U.S. patent application number 11/651268 was filed with the patent office on 2007-06-07 for endovascular tissue removal device.
Invention is credited to Robert I. Rudko, Mark R. Tauscher, Richard P. JR. Yeomans.
Application Number | 20070129710 11/651268 |
Document ID | / |
Family ID | 34103447 |
Filed Date | 2007-06-07 |
United States Patent
Application |
20070129710 |
Kind Code |
A1 |
Rudko; Robert I. ; et
al. |
June 7, 2007 |
Endovascular tissue removal device
Abstract
An endovascular tissue removal device including a lumen with a
distal steerable tip portion extending from a joint portion,
registration means for holding the joint portion fixed in place in
the vasculature, and a source of ablation energy in communication
with the lumen whereby tissue can be resected by ablation energy as
the tip portion is steered within the vasculature.
Inventors: |
Rudko; Robert I.;
(Holliston, MA) ; Tauscher; Mark R.; (Medfield,
MA) ; Yeomans; Richard P. JR.; (Medway, MA) |
Correspondence
Address: |
Iandiorio &Teska
260 Bear Hill Road
Waltham
MA
02451-1018
US
|
Family ID: |
34103447 |
Appl. No.: |
11/651268 |
Filed: |
January 9, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10628794 |
Jul 28, 2003 |
7204255 |
|
|
11651268 |
Jan 9, 2007 |
|
|
|
Current U.S.
Class: |
606/7 ;
606/27 |
Current CPC
Class: |
A61B 2017/22069
20130101; A61B 18/24 20130101; A61B 2017/00243 20130101; A61B
2017/22097 20130101 |
Class at
Publication: |
606/007 ;
606/027 |
International
Class: |
A61B 18/18 20060101
A61B018/18 |
Claims
1. An endovascular tissue removal device comprising: a lumen
including a distal steerable tip portion extending from a joint
portion; registration means for holding the joint portion fixed in
place in the vasculature; and a source of ablation energy in
communication with the lumen whereby tissue can be resected by
ablation energy as the tip portion is steered within the
vasculature.
2. The device of claim 1 in which the registration means includes
an inflatable balloon about the joint portion.
3. The device of claim 1 in which the source of ablation energy is
a laser.
4. The device of claim 3 in which the distal steerable tip portion
includes a deflectable tip catheter.
5. The device of claim 4 in which there is an optical fiber inside
the deflectable tip catheter and connected to the laser.
6. The device of claim 1 further including an expandable barrier
for trapping any debris resected.
7. The device of claim 1 further including an expandable mechanism
inflatable on the ventricular side of the valve for supporting the
leaflets of the valve.
8. The device of claim 7 further including an absorptive surface on
the expandable mechanism for absorbing ablation energy.
9. The device of claim 7 in which the expandable mechanism is a
ballon.
10. An endovascular tissue removal device comprising: a lumen
including a distal steerable tip portion extending from a joint
portion; an inflatable balloon about the joint portion for
registering the joint portion fixed in place in vasculature; and a
source of ablation energy in communication with the lumen whereby
tissue can be resected by ablation energy as the tip portion is
steered within the vasculature.
11. An endovascular tissue removal device comprising: a lumen
including a distal steerable tip portion extending from a joint
portion; registration means for holding the joint portion fixed in
place in vasculature; and an optical fiber within the lumen and
steerable by the distal steerable tip portion and connected to a
source of ablation energy to resect tissue as the tip portion is
steered within the vasculature.
12. An endovascular tissue removal device comprising: a lumen
including a deflectable tip catheter; registration means for
holding the catheter fixed in place in vasculature; and a source of
ablation energy in communication with the lumen to resect tissue by
ablation energy as the deflectable tip is steered within the
vasculature.
13. An endovascular heart removal device comprising: a catheter
including a deflectable tip; a laser source; an optical fiber
within the catheter connected to the laser source; and an
inflatable balloon for registering the deflectable tip in
vasculature to resect a heart valve with laser energy as the
deflectable tip portion is used to steer the distal end of the
optical fiber within vasculature.
14. The device of claim 13 further including an expandable barrier
for trapping debris during resection.
15. An endovascular heart removal device comprising: a catheter
including a deflectable tip; a laser source; an optical fiber
within the catheter connected to the laser source; a first
inflatable balloon for registering the deflectable tip in
vasculature to resect a heart valve with laser energy as the
deflectable tip portion is used to steer the distal end of the
optical fiber within vasculature; and a second balloon inflatable
on the ventricular side of the valve for supporting the leaflets of
the valve.
