U.S. patent application number 14/670990 was filed with the patent office on 2015-07-16 for radio frequency catheter to target ligamentum flavum.
This patent application is currently assigned to Kyphon SARL. The applicant listed for this patent is KYPHON SARL. Invention is credited to Mojan Goshayeshgar.
Application Number | 20150196358 14/670990 |
Document ID | / |
Family ID | 51530900 |
Filed Date | 2015-07-16 |
United States Patent
Application |
20150196358 |
Kind Code |
A1 |
Goshayeshgar; Mojan |
July 16, 2015 |
RADIO FREQUENCY CATHETER TO TARGET LIGAMENTUM FLAVUM
Abstract
A device for performing a surgical procedure comprising an
elongated shaft extending between a proximal end and a distal end
and including an outer surface and an inner surface, the inner
surface defining a passageway. A stylet is configured for moveable
disposal within the passageway of the elongated shaft. The stylet
includes a blunt distal tip configured for disposal outside the
distal end of the elongated shaft and to prevent damage to adjacent
tissue. An expandable member includes a proximal end and a distal
end. The proximal end of the expandable member is disposed with the
distal end of the elongated shaft and the distal end of the
expandable member is connected to the distal end of the stylet. At
least one electrode disposed with the expandable member.
Inventors: |
Goshayeshgar; Mojan;
(Atherton, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KYPHON SARL |
NEUCHATEL |
|
CH |
|
|
Assignee: |
Kyphon SARL
|
Family ID: |
51530900 |
Appl. No.: |
14/670990 |
Filed: |
March 27, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13803146 |
Mar 14, 2013 |
9028488 |
|
|
14670990 |
|
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|
Current U.S.
Class: |
606/46 ;
606/41 |
Current CPC
Class: |
A61B 2018/00589
20130101; A61B 2018/00714 20130101; A61B 2018/00267 20130101; A61B
2018/00285 20130101; A61B 2018/00339 20130101; A61B 2018/00434
20130101; A61B 90/04 20160201; A61B 2018/1467 20130101; A61B
18/1492 20130101; A61B 2018/0044 20130101; A61B 2018/0022 20130101;
A61B 2018/00577 20130101; A61B 2018/00023 20130101; A61B 18/14
20130101; A61B 2018/00333 20130101 |
International
Class: |
A61B 18/14 20060101
A61B018/14; A61B 19/00 20060101 A61B019/00 |
Claims
1. A device for performing a surgical procedure comprising: an
elongated shaft extending between a proximal end and a distal end
and includes an outer surface and an inner surface, the inner
surface defining a passageway; a stylet configured for moveable
disposal within the passageway of the elongated shaft and the
stylet includes a blunt distal tip configured for disposal outside
the distal end of the elongated shaft and to prevent damage to
adjacent tissue; an expandable member including a proximal end and
a distal end, wherein the proximal end of the expandable member is
disposed with the distal end of the elongated shaft and the distal
end of the expandable member is connected to the distal end of the
stylet; and at least one electrode disposed with the expandable
member.
2. A device as recited in claim 1, wherein the expandable member
includes a wall defining a thickness and the at least one electrode
is disposed within the thickness of the wall.
3. A device as recited in claim 1, wherein the expandable member
includes an outer surface and the at least one electrode is
disposed on the outer surface.
4. A device as recited in claim 1, wherein the expandable member
includes an inner surface and the at least one electrode is
disposed on the inner surface.
5. A device as recited in claim 1, further including a cooling
mechanism in communication with a liquid pumping system and
configured for disposal with the expandable member.
6. A device as recited in claim 1, wherein the at least one
electrode is configured to emit a RF signal to ablate tissue.
7. A device as recited in claim 6, wherein the RF signal is
configured to be maintained at a subablative controlled
temperature.
8. A device as recited in claim 1, wherein the stylet is configured
to expand and collapse the expandable member.
9. A device as recited in claim 1, wherein the expandable member is
an expandable cage.
10. A device as recited in claim 1, wherein the device includes a
balloon disposed within the expandable member and configured to
distract an interlaminar space.
