U.S. patent application number 09/861727 was filed with the patent office on 2002-11-21 for apparatus and methods for valve removal.
Invention is credited to Quijano, Rodolfo C., Tu, Hosheng.
Application Number | 20020173811 09/861727 |
Document ID | / |
Family ID | 25336589 |
Filed Date | 2002-11-21 |
United States Patent
Application |
20020173811 |
Kind Code |
A1 |
Tu, Hosheng ; et
al. |
November 21, 2002 |
Apparatus and methods for valve removal
Abstract
This invention discloses a medical catheter and methods for
removing a defective valve from a patient endoluminally. The method
may comprise inserting a medical catheter endoluminally to a site
of the defective valve; deploying a coupling mechanism of said
medical catheter to stabilize and immobilize a free edge of at
least one valve leaflet; deploying a cutting mechanism of said
medical catheter to cut a valve base of said defective valve; and
removing said defective valve from the patient.
Inventors: |
Tu, Hosheng; (Tustin,
CA) ; Quijano, Rodolfo C.; (Laguna Hills,
CA) |
Correspondence
Address: |
Hosheng Tu
15 Riez
Newport Coast
CA
92657
US
|
Family ID: |
25336589 |
Appl. No.: |
09/861727 |
Filed: |
May 21, 2001 |
Current U.S.
Class: |
606/159 |
Current CPC
Class: |
A61B 17/221 20130101;
A61B 2017/00345 20130101; A61B 17/22031 20130101; A61B 2018/2238
20130101; A61B 2017/22097 20130101; A61B 2017/2215 20130101; A61B
17/320016 20130101; A61B 18/245 20130101; A61B 2017/00353 20130101;
A61B 17/30 20130101; A61B 2017/00243 20130101 |
Class at
Publication: |
606/159 |
International
Class: |
A61B 017/22 |
Claims
What is claimed is:
1. A method for removing a defective valve from a patient, the
method comprising: immobilizing at least a valve leaflet of said
defective valve; separating a valve base from a valve root of the
defective valve, wherein the valve base comprises at least one
commissure; and removing said defective valve.
2. The method according to claim 1, wherein a step of immobilizing
the at least one valve leaflet comprises coupling a free edge of
the at least one valve leaflet using a coupling mechanism of an
endoluminal catheter, wherein said catheter has a cutting mechanism
for separating the valve base from the valve root of said defective
valve.
3. The method according to claim 2, wherein the cutting mechanism
is located at a distal section of said catheter and configured to
be at a predetermined position relative to the coupling
mechanism.
4. The method according to claim 1, wherein the defective valve is
a venous valve.
5. The method according to claim 1, wherein the defective valve is
a cardiac valve.
6. The method according to claim 5, wherein the cardiac valve is a
mitral valve.
7. The method according to claim 5, wherein the cardiac valve is an
aortic valve.
8. The method according to claim 5, wherein the cardiac valve is a
pulmonary valve.
9. The method according to claim 5, wherein the cardiac valve is a
tricuspid valve.
10. The method according to claim 2, wherein the cutting mechanism
is a sharp-edge element configured to separate the valve base from
the valve root of the defective valve.
11. The method according to claim 10, wherein a radiofrequency
source is coupled to the sharp-edge element configured for heating
and cutting said valve base.
12. The method according to claim 2, wherein the method is
performed by an endoluminal procedure.
13. The method according to claim 2, wherein the cutting mechanism
is a fiber optic laser element configured to separate the valve
base from the valve root of the defective valve.
14. A medical catheter for removing a defective valve from a
patient comprising: an elongate catheter shaft having a catheter
distal end, a catheter distal section, a catheter proximal end, and
at least a lumen between said catheter distal end and said catheter
proximal end; a deployable inner catheter located within one of
said at least a lumen; a coupling mechanism located at the catheter
distal section configured to grip and immobilize a free edge of at
least one valve leaflet of the defective valve; and a cutting
mechanism mounted at a distal end of the deployable inner catheter,
wherein the cutting mechanism is configured to cut and separate a
valve base of said defective valve from a valve root of said
defective valve.
