U.S. patent application number 11/125643 was filed with the patent office on 2005-11-24 for mitral valve therapy assembly and method.
Invention is credited to Mathis, Mark L..
Application Number | 20050261704 11/125643 |
Document ID | / |
Family ID | 25322496 |
Filed Date | 2005-11-24 |
United States Patent
Application |
20050261704 |
Kind Code |
A1 |
Mathis, Mark L. |
November 24, 2005 |
Mitral valve therapy assembly and method
Abstract
An assembly for effecting the condition of a mitral valve of a
heart includes a mitral valve therapy device, a guide wire, and a
guide tube. The mitral valve therapy device is configured to
reshape the mitral valve annulus of the heart when placed within
the coronary sinus adjacent the mitral valve annulus. The guide
wire is configured to be fed into the coronary sinus of the heart
adjacent the mitral valve annulus. The guide tube has a distal end,
a proximal end, and a lumen extending between the distal end and
the proximal end. The guide tube further includes a side port,
intermediate the distal and proximal ends which communicates with
the lumen. This permits the guide tube to be slidingly received on
the guide wire with the guide wire extending from the distal end,
through the lumen, and out the side port. In use, the guide tube is
slid along the guide wire into the coronary sinus. The mitral valve
therapy device is then delivered by the guide tube into the
coronary sinus adjacent the mitral valve annulus.
Inventors: |
Mathis, Mark L.; (Kirkland,
WA) |
Correspondence
Address: |
WILSON SONSINI GOODRICH & ROSATI
650 PAGE MILL ROAD
PALO ALTO
CA
94304-1050
US
|
Family ID: |
25322496 |
Appl. No.: |
11/125643 |
Filed: |
May 9, 2005 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11125643 |
May 9, 2005 |
|
|
|
10659010 |
Sep 10, 2003 |
|
|
|
10659010 |
Sep 10, 2003 |
|
|
|
09855946 |
May 14, 2001 |
|
|
|
6676702 |
|
|
|
|
Current U.S.
Class: |
606/108 ;
623/2.11 |
Current CPC
Class: |
A61F 2/2451 20130101;
Y10S 623/904 20130101; A61B 17/3421 20130101; A61B 2017/00243
20130101 |
Class at
Publication: |
606/108 ;
623/002.11 |
International
Class: |
A61B 017/12 |
Claims
1.-24. (canceled)
25. A guide tube for delivering a medical device into a body, the
guide tube having a distal end, a proximal end, and a lumen
extending between the distal end and the proximal end and
dimensioned to receive the medical device, the guide tube further
including a side port, intermediate the distal end and the proximal
end and communicating with the element, to permit the guide tube to
be slidingly received on a guide wire with the guide wire extending
from the distal end, through the lumen, and out the side port,
whereby the guide tube is slidable along the guide wire to a
position within the body.
Description
FIELD OF THE INVENTION
[0001] The present invention generally relates to a system and
method for treating a deformed heart valve. The present invention
more particularly relates to a system and method for delivering a
mitral valve therapy device into the coronary sinus of a heart to
treat mitral valve dilation.
BACKGROUND OF THE INVENTION
[0002] The human heart generally includes four valves. Of these
valves, a most critical one is known as the mitral valve. The
mitral valve is located in the left atrial ventricular opening
between the left atrium and left ventricle. The mitral valve is
intended to prevent regurgitation of blood from the left ventricle
into the left atrium when the left ventricle contracts. In
preventing blood regurgitation the mitral valve must be able to
withstand considerable back pressure as the left ventricle
contracts.
[0003] The valve cusps of the mitral valve are anchored to muscular
wall of the heart by delicate but strong fibrous cords in order to
support the cusps during left ventricular contraction. In a healthy
mitral valve, the geometry of the mitral valve ensures that the
cusps overlie each other to preclude regurgitation of the blood
during left ventricular contraction.
[0004] The normal functioning of the mitral valve in preventing
regurgitation can be impaired by dilated cardiomyopathy caused by
disease or certain natural defects. For example, certain diseases
may cause dilation of the mitral valve annulus. This can result in
deformation of the mitral valve geometry to cause ineffective
closure of the mitral valve during left ventricular contraction.
Such ineffective closure results in leakage through the mitral
valve and regurgitation. Diseases such as bacterial inflammations
of the heart or heart failure can cause the aforementioned
distortion or dilation of the mitral valve annulus. Needless to
say, mitral valve regurgitation must not go uncorrected.
