910-1). For example, short, high current stimulus pulses can be
transmitted via the proximal or distal rings and the resultant
nerve activity can be recorded by the opposing ring(s). The method
2900B can then determine whether the nerves have been adequately
modulated (block 2912). For example, if the current density or
other parameter observed in the recording electrodes proximate the
nerve locations is below a threshold value, then the
neuromodulation step may have effectively modulated or stopped
conduction of the adjacent nerves and the neuromodulation process
can be complete. On the other hand, if nerve activity is detected
above a threshold value, the process of neuromodulating (block
2908) and monitoring the resultant nerve activity (block 2910-1)
can be repeated until the nerves have been effectively
modulated.
[0151] In various embodiments, the methods 2900A and 2900B can also
include repeating the nerve monitoring and neuromodulation steps in
the opposite direction to confirm that the nerves have been
adequately modulated. The methods 2900A and 2900B can also
optionally be repeated after a time period (e.g., 5-30 minutes, 2
hours, 1 day, etc.) to confirm that the nerves were adequately
ablated (e.g., rather than merely stunned) and have not resumed
conduction.
[0152] In other embodiments, the methods 2900A and 2900B can be
performed using other nerve monitoring assemblies or electrode
arrays described above with reference to FIGS. 21A-28 and/or other
suitable electrode arrangements. For example, the therapeutic
assembly can include multiple point electrodes spaced around the
circumference of a balloon as described above with respect to FIG.
26. In other embodiments, continuous wire loop electrodes and/or
conductive strips on balloons can be used to identify nerve
location and monitor nerve activity.
III. EXAMPLES
[0153] 1. A catheter apparatus, comprising:
[0154] an elongated shaft having a proximal portion and a distal
portion, wherein the distal portion of the shaft is configured for
intravascular delivery to a body vessel of a human patient;
[0155] an energy delivery element positioned along the distal
portion of the shaft; and
[0156] a plurality of deflectable members spaced apart about a
circumference of the distal portion of the shaft, wherein each of
the deflectable members is configured to transform from a
low-profile state to a deployed state, thereby bending the distal
portion and placing the energy delivery element in apposition with
a wall of the body vessel.
2. The catheter apparatus of example 1 wherein the distal portion
of the elongated shaft is sized and configured for intravascular
delivery into the pulmonary artery. 3. The catheter apparatus of
example 1 or example 2 wherein the each of the deflectable members
comprises a bimetallic strip including a first material having a
first coefficient of thermal expansion (CTE) positioned adjacent a
second material having a second CTE that is different than the
first CTE. 4. The catheter apparatus of any of examples 1-3 wherein
each of the deflectable members comprises a bimetallic strip
including a piezoelectric material and a substrate material coupled
to one another along their lengths, wherein the piezoelectric
material has a first CTE and the substrate material has a second
CTE that is different than the first CTE. 5. The catheter apparatus
of any of examples 1-4 wherein the therapeutic assembly comprises
four deflectable members, wherein each of the deflectable members
corresponds to a distinct quadrant of the shaft. 6. The catheter
apparatus of any of examples 1-5 wherein the deflectable members
extend along a length of the shaft and have a proximal terminus
within the distal portion of the elongated shaft. 7. The catheter
apparatus of any of examples 1-6 wherein the deflectable members
have a length less than a length of the elongated shaft and a
proximal terminus spaced distally apart from a proximal portion of
the shaft. 8. The catheter apparatus of any of examples 1-7 wherein
the deflectable members have distal terminus spaced proximally of
the energy delivery device and a proximal terminus within the
distal portion of the elongated shaft. 9. The catheter apparatus of
any of examples 1-8 wherein the energy delivery element is a single
energy delivery element positioned at a distal terminus of the
shaft. 10. The catheter apparatus of any of examples 1 and 3-10
wherein the distal portion of the elongated shaft is sized and
configured for intravascular delivery into the renal artery. 11.