15. The medical catheter according to claim 14, wherein the
coupling mechanism comprises a stapling element configured to
couple a free edge of said at least one valve leaflet onto said
stapling element.
16. The medical catheter according to claim 14, wherein the
coupling mechanism comprises a gripping element configured to
couple a free edge of said at least one valve leaflet onto said
gripping element.
17. The medical catheter according to claim 14, wherein the
coupling mechanism comprises a gluing element configured to glue
and bond a free edge of said at least one valve leaflet onto said
gluing element.
18. The medical catheter according to claim 14, wherein the cutting
mechanism comprises a sharp-edge element, and wherein a
radiofrequency source is coupled to said sharp-edge element adapted
for enhancing separation of the valve base of said defective
valve.
19. The medical catheter according to claim 14, wherein the cutting
mechanism comprises a fiber optic laser element, and wherein a
laser energy source is coupled to said fiber optic laser element
adapted for separating the valve base of said defective valve.
20. A method for removing a defective valve from a patient
endoluminally, the method comprising: (a) inserting a medical
catheter endoluminally to a site of the defective valve; (b)
deploying a coupling mechanism of said medical catheter to
stabilize and immobilize a free edge of at least one valve leaflet;
(c) deploying a cutting mechanism of said medical catheter to cut a
valve base of said defective valve; and (d) removing said defective
valve from the patient.
21. The method according to claim 20, wherein the defective valve
is a venous valve.
22. The method according to claim 20, wherein the defective valve
is a cardiac valve.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention generally relates to medical apparatus
and methods for valve removal from a patient. More particularly,
the invention relates to an endoluminal catheter and methods for
removing a defective valve and adapted for implantation of a
valvular prosthesis.
BACKGROUND OF THE INVENTION
[0002] A valve in a body circulation system is to ensure
uni-directional blood flow. When a valve is defective, a person
feels weak and appears difficult to handle route physical workload
or exercise. A defective valve may include a stenotic valve that
can't open completely, a valve unable to close completely leading
to regurgitation of blood back through the valve, or an infected
valve. Other conditions leading to a defective valve may include
changes in valve structure, rheumatic fever or other unknown
reasons.
[0003] Defective cardiac valves have been routinely treated using
an open-chest surgery for repair or replacement of aortic, mitral
and other heart valves. Valves that are heavily calcified or
significantly compromised by disease may need to be replaced. These
procedures typically involve a full sternotomy and quadrangular
resection of the anterior leaflet, while on cardiopulmonary
bypass.
[0004] One emerging technique for valve replacement is a minimally
invasive endoluminal procedure. This may be performed by a
catheter-based percutaneous, endoscopic, or laparoscopic procedure.
Before a valvular prosthesis can be implanted, the whole valve,
including the valve base and its associated valve leaflets need to
be removed from a patient.
[0005] Certain conventional surgical endoscopic, and laparoscopic
procedures utilize staples or clips for repair of incisions or
wounds, implantation of prostheses, anastomoses and the like. For
example, surgical staples have been disclosed comprising angled and
arcuate central and leg regions which can be flattened by a
stapling tool having an anvil and driving structure. One such
staple has been disclosed with side portions curved substantially
in the form of an arc of a circle to prevent tearing of tissue by
producing puncture channels.
[0006] Various forms of stapling tools have been disclosed. One
such surgical instrument consists of an anvil adapted to lie flush
with the skin, a cartridge containing a plurality of staples and a
U-shaped pusher for bending the staples around the anvil. Such
instruments typically have mechanical actuators within a handle
mechanism for positioning the staples and activating the driver or
pusher against the staple and anvil.