Description
RELATED APPLICATIONS
[0001] This is a Divisional application of U.S. patent application
Ser. No. 10/628,794, filed on Jul. 28, 2003, hereby incorporated by
reference herein.
FIELD OF THE INVENTION
[0002] This invention relates to endovascular aortic valve
replacement.
BACKGROUND OF THE INVENTION
[0003] Currently, replacement of a malfunctioning heart valve is
accomplished by a major open-heart surgical procedure requiring
general anesthesia, full cardio-pulmonary bypass with complete
cessation of cardio-pulmonary activity, and a long period of
hospitalization and recuperation. In most cases, the native valve
is resected (cut-out) and the replacement valve then installed.
[0004] As an alternative to open heart surgery, those skilled in
the art have attempted to devise systems for endovascular heart
valve replacement to overcome the disadvantages associated with
open-heart surgery. U.S. Pat. No. 5,370,685, for example, discloses
a procedure device capsule connected to a tube and delivered to the
site via a guide wire introduced in the femoral artery of a
patient. The device capsule houses an expandable barrier attached
to balloon segments. Once the guide wire is removed and the barrier
is expanded, a tissue cutting blade assembly is advanced in the
tube and rotated by a DC motor to resect the existing valve. The
barrier traps any debris cut by the tissue cutting blade assembly.
Tissue is then suctioned out via the tube. Next, the cutting blade
assembly is removed, the barrier balloons are deflated, and the
barrier is brought back into the capsule and the capsule itself is
removed.
[0005] Then, a valve introducer capsule is advanced to the site.
The capsule houses a replacement valve and includes a pusher disk
and inflatable balloon segments. After the balloon segments are
inflated, the pusher disk pushes the replacement valve into
position and a mounting balloon is used to expand the replacement
valve and to secure it in place. Then, the introducer capsule is
removed. The '685 patent is hereby incorporated herein. See also
U.S. Pat. Nos. 5,545,214; 6,168,614; 5,840,081; 5,411,552;
5,370,685; and published Patent Application No. U.S. 2002/0058995
A1. These patents are also incorporated herein.
[0006] The problem with such a system is that the tissue cutting
blade assembly is less than optimal and does not provide very
precise cutting especially given the fact that the valve is made of
both soft and hard tissue because it is heavily calcified or
contains fibrotic tissue. Thus, the blades may buckle or bind as
they alternately contact soft and hard tissue.
[0007] It is also presumed that pressure must be exerted on the
blades. Control of this pressure and the control of the rotation
rate, however, is not disclosed in the '685 patent. There is no
margin for error in the resection procedure. If too much tissue is
cut in certain areas, for example, the aorta can be permanently
damaged. Moreover, the existing valve typically fails because of
calcification of the valve resulting in stenosis or insufficiency.
Using cutting blades for valve resection and an improper
orientation or improper pressure on the cutting blades or the wrong
rate of rotation can result in too little or too much tissue
removal and/or imprecise cutting and/or blade buckling or binding
as the blades alternately contact soft and hard (calcified)
tissue.
[0008] Other relevant art includes the following, also included
herein by this reference. Published Patent Application No. U.S.
2002/0095116 A1 discloses an aortic filter, an artery filter, and a
check valve attached to the distal end of a canula for resecting an
aortic valve from within the aorta. The mechanism for resecting the
aortic valve, however, is not disclosed. U.S. Pat. No. 6,287,321
also discloses a percutaneous filtration catheter. U.S. Pat. No.
5,554,185 discloses an inflatable prosthetic cardiovascular valve
but does not disclose any specific method of resecting the existing
or native valve.
[0009] U.S. Pat. No. 6,425,916 discloses a percutaneous approach
with a valve displacer for displacing and holding the native valve
leaflets open while a replacement valve is expanded inside the
native valve. In this way, the native valve does not need to be
resected. In many cases, however, such a procedure can not be
carried out due to the poor condition of the native valve. And,
because the native valve occupies space, the largest aperture
possible by the replacement valve may not provide sufficient blood
flow.
[0010] U.S. Pat. Nos. 6,105,515 and 6,485,485, also incorporated
here by this reference, disclose various expandable laser catheter
designs.
SUMMARY OF THE INVENTION
[0011] It is therefore an object of this invention to provide a
more precise tissue cutting apparatus for endovascular heart valve
replacement.
[0012] It is a further object of this invention to provide such a
tissue cutter which is more effective than prior art blade type
tissue cutters.