11. A device for ablating tissue comprising: a cannula extending
between a proximal end and a distal end and includes an outer
surface and an inner surface, the inner surface defining a
passageway; a stylet configured for moveable disposal within the
passageway of the cannula and the stylet includes a blunt distal
tip configured for disposal outside the distal end of the cannula
and to prevent damage to adjacent tissue; an expandable cage
including a proximal end and a distal end, wherein the proximal end
of the expandable cage is disposed with the distal end of the
cannula and the distal end of the expandable cage is connected to
the distal end of the stylet; and at least one RF electrode
disposed with the expandable cage.
12. A device as recited in claim 11, wherein the expandable cage
includes a wall defining a thickness and the at least one RF
electrode is disposed within the thickness of the wall.
13. A device as recited in claim 11, wherein the expandable cage
includes an outer surface and the at least one RF electrode is
disposed on the outer surface.
14. A device as recited in claim 11, wherein the expandable cage
includes an inner surface and the at least one RF electrode is
disposed on the inner surface.
15. A device as recited in claim 11, further including a cooling
mechanism in communication with a liquid pumping system and
configured for disposal with the expandable cage.
16. A device as recited in claim 11, wherein a RF signal emitted by
the at least one RF electrode is configured to be maintained at a
subablative controlled temperature.
17. A device as recited in claim 11, wherein the stylet is
configured to expand and collapse the expandable cage.
18. A device as recited in claim 11, wherein the device includes a
balloon disposed within the expandable cage and configured to
distract an interlaminar space.
19. A method for ablating tissue at a surgical site comprising:
providing a device comprising: a cannula extending between a
proximal end and a distal end and includes an outer surface and an
inner surface, the inner surface defining a passageway; a stylet
configured for moveable disposal within the passageway of the
cannula and the stylet includes a blunt distal tip configured for
disposal outside the distal end of the cannula and to prevent
damage to adjacent tissue; an expandable cage including a proximal
end and a distal end, wherein the proximal end of the expandable
cage is disposed with the distal end of the cannula and the distal
end of the expandable cage is connected to the distal end of the
stylet; and at least one RF electrode disposed with the expandable
cage; creating an access path to the surgical site; inserting the
expandable cage into the surgical site and extending the stylet to
expand the expandable cage; and emitting RF signals through the
electrodes to thermally ablate tissue.
20. A method as recited in claim 19, further including manipulating
a balloon to move bone and create a void, wherein the balloon is
disposed within the expandable cage and configured to distract an
interlaminar space.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/803,146, filed Mar. 14, 2013.
TECHNICAL FIELD
[0002] The present disclosure generally relates to medical devices
for the treatment of nerve pain, and more particularly to a
surgical system and method employing a radio frequency catheter to
coagulate and shrink ligamentum flavum and an inflatable bone tamp
for nerve destruction.
BACKGROUND
[0003] Standard methods of cutting tissue may include using a
scalpel, scissors, and radio frequency energy. Electrosurgical
procedures and techniques using radio frequency energy are
currently used since they generally reduce patient bleeding and
trauma associated with cutting operations. Additionally,
electrosurgical ablation procedures, where tissue surfaces and
volume may be reshaped, cannot be duplicated through other
treatment modalities.
[0004] Minimally invasive procedures in nerve and/or soft tissue
such as the spine or the breast, however, are difficult to perform
using standard scissors and scalpel. Furthermore, in a closed
environment, radio frequency current dissipates into the
surrounding tissue causing a decreased ability to achieve a current
at the cutting electrode of sufficiently high density to initiate a
cut. To overcome this problem, high power settings are often
required to initiate the cut which often is painful and increases
thermal damage to the tissue whether using a standard or a custom
electrosurgical generator.
[0005] Another problem associated with cutting tissue is the
control of bleeding. Radio frequency energy controls bleeding by
coagulating small blood vessels. Another method of controlling
bleeding is through the use of heat. For example, some commercially
available scalpels use direct heat to control bleeding. However,
while the bleeding is generally controlled, the cutting of tissue
is often slower than with radio frequency energy and the knife edge
readily dulls. Other commercially available scalpels use ultrasonic
energy generally at 50 kHz to heat the tissue so as to coagulate
severed blood vessels but cut slower than a standard
electrosurgical electrode and are costly as a custom ultrasonic
generator is required.
[0006] A further disadvantage of using radio frequency energy is
the generation of smoke. The smoke is malodorous and can contain
airborne viral particles that may be infectious. Furthermore, the
smoke often obscures visualization of the procedure. When the smoke
becomes too dense, the procedure is delayed until the smoke is
released through one of the trocar ports and after enough carbon
dioxide gas has reinsufflated the abdominal cavity. This
unnecessarily prolongs the operative time.