[0007] Laparoscopic procedures have also used staples, balloons and
clip appliers or staple guns for procedures such as
cholecystostomies, ligation and hernia repair. Laufer et al. in
U.S. Pat. No. 6,149,660 discloses such systems for intraluminally
repairing blood vessels or vein valves. The Laufer et al. patent
discloses the minimally invasive system for intraluminal repair of
a body organ, lumen or cavity, for example, a blood vessel or a
vein valve, using a catheter based system for deploying a bendable
clip appliance, the entire contents of which are incorporated
herein by reference.
[0008] Kuehn et al. in U.S. Pat. No. 6,165,183 discloses a leaflet
fastener applicator generally has a size allowing insertion through
a catheter and is capable of holding portions of opposing heart
valve leaflets. Kuehn et al. also refers to a valve repair
technique of an edge-to-edge suturing of the mitral leaflets,
commonly referred to as a "bow-tie" repair. The bow-tie repair
generally involves the use of a centrally located suture, although
a suture can be placed close to a commissure, or multiple sutures
can be used to complete the repair. A centrally placed suture
creates a double orifice valve, which resembles a bow-tie. The
entire contents of Kuehn et al. patent are incorporated herein by
reference.
[0009] Williamson, IV et al. in U.S. Pat. No. 6,162,233 discloses
wire fasteners having legs with lengths that are used to secure
items, such as prosthesis valves to a patient during minimally
invasive surgery. The fasteners are manipulated, tensioned and
formed from the leg end of the fasteners and tools for initially
placing the fasteners and for immobilizing, tensioning, cutting and
bending the fasteners legs are disclosed. The entire contents of
Williamson, IV et al. patent are incorporated herein by
reference.
[0010] Stevens et al. in U.S. Pat. No. 6,125,852 and Donlon et al.
in U.S. Pat. No. 6,010,531 disclose a minimally invasive device and
methods for heart valve surgery, the entire contents of which are
incorporated herein by reference. The surgical intervention may
comprise replacing the cardiac valve with a prosthetic valve,
wherein the native valve is removed using a tissue removal
instrument.
[0011] Hamblin, Jr. et al. in U.S. Pat. No. 6,033,419 discloses an
apparatus for cutting a heart valve annulus, the entire contents of
which are incorporated herein by reference. The disadvantage of
Hamblin, Jr. apparatus is that without immobilizing and stabilizing
the valve leaflets, the apparatus may swing or float within the
blood flow due to systolic and diastolic flows. Therefore, it is
difficult to target the anatomic site of the valve structure
remotely and cut the heart valve base effective for implantation of
a prosthetic valve.
[0012] The above-mentioned patents disclose methods for fastening
the leaflets or methods of removing a native valve using a tissue
removal instrument, or methods for repairing a heart valve.
However, no prior art has disclosed an endoluminal catheter
generally having suitable dimensions for deployment and insertion
into a human cardiovascular system in the vicinity of a defective
valve by immobilizing the valve leaflets, separating a valve base
of the defective valve, and removing said defective valve.
[0013] Therefore, it is an object of the present invention to
overcome the disadvantages of the prior art and provide an improved
apparatus and methods for removing a defective valve, wherein the
removed annular space is suitable with implantation of a
replacement valve.
SUMMARY OF THE INVENTION
[0014] In general, it is an object of the present invention to
provide a method and an improved apparatus for removing a defective
valve from a patient, the method comprising immobilizing valve
leaflets of the defective valve, separating a valve base from a
valve root of the defective valve, wherein the valve base comprises
at least one commissure, and thereafter removing the defective
valve from the patient. The valve base to be removed is configured
to yield suitable dimensions so as the annular space is effective
for implantation of a replacement valve, such as a mechanical
valve, a biological valve, or a valved conduit. The method may be
performed by an endoluminal, laparoscopic, and/or percutaneous
procedure.