The catheter apparatus of any of examples 1-10, further comprising
a handle at the proximal portion of the shaft, the handle including
an actuator that is electrically coupled to each of the deflectable
members, and wherein the deflectable members are independently
transformable between their respective low-profile states and
deployed states by activating the actuator. 12. The catheter
apparatus of any of examples 1-11 wherein the energy delivery
element is spaced apart from the deflectable members along the
shaft. 13. The catheter apparatus of any of examples 1-11 wherein
the energy delivery element is positioned on one or more of the
deflectable members. 14. The catheter apparatus of any of examples
1-13 wherein the energy delivery element is a first energy delivery
element, and wherein the catheter apparatus further comprises a
second delivery element. 15. A catheter apparatus, comprising:
[0157] an elongated shaft having a proximal portion and a distal
portion, wherein the distal portion of the shaft is configured for
intravascular delivery to a body vessel of a human patient;
[0158] a deflectable member at the distal portion of the shaft and
electrically coupled to the proximal portion, wherein the
deflectable member comprises a bimetallic strip including a first
material having a first CTE positioned adjacent a second material
having a second CTE that is different than the first CTE; and
[0159] an energy delivery element on the deflectable member,
wherein heating the deflectable member deforms the deflectable
member, thereby placing the energy delivery element in apposition
with a wall of the body vessel.
16. The catheter apparatus of example 15 wherein the energy
delivery element is a first energy delivery element, and wherein
the catheter apparatus further comprises a second delivery element
on the deflectable member. 17. The catheter apparatus of example 15
or example 16 wherein the energy delivery element is in direct
contact with the deflectable member. 18. The catheter apparatus of
any of examples 15-17 wherein the deflectable element is a first
deflectable element, and wherein the catheter apparatus further
comprises a second deflectable element. 19. A method,
comprising:
[0160] intravascularly positioning a therapeutic assembly at a
treatment site within a blood vessel, wherein the therapeutic
assembly includes a deflectable member and an energy delivery
element;
[0161] heating the deflectable member to position the energy
delivery element in apposition with the blood vessel wall; and
[0162] ablating nerves proximate the treatment site via the energy
delivery element.
20. The method of example 19 wherein intravascularly positioning
the therapeutic assembly includes intravascularly positioning the
therapeutic assembly within a pulmonary blood vessel. 21. The
method of example 19 wherein intravascularly positioning the
therapeutic assembly includes intravascularly positioning the
therapeutic assembly within a renal blood vessel. 22. A treatment
device, comprising:
[0163] a shaft including a proximal portion and a distal portion,
wherein the shaft is configured to intravascularly locate the
distal portion at a treatment site within a pulmonary blood vessel
of a human patient;
[0164] a balloon at the distal portion of the shaft;
[0165] a lumen extending distally from a proximal portion of the
shaft to an output port at the distal portion, wherein the output
port is positioned along a portion of the shaft within the balloon,
and wherein the output port is configured to deliver a cooling
agent to an interior portion of the balloon;
[0166] a first electrode positioned on the outer surface of the
balloon and extending about at least a portion of the circumference
of the balloon;
[0167] a second electrode positioned on the outer surface of the
balloon and extending about at least a portion of the circumference
of the balloon, wherein the first electrode is spaced apart from
and out of contact with the second electrode along the balloon;
[0168] wherein the first and second electrodes are configured to--
[0169] deliver therapeutic neuromodulation to nerves in
communication with the pulmonary system proximate the treatment
site, and [0170] stimulate nerves and/or record nerve activity at
the treatment site. 23. The treatment device of example 22 wherein
the first electrode is configured to stimulate nerves proximate the
treatment site and the second electrode is configured to record
nerve activity at the treatment site during and/or after the
therapeutic neuromodulation. 24. The treatment device of example 22
or example 23, further comprising an insulated portion between the
first electrode and the second electrode on the outer surface of
the balloon. 25. The treatment device of any of examples 22-24
wherein:
[0171] the first electrode is configured to deliver energy
sufficient to modulate the nerves in communication with the
pulmonary system; and
[0172] the second electrode is configured for bipolar recording of
renal nerve activity before, during, and/or after energy
application.
