U.S. patent application number 09/777018 was filed with the patent office on 2002-02-14 for magnetically guided atherectomy.
Invention is credited to Hall, Andrew F., Hastings, Roger N., Sell, Jonathan C..
Application Number | 20020019644 09/777018 |
Document ID | / |
Family ID | 23384037 |
Filed Date | 2002-02-14 |
United States Patent
Application |
20020019644 |
Kind Code |
A1 |
Hastings, Roger N. ; et
al. |
February 14, 2002 |
Magnetically guided atherectomy
Abstract
Atherectomy device are guided by and manipulated by externally
applied magnetic fields to treat total or partial occlusions of a
patient's vasculature.
Inventors: |
Hastings, Roger N.; (Maple
Grove, MN) ; Hall, Andrew F.; (St. Charles, MO)
; Sell, Jonathan C.; (Eagan, MN) |
Correspondence
Address: |
Harness, Dickey & Pierce
Suite 400
7700 Bonhomme
St. Louis
MO
63105
US
|
Family ID: |
23384037 |
Appl. No.: |
09/777018 |
Filed: |
February 5, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09777018 |
Feb 5, 2001 |
|
|
|
09352161 |
Jul 12, 1999 |
|
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Current U.S.
Class: |
606/159 ;
606/41 |
Current CPC
Class: |
A61B 18/1492 20130101;
A61B 2018/00011 20130101; A61B 2017/320004 20130101; A61M 25/0127
20130101; A61B 17/22012 20130101; A61B 2034/2051 20160201; A61B
34/73 20160201; A61B 17/320758 20130101; A61B 17/22 20130101; A61B
2017/00061 20130101; A61B 18/08 20130101; A61B 2017/22094 20130101;
A61M 2025/0166 20130101; A61B 34/20 20160201; A61B 18/28 20130101;
A61B 2017/22042 20130101 |
Class at
Publication: |
606/159 ;
606/41 |
International
Class: |
A61B 017/22 |
Claims
What is claimed is:
1. A catheter for treating an occluded vessel comprising: a
catheter body having a proximal end and a distal end, said distal
end terminating in a distal tip; an energy source coupled to said
distal tip for supplying energy to the distal tip for treating an
occlusion; a magnetically active element located proximate said
distal tip responsive to externally applied magnetic fields whereby
said externally applied magnetic fields direct and orient said
distal tip.
2. The catheter of claim 1 wherein said magnetically active element
forms at least a portion of said distal tip.
3. The catheter of claim 1 further including a lumen positioned in
said catheter body extending form said proximal end to said distal
end.
4. The catheter of claim 1 further including one or more electrical
coils located proximate said distal tip for cooperation with a
localization device.
5. A sheath for use with a catheter of claim 1 for treating a
vessel occlusion comprising: a sheath body having a proximal end
and having a distal end; a lumen extending from said proximal end
to said distal end; a magnetically active element located proximate
said distal tip.
6. A system for treating a vessel occlusion comprising: a sheath,
having a sheath body, said sheath body having a proximal end and
having a distal end; a lumen extending through said sheath body
from said proximal end to said distal end; a catheter having a
catheter body having a proximal end and a distal end terminating in
distal tip; an energy source coupled to said distal tip; a
magnetically active element located proximate said distal tip of
said catheter body.
7. A system for treating a vessel occlusion comprising: a sheath,
having a sheath body, said sheath body having a proximal end and
having a distal end; a lumen extending through said sheath body
from said proximal end to said distal end; a catheter having a
catheter body having a proximal end and a distal end; an energy
source coupled to said distal tip for delivering therapeutic energy
to a vessel occlusion; a magnetically active element forming a
portion of said distal tip of said sheath body.
8. The catheter of claim 1 including a first metallic element
located proximate said distal tip adapted for coupling to a remote
radio frequency energy source whereby RF energy coupled to said
metallic element heats said metallic element.
9. The catheter of claim 8 wherein said metallic element forms one
pole of a monopolar energy distribution system.
10. The catheter of claim 9 further comprising a second metallic
element proximate said distal tip forming a pole of a bipolar
energy distribution system.
11. The catheter of claim 1 including a thermally conductive
element located proximate said distal tip adapted for coupling to a
remote optical laser energy source whereby optical energy coupled
to said thermally conductive element heats said thermally
conductive element.
12. The catheter of claim 11 wherein said thermally conductive
element is metallic.
13. The catheter of claim 1 further including an ultrasonic
waveguide element located proximate said distal tip adapted for
coupling to a remote ultrasonic frequency energy source.
14. The catheter of claim 1 further including a resistance heating
element located proximate said distal tip adapted for coupling to a
remote electrical energy source.
15. The catheter of claim 14 further including a resistance heating
element located proximate said distal tip adapted for coupling to a
remote AC elect5rical energy source.
16. The catheter of claim 14 further including a resistance heating
element located proximate said distal tip adapted for coupling to a
remote DC electrical energy source.
17. The catheter of claim 1 further including a fluid directing
element located proximate said distal tip adapted for coupling to a
remote hydraulic energy source, whereby fluid coupled to said
device extracts occlusive material from locations near the distal
tip.
18. The catheter of claim 3 further including a laser imaging
device located in said lumen for observing an occlusion.
19. The catheter of claim 3 further including an ultrasonic imaging
device located in said lumen for observing an occlusion.
20. A system for treating total occlusions of a patient's
vasculature comprising: a catheter having an elongate body and a
distal tip; a heated element located proximate the distal tip of
the catheter; a magnetic element located proximate distal tip; a
magnetic surgery system for interacting with said magnetic element;
said magnetic surgery system including a localization device to
determine the location of the catheter distal tip within the body;
said magnetic surgery system including an occlusion visualization
device for presenting an image to a user which depicts the location
of the catheter tip.