[0007] Radiofrequency (RF) energy is used in a wide range of
surgical procedures because it provides efficient tissue resection
and coagulation and relatively easy access to the target tissues
through a portal or cannula. Conventional monopolar high frequency
electrosurgical devices typically operate by creating a voltage
difference between the active electrode and the target tissue,
causing an electrical arc to form across the physical gap between
the electrode and tissue. At the point of contact of the electric
arcs with tissue, rapid tissue heating occurs due to high current
density between the electrode and tissue. This high current density
causes cellular fluids to rapidly vaporize into steam, thereby
producing a "cutting effect" along the pathway of localized tissue
heating. Thus, the tissue is parted along the pathway of evaporated
cellular fluid, inducing undesirable collateral tissue damage in
regions surrounding the target tissue site. This collateral tissue
damage often causes indiscriminate destruction of tissue, resulting
in the loss of the proper function of the tissue. In addition, the
device does not remove any tissue directly, but rather depends on
destroying a zone of tissue and allowing the body to eventually
remove the destroyed tissue.
[0008] Present electrosurgical techniques used for tissue ablation
may suffer from an inability to provide the ability for fine
dissection of soft tissue. The distal end of electrosurgical
devices is wide and flat, creating a relatively wide area of
volumetric tissue removal and making fine dissections along tissue
planes more difficult to achieve because of the lack of precision
provided by the current tip geometries.
[0009] In addition, identification of the plane is more difficult
because the large ablated area and overall size of the device tip
obscures the physician's view of the surgical field. The inability
to provide for fine dissection of soft tissue is a significant
disadvantage in using electrosurgical techniques for tissue
ablation, particularly in arthroscopic, otolaryngological, and
spinal procedures.
[0010] Traditional monopolar RF systems can provide fine dissection
capabilities of soft tissue, but may also cause a high level of
collateral thermal damage. Further, these devices may suffer from
an inability to control the depth of necrosis in the tissue being
treated. The high heat intensity generated by these systems causes
burning and charring of the surrounding tissue, leading to
increased pain and slower recovery of the remaining tissue.
Further, the desire for an electrosurgical device to provide for
fine dissection of soft tissue may compromise the ability to
provide consistent ablative cutting without significant collateral
damage while allowing for concomitant hemostasis and good
coagulation of the remaining tissue.
[0011] Further, the health care practitioner may have difficulty
positioning the tip of the device in the optimal location to get an
optimal and consistent clinical result. This may also result in
unwanted necrosis of adjacent tissue, which can lead to clinical
adverse events including subsequent repair of the necrotic
tissue.
[0012] Accordingly, there is a need for devices and methods to
provide efficient severing or cutting of nerve and/or soft tissue
that can be used during a minimally invasive procedure and/or
during an open surgical procedure. Further, there is also a need
for devices and methods that provide fine dissection capabilities
of nerve and/or soft tissue. Devices and methods that do not cause
a high level of collateral thermal damage and allow for the control
of necrosis in the tissue being treated are also needed. Devices
and methods that provide efficient, controlled and safe debulking
of tissue would also be beneficial.
SUMMARY
[0013] In one embodiment, in accordance with the principle so the
present disclosure, a device for performing a surgical procedure is
provided. The device includes an elongated shaft extending between
a proximal end and a distal end and includes an outer surface and
an inner surface, the inner surface defining a passageway. A stylet
is configured for moveable disposal within the passageway of the
elongated shaft. The stylet includes a blunt distal tip configured
for disposal outside the distal end of the elongated shaft and to
prevent damage to adjacent tissue. An expandable member includes a
proximal end and a distal end. The proximal end of the expandable
member is disposed with the distal end of the elongated shaft and
the distal end of the expandable member is connected to the distal
end of the stylet. At least one electrode disposed with the
expandable member.
[0014] In one embodiment, a device for ablating tissue includes a
cannula extending between a proximal end and a distal end and
includes an outer surface and an inner surface, the inner surface
defining a passageway. A stylet configured for moveable disposal
within the passageway of the elongated shaft. The stylet includes a
blunt distal tip configured for disposal outside the distal end of
the elongated shaft and to prevent damage to adjacent tissue. An
expandable cage including a proximal end and a distal end. The
proximal end of the expandable cage is disposed with the distal end
of the elongated shaft and the distal end of the expandable cage is
connected to the distal end of the stylet. At least one RF
electrode disposed with the expandable cage.