[0015] In a preferred embodiment, the method comprises the step of
immobilizing the valve leaflets by clamping a free edge of the at
least one valve leaflet using a coupling mechanism of an
endoluminal catheter, wherein the catheter also has a cutting
mechanism for separating the valve base from the valve root of the
defective valve. The cutting mechanism is preferably located at a
distal section of the endoluminal catheter and configured to be at
a predetermined position relative to the coupling mechanism. The
relative position of the coupling mechanism and the cutting
mechanism of the catheter is to facilitate precise separation of
the valve base from the valve root and create a suitable annular
space for valve implantation.
[0016] Further, the cutting mechanism may be a sharp-edge element
configured to separate the valve base from the valve root of the
defective valve. A radiofrequency source may be coupled to the
sharp-edge element configured for heating and cutting the valve
base. In an alternate embodiment, the cutting mechanism may be a
fiber optic laser element configured to separate the valve base
from the valve root of the defective valve.
[0017] The defective valves to be removed in the present invention
may include, but not limited to, mitral valves, aortic valves,
pulmonary valves, tricuspid valves, venous valves and the like.
[0018] It is another object of the present invention to provide a
medical catheter for removing a defective valve from a patient
comprising an elongate catheter shaft having a catheter distal end,
a catheter distal section, a catheter proximal end, and at least a
lumen between the catheter distal end and the catheter proximal
end; a deployable inner catheter located within one of the at least
one lumen; a coupling mechanism located at the catheter distal
section, wherein the coupling mechanism is configured to couple,
grip and immobilize a free edge of the at least one valve leaflet
of the defective valve; and a cutting mechanism mounted at a distal
end of the deployable inner catheter configured to cut and separate
a valve base of the defective valve from a valve root of the
defective valve.
[0019] The coupling mechanism of the medical catheter may further
comprise a stapling element configured to couple each free edge of
the valve leaflets onto said stapling element. Alternately, the
coupling mechanism may comprise a gripping element or a gluing
element configured to couple each free edge of the valve leaflets
onto the gripping element or the gluing element, respectively.
Other coupling mechanism, such as with clips, fasteners or suction,
may also be applicable.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Additional objects and features of the present invention
will become more apparent and the invention itself will be best
understood from the following Detailed Description of Exemplary
Embodiments, when read with reference to the accompanying
drawings.
[0021] FIG. 1 is an overall view of a medical catheter for valve
removal constructed in accordance with the principles of the
present invention.
[0022] FIG. 2 is a cross-sectional view of the distal section of
the medical catheter.
[0023] FIG. 3 is a transverse cross-sectional view of the distal
section, section 1-1 of FIG. 2.
[0024] FIG. 4A is an illustrative view for deploying the cutting
mechanism: Stage #1 showing the cutting mechanism retracted within
the catheter shaft during the catheter insertion operation.
[0025] FIG. 4B is an illustrative view for deploying the cutting
mechanism: Stage #2 showing the cutting mechanism in the process of
deployment out of the catheter shaft.
[0026] FIG. 4C is an illustrative view for deploying the cutting
mechanism: Stage #3 showing the cutting mechanism fully deployed
out of the catheter shaft.
[0027] FIG. 5A is an embodiment of the coupling mechanism of the
present invention comprising a stapling element for coupling the
leaflets onto the medical catheter.
[0028] FIG. 5B is an embodiment of the coupling mechanism of the
present invention comprising a gripping element for coupling the
leaflets onto the medical catheter.
[0029] FIG. 5C is an embodiment of the coupling mechanism of the
present invention comprising a gluing element for coupling the
leaflets onto the medical catheter.
[0030] FIG. 6 is a perspective view for operating the medical
catheter of the present invention in an illustrative example of the
aortic valve removal.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0031] Referring to FIGS. 1 to 6, what is shown is an embodiment of
the medical catheter system, comprising a coupling mechanism for
coupling, immobilizing, and stabilizing the free edge of at least
one valve leaflet and a cutting mechanism to separate the valve
base from the defective valve adapted for replacement of a
prosthetic valve or a cryo-preserved autologous valve.