21. The system of claim 20 wherein said visualization device is an
ultrasonic imaging wire.
22. The system of claim 20 wherein said visualization device is a
laser imaging wire.
23. A system for treating occlusions of a patient's vasculature
comprising: a catheter having an elongate body and a distal tip; a
heated element located proximate the distal tip of the catheter; a
magnetic element located proximate the distal tip; a magnetic
surgery system for interacting with said magnetic element; said
magnetic surgery system including a localization device to
determine the location of the catheter distal tip within the body;
said magnetic surgery system including a catheter location
visualization device for presenting an image to a user which
depicts the location of the catheter tip.
24. The system of claim 23 wherein said catheter location
visualization device is a preoperative CT image.
25. The system of claim 23 wherein said catheter location
visualization device is a preoperative MRI image.
26. A method of treating a total vascular occlusion comprising the
steps of: inserting a catheter having a magnetic tip into the body;
directing the catheter to the location of the total occlusion;
imaging the catheter tip to confirm and direct therapy; energizing
said catheter to heat said distal tip; manipulating said distal tip
by the application of external magnetic fields, directing said
catheter tip into said occlusion.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 09/352,161 filed Jul. 12, 1999, incorporated
herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the removal of
occlusive material from body lumens, and more particularly both
methods and devices for magnetically guided atherectomy of totally
occluded arterial vasculature. Catheters which employ thermal as
well as other energy sources are disclosed along with complementary
equipment for carrying out the procedures.
DESCRIPTION OF THE PRIOR ART
[0003] Arteriolosclerosis is a progressive disease marked by
deposits within the lumen of arterial vessels. Removal of these
deposits restores blood flow and is a preferred treatment for this
disease. In instances where the vessel cannot be salvaged, bypass
grafts may be used to treat the disorder.
[0004] A wide range of recannalization techniques have been
developed over time. The primary technique in clinical use today is
balloon angioplasty. This is a "mechanical" treatment where a
balloon at the treatment site is inflated to compress obstructive
material against the vessel wall. In most treatment protocols the
recannalization device is navigated to the treatment site through
the patent's vasculature. The so-called "Seldinger" technique is
used most often to gain access to and navigate through the blood
vessels. In this technique the catheter enters the body in the
groin area and is moved through the vasculature to the heart with
the assistance of both guide wire and occasionally guide catheters
or sheaths.
[0005] Although balloon angioplasty is probably the most common
procedure, there are several drawbacks to this type of device. One
problem is that the vascular occlusion must first be crossed with a
guide wire to position the balloon. The balloon device follows the
guide wire through the lesion and the wire biases the balloon
against the walls of the vessel. If the vessel is totally occluded
the wire cannot cross the lesion and therefore cannot be used to
guide the balloon.
[0006] Energy sources for recannalization have been proposed and
studied as well. For example, Carter, U.S. Pat. No. 5,318,014,
(incorporated herein by reference), teaches a device to treat
occlusions with ultrasound. Drasler, U.S. Pat. No. 5,370,609,
(incorporated herein by reference) teaches the use of a high-energy
rearward facing water jet to remove occlusive material. The art
also teaches the use of rotating mechanical burrs or blades for
removing material. See for example Pannek, U.S. Pat. No. 5,224,945
(incorporated herein by reference). Also the use of heat to reform
and remodel a vessel is known from Eggers, U.S. Pat. No. 4,998,933,
among others.
SUMMARY
[0007] The atherectomy devices according to the invention include a
magnetic element that allows for the remote manipulation of the
distal end of working tip of the device by a magnetic surgery
system (MSS) or other magnetic field generator operated outside of
the patient.
[0008] The application of external fields and gradients allows the
physician to control the orientation and location of the distal tip
of the catheter in the vessel at the treatment site. This permits
the use of small and potentially single size catheters to treat
either partial or total occlusions in the vasculature. In operation
the device is moved to various treatment sites or locations in a
vessel under the guidance of the MSS. The methods of the invention
may be partially automated in the sense that the physician can
image the current location of the device and program a desired
location with the MSS and designate a location or orientation of
the device in a vessel. The MSS system can provide feedback to the
physician to help the physician direct the device as "planned" with
the MSS workstation. Robotic control of the device is also
contemplated wherein the motion of the device in the vessel is
entirely under software control. In this instance physician
observation and transducer feedback manages the procedure.
[0009] Any of a variety of energy sources can be used to carry out
the recannalization process of the invention, although thermal
energy is preferred and is used as an illustrative energy source.
The source of heat may include optical or radio frequency energy
sources. However, the device is also useful with hydraulic energy,
direct laser sources, ultrasonic energy sources, or mechanical
energy sources. Physician supplied energy is contemplated as well
in the sense that a doddering wire may be manipulated by the
physician and guided magnetically to treat the occlusion.
[0010] Devices which rely on heat or which generate heat in the
body may include fluid cooling to manage the distribution of heat,
several device with adjunctive fluid delivery are shown as
illustrative of the invention.
[0011] Additional "delivery" structures are present in some
embodiments of the device and may be used to accommodate various
medical techniques and methods. For example lumens for "over the
wire" and "rapid exchange" delivery of the catheters are shown.
Also these lumens may be used with imaging and localization devices
to carry out the methods of the invention. These lumens may also be
used to introduce contrast agent into the treatment site.
[0012] Localization structures are disclosed for use in the
procedure. Preoperative Magnetic Resonance Imaging (MRI), Computed
Tomography (CT) or Ultrasound scans provide a "roadmap" for the
procedure while X-ray, Doppler ultrasound, or other localization
techniques are used to display the current real time position of
the device in the lumen.