[0015] In one embodiment, a method for ablating tissue at a
surgical site is provided. The method includes providing a device
comprising: a cannula extending between a proximal end and a distal
end and includes an outer surface and an inner surface, the inner
surface defining a passageway, a stylet configured for moveable
disposal within the passageway of the elongated shaft and the
stylet includes a blunt distal tip configured for disposal outside
the distal end of the elongated shaft and to prevent damage to
adjacent tissue, an expandable cage including a proximal end and a
distal end, wherein the proximal end of the expandable cage is
disposed with the distal end of the elongated shaft and the distal
end of the expandable cage is connected to the distal end of the
stylet, and at least one RF electrode disposed with the expandable
cage, creating an access path to the surgical site, inserting the
expandable cage into the surgical site and extending the stylet to
expand the expandable cage and emitting RF signals through the
electrodes to thermally ablate tissue.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The present disclosure will become more readily apparent
from the specific description accompanied by the following
drawings, in which:
[0017] FIG. 1 is a perspective view, with partial cross section, of
one embodiment of a surgical system in accordance with the
principles of the present disclosure; and
[0018] FIG. 2 is a perspective view, with partial cross section, of
one embodiment of a surgical system in accordance with the
principles of the present disclosure.
[0019] Like reference numerals indicate similar parts throughout
the figures.
DETAILED DESCRIPTION
[0020] The exemplary embodiments of the surgical system and related
methods of use disclosed are discussed in terms of medical devices
for the treatment of musculoskeletal disorders and more
particularly, in terms of a surgical system and method for nerve
destruction.
[0021] Devices for efficient severing or cutting of a material or
substance such as nerve and/or soft tissue suitable for use in open
surgical and/or minimally invasive procedures are disclosed. The
following description is presented to enable any person skilled in
the art to make and use the present disclosure. Descriptions of
specific embodiments and applications are provided only as examples
and various modifications will be readily apparent to those skilled
in the art.
[0022] Lumbar spinal stenosis (LSS) may occur from hypertrophied
bone or ligamentum flavum, or from a lax ligamentum flavum that
collapses into the spinal canal. LSS can present clinical symptoms
such as leg pain and reduced function. Conventional treatments
include epidural steroid injections, laminotomy, and laminectomy.
Surgical interventions which remove at least some portion of the
lamina are usually performed through a relatively large incision,
and may result in spinal instability from removal of a large
portion of the lamina. Consequently, a percutaneous approach which
removes just enough tissue (lamina or ligamentum flavum) to be
effective is provided.
[0023] In one embodiment, a deployable RF catheter is provided to
target the hypertrophied ligamentum Flavum in Lumbar Spinal
Stenosis. The system comprises an access cannula and a blunt stylet
to access the ligamentum flavum through the interlaminar space.
After access to the ligamentum flavum, the catheter will be
deployed to the interlaminar space so as to distract the
interlaminar space. The catheter placement will be confirmed under
imaging guide. Then the catheter will be energized with RF at
subablative controlled temperature. In one embodiment, the catheter
may also include a balloon to distract the interlaminar space and
deploy the basket.
[0024] The balloon can be constructed of one or multiple RF
electrodes. The electrodes can be straight, helical or curved. The
electrodes can be positioned inside, outside or within the wall of
the balloon. The electrodes are deployed with the balloon. In one
embodiment, a liquid pumping system may be connected to the balloon
to inflate and cool down the inflation liquid dynamically (active
cooling) or the balloon may be inflated with a cooled liquid
(passive cooling).
[0025] It is contemplated that one or all of the components of the
surgical system may be disposable, peel-pack, pre-packed sterile
devices. One or all of the components of the surgical system may be
reusable. The surgical system may be configured as a kit with
multiple sized and configured components, such as, for example,
inflatable members (balloons) that are preformed to have different
sizes and shapes.