[0032] To provide consistency with the common usage of terms used
in the present invention and in medical surgery arts, the term
"valve base" in this invention refers to any tissue surrounding the
valvular structure so that, upon removal of the valve base, an
annular space is configured having suitable dimension and defined
effective for implantation of a replacement valvular prosthesis. In
the example of mitral or tricuspid valves, the valve base may refer
to the continuum mechanism that consists of myocardium, papillary
muscles, chordae tendinae and commissures. In the example of the
aortic valves, the valve base may refer to the commissures and its
associated tissue at the valvular annulus. However, the valve base
may not include the aortic root, unless the aortic root is
aneurysmal or totally dilated that needs removal. In the example of
a venous valve, the valve base may refer to commissures and the
tissue around the commissures. A combination of the valve base and
its associated leaflets is the structure to be removed defined in
the present invention.
[0033] FIG. 1 shows an overall view of a medical catheter for valve
removal constructed in accordance to the principles of the present
invention. The medical catheter 11 comprises a catheter shaft 19, a
distal end 12, a proximal end 13, a distal section 14, and at least
a lumen 21 between the distal end 12 and the proximal end 13. The
catheter further comprises a handle 16 attached to the proximal end
13 of the catheter shaft 19. A cutting mechanism for separating the
valve base from the valve root may be secured to a cutting
deployment control 17 at the handle 16. Typically the cutting
deployment control 17 is a push-pull or rotating mechanism which is
well known to an ordinary artisan skilled in the art. Similarly, a
coupling mechanism for coupling the free edge of a leaflet may be
secured to a coupling deployment control 18 at the handle 16. A
coupling mechanism may include a stapling element, a gripping
element, a gluing element, and/or a suction element. Other coupling
means for securely coupling the free edge of the leaflets to the
appropriate catheter end is also applicable. The coupling mechanism
of the present invention may be a temporary coupling of the leaflet
with the catheter, such as a suction element. However, a permanent
coupling or semi-permanent coupling is also applicable.
[0034] Valve removal may be performed by an open surgery procedure,
a laparoscopic procedure, or a percutaneous procedure. To
effectively cut the valve base and remove a defective valve, it is
usually preferred to apply an endoluminal catheter from the outflow
side toward the free edge of the leaflets so as to grip the free
edge(s) by the coupling mechanism. Once at least one free edge of
the leaflets is secured and coupled to the catheter, force may be
exerted onto the cutting mechanism for enhanced separating the
valve base from the valve root.
[0035] The catheter of the present invention may be made of any
suitable biocompatible material such as polyurethane, silicone,
polyimide, Nylon, polyester or the like. The construction material
for the cutting mechanism may be a metallic material, a plastic, or
rigid conductive non-metallic material that has strength,
pushability and flexibility. The coupling mechanism may be made of
any suitable biomaterial adapted for the intended use. Additional
features to make the medical catheter better suit for the intended
use are also included within the scope of the present invention.
They may include irrigation, guidewire lumen, ultrasound
guiding/imaging, and other means for ablating the tissue of the
valve base.
[0036] FIG. 2 shows a cross-sectional view of the distal section 14
of the medical catheter 11. There is at least an opening 15 at the
distal end 12 of the catheter. A deployable inner catheter 77 is
located within one of the at least one lumen 21, wherein a cutting
mechanism 22 is attached to the distal end of the inner catheter
and is located at the catheter distal section 14. The cutting
mechanism 22 is configured to cut and separate a valve base of the
defective valve from a valve root of the defective valve. The
cutting mechanism may have a sharp-edge cutting element 24, a fiber
optic laser element 28A, an ultrasonic ablation element, or other
appropriate means for separating the valve base from the valve
root. The proximal end of the deployable inner catheter is secured
to the cutting deployment control 17. A coupling mechanism is
located within the lumen of the cutting mechanism 22. The cutting
mechanism and the coupling mechanism can be operated independently
or controlled by a robot.