[0013] It is a further object of this invention to provide a tissue
cutter which provides effective resection even if the valve is
heavily calcified or has fibrotic tissue.
[0014] It is a further object of this invention to provide such a
tissue cutter which does not require a high rate of rotation.
[0015] It is a further object of this invention to provide such a
tissue cutter which eliminates the need for precise pressure
control.
[0016] The invention results from the realization that a more
effective and more precise tissue cutting apparatus for
endovascular heart valve replacement is effected by the use of an
optical fiber inside a deflectable tip catheter and an expandable
balloon which registers the assembly inside the heart for resection
by laser ablation as the deflectable tip steers the distal end of
the optical fiber.
[0017] This invention features an endovascular tissue removal
device comprising a lumen including a distal steerable tip portion
extending from a joint portion, registration means for holding the
joint portion fixed in place in the vasculature, and a source of
ablation energy in communication with the lumen whereby tissue can
be resected by ablation energy as the tip portion is steered within
the vasculature.
[0018] In the preferred embodiment, the registration means includes
an inflatable balloon about the joint portion, the source of
ablation energy is a laser, the distal steerable tip portion
includes a deflectable tip catheter, and there is an optical fiber
inside the deflectable tip catheter and connected to the laser. The
device may further include an expandable barrier for trapping any
debris resected. The device, in one embodiment, includes an
expandable mechanism inflatable on the ventricular side of the
valve for supporting the leaflets of the valve. An absorptive
surface on the expandable mechanism absorbs ablation energy.
Typically, the expandable mechanism is a balloon.
[0019] An endovascular tissue removal device in accordance with
this invention features a lumen including a distal steerable tip
portion extending from a joint portion, an inflatable balloon about
the joint portion for registering the joint portion fixed in place
in vasculature, and a source of ablation energy in communication
with the lumen whereby tissue can be resected by ablation energy as
the tip portion is steered within the vasculature.
[0020] A lumen includes a distal steerable tip portion extending
from a joint portion, registration means holds the joint portion
fixed in place in vasculature, and an optical fiber is disposed
within the lumen and steerable by the distal steerable tip portion
and connected to a source of ablation energy to resect tissue as
the tip portion is steered within the vasculature.
[0021] In the preferred embodiment, the endovascular heart removal
device of this invention includes a catheter including a
deflectable tip, a laser source, an optical fiber within the
catheter connected to the laser source, and an inflatable balloon
for registering the deflectable tip in vasculature to resect a
heart valve with laser energy as the deflectable tip portion is
used to steer the distal end of the optical fiber within
vasculature.
[0022] A method of resecting a valve, the method in accordance with
this invention includes endovascularly introducing a lumen with a
distal steerable tip portion to a position proximate a valve to be
resected; registering the lumen in place in the vasculature;
directing ablation energy through the lumen; and steering the
distal steerable tip portion to resect the valve. In one example,
an expandable mechanism is positioned on the ventricular side of
the valve and inflated to support the leaflets of the valve during
resection.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0023] Other objects, features and advantages will occur to those
skilled in the art from the following description of a preferred
embodiment and the accompanying drawings, in which:
[0024] FIG. 1 is a schematic view showing a typical human
heart;
[0025] FIG. 2 is a schematic view of a prior art inflatable barrier
used in endovascular aortic valve replacement procedures;
[0026] FIG. 3 is a schematic view showing a prior art tissue cutter
used in endovascular aortic valve replacement procedures;
[0027] FIG. 4 is a schematic three-dimensional view showing the
primary components associated with the endovascular tissue removal
device of the subject invention; and
[0028] FIG. 5 is a schematic three-dimensional view showing another
embodiment of the tissue removal device of the subject
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Aside from the preferred embodiment or embodiments disclosed
below, this invention is capable of other embodiments and of being
practiced or being carried out in various ways. Thus, it is to be
understood that the invention is not limited in its application to
the details of construction and the arrangements of components set
forth in the following description or illustrated in the
drawings.
[0030] FIG. 1 schematically shows heart 10 with aorta 11, aortic
valve 12, mitral valve 14, and coronary arteries 16 and 18. The
idea behind percutaneous valve replacement surgery is to deliver a
catheter 20 proximate valve 12 to resect it and to secure a
replacement prosthetic valve in place. Resecting the native valve,
however, is problematic. Those skilled in the art have devised
inflatable barriers such as barrier 30, FIG. 2 used to trap tissue
during resection. See also U.S. Pat. No. 6,287,321 and Published
Patent Application No U.S. 2002/0095116 A1. Barrier 30 traps any
tissue cut during valve resection.