[0026] It is envisioned that the present disclosure may be employed
to treat bones, and in particular arm bones such as a distal
radius. It should be understood that the present principles are
applicable to any bone structures, including but not limited to
bones of the spine, legs, feet, arms, etc. It is contemplated that
the present disclosure may be employed with other osteal and bone
related applications, including those associated with diagnostics
and therapeutics. It is further contemplated that the disclosed
surgical system and methods may alternatively be employed in a
surgical treatment with a patient in a prone or supine position,
and/or employ various surgical approaches, including anterior,
posterior, posterior mid-line, direct lateral, postero-lateral,
antero-lateral, etc. approaches in the calcaneus, spine or other
body regions. The present disclosure may also be alternatively
employed with procedures for treating the muscles, ligaments,
tendons or any other body part. The system and methods of the
present disclosure may also be used on animals, bone models and
other non-living substrates, such as, for example, in training,
testing and demonstration.
[0027] The present disclosure may be understood more readily by
reference to the following detailed description of the disclosure
taken in connection with the accompanying drawing figures, which
form a part of this disclosure. It is to be understood that this
disclosure is not limited to the specific devices, methods,
conditions or parameters described and/or shown herein, and that
the terminology used herein is for the purpose of describing
particular embodiments by way of example only and is not intended
to be limiting of the claimed disclosure. Also, as used in the
specification and including the appended claims, the singular forms
"a," "an," and "the" include the plural, and reference to a
particular numerical value includes at least that particular value,
unless the context clearly dictates otherwise. Ranges may be
expressed herein as from "about" or "approximately" one particular
value and/or to "about" or "approximately" another particular
value. When such a range is expressed, another embodiment includes
from the one particular value and/or to the other particular value.
Similarly, when values are expressed as approximations, by use of
the antecedent "about," it will be understood that the particular
value forms another embodiment. It is also understood that all
spatial references, such as, for example, horizontal, vertical,
top, upper, lower, bottom, left and right, are for illustrative
purposes only and can be varied within the scope of the disclosure.
For example, the references "upper" and "lower" are relative and
used only in the context to the other, and are not necessarily
"superior" and "inferior".
[0028] Further, as used in the specification and including the
appended claims, "treating" or "treatment" of a disease or
condition refers to performing a procedure that may include
administering one or more drugs to a patient (human, normal or
otherwise or other mammal), in an effort to alleviate signs or
symptoms of the disease or condition. Alleviation can occur prior
to signs or symptoms of the disease or condition appearing, as well
as after their appearance. Thus, treating or treatment includes
preventing or prevention of disease or undesirable condition (e.g.,
preventing the disease from occurring in a patient, who may be
predisposed to the disease but has not yet been diagnosed as having
it). In addition, treating or treatment does not require complete
alleviation of signs or symptoms, does not require a cure, and
specifically includes procedures that have only a marginal effect
on the patient. Treatment can include inhibiting the disease, e.g.,
arresting its development, or relieving the disease, e.g., causing
regression of the disease. For example, treatment can include
reducing acute or chronic inflammation; alleviating pain and
mitigating and inducing re-growth of new ligament, bone and other
tissues; as an adjunct in surgery; and/or any repair procedure.
Also, as used in the specification and including the appended
claims, the term "tissue" includes soft tissue, ligaments, tendons,
cartilage and/or bone unless specifically referred to
otherwise.
[0029] The components of system 10 can be fabricated from
biologically acceptable materials suitable for medical
applications, including metals, synthetic polymers, ceramics and
bone material and/or their composites, depending on the particular
application and/or preference of a medical practitioner. For
example, the components of system 10, individually or collectively,
can be fabricated from materials such as stainless steel alloys,
commercially pure titanium, titanium alloys, Grade 5 titanium,
super-elastic titanium alloys, cobalt-chrome alloys, stainless
steel alloys, superelastic metallic alloys (e.g., Nitinol, super
elasto-plastic metals, such as GUM METAL.RTM. manufactured by
Toyota Material Incorporated of Japan), ceramics and composites
thereof such as calcium phosphate (e.g., SKELITE.TM. manufactured
by Biologix Inc.), thermoplastics such as polyaryletherketone
(PAEK) including polyetheretherketone (PEEK), polyetherketoneketone
(PEKK) and polyetherketone (PEK), carbon-PEEK composites,
PEEK-BaSO.sub.4 polymeric rubbers, polyethylene terephthalate
(PET), fabric, silicone, polyurethane, silicone-polyurethane
copolymers, polymeric rubbers, polyolefin rubbers, hydrogels,
semi-rigid and rigid materials, elastomers, rubbers, thermoplastic
elastomers, thermoset elastomers, elastomeric composites, rigid
polymers including polyphenylene, polyamide, polyimide,
polyetherimide, polyethylene, epoxy, bone material including
autograft, allograft, xenograft or transgenic cortical and/or
corticocancellous bone, and tissue growth or differentiation
factors, partially resorbable materials, such as, for example,
composites of metals and calcium-based ceramics, composites of PEEK
and calcium based ceramics, composites of PEEK with resorbable
polymers, totally resorbable materials, such as, for example,
calcium based ceramics such as calcium phosphate, tri-calcium
phosphate (TCP), hydroxyapatite (HA)-TCP, calcium sulfate, or other
resorbable polymers such as polyaetide, polyglycolide, polytyrosine
carbonate, polycaroplaetohe and their combinations. Various
components of system 10 may have material composites, including the
above materials, to achieve various desired characteristics such as
strength, rigidity, elasticity, compliance, biomechanical
performance, durability and radiolucency or imaging preference.