[0013] It is also contemplated that the "open" lumens of the device
can be used with ultrasonic, optical coherence tomographic, or
laser based imaging systems to characterize the nature of the
occlusion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Throughout the various figures of the drawing like reference
numerals refer to identical structure. A typical and exemplary set
of embodiments of the invention are shown in the drawing but
various changes to the devices may be made without departing from
the scope of the invention wherein:
[0015] FIG. 1 is schematic diagram of a thermal catheter in a
vessel;
[0016] FIG. 2 is a schematic diagram of a bipolar thermal
catheter;
[0017] FIG. 3 is a schematic diagram of a resistance heated thermal
catheter;
[0018] FIG. 4 is a schematic of a laser-heated catheter;
[0019] FIG. 5 is a schematic of a thermal catheter having an
additional lumen;
[0020] FIG. 6 is a RF heated catheter with a rapid exchange
lumen;
[0021] FIG. 7 is an ultrasound atherectomy device driven by an
external horn;
[0022] FIG. 8 is a hydraulic catheter;
[0023] FIG. 9 is an optically heated catheter in a sheath;
[0024] FIG. 10 is an optically heated device with an auxiliary
lumen;
[0025] FIG. 11 is an optically heated device with multiple
lumens;
[0026] FIG. 12 is an optically heated device with a distal port;
and
[0027] FIG. 13 is a schematic overview of the automated
workstation.
[0028] FIG. 14 is an exploded perspective view of a second
embodiment of a magnetically guided atherectomy device constructed
according to the principles of this invention;
[0029] FIG. 15 is a longitudinal cross-sectional view of the distal
end portion of the magnetically guided atherectomy device of the
second embodiment;
[0030] FIG. 16 is a perspective view of the distal end portion of
the magnetically guided atherectomy device of the second
embodiment;
[0031] FIG. 17 is an exploded perspective view of a third
embodiment of a magnetically guided atherectomy device constructed
according to the principles of this invention;
[0032] FIG. 18 is a longitudinal cross-sectional view of the distal
end portion of the magnetically guided atherectomy device of the
third embodiment;
[0033] FIG. 19 is a perspective view of the distal end portion of
the magnetically guided atherectomy device of the third
embodiment;
[0034] FIG. 20 is an exploded perspective view of a fourth
embodiment of a magnetically guided atherectomy device constructed
according to the principles of this invention;
[0035] FIG. 21 is a longitudinal cross-sectional view of the distal
end portion of the magnetically guided atherectomy device of the
fourth embodiment;
[0036] FIG. 22 is a longitudinal cross-sectional view of a first
alternate construction of a fifth embodiment of a magnetically
guided atherectomy device constructed according to the principles
of this invention;
[0037] FIG. 23 is a longitudinal cross-sectional view of a second
alternate construction of a fifth embodiment of a magnetically
guided atherectomy device constructed according to the principles
of this invention;
[0038] FIG. 24 is a longitudinal cross-sectional view of a third
alternate construction of a fifth embodiment of a magnetically
guided atherectomy device constructed according to the principles
of this invention;
[0039] FIG. 25 is a longitudinal cross-sectional view of a first
alternate construction of a sixth embodiment of a magnetically
guided atherectomy device constructed according to the principles
of this invention;
[0040] FIG. 26 is a longitudinal cross-sectional view of a second
alternate construction of a sixth embodiment of a magnetically
guided atherectomy device constructed according to the principles
of this invention; and
[0041] FIG. 27 is a longitudinal cross-sectional view of a third
alternate construction of a sixth embodiment of a magnetically
guided atherectomy device constructed according to the principles
of this invention.
DETAILED DESCRIPTION THE INVENTION
[0042] FIG. 1 shows a thermal catheter 10 in a vessel 12. The
distal tip section 14 of the device is shown in a vessel while the
proximal section 15 is illustrated as a fragment located outside of
the vessel 12. In general, the construction of the proximal end of
the device and configuration and power couplings are within the
ordinary skill of this art and are illustrated schematically in
FIG. 1. For clarity the detailed disclosure is directed to the
distal tip structures. However it should be recognized that the
devices are intended for use in coronary vessels, the overall
length of devices in accordance with this invention are 30 or more
inches long and typical are between 2 and 12 French in diameter. It
should be understood that coronary use is merely illustrative and
other vessels and body lumens may be addressed therapeutically
using the invention. The proximal end will carry suitable hubs and
connections for the wires and lumens discussed in connection with
the distal tip.
[0043] In FIG. 1 the distal tip 14 of the catheter 10 abuts a total
occlusion 16. A guide wire 18 shown in phantom, and sheath 20 may
be used together to deliver the catheter 10 to the treatment site
near the occlusion 16. Either or both of the guide wire or sheath
may have a magnetic element 22 included in its design to assist in
access to the treatment site. For instance the guide wire 18 may
have a magnet 22 located at its distal tip. Similarly the sheath
may have a magnetic tube 24 located at its distal tip. However, for
the purpose of this disclosure the magnetic elements on the guide
wire or sheath permit the applied field or gradient to orient the
distal tip. In FIG. 1 the forces generated on the tip by an
external magnet are shown by vectors indicated by reference numeral
9. The physician can advance the guide wire or sheath by pushing on
the proximal end of end of the device with the distal tip direction
determined in part by the magnetic forces represented at 9. The
magnetic orientation of the tip coupled with physical motion
applied to the proximal end of the device positions the device. The
physical motion can be supplied by either the physician or a
robotic element.