26. The treatment device of any of examples 22-25 wherein the lumen
is a first lumen, and wherein the shaft further includes a second
lumen extending distally to an inlet port positioned along a
portion of the shaft within the balloon. 27. The treatment device
of any of examples 22-26 wherein at least one of the first and
second electrodes includes a multi-electrode loop having at least
two electrodes spaced circumferentially about the loop. 28. The
treatment device of any of examples 22-27 wherein at least one of
the first electrode and the second electrode is configured to
deliver radio frequency (RF) energy sufficient to ablate nerves in
communication with the pulmonary system proximate the treatment
site. 29. The treatment device of any of examples 22-28 wherein the
balloon is transformable between a delivery state and a deployed
state and wherein, in the deployed state, the balloon is sized and
shaped to occlude the pulmonary blood vessel. 30. The treatment
device of any of examples 22-29 wherein the balloon is
transformable between a delivery state and a deployed state and
wherein, in the deployed state, the balloon is sized and shaped to
place the first electrode and second electrode in apposition with
an inner wall of the pulmonary blood vessel. 31. A method,
comprising:
[0173] intravascularly deploying a treatment device in a pulmonary
blood vessel of a human patient at a treatment site, wherein the
treatment device includes an elongated shaft, a balloon at a distal
portion of the shaft, and first and second electrodes on an outer
surface of the balloon;
[0174] ablating the renal nerves via radio frequency (RF) energy
delivered from the first electrode and/or the second electrode;
[0175] before ablation, stimulating nerves in communication with
the pulmonary system near the treatment site and recording the
resulting nerve activity; and
[0176] after ablation, stimulating the nerves and recording the
resulting nerve activity.
32. The method of example 31, further comprising confirming the
effectiveness of the ablation on the nerves based on the
post-ablation recording. 33. The method of example 31 or example 32
wherein stimulating the nerves in communication with the pulmonary
system before and/or after ablation is performed by the first
electrode and recording nerve activity before and/or after ablation
is performed with the second electrode. 34. The method of any of
examples 31-33 wherein:
[0177] stimulating the nerves in communication with the pulmonary
system before and after ablation comprises providing bipolar
stimulation to the nerves; and
[0178] recording nerve activity before and after ablation comprises
providing bipolar recording of the nerve activity with the second
electrode, wherein the second electrode is distal to the first
electrode.
35. The method of any of examples 31-34 wherein:
[0179] stimulating the nerves in communication with the pulmonary
system before and/or after ablation comprises delivering a
plurality of stimulus pulses with the first electrode; and
[0180] recording nerve activity before and after ablation is
performed by the second electrode, wherein recording comprises
recording an electrogram of the second electrode and that
corresponds to the nerve activity resulting from the corresponding
stimulus pulses.
36. The method of any of examples 31-35 wherein deploying the
treatment device includes deploying the first electrode proximal to
the second electrode, wherein the first and second electrodes each
comprise a loop electrode. 37. The method of any of examples 31-36
wherein deploying the treatment device in the pulmonary blood
vessel comprises deploying the first electrode proximal to the
second electrode. 38. The method of any of examples 31-37 wherein
deploying the treatment device in the pulmonary blood vessel
comprises inflating the balloon within a pulmonary artery, wherein
the inflated balloon contacts an inner wall of the pulmonary
artery. 39. The method of any of examples 31-38 wherein deploying
the treatment device in the pulmonary blood vessel comprises
inflating the balloon within a pulmonary artery, wherein the
inflated balloon, the first electrode, and the second electrode
contact an inner wall of the pulmonary artery. 40. The method of
any of examples 31-39 wherein:
[0181] stimulating nerves after ablation and recording the
resulting nerve activity is performed after delivering a first
cycle of ablation to nerves in communication with the pulmonary
system; and
[0182] the method further comprises delivering a second cycle of
ablation to nerves in communication with the pulmonary system with
the first and/or second electrodes when the recorded post-ablation
nerve activity from the first cycle is above a predetermined
threshold.