[0030] The components of system 10, individually or collectively,
may also be fabricated from a heterogeneous material such as a
combination of two or more of the above-described materials. The
components of system 10 may be monolithically formed, integrally
connected or include fastening elements and/or instruments, as
described herein.
[0031] The following discussion includes a description of a system
for performing a surgical procedure and related methods of
employing the system in accordance with the principles of the
present disclosure. Alternate embodiments are also disclosed.
Reference will now be made in detail to the exemplary embodiments
of the present disclosure, which are illustrated in the
accompanying figures. Turning now to FIGS. 1-2, there are
illustrated components of the system for performing a surgical
procedure in accordance with the principles of the present
disclosure.
[0032] As shown in FIGS. 1-2, balloon system 10 includes an
elongated shaft, such as, for example, a cannula 12. Cannula 12
extends between a proximal end 14 and a distal end 16. Cannula 12
includes an outer surface 18 and an inner surface 20. Inner surface
20 defines a passageway 22. Passageway 22 extends the entire length
of cannula 12 and has a cylindrical cross sectional configuration
having a uniform diameter along the length of passageway 22. In
some embodiments, passageway 22 may have alternate cross section
configurations, such as, for example, oval, oblong, triangular,
square, hexagonal, polygonal, irregular, uniform, non-uniform
and/or tapered.
[0033] A rod, such as, for example, a stylet 24 is configured for
moveable disposal within passageway 22. Stylet 24 includes a distal
end 26 ending with a blunt distal tip 28. The blunt distal tip 28
is specifically designed so as to be an atraumatic tip. That is,
the blunt distal tip 28 is specifically designed so as to prevent
or minimize damage to tissue as the device in used in situ. The
distal blunt tip 28 can have different configurations such as
circular, oval, arcuate, trapezoidal with rounded corners or any
other configuration that would not damage tissue as the device is
used in situ. The surface of the blunt distal tip 28 is
non-abrasive so that it slides across tissue as the device is moved
about at the surgical site and does not damage adjacent tissue.
Distal end 26 is configured for disposal outside distal end 16 of
cannula 12.
[0034] An expandable member, such as, for example, an expandable
cage 30 is disposed with distal end 16 of cannula 12. Expandable
cage 30 includes a proximal end 32 and a distal end 34. Proximal
end 32 is disposed with distal end 16 of shaft 12. Distal end 34 is
connected to distal end 26 of stylet 24 such that blunt distal tip
28 is exposed. Expandable cage 30 includes an outer surface 36 and
an inner surface 38. Surface 36 defines a cavity 40 extending the
entire length of cage 30. Cage 30 includes at least one wall 42
extending between surfaces 36 and 38 and defines a thickness t.
Stylet 24 is configured to expand and collapse expandable cage 30.
It is envisioned that the shapes and sizes of cage 30 when in the
expanded configuration can be selected to provide a desired result
during a procedure. For example, cage 30 may include shapes such as
spheres, cylinders, etc. and have different dimensions to make cage
30 narrower or wider in a longitudinal direction, or extend further
in a radial direction.