[0005] One method of repairing a mitral valve having impaired
function is to completely replace the valve. This method has been
found to be particularly suitable for replacing a mitral valve when
one of the cusps has been severely damaged or deformed. While the
replacement of the entire valve eliminates the immediate problem
associated with a dilated mitral valve annulus, presently available
prosthetic heart valves do not possess the same durability as
natural heart valves.
[0006] Various other surgical procedures have been developed to
correct the deformation of the mitral valve annulus and thus retain
the intact natural heart valve function. These surgical techniques
involve repairing the shape of the dilated or deformed valve
annulus. Such techniques, generally known as annuloplasty, require
surgically restricting the valve annulus to minimize dilation.
Here, a prosthesis is typically sutured about the base of the valve
leaflets to reshape the valve annulus and restrict the movement of
the valve annulus during the opening and closing of the mitral
valve.
[0007] Many different types of prostheses have been developed for
use in such surgery. In general, prostheses are annular or
partially annular shaped members which fit about the base of the
valve annulus. The annular or partially annular shaped members may
be formed from a rigid material, such as a metal, or from a
flexible material.
[0008] While the prior art methods mentioned above have been able
to achieve some success in treating mitral regurgitation, they have
not been without problems and potential adverse consequences. For
example, these procedures require open heart surgery. Such
procedures are expensive, are extremely invasive requiring
considerable recovery time, and pose the concomitant mortality
risks associated with such procedures. Moreover, such open heart
procedures are particularly stressful on patients with a comprised
cardiac condition. Given these factors, such procedures are often
reserved as a last resort and hence are employed late in the mitral
regurgitation progression. Further, the effectiveness of such
procedures is difficult to assess during the procedure and may not
be known until a much later time. Hence, the ability to make
adjustments to or changes in the prostheses to obtain optimum
effectiveness is extremely limited. Later corrections, if made at
all, require still another open heart surgery.
[0009] An improved therapy to treat mitral regurgitation without
resorting to open heart surgery has recently been proposed. This is
rendered possible by the realization that the coronary sinus of a
heart is near to and at least partially encircles the mitral valve
annulus and then extends into a venous system including the great
cardiac vein. As used herein, the term "coronary sinus" is meant to
refer to not only the coronary sinus itself but in addition, the
venous system associated with the coronary sinus including the
great cardiac vein. The therapy contemplates the use of a device
introduced into the coronary sinus to reshape and advantageously
effect the geometry of the mitral valve annulus.
[0010] The device includes a resilient member having a cross
sectional dimension for being received within the coronary sinus of
the heart and a longitudinal dimension having an unstressed arched
configuration when placed in the coronary sinus. The device
partially encircles and exerts an inward pressure on the mitral
valve. The inward pressure constricts the mitral valve annulus, or
at least a portion of it, to essentially restore the mitral valve
geometry. This promotes effective valve sealing action and
eliminates mitral regurgitation.
[0011] The device may be implanted in the coronary sinus using only
percutaneous techniques similar to the techniques used to implant
cardiac leads such as pacemaker leads. One proposed system for
implanting the device includes an elongated introducer configured
for being releasably coupled to the device. The introducer is
preferably flexible to permit it to advance the device into the
heart and into the coronary sinus through the coronary sinus
ostium. To promote guidance, an elongated sheath is first advanced
into the coronary sinus. Then, the device and introducer are moved
through a lumen of the sheath until the device is in position
within the coronary sinus. Because the device is formed of
resilient material, it conforms to the curvatures of the lumen as
it is advanced through the sheath. The sheath is then partially
retracted to permit the device to assume its unstressed arched
configuration. Once the device is properly positioned, the
introducer is then decoupled from the device and retracted through
the sheath. The procedure is then completed by the retraction of
the sheath. As a result, the device is left within the coronary
sinus to exert the inward pressure on the mitral valve to restore
mitral valve geometry.
[0012] The foregoing therapy has many advantages over the
traditional open heart surgery approach. Since the device, system
and method may be employed in a comparatively noninvasive
procedure, mitral valve regurgitation may be treated at an early
stage in the mitral regurgitation progression. Further, the device
may be placed with relative ease by any minimally invasive
cardiologist. Still further, since the heart remains completely
intact throughout the procedure, the effectiveness of the procedure
may be readily determined. Moreover, should adjustments be deemed
desirable, such adjustments may be made during the procedure and
before the patient is sent to recovery.