[0031] But, the prior art teaches resection of the native valve
tissue by tissue cutter 40, FIG. 3 with blades 42. Tissue cutter 40
is connected to shaft 44 rotated by a DC motor presumably at a very
high rate of rotation in order to effect tissue cutting. It is also
presumed that pressure must be exerted on the blades. Control of
this pressure and the control of the rotation rate, however, is not
disclosed in the '685 or '321 patents.
[0032] As shown in FIG. 1, there is no margin for error in the
resection procedure. If too much tissue is cut in areas 50 or 52,
for example, the aorta can be permanently damaged. Moreover,
existing valve 12 (or 14) typically fails because of calcification
of the valve resulting in stenosis or insufficiency. Using cutting
blades for valve resection and an improper orientation or improper
pressure on the cutting blades or the wrong rate of rotation can
result in too little or too much tissue removal and/or imprecise
cutting and/or blade buckling or binding as the blades alternately
contact soft and hard (calcified) tissue.
[0033] The problem is so profound that some skilled in the art have
attempted to eliminate native valve resection and instead theorize
that a prosthetic valve can be expanded directly within native
valve 12 (or 14) using a valve displacer to hold the native valve
open. As delineated above, however, due to the condition of the
native valve, such a procedure is not always possible or
effective.
[0034] In the subject invention, more precise tissue cutting is
effected even if native valve 12, FIG. 4 is heavily calcified or
has fibrotic tissue. The preferred endovascular tissue removal
device of this invention includes lumen 100 advanceable within the
patient's vascular with distal steerable tip portion 102, typically
a deflectable tip catheter which employs wire 104 to maneuver tip
portion as shown in phantom at 106 and 108. One such deflectable
tip catheter is sold by Cardima of Freemont, Calif. under the
trademark Naviport.RTM.. Optical fiber 110 is disposed in catheter
100. The distal end of optical fiber 110 extends to, nearly to, or
slightly beyond the distal end of catheter 100. In the preferred
embodiment, optical fiber 110 is connected to laser source 112.
Other sources of ablation energy, however, may be used. The subject
invention also features registration means for holding joint
portion 114 of lumen 100 fixed in place in the vasculature for
precise steering of distal steerable portion 102 to resect valve 12
with laser energy. In the preferred embodiment, the registration
means includes inflatable balloon 116 about joint portion 114
inflated with insuflation gas from source 111.
[0035] A complete system would include an expandable barrier such
as barrier 30, FIG. 2 to trap tissue during resection. In one
example, the subject invention is used as follows. Device capsule
29, FIG. 2 is delivered to the site and barrier 30 expanded. Lumen
100, FIG. 4 is then delivered within tube 127 and balloon 116
inflated. The physician then manipulates wire 104 to steer tip
portion 102 as shown at 106 and 108 to resect valve 12 using laser
energy from source 112. After full resection, balloon 116 is
deflated and lumen 100 removed. The tissue is then sucked out of
tube 27 and barrier 30 is brought back into capsule 29 which is
then withdrawn. Finally, a valve introducer is advanced to the site
and the replacement valve installed.
[0036] In this way, the problems associated with prior art blade
type tissue cutters are eliminated and tissue cutting is far more
precise by the use of optical fiber 110 within deflectable tip
catheter 100 and expandable balloon 116 which registers the
assembly inside the heart for resection by laser ablation as the
deflectable tip portion steers the distal end of optical fiber
110.
[0037] A more complete system is shown in FIG. 5 including tissue
removal device 102 and lower balloon 200 disposable on the
ventricular side of the heart valve under leaflets 202 and 204.
Balloon 200 is connected to inflation conduit 206 which extends
within multi-lumen catheter 100. An outer suction conduit may
include a port for withdrawing tissue. Balloon 200 performs several
important functions. First, it supports leaflets 202 and 204 of the
valve as they are pushed closed by tissue removal device 102 as
shown in FIG. 5 before cutting for more accurate cutting. Balloon
200 with laser energy absorption layer 212 also prevents
inadvertent cutting of any portion of mitral valve 216.
[0038] Although specific features of the invention are shown in
some drawings and not in others, this is for convenience only as
each feature may be combined with any or all of the other features
in accordance with the invention. The words "including",
"comprising", "having", and "with" as used herein are to be
interpreted broadly and comprehensively and are not limited to any
physical interconnection. Moreover, any embodiments disclosed in
the subject application are not to be taken as the only possible
embodiments.
[0039] Other embodiments will occur to those skilled in the art and
are within the following claims:
* * * * *