[0035] In one embodiment, the distal end 34 of the expandable cage
30 is attached to a ring-shaped member 48 having an inner surface
defining an opening. The opening having a diameter that is smaller
than the cross-section of the blunt tip 28 so that the blunt tip 28
is positioned within the opening but cannot pass through the
opening. Stylet 24 is positioned within the opening of the ring
shaped member 48 and attached to the distal blunt tip 28 so that
when the stylet 24 is pulled towards cannula 12 the blunt tip 28
draws the ring shaped member 48 in the same direction so as to
cause the cage 30 to expend. Similarly, when the stylet is moved
away from distal end 16 of cannula 12 the cage 30 contracts to give
a slimmer profile.
[0036] In one embodiment, the cage 30 comprises a plurality of
walls 42 in the form of elongated strips that are spaced apart from
one another and attached to the ring-shaped member 48 at one end
and the cannula 12 at the other end. In this embodiment, when the
stylet 24 is drawn towards the cannula 12 the distance between each
elongated strip increases so as to expand the cage 30 to an
expanded configuration. Similarly, when the stylet 24 is moved away
from distal end 16 of cannula 12 the distance between the elongated
strips returns back to the original position and cage 30 contracts
to an unexpanded configuration.
[0037] In one embodiment, at least one electrode 44 is disposed
with cage 30. Electrode 44 is configured to emit an RF frequency
for cutting and/or destroying tissue or nerves. In one embodiment,
as shown in FIG. 1, electrode 44 is disposed on outer surface 36.
In one embodiment, electrode 44 is disposed on inner surface 38. In
one embodiment, electrode 44 is disposed within wall 42. Electrode
placement can be varied depending on the required contact with the
ligamentum flavum and the particular procedure. Electrode 44 can be
of any shape such as, for example, straight, helical or curved. If
more than one electrode 44 is provided, they can be positioned
symmetrically or directionally along cage 30. The RF signal is
configured to ablate a hypertrophied ligamentum flavum in lumbar
spinal stenosis. The RF signal is configured to be maintained at a
subablative controlled temperature.
[0038] In one embodiment, as shown in FIG. 2, a balloon 46 is
disposed at distal end 16 of cannula 12 and within cavity 40.
Balloon 46 is configured to distract an interlaminar space. Cannula
12 may be attached to a fill tube (not shown) such that a material,
such as, for example, saline, a contrast solution or compressed air
may be delivered from the tube, through passageway 22 and into
balloon 46. As the material fills balloon 46, balloon 46 moves from
an unexpanded configuration, to an expanded configuration such that
balloon 46 also expands cage 30. It is envisioned that the shapes
and sizes of balloon 46 when in the expanded configuration can be
selected to provide a desired result during a procedure. For
example, balloon 46 may include shapes such as spheres, cylinders,
etc. and have different dimensions to make balloon 46 narrower or
wider in a longitudinal direction, or extend further in a radial
direction. Balloon 46 comprises a compliant material, such as, for
example, polyurethane, polyethane, polyethylene, silicone,
cronoprene or non-compliant material such as Nylon.
[0039] It is envisioned that balloon 46 can be a single or
multi-layered balloon where each balloon layer has the same
diameter and/or wall thickness, is comprised of the same material
or materials having substantially identical mechanical properties,
and has the same degree of molecular orientation in the body
portion of the balloon. It will be apparent that in some situations
it will be desirable to have some balloon layers having different
thicknesses, materials, and/or degree of molecular orientations
upon deflation, while at the same time having equivalent size,
mechanical properties, and/or orientation upon inflation or
expansion. For other applications, it will be apparent that one can
vary size, material, and/or orientation to at least some degree,
depending upon the requirements of a particular application.
[0040] It is contemplated that balloon 46 may include an
impenetrable structural layer having low friction surfaces so as to
facilitate deployment through a delivery tube, such as, for
example, through cannula 12 and prevent rupture of balloon 46 as it
is inflated or expanded in situ. Further variations are
contemplated involving different combinations of lubricating layers
and structural layers. In some embodiments, structural layers of
balloon 46 can contain polyamides, polyesters, polyethylenes,
polyurethanes, their co-polymers and combinations thereof.
[0041] In one embodiment, a cooling mechanism (not shown) is
provided and is configured to cool balloon 46 and/or cage 30. In
one embodiment, active cooling is providing by the cooling
mechanism including a cooling tube connected to a liquid pumping
system (not shown). In one embodiment, passive cooling is providing
by having the cooling mechanism include cooling the inflation
material prior to filling balloon 46.