[0013] Unfortunately, the human anatomy does impose some obstacles
to this recently proposed procedure for treating mitral
regurgitation. More specifically, the human heart includes a
coronary artery which descends from the aorta. One branch of the
coronary artery is the circumflex artery which, in turn, includes
the left marginal branch of the circumflex artery. As used herein,
the term "circumflex artery" is taken to include the circumflex
artery itself or any branch therefrom. The circumflex artery
extends distally generally along the coronary sinus but at a point
proximal to the coronary artery, it passes under the coronary
sinus. The circumflex artery supports blood flow important to the
viability of the heart. Hence, reduction in this blood flow must be
avoided. As a result, a device placed in the coronary sinus must
not be permitted to extend within the coronary sinus beyond the
crossover point of the circumflex artery and the coronary sinus to
avoid constriction of the circumflex artery. This contemplates the
need to know the location of the circumflex artery and coronary
sinus crossover point. It also contemplates accurate positioning of
the device within the coronary sinus to assure that the device does
not extend over the circumflex artery.
[0014] The present invention addresses these issues. The present
invention provides a therapy system and procedure which enables
accurate positioning of the therapy device. This enables effective
treatment while also avoiding the crossover of the circumflex
artery with the coronary sinus. Further, the present invention
enables the positioning of the device with relative ease.
SUMMARY OF THE INVENTION
[0015] The present invention provides an assembly for effecting the
condition of a mitral valve of a heart. The assembly includes a
mitral valve therapy device configured to reshape the mitral valve
annulus of the heart when placed within the coronary sinus adjacent
the mitral valve annulus, a guide wire configured to be fed into
the coronary sinus of the heart adjacent the mitral valve annulus,
and a guide tube having a distal end, a proximal end, and a lumen
extending between the distal end and the proximal end, the guide
tube further including a side port, intermediate the distal end and
the proximal end and communicating with the lumen, to permit the
guide tube to be slidingly received on the guide wire with the
guide wire extending from the distal end, through the lumen, and
out the side port. As a result, the guide tube is slidable along
the guide wire to a position adjacent the mitral valve annulus
within the coronary sinus and the mitral valve therapy device is
guidable within the guide tube for placement in the coronary sinus
adjacent the mitral valve annulus.
[0016] The present invention further provides a method of deploying
a mitral valve therapy device within the coronary sinus of a heart
adjacent the mitral valve annulus. The method includes the steps of
providing an elongated flexible guide wire having a cross sectional
dimension, feeding the guide wire into the coronary sinus of the
heart, providing an elongated flexible guide tube having a proximal
end, a distal end, a lumen, and a side port communicating with the
lumen, and feeding the guide tube into the coronary sinus of the
heart with the guide wire extending through the lumen from the
distal end to and through the side port. The method further
includes the steps of providing a mitral valve therapy device
configured to be slidingly received within the lumen of the guide
tube, the device including a proximal end, providing a flexible
elongated introducer configured to be slidingly received within the
lumen of the guide tube, the introducer having a distal end,
placing the device into the guide tube lumen, placing the
introducer into the guide tube lumen, engaging the distal end of
the introducer with the proximal end of the device, pushing the
device with the introducer in a distal direction within the guide
tube lumen until the device is at least partially encircling the
mitral valve within the coronary sinus of the heart, and releasing
the device from the guide tube into the coronary sinus of the heart
adjacent to the mitral valve annulus.
[0017] The guide wire may be visible under X ray fluoroscopy and
the method may include the further steps of inserting a second wire
into the circumflex artery of the heart, the second wire being
visible under X ray fluoroscopy, subjecting the heart to X ray
fluoroscopic examination to visualize the crossover point of the
guide wire and the second wire, and releasing the mitral valve
annulus therapy device within the coronary sinus in a position such
that the device is proximal to the crossover point of the guide
wire and the second wire.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The features of the present invention which are believed to
be novel are set forth with particularity in the appended claims.
The invention, together with further aspects and advantages
thereof, may best be understood by making reference to the
following description taken in conjunction with the accompanying
drawings, and the several figures of which like reference numerals
identify identical elements, and wherein:
[0019] FIG. 1 is a superior view of a human heart with the atria
removed;
[0020] FIG. 2 is a perspective view of a mitral valve annulus
constricting device which may be utilized in accordance with an
embodiment of the present invention;
[0021] FIG. 3 is a perspective view of an assembly for treating a
mitral valve in accordance with a preferred embodiment of the
present invention;
[0022] FIG. 4 is another superior view of a human heart
illustrating deployment of a mitral valve therapy device in
accordance with the preferred embodiment of the present
invention;
[0023] FIG. 5 is another superior view of a human heart
illustrating an implanted mitral valve therapy device embodying the
present invention;
[0024] FIG. 6 is another view of a human heart illustrating the
method of determining the crossover point of the circumflex artery
and the coronary sinus in accordance with the present invention;
and
[0025] FIG. 7 is a perspective view of another assembly embodying
the present invention for treating a mitral valve.