[0044] The thermal catheter embodiment of FIG. 1 has a heated tip
26. Preferably this tip is formed from Hiperco or other
magnetically active metallic material. In this context
iron-containing alloys of steel which are attracted to magnets are
suitable choices for the tip material. Although the distal tips are
shown in hemispheric in shape for consistency of explanation it
should be understood that other forms and shapes are operable so
the shape should be understood as illustrative and not limiting. In
use heat is delivered by the tip 26. More specifically the tip
generates heat in the tissue distal to the tip. The lines located
by reference numeral 38 represent heat transfer to the occlusion
16, which allows the tip 26 to move through the occlusion 16. In
this embodiment the tip 26 is heated with RF energy from an RF
source 28. The RF source is coupled to the tip by a wire 32. A
patch electrode 34 having a large area may be placed on the patient
to complete the circuit to the RF source 28 through wire 36. This
configuration may be called "monopolar" in contrast to the "bipolar
configuration shown in FIG. 2. A coating 27 may be applied to the
surface of the distal tip to prevent sticking or adhesions. The
coating 27 may also increase biocompatibility or improve heat
transfer through the device. Both polymeric materials such as
Teflon and metallic materials such as titanium nickel alloy are
suitable for this application. Therefore the illustrative
embodiments of the invention should be considered to be "composite"
constructions where individual elements may be made of more than
one material as indicated by coating 29.
[0045] FIG. 2 shows a distal tip embodiment for a thermal catheter
10, which includes two metal structures that are insulated from
each other. The first structure is the distal tip 40 which is metal
and may be magnetically active. The wire 32 couples this tip to the
RF source 28. The second element is the return electrode 42.
Preferably this function is served by metallic ring or bank 42
which is coupled to the RF source 28 through the wire 36. In this
embodiment one or both of the metallic elements may be magnetically
active. Also partial rings which surround only part of the catheter
are contemplated within the scope of the invention although they
are not preferred. In general the exact shape of the distal rings
will not be critical to the operation of the invention.
[0046] FIG. 3 shows a resistance-heated embodiment of a thermal
catheter 10 where the distal tip 44 is magnetically active metal.
The tip 44 is electrically isolated from, but in thermal contact
with the resistance wire heater 46 located near the tip. Wire 48
and wire 50 couple the heater 46 to the electrical power source 52
which may be an AC or DC source which may be modulated to control
the energy delivery to the tip.
[0047] FIG. 4 shows a laser-heated embodiment of the thermal
catheter device 10. In this embodiment the tip 60 absorbs radiation
from the optical wave guide 62 coupled to the laser source 64. In
operation the laser energy source may operate continuously or
intermittently to deliver energy to the tip 60. In operation the
laser light impinges on the tip structure and it is absorbed and
converted to heat. The distal tip 60 may be magnetic or may be made
from a magnetically active material. In general, and depending on
detail design issues the surface of the tip may or may not be
electrically conductive. In this particular embodiment it should be
clear that the thermal requirements of the tip are significant in
contrast to other embodiments where electrical conductivity is
critical. It is contemplated that the distal tip may be made of
ceramic or "glassy" material.
[0048] FIG. 5 shows an embodiment of the invention wherein thermal
catheter 10 has a distal tip 70 which has a tube 71 that has an
open lumen 72 which communicates to the proximal end of the device.
This lumen 72 can be used for several purposes. For example, the
lumen can accommodate either an imaging wire 76, ultrasonic or
laser imaging, or a guide wire 74. In operation the preferred
ultrasonic imaging wire can be used to visualize and locate the
occlusion. Once the occlusion has been located and characterized,
the correct amount of power can be delivered to the distal tip 70.
Typically the ultrasound imaging wire would be withdrawn and parked
in the lumen 72 proximally to prevent heat damage to the transducer
of the imaging wire. During device placement the lumen can be used
with guide wire 74 to access the treatment site.
[0049] The lumen can also be used with an optical fiber to perform
laser induced florescence spectroscopy or optical low coherence
reflectometry or optical coherence tomography. These procedures can
be used to "look at" and evaluate the obstruction during
treatment.
[0050] FIG. 6 is an example of a "rapid exchange" delivery
configuration for the thermal catheter 10. The distal tip 80 as an
open lumen 82 which is relatively short and exits the side of the
catheter body 84 at a location distal of the proximal end of the
device 10. This opening can receive a guide wire which can be used
to position the device near the occlusion.
[0051] FIG. 7 represents an ultrasound energy source catheter 92.
The ultrasonic hom 94 is coupled to the waveguide 96 which in turn
terminates in a distal tip 90. The waveguide may extend beyond the
tip. In operation the delivery of ultrasound energy to the distal
tip results in the formation of very small bubbles which dislodge
the nearby plaque or other obstructing material. In this embodiment
the distal tip 90 may be formed of Hiperco or other magnetically
active material.
[0052] FIG. 8 represents a hydraulic catheter 91 which uses the
force of a jet of fluid emerging from nozzle 93 to disrupt the
occlusive material. In this device the distal tip 100 may be made
from Hiperco or another magnetically active material.
[0053] FIG. 9 shows the device 10 of FIG. 5 located in a sheath
120. The space between the sheath and the catheter body 122 can be
flooded with contrast agent to reveal the location of the catheter
with respect to the occlusion. At some power levels the space can
be used to conduct cooling fluid to the tip to help regulate the
temperature and temperature distribution of the device 124. Saline
injection can also be used to prevent implosion of vapors in the
blood at the treatment site.
[0054] FIG. 10 shows the device 78 of FIG. 5 in a sheath that
limits the movement of the distal tip 70. In this version of the
device the sheath 130 positions the distal tip 70 near the guide
magnets 134. This allows the physician to move the tip with the MSS
and to control the exit of fluid from the sheath.
[0055] FIG. 11 represents a multi-lumen construction where a fluid
supply lumen 140 is provided to irrigate the tip 144 of the
catheter 146. An offset guide wire lumen 148 is provided for used
with imaging and locating devices.