[0042] In some embodiments, cannula 12 and/or balloon 46 and/or
cage 30 includes one or a plurality of marker bands (not shown)
comprising a radiopaque material. In one embodiment, the polymeric
material is polyether block amide. In some embodiments, the highly
radiopaque material incorporated into the polymeric material is
barium sulfate, bismuth subcarbonate, tungsten, or a combination
thereof.
[0043] In assembly, operation and use, system 10 is employed with a
surgical procedure, such as, for a treatment of a hypertrophied
ligamentum flavum. It is contemplated that one or all of the
components of system 10 can be delivered or implanted as a
pre-assembled device or can be assembled in situ. System 10 may be
completely or partially revised, removed or replaced. It is
envisioned that system 10 may also be used to treat other affected
portions of the patient, such as, for example, a calcaneus bone,
bones of the feet or hands, bones of the spine, bones of the arms
and legs, etc.
[0044] In use, to a hypertrophied ligamentum flavum, the medical
practitioner obtains access to a surgical site including in any
appropriate manner, such as through the skin, or through an
incision and retraction of tissues. In one embodiment, a drill is
employed to remove bone tissue to provide access to a repair site.
It is envisioned that system 10 can be used in any existing
surgical method or technique including open surgery, mini-open
surgery, minimally invasive surgery and percutaneous surgical
implantation, whereby the fractured or injured bone is accessed
through a mini-incision or sleeve that provides a protected
passageway to the area. Once access to the surgical site is
obtained, the particular surgical procedure can be performed for
treating the injury or disorder. The configuration and dimension of
system 10 is determined according to the configuration, dimension
and location of a selected section of nerves and the requirements
of a particular application.
[0045] An incision is made in the body of a patient and a cutting
instrument (not shown) creates a surgical pathway for implantation
of components of system 10. This may include the use of a cannula
or other device. A preparation instrument (not shown) can be
employed to prepare tissue surfaces, as well as for aspiration and
irrigation of a surgical region according to the requirements of a
particular surgical application.
[0046] Cage 30 is inserted to the surgical site and stylet 24 is
manipulated to obtain the proper positioning of cage 30. Blunt
distal tip 28 prevents adjacent tissue from being damaged. Once
cage 30 is properly positioned, RF signals are emitted through
electrodes 44. Stylet 24 can be manipulated to collapse cage 30 for
removal from the patient.
[0047] In one embodiment, balloon 46 may be inserted through
cannula 12 and is inflated with an inflation material to distract
the interlaminar space. In one embodiment, inflation material can
be delivered via a single gas source with a manifold and
independently controlled valves such that the valves may be
employed in controlled pressurized fluid flow to balloon 46. Other
inflation methods are also contemplated.
[0048] A material, such as, for example, saline, a contrast
solution or compressed air may be delivered through cannula 12 and
passageway 22 and into balloon 46. The material may be delivered
until balloon 46 assumes the desired profile. Balloon 46 can be
manipulated to move bone and create a void at the desired location
by viewing balloon 46 with use of markers. Removal of the material
from balloon 46 to move from the expanded configuration to the
unexpanded for removal form the patient.
[0049] In some embodiments, shaft 12 and/or balloon 46 and/or cage
30 includes one or a plurality of marker bands (not shown)
comprising a radiopaque material. In one embodiment, the polymeric
material is polyether block amide. In some embodiments, the highly
radiopaque material incorporated into the polymeric material is
barium sulfate, bismuth subcarbonate, tungsten, or a combination
thereof.
[0050] It will be understood that various modifications may be made
to the embodiments disclosed herein. Therefore, the above
description should not be construed as limiting, but merely as
exemplification of the various embodiments. Those skilled in the
art will envision other modifications within the scope and spirit
of the claims appended hereto. The balloon can be modified or
extended to accommodate particular formulations of balloon
construction materials or fabrication techniques. Different balloon
materials and surface coatings, or outer layers of different
materials or surface coatings may also be applied to the balloon to
facilitate a smaller balloon profile, biocompatibility, lubrication
as well as other properties. The embodiments above can also be
modified so that some features of one embodiment are used with the
features of another embodiment. One skilled in the art may find
variations of these preferred embodiments, which, nevertheless,
fall within the spirit of the present invention, whose scope is
defined by the claims set forth below.
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