DETAILED DESCRIPTION OF THE INVENTION
[0026] Referring now to FIG. 1, it is a superior view of a human
heart 10 with the atria removed to expose the mitral valve 12, the
coronary sinus 14, the coronary artery 15, and the circumflex
artery 17 of the heart 10 to lend a better understanding of the
present invention. Also generally shown in FIG. 1 are the pulmonary
valve 22, the aortic valve 24, and the tricuspid valve 26 of the
heart 10.
[0027] The mitral valve 12 includes an anterior cusp 16, a
posterior cusp 18 and an annulus 20. The annulus encircles the
cusps 16 and 18 and maintains their spacing to provide a complete
closure during a left ventricular contraction. As is well known,
the coronary sinus 14 partially encircles the mitral valve 12
adjacent to the mitral valve annulus 20. As is also known, the
coronary sinus is part of the venus system of the heart and extends
along the AV groove between the left atrium and the left ventricle.
This places the coronary sinus essentially within the same plane as
the mitral valve annulus making the coronary sinus available for
placement of the mitral valve therapy device of the present
invention therein.
[0028] Of particular importance is the physiological relationship
of the coronary sinus 14 and the circumflex artery 17. The
circumflex artery 17 branches from the coronary artery 15 and
supplies blood flow to critical tissue of the heart 10. The
circumflex artery passes beneath the coronary sinus 14 at a
crossover point 19. It is one aspect of the present invention to
avoid constriction of blood flow through the circumflex artery 17
when a mitral valve therapy device is deployed in the coronary
sinus 14.
[0029] FIG. 2 shows a mitral valve therapy device 30 embodying the
present invention. As may be noted in FIG. 2, the device is
elongated and has an arched configuration to at least partially
encircle the mitral valve 12 adjacent to the mitral valve annulus
20 when implanted in the coronary sinus 14. The device 30 has an
unstressed preformed arched radius smaller than the radius of the
dilated mitral valve annulus 20. This causes the device 30 to
constrict the mitral valve annulus and impart an inward, generally
radial force on the mitral valve annulus 20 when implanted in the
coronary sinus of the heart. This force reshapes and returns the
mitral valve annulus 20 to its original or substantially original
geometry to permit the cusps 16 and 18 to more fully come together
for sealing the left atrium during left ventricular
contraction.
[0030] The device 30 has a cross section dimension to be received
by the coronary sinus. It is preferably formed of a resilient
material permitting the device to be straightened and/or bent for
being advanced into the coronary sinus. After being positioned
within the coronary sinus, the device is permitted to assume its
preformed arched configuration to act upon the mitral valve annulus
as previously described. To that end, the device may be formed of,
for example, Nitinol, a nickel titanium alloy, well known in the
art. This material, as is well known, is capable of being preformed
but manipulated to be straight or partially bent while having
sufficient memory to return to its preformed configuration.
Stainless steel is also among the materials which may be used in
forming the device 30. In order to be received within the coronary
sinus, the device may have a cross sectional dimension of, for
example, on the order of four or five french.
[0031] With continued reference to FIG. 2, the device 30 has a
distal end 34 and a proximal end 36. Between the distal end 34 and
proximal end 36 the device further includes a channel 38 which is
aligned with a bore 40 extending through the distal end 34. As will
be seen subsequently, the bore 40 permits the device to be
slidingly received by a guide wire during deployment of the device
30. The guide wire, during deployment, is confined within the
channel 38.
[0032] FIG. 3 illustrates an assembly 50 for deploying or
implanting the mitral valve therapy device 30. The assembly 50
includes a guide wire 52, a guide tube 54, and an elongated
introducer 56.
[0033] The guide wire 52 is preferably an elongated coil. It has an
outer dimension to permit the guide wire 52 to be passed through
the bore 40 of the device 30. This enables the device 30 to be
slidingly received on the guide wire 52 with the guide wire
confined within the channel 38 of the device 30.
[0034] The guide tube 54 is elongated and formed of a flexible
biocompatible material. It includes an inner lumen 55 extending
between a distal end 57 and a proximal end 59 permitting the device
30 and the introducer 56 to be received therein. The guide tube 54
further includes a side port 58 between the distal end 57 and the
proximal end 59. The side port 58 communicates with the lumen 55 to
permit the guide tube 54 to be received on the guide wire 52. More
specifically, the guide tube 54 is slidingly received on the guide
wire 52 with the guide wire extending through the lumen from the
distal end 57 to and through the side port 58. This permits the
guide tube 54 to be advanced along the guide wire 52 during implant
of the device 30.