41. The method of any of examples 31-40 wherein recording nerve
activity before and after ablation comprises providing bipolar
recording of the nerve activity with the second electrode, wherein
the second electrode is distal to the first electrode. 42. The
method of any of examples 31-40 wherein recording nerve activity
before and after ablation is performed by the second electrode,
wherein recording comprises recording an electrogram of the second
electrode and that corresponds to the nerve activity resulting from
the corresponding stimulus pulses. 43. The method of any of
examples 31-42 further comprising delivering a second cycle of
ablation to nerves in communication with the pulmonary system with
the first and/or second electrodes when the recorded post-ablation
nerve activity from the first cycle is above a predetermined
threshold.
IV. CONCLUSION
[0183] Although many of the embodiments are described below with
respect to systems, devices, and methods for PN, the technology is
applicable to other applications such as modulation of other nerves
that communicate with the renal system, modulation of peripheral
nerves, and/or treatments other than neuromodulation. Any
appropriate site within the body may be modulated or otherwise
treated including, for example, the pulmonary inflow tract,
pulmonary veins, pulmonary arteries, the carotid artery, renal
arteries and branches thereof. In some embodiments, cardiac tissue
(e.g., the left and/or right atrium of the heart) may be modulated
(e.g., to modulate electrical signals). Moreover, as further
described herein, while the technology may be used in helical or
spiral neuromodulation devices, it may also be used in non-helical
or non-spiral neuromodulation devices as appropriate. Furthermore,
other embodiments in addition to those described herein are within
the scope of the technology. For example, in some embodiments the
therapeutic assembly can include an expandable basket structure
having one or more energy delivery elements positioned on the arms
of the basket. Additionally, several other embodiments of the
technology can have different configurations, components, or
procedures than those described herein. A person of ordinary skill
in the art, therefore, will accordingly understand that the
technology can have other embodiments with additional elements, or
the technology can have other embodiments without several of the
features shown and described below with reference to FIGS.
1-28.
[0184] Although many embodiments of the present technology are
described for use in an intravascular approach, it is also possible
to use the technology in a non-vascular approach, such as a
cutaneous and/or transcutaneous approach to the nerves that
innervate the pulmonary system. For example, the vagal and phrenic
nerves may lie outside the lungs (e.g., in the neck region and/or
in the inlet to the thoracic cavity) at various locations that may
render them amenable to access via cutaneous puncture or to
transcutaneous denervation. As such, devices and/or methods
described herein may be used to effect modulation of vagal and/or
phrenic nerves from within a carotid vein and/or a jugular vein.
Neuromodulation at one or both of those locations may be effective
(e.g., may provide a therapeutically beneficial effect with respect
to treating pulmonary hypertension).
[0185] The above detailed descriptions of embodiments of the
technology are not intended to be exhaustive or to limit the
technology to the precise form disclosed above. Although specific
embodiments of, and examples for, the technology are described
above for illustrative purposes, various equivalent modifications
are possible within the scope of the technology, as those skilled
in the relevant art will recognize. For example, while steps are
presented in a given order, alternative embodiments may perform
steps in a different order. The various embodiments described
herein may also be combined to provide further embodiments.
[0186] From the foregoing, it will be appreciated that specific
embodiments of the technology have been described herein for
purposes of illustration, but well-known structures and functions
have not been shown or described in detail to avoid unnecessarily
obscuring the description of the embodiments of the technology.
Where the context permits, singular or plural terms may also
include the plural or singular term, respectively.
[0187] Moreover, unless the word "or" is expressly limited to mean
only a single item exclusive from the other items in reference to a
list of two or more items, then the use of "or" in such a list is
to be interpreted as including (a) any single item in the list, (b)
all of the items in the list, or (c) any combination of the items
in the list. Additionally, the term "comprising" is used throughout
to mean including at least the recited feature(s) such that any
greater number of the same feature and/or additional types of other
features are not precluded. It will also be appreciated that
specific embodiments have been described herein for purposes of
illustration, but that various modifications may be made without
deviating from the technology. Further, while advantages associated
with certain embodiments of the technology have been described in
the context of those embodiments, other embodiments may also
exhibit such advantages, and not all embodiments need necessarily
exhibit such advantages to fall within the scope of the technology.
Accordingly, the disclosure and associated technology can encompass
other embodiments not expressly shown or described herein.
* * * * *