[0037] The sharp-edge cutting element 24 may comprise a hole-saw
teeth or other configuration for cutting into the tissue. The
sharp-edge cutting element may also be rotatable to enhance the
cutting efficiency. Other mechanical, chemical, electrical or
physical cutting means would also be applicable in the present
prevention.
[0038] A circular supporting ring 23 may be located at the distal
section 14 of the catheter shaft 19 between the inner wall of the
catheter shaft and the outer surface of the cutting mechanism,
wherein the supporting ring 23 or other appropriate means is
adapted for supporting and guiding the distal portion of the
cutting mechanism 22 at along the central axis of the catheter
shaft 19.
[0039] FIG. 3 shows a transverse cross-sectional view of the distal
section 14, section 1-1 of FIG. 2, wherein a coupling mechanism
comprises a plurality of members 25A, 25B, 25C in the form of a
stapling element 31, a gripping element 42 or a gluing element
51.
[0040] The coupling mechanism is mounted at a distal section 14 of
the catheter 11 and is deployably controlled by the coupling
deployment control 18 at the handle 16, wherein the coupling
mechanism is configured to grip and immobilize a free edge of at
least one valve leaflet of the defective valve.
[0041] FIGS. 4A-4C show an illustrative view for deploying the
cutting mechanism in three consecutive stages. FIG. 4A shows the
stage #1 cutting mechanism 22 that is retracted within the catheter
shaft 19 during the catheter insertion or removing operation.
[0042] In one embodiment, a fiber optic laser element 28A is
mounted at the very distal tip of the cutting mechanism 22. An
external laser energy source is coupled to each of the laser optic
fibers configured for cutting and separating the valve base from
the valve root of the defective valve. The laser energy source may
be supplied to one or more optic fibers simultaneously,
sequentionally or in other desired operating mode. The cutting
mechanism is deployable with a forward or backward movement by the
cutting deployment control 17 at the handle 16.
[0043] FIG. 4B shows the stage #2 cutting mechanism 22 in the
process of deployment out of the opening 15 of the catheter shaft
19. The fiber optic laser element 28B for the stage #2 may be
self-expandable upon releasing from the constraint of the catheter
shaft 19. The circumferential dimension of the expanded element 28B
is adapted to cause the valve base being separated from the valve
root. The circumferential shape, size and configuration of the
fiber optic laser element 28B may be predetermined, pre-shaped, or
designed accordingly.
[0044] If a larger circumferential space is needed to cut the
adequate valve base, then the expandable fiber optic laser element
28C is to be deployed further as shown in FIG. 4C. FIG. 4C shows
the stage #3 cutting mechanism 28C that is fully deployed out of
the opening 15 of the catheter shaft 19. The cutting mechanism is
deployable and retractable.
[0045] As discussed herein, there disclosed a method for removing a
defective valve from a patient endoluminally, the method comprising
several major steps of: (a) inserting a medical catheter
endoluminally to a site of the defective valve; (b) deploying a
coupling mechanism of the medical catheter to stabilize and
immobilize a free edge of at least one valve leaflet; (c) deploying
a cutting mechanism of the medical catheter to cut a valve base of
the defective valve; and (d) removing the defective valve from the
patient.
[0046] FIG. 5A shows an embodiment of the coupling mechanism of the
present invention comprising a stapling element 31 with a plurality
of stapling members 34A, 34B and 34C for coupling the one or more
leaflets onto the medical catheter 11. In a preferred embodiment,
each coupling member 34A, 34B or 34C passes through a restraining
passageway 37A, 37B, or 37C of a restraining support 36,
respectively. The restraining support 36 also serves as a
supporting means for supporting the coupling members from drifting
away off the central axis of the catheter shaft 19. The stapling
members have staples 35A, 35B or 35C at the distal end for stapling
the free edge of each leaflet onto each corresponding coupling
staple member. The stapling mechanism and structure has been
disclosed in U.S. Pat. No. 6,149,660, entire contents of which are
incorporated herein by reference.