[0056] FIG. 12 shows an embodiment of the catheter where the fluid
exiting the tip through a port 150 serves to cool the catheter body
152. In this device the exterior wall of the catheter forms a
central lumen which may be filled with a cooling solution. In
general this volume may be too large to use for contrast injection.
The fluid pressure in this sheath could also be reversed to create
a vacuum on the occlusive material and remove it from the body
during ablation.
[0057] FIG. 13 is a schematic diagram of a MSS system for using the
catheters in a patient. In operation the physician user interacts
with the patient 302 and the workstation console 300. The software
used by the workstation coordinates several separate sources of
data and control certain hardware as well. For example information
from a preoperative scan 305 is loaded into the workstation 300 to
provide a template of the treatment site. This preoperative data
may be collected from MRI, CT, ultrasound, or other diagnostic
imaging scans. Real time biplane x-ray data is supplied by an x-ray
machine 303 and 304 to the workstation as well for display against
the template and for interaction with the physician. As an
alternative, orthogonal coils 301 and 302 may be used with an RF
location system to localize the position of the catheter.
[0058] In general a fiducial marker on the catheter allows the
preoperative scan and the real time scans to be appropriately
merged. In operation the user can define a location on the MSS
workstation 300 with a mouse or other pointing device which
identifies the desired location of the therapy. Next the MSS
workstation computes the forces and required fields and gradients
required to navigate the catheter to the new location. This
information controls the magnet system 308. An appropriate set of
catheter actuators 306 may be provided to allow the MSS to move the
catheter as well.
[0059] A second embodiment of a magnetically guided atherectomy
device is indicated generally as 400 in FIGS. 14-16. The
magnetically guided atherectomy device 400 comprises an elongate
catheter 402, having a proximal end (not shown) and a distal end
406, with a lumen 408 therebetween. The catheter 402 can be made of
any flexible, biocompatible material conventionally used for
medical catheters, for example Pebax.
[0060] A support 410 is mounted in the lumen adjacent the distal
end 406. This support 410 can be permanently affixed within the
catheter 402, with only the distal portion of the support
projecting beyond the distal end 406 of the catheter. The support
410 is preferably made of a transparent, biocompatible material,
such as polyethylene, polycarbonate, Pebax, or other suitable
material. The support 410 includes passages for the ablation
electrode conductor, and imaging, and preferably also includes
compartments for receiving magnet body as described in more detail
below.
[0061] The magnetically guided atherectomy device further includes
an ablation electrode 414, on the distal end of the support 412.
The ablation electrode 414 has a smoothly contoured, rounded shape,
with a radius of curvature selected to selectively heat the
material in front of, and closely adjacent to, the ablation
electrode. An electrode conductor 416 extends from the proximal
side of the electrode 414, through a conductor passage 418 in the
support 410 and through the catheter 402 to the proximal end.
[0062] One or more optical fibers terminate in the body, facing
generally radially outwardly for imaging the vessel in which the
device 400 is located. In this preferred embodiment there are two
optical fibers 420 and 422, having beveled distal ends 424 and 426,
respectively. The optical fibers 420 and 422 extend proximally to
the proximal end of the catheter 402, where the optical fibers are
connected an imaging system. The imaging system may be an optical
imaging system, or preferably an optical coherence tomography
system. Optical coherence tomography provides imaging capability
within the blood vessel and has been used in navigable medical
devices such as Colston et al., U.S. Pat. No. 6,175,669, Teamey et
al., U.S. Pat. No. 6,134,003, Selmon et al., U.S. Pat. No.
6,120,516, Gregory, U.S. Pat. No. 6,117,128, Townsend et al., U.S.
Pat. No. 6,066,102, Whayne et al., U.S. Pat. No. 6,047,218, Selmon
et al., U.S. Pat. No., 6,010,449, Selmon et al., U.S. Pat. No.
5,968,064, Swanson et al., U.S. Pat. No. 5,804,651, McGee, U.S.
Pat. No. 5,752,518, Hanson et al., U.S. Pat. No. 5,741,270, McGee,
U.S. Pat. No. 5,722,403, the disclosures of which are incorporated
herein by reference. The catheter 402 can be rotated, or the
individual optical fibers 420 and 422 can be rotated to imaging
substantially the entire (and preferably the entire) interior
circumference of the vessel in which the device is located.
[0063] At least one magnet member is disposed in the distal end
portion of the device 400. In this second preferred embodiment,
there are two magnet members 432, each having a D-shaped transverse
cross-section, and disposed in correspondingly shaped passages 434
in the support 410. The magnet members 432 may be made of a
permanent magnetic material, for example a neodymium-iron-boron
(Nd--Fe--B) material, or a permeable magnetic material such as
hiperco. The magnet members are sized and shaped so that they tend
to align the distal end portion of the device 400 with an
externally applied magnetic field. Thus, through the application of
the appropriate field with the magnet(s) of an external magnetic
surgical system, the distal end of the device can be oriented in
any selected direction.
[0064] The magnetically guided atherectomy device 400 is oriented
in the desired direction by the application of the appropriate
magnetic fields with the magnetic surgery system, and the device is
advanced, for example by mechanically pushing the proximal end.
When the device 400 encounters plaque or other atheramatous
material, heat can be applied to the blockage to destroy it by
applying energy to the electrode 414 via conductor 416. A grounding
pad applied to the patient provides a current path. The current
density is so great in the material immediately adjacent (within a
few millimeters) the electrode 414 that the material heats up and
is ablated, while the vessel walls and other tissues are not
damaged.