[0047] Similarly, FIG. 5B shows an embodiment of the coupling
mechanism of the present invention comprising a gripping element 42
with a plurality of gripping members 44A, 44B and 44C for coupling
the leaflets onto the medical catheter 11. As shown in FIG. 5B,
each gripping member 44A, 44B or 44C passes through a restraining
passageway 47A, 47B or 47C of a restraining support 46. Each
gripping member 44A, 44B or 44C has a pair of gripping arms
45A/42A, 45B/42B, or 45C/42C at its distal end for gripping the
free edge of each leaflet onto each corresponding gripping member.
The gripping mechanism and methods has been disclosed in U.S. Pat.
No. 5,885,238, entire contents of which are incorporated herein by
reference.
[0048] FIG. 5C shows an embodiment of the coupling mechanism of the
present invention comprising a gluing element 51 with a plurality
of gluing members 54A, 54B and 54C for coupling the leaflets onto
the medical catheter 11. For example, each gluing member 54A, 54B
or 54C passes through a restraining passageway 57A, 57B or 57C of a
restraining support 56. Each gluing member, for example 54A, 54B or
54C, has a glue-supplying source 55A, 55B or 55C for providing
biocompatible glue at a glue vent opening 52A, 52B or 52C. Other
biocompatible adhesive or bonding agent may also be applicable.
[0049] FIG. 6 shows a perspective view for operating the medical
catheter 11 of the present invention in an illustrative example of
the aortic valve removal. A catheter 11 with a deployable inner
catheter 77 is inserted endoluminally through the aorta 61. The
catheter passes the aortic arch 62 into the ascending aorta 63.
When approaching the anatomic site of the defective aortic valve,
the coupling members 34A, 34B and/or 34C of the stapling mechanism
31 are deployed to couple and staple each leaflet. Upon stabilizing
and immobilizing the leaflets, the cutting mechanism 24 is deployed
at an appropriate self-expanding degree adapted for defining the
valve base that is to be separated from the valve root. Then a
cutting operation either by radiofrequency enhanced cutting or
laser energized cutting is applied. The separated valve base along
with its coupled leaflets can be removed out of a patient using a
standard catheter-based removing procedure.
[0050] Briefly, heat is generated by supplying RF energy to at
least one sharp-edge cutting member, which comprises a conductive
contact end in contact with the valve base tissues. The RF energy
can be applied to the conductive contact end(s) and consequently to
the tissues. In a bipolar embodiment, a DIP (dispersive indifferent
pad) type pad or electrode, that contacts the patient, is connected
to the Indifferent Electrode Connector on a RF energy generator.
Therefore, the RF energy delivery becomes effective when a close
circuit from a RF generator through a patient and returning to the
RF generator is formed. The generator should be grounded to avoid
electrical interference. Heat is controlled by the power of the RF
energy delivered, the delivery mode, and by the delivery duration.
The standard RF energy generator means and its applications through
conductive electrode means, to a patient are well known for those
who are skilled in the art. A mono-polar radiofrequency procedure
may also be applicable.
[0051] From the foregoing description, it should now be appreciated
that a medical catheter and methods for removing a defective valve
by immobilizing at least one valve leaflet of said defective valve
and separating a valve base from a valve root of the defective
valve, wherein the valve base comprises at least one commissure has
been disclosed. While the invention has been described with
reference to a specific embodiment, the description is illustrative
of the invention and is not to be construed as limiting the
invention. Various modifications and applications may occur to
those who are skilled in the art, without departing from the true
spirit and scope of the invention, as described by the appended
claims.
* * * * *