[0065] Through a combination of localization, for example with
bi-planar fluoroscopic imaging, and imaging, for example with OCT,
the location and orientation of the device within the walls of the
vessel, an image of the device and its position and orientation in
the vessel can be displayed so that through a simply user
interface, for example an interface that allows the user to "click"
on a cross-sectional image of the device within a vessel, and cause
a controller (for example a computer or other microprocessor based
controller) to operate the magnetic surgery system to change the
field to cause the device to move in the indicated desired
direction, or to cause the device to move to the indicated desired
position. Complex movement patterns can also be programmed, for
example the physician could indicate a size and or shape for the
lumen of the vessel, and through the processing of information
obtained from the localization and imaging system the controller to
automatically control the device 400 to clear the indicated size
and shape.
[0066] A third embodiment of a magnetically guided atherectomy
device is indicated generally as 500 in FIGS. 17-19. The
magnetically guided atherectomy device 500 comprises an elongate
catheter 502, having a proximal end (not shown) and a distal end
506, with a plurality of lumens 508 therebetween. The catheter 502
can be made of any flexible, biocompatible material conventionally
used for medical catheters, for example Pebax, and is preferably
transparent.
[0067] There is a disc-shaped electrode 510 on the distal end of
the catheter 502. The electrode 510 has an opening 512 therein,
generally transverse to the plane of the disc. A conduit 514 can
extend through a generally central passageway 516 in the catheter
502 and through the opening 512 in the electrode 510, to make an
electrical connection with the electrode, and provide energy to the
electrode 510 for ablating atheramatous material that the electrode
contacts. In this preferred embodiment the conduit 514 can be
extended relative to the distal end and/or the catheter can be
retracted relative to the conduit 514 to leave the conduit 514 as a
guide so that the catheter 500 can be quickly and easily navigated
to the surgical site.
[0068] The ablation electrode 510 has a smoothly contoured, rounded
shape, with a radius of curvature selected to selectively heat the
material in front of, and closely adjacent to, the ablation
electrode.
[0069] The catheter 502 includes passages for the conduit 514 and
for optical fibers for imaging, and compartment for receiving
magnet bodies as described in more detail below.
[0070] One or more optical fibers terminate in the catheter 502,
facing generally radially outwardly for imaging the vessel in which
the device 500 is located. In this preferred embodiment there are
two optical fibers 518 and 520, having beveled distal ends 518 and
520, respectively. The optical fibers 522 and 524 extend proximally
to the proximal end of the catheter 502, where the optical fibers
are connected an imaging system. The imaging system may be an
optical imaging system, or preferably an optical coherence
tomography system. The catheter 502 can be rotated, or the
individual optical fibers 518 and 520 can be rotated to imaging
substantially the entire (and preferably the entire) interior
circumference of the vessel in which the device is located.
[0071] At least one magnet member is disposed in the distal end
portion of the device 500. In this second preferred embodiment,
there are two magnet members 526, each having a D-shaped transverse
cross-section, and disposed in correspondingly shaped passages 528
in the distal end of the device 506; . The magnet members 526 may
be made of a permanent magnetic material, for example a
neodymium-iron-boron (Nd--Fe--B) material, or a permeable magnetic
material, such as hiperco. The magnet members 526 are sized and
shaped so that they tend to align the distal end portion of the
device 500 with an externally applied magnetic field. Thus, through
the application of the appropriate field with the magnet(s) of an
external magnetic surgical system, the distal end of the device can
be oriented in any selected direction.
[0072] The magnetically guided atherectomy device is oriented in
the desired direction by the application of the appropriate
magnetic fields with the magnetic surgery system, and the device is
advanced, for example by mechanically pushing the proximal end.
When the device 500 encounters plaque or other atheramatous
material, heat can be applied to the blockage to destroy it by
applying energy to the electrode 510 via conduit 514. A grounding
pad applied to the patient provides a current path. The current
density is so great in the material immediately adjacent (within a
few millimeters) the electrode 510 that the material heats up and
is ablated, while the vessel walls and other tissues are not
damaged.
[0073] Through a combination of localization, for example with
bi-planar fluoroscopic imaging, and imaging, for example with OCT,
the location and orientation of the device within the walls of the
vessel, an image of the device and its position and orientation in
the vessel can be displayed so that through a simply user
interface, for example an interface that allows the user to "click"
on a cross-sectional image of the device within a vessel, and cause
a controller (for example a computer or other microprocessor based
controller) to operate the magnetic surgery system to change the
field to cause the device to move in the indicated desired
direction, or to cause the device to move to the indicated desired
position. Complex movement patterns can also be programmed, for
example the physician could indicate a size and or shape for the
lumen of the vessel, and through the processing of information
obtained from the localization and imaging system the controller to
can automatically adjust the magnetic surgery system to move the
device to clear the indicated desired path.
[0074] A fourth embodiment of a magnetically guided atherectomy
device is indicated generally as 600 in FIGS. 20-21. The
magnetically guided atherectomy device 600 comprises an elongate
catheter 602, having a proximal end (not shown) and a distal end
606, with at least one lumen 608 therebetween. The catheter 602 can
be made of any flexible, biocompatible material conventionally used
for medical catheters, for example Pebax, and is preferably
transparent.
[0075] There is a dome-shaped cutting head 610 on the distal end of
the elongate catheter 602. The cutting head 610 has a centrally
opening an annular cutting edge 612 aligned with the lumen of the
catheter. The smooth, dome shape allows distal end of the device to
be manipulated within the blood vessel without damaging the inside
structure of the blood vessels. The opening allows material that
has been cored from the blood vessel to pass through the cutting
head 610 to the lumen of the catheter where it can be accumulated
or flushed out of the system.
[0076] One or more optical fibers terminate in the body, facing
generally radially outwardly for imaging the vessel in which the
device 600 is located. In this preferred embodiment there is a
single optical fiber 614, having a beveled distal end 616. The
optical fiber extends proximally to the proximal end of the
catheter 602, where the optical fiber is connected to an imaging
system. The imaging system may be an optical imaging system, or
preferably an optical coherence tomography system. The catheter 602
can be rotated, or the individual optical fiber 614 can be rotated
to imaging substantially the entire (and preferably the entire)
interior circumference of the vessel in which the device is
located.
[0077] At least one magnet member is disposed in the distal end
portion of the device 600. In this fourth preferred embodiment,
there is a single magnet member 618, having a generally C-shaped
transverse crosssection, and disposed in correspondingly shaped
passages 620 in the distal end of the device 600. The magnet member
618 may be made of a permanent magnetic material, for example a
neodymium-iron-boron (Nd--Fe--B) material, or a permeable magnetic
material, for example hiperco. The magnet members are sized and
shaped so that they tend to align the distal end portion of the
device 600 with an externally applied magnetic field. Thus, through
the application of the appropriate field with the magnet(s) of an
external magnetic surgical system, the distal end of the device can
be oriented in any selected direction.
[0078] The magnetically guided atherectomy device is oriented in
the desired direction by the application of the appropriate
magnetic fields with the magnetic surgery system, and the device is
advanced, for example by mechanically pushing the proximal end.
When the device 600 encounters plaque or other atheramatous
material, the device is advanced against the material so that the
head 610 cuts a passage through the atheramatous. Through a
combination of localization, for example with bi-planar
fluoroscopic imaging, and imaging, for example with OCT, the
location and orientation of the device within the walls of the
vessel, an image of the device and its position and orientation in
the vessel can be displayed so that through a simply user
interface, for example an interface that allows the user to "click"
on a cross-sectional image of the device within a vessel, and cause
a controller (for example a computer or other microprocessor based
controller) to operate the magnetic surgery system to change the
field to cause the device to move in the indicated desired
direction, or to cause the device to move to the indicated desired
position. Complex movement patterns can also be programmed, for
example the physician could indicate a size and or shape for the
lumen of the vessel, and through the processing of information
obtained from the localization and imaging system the controller to
can automatically adjust the magnetic surgery system to move the
device to clear the indicated desired path.
[0079] A fifth embodiment of a magnetically guided atherectomy
device is indicated generally as 700 in FIGS. 22-25. A first
alternate construction of the device 700 is shown in FIG. 22. The
device 700 comprises a catheter 702 having a proximal end 704 and a
distal end 706, and a lumen 708 therebetween. A rotatable cutting
member 710, having a proximal end 712 and a distal end 714, is
disposed in the lumen 708. The rotatable cutting member 710
comprises a flexible drive shaft 716, which may be for example a
flexible coil, with a cutting head 718 thereon. The cutting head
718 has a distal annular cutting edge 720, and an axial passage 722
for receiving material "cored" by the annular cutting edge. The
flexible drive shaft 716 is preferably surrounded by a sheath 724
to protect in the inner wall of the catheter 702.
[0080] In this first alternate construction of the fifth preferred
embodiment the sheath 724 includes an optical fiber 726, having a
bevel distal end 728, facing generally radially outwardly for
imaging the vessel in which the device 700 is located. The optical
fiber 726 extends proximally to the proximal end of the catheter
702, where the optical fiber is connected an imaging system. The
imaging system may be an optical imaging system, or preferably an
optical coherence tomography system. As the rotatable cutting
member 710 rotates, the sheath 724 and the optical fiber rotates
with it, and the imaging system acquires an image of substantially
the entire (and preferably the entire) interior circumference of
the vessel in which the device is located.
[0081] At least one magnet member is disposed in the distal end
portion of the device 700. The magnet member can be disposed in the
wall of the catheter 702, or somehow associated with the rotatable
cutting member 718, such as by making the cutting member 718 out of
a magnetic or a magnetically permeable material. The magnet member
may be made of a permanent magnetic material, for example a
neodymium-iron-boron (Nd--Fe--B) material, or a permeable magnetic
material, for example hiperco.
[0082] A second alternate construction of the device 700' is shown
in FIG. 23. The device 700' is similar in construction to device
700, and corresponding parts are identified with corresponding
reference numerals. As shown in FIG. 23, the device 700' comprises
a catheter 702' having a proximal end 704 and a distal end 706, and
a lumen 708 therebetween. A rotatable cutting member 710', having a
proximal end 712 and a distal end 714, is disposed in the lumen
708. The rotatable cutting member 710' comprises a flexible drive
shaft 716, which may be for example a flexible coil, with a cutting
head 718' thereon. The cutting head 718' unlike cutting head 718 of
device 700, has an oblate spheroidal shape, i.e., it is generally
football shaped, having a roughed distal surface for cutting
atheramatous material.
[0083] In this second alternate construction of the fifth preferred
embodiment the catheter 702' includes an optical fiber 726, having
a bevel distal end 728, facing generally radially outwardly for
imaging the vessel in which the device 700' is located. The optical
fiber 726 extends proximally to the proximal end of the catheter
702', where the optical fiber is connected an imaging system. The
imaging system may be an optical imaging system, or preferably an
optical coherence tomography system. As the rotatable cutting
member 710 rotates, the catheter 702' can be rotated so that the
imaging system acquires an image of substantially the entire (and
preferably the entire) interior circumference of the vessel in
which the device is located.
[0084] At least one magnet member is disposed in the distal end
portion of the device 700'. The magnet member can be disposed in
the wall of the catheter 702', or somehow associated with the
rotatable cutting member 718', such as by making the cutting member
718' out of a magnetic or a magnetically permeable material. The
magnet members may be made of a permanent magnetic material, for
example a boron-iron-boron (Nd--Fe--B) material, or a permeable
magnetic material, for example hiperco.
[0085] A third alternate construction of the device 700" is shown
in FIG. 24. The device 700" is similar in construction to devices
700 and 700', and corresponding parts are identified with
corresponding reference numerals. As shown in FIG. 24, the device
700" comprises a catheter 702" having a proximal end 704 and a
distal end 706, and a lumen 708 therebetween. A rotatable cutting
member 710", having a proximal end 712 and a distal end 714, is
disposed in the lumen 708. The rotatable cutting member 710"
comprises a flexible drive shaft 716, which may be for example a
flexible coil, with a cutting head 718" thereon. The cutting head
718", like cutting head 718' of device 700', but unlike cutting
head 718 of device 700, has an oblate spheroidal shape, i.e., it is
generally football shaped, having a roughed distal surface for
cutting atheramatous material. There is a sheath 720" surrounding
the flexible drive shaft 716.
[0086] In this third alternate construction of the fifth preferred
embodiment the sheath 720" includes an optical fiber 726, having a
beveled distal end 728, facing generally radially outwardly for
imaging the vessel in which the device 700" is located. The optical
fiber 726 extends proximally to the proximal end of the catheter
702, where the optical fiber is connected an imaging system. The
imaging system may be an optical imaging system, or preferably an
optical coherence tomography system. As the rotatable cutting
member 710" rotates, the optical fiber 726 rotates so that the
imaging system acquires an image of substantially the entire (and
preferably the entire) interior circumference of the vessel in
which the device is located.
[0087] At least one magnet member is disposed in the distal end
portion of the device 700". The magnet member can be disposed in
the wall of the catheter 702, or somehow associated with the
rotatable cutting member 710", such as by making the cutting head
718" out of a magnetic or a magnetically permeable material. The
magnet members may be made of a permanent magnetic material, for
example a neodymium-iron-boron (Nd--Fe--B) material, or a permeable
magnetic material, for example hiperco.
[0088] A sixth embodiment of a magnetically guided atherectomy
device is indicated generally as 800 in FIGS. 25-27. A first
alternate construction of the magnetically guided atherectomy
device is indicated generally as 800 in FIG. 26. The device 800
comprises a catheter 802, having a proximal end 804, and a distal
end 806, and a lumen 808 therebetween. A laser ablation tool 810 is
disposed in the lumen of the catheter 802. The laser can heat the
material distal to the distal end directly or heat the tip to heat
this material. The laser ablation tool 810 has a distal end 812,
and a first lumen 814 opening at the distal end, for receiving an
optical fiber 816 for conducting ablating laser energy to the
distal end of the tool to ablate atheramatous material distal to
the tool. The tool 810 also includes a passage 818 for
accommodating a guide wire to facilitate the navigation and control
of the device 800.
[0089] Magnet members can be provided in wall of the catheter 802,
and/or a portion of the tool 810 can be made of a magnetic
material, or a magnetically permeable material. In the first
alternate construction shown in FIG. 25, an annular magnet member
820 is incorporated into the sidewall of the catheter 802.
[0090] As shown in FIG. 25, irrigating fluid can be delivered to
the treatment site through the annular space between the catheter
802 and the tool 810.
[0091] A second alternate construction of the device of the sixth
embodiment, indicated generally as 800' is shown in FIG. 26. The
device 800' is similar in construction to device 800, and
corresponding parts are identified with corresponding reference
numerals. The device 800' comprises a catheter 802', having a
proximal end 804, and a distal end 806, and a lumen 808
therebetween. A laser ablation tool 810 is disposed in the lumen of
the catheter 802. The laser ablation tool 810 has a distal end 812,
and a first lumen 814 opening at the distal end, for receiving an
optical fiber 816 for conducting ablating laser energy to the
distal end of the tool to ablate atheramatous material distal to
the tool. The tool 810 also includes a passage 818 for
accommodating a guide wire to facilitate the navigation and control
of the device 800.
[0092] Magnet members can be provided in wall of the catheter 802,
and/or a portion of the tool 810 can be made of a magnetic
material, or a magnetically permeable material. In the second
alternate construction shown in FIG. 26, magnet member 820' is
incorporated into the tool 810, just proximal to the distal end.
The magnet member 820 has passages therein for accommodating the
optical fiber and the guide wire.
[0093] As shown in FIG. 26, irrigating fluid can be delivered to
the treatment site through the annular space between the catheter
802 and the tool 810'.
[0094] A third second alternate construction of the device of the
sixth embodiment, indicated generally as 800" is shown in FIG. 26.
The device 800" is similar in construction to device 800, and
corresponding parts are identified with corresponding reference
numerals. The device 800" comprises a catheter 802, having a
proximal end 804, and a distal end 806, and a lumen 808
therebetween. A laser ablation tool 810" is disposed in the lumen
of the catheter 802. The laser ablation tool 810" has a distal end
812, and a first lumen (not shown) opening at the distal end, for
receiving an optical fiber (not shown) for conducting ablating
laser energy to the distal end of the tool to ablate atheramatous
material distal to the tool. The tool 810 also includes a passage
818 for accommodating a guide wire to facilitate the navigation and
control of the device 800. In addition the tool 800" has a closed
loop path 822 for the circulation of cooling fluid to cool the
distal end portion of the tool 810".
[0095] Magnet members can be provided in wall of the catheter 802,
and/or a portion of the tool 810 can be made of a magnetic
material, or a magnetically permeable material. In the third
alternate construction shown in FIG. 27, magnet member 820" is
incorporated into the tool 810, just proximal to the distal end.
The magnet member 820" has passages therein for accommodating the
optical fiber and the guide wire.
[0096] As was shown in FIGS. 25 and 26, irrigating fluid can be
delivered to the treatment site through the annular space between
the catheter 802 and the tool 810'.
* * * * *