[0035] The introducer 56 preferably takes the form of an elongated
tube having an inner channel 60 and a slot 62 at its distal end
dimensioned to be received by and slid onto the guide wire 52. This
enables the introducer 56 to be slid onto the guide wire 52 and to
engage the proximal end of the device 30 during deployment of the
device.
[0036] As previously mentioned, the circumflex artery 17 passes
under the coronary sinus 14. When the device 30 is deployed, it
should not be permitted to exert a force from the coronary sinus
against the circumflex artery. Hence, in accordance with one
embodiment of the present invention, the device is implanted within
the coronary sinus at a position whereby the distal end 34 of the
device 30 is proximal to the crossover point of the circumflex
artery and the coronary sinus. This requires determination of the
crossover point. FIG. 6 illustrates how such a determination may be
made in accordance with the present invention.
[0037] An elongated member, such as an elongated wire or coil wire
70 is inserted into the circumflex artery 17. The wire 70 may be
formed of a material visible under X ray fluoroscopy or be of other
material having a coating which is visible under X ray fluoroscopy.
Next, another wire which may be the guide wire 52 is inserted into
the coronary sinus 14 by way of the ostium of coronary sinus 13.
Again, the wire 52 is preferably of a material visible under X ray
fluoroscopy or of another material having a coating which is
visible under X ray fluoroscopy. Preferably, the wires 52 and 70
are elongated coils formed of stainless steel.
[0038] The heart 10 or at least that portion of the heart 10 where
the circumflex artery passes under the coronary sinus is subjected
to X ray fluoroscopy. X ray fluoroscopy is well known in the art.
The crossover point 19 where the wires 52 and 70 cross and hence
where the circumflex artery and coronary sinus cross may then be
readily observed by X ray fluoroscopic examination. This locates
the crossover point 19 which is to be distal to the distal end 34
of the device 30 when the device 30 is positioned within the
coronary sinus.
[0039] Once the crossover point 19 has been determined, the device
30 may be deployed. During the deployment of the device, the first
wire 70 may be left in the circumflex artery to permit continuous X
ray fluoroscopic examination or later X ray fluoroscopic
examination to confirm proper device positioning.
[0040] FIG. 4 shows how the assembly 50 may be used to implant the
device 30. Presumably the guide wire 52 has already been positioned
in the coronary sinus 14 to support the determination of the
circumflex artery and coronary sinus crossover point as described
above. As also described above, wire 70 may also be left in the
heart at this time.
[0041] Next, the device 30 is threaded onto the guide wire 52 and
the guide tube 54 is slidingly mounted on the guide wire 52 as
shown in FIG. 3. The device 30 is then slid into the distal end 57
of the guide tube 54. The guide tube 54 is then advanced into the
heart. The guide tube is advanced on the guide wire 52. The guide
wire hence guides the guide tube 54 into the coronary sinus where
the device is to be implanted.
[0042] When the guide tube 54 is positioned in the coronary sinus,
the introducer 56 is then advanced into the guide tube 54 and over
the guide wire 52. The distal end of the introducer 56 engages the
proximal end 36 of the device 30.
[0043] With the distal end of the introducer 56 engaging the
proximal end 36 of the device 30, the guide tube may be slightly
retracted and the device may then be pushed by the introducer 56
out of the guide tube 54 and into the coronary sinus 14 while
remaining on the guide wire 52.
[0044] When the device is positioned within the coronary sinus 14
with its distal end proximal to the crossover point 19 and its
position is confirmed by X ray fluoroscopy, the introducer may be
removed. Then, the guide tube 54 may also be retracted leaving the
device in place but still on the guide wire 52. The performance of
the device 30 may now be evaluated.
[0045] Once the device satisfies the requirements of the procedure,
the guide wire 52, and the wire 70 if still within the heart, may
be removed. This leaves the device 30 in its proper position as
illustrated in FIG. 5. Here it may be seen that the device 30
partially encircles the mitral valve 12 within the coronary sinus
14 and adjacent to the mitral valve annulus. The distal end 34 of
the device 30 is proximal to the crossover point 19. The proximal
end 36 of the device protrudes slightly into the right atrium (not
shown) through the ostium of coronary sinus 13.
[0046] FIG. 7 shows another assembly 150 for treating a mitral
valve embodying the present invention. The assembly may utilize the
same device 30 and guide wire 52 as previously described. Here,
however, a different guide tube 154 and introducer 156 are
employed. The guide tube includes a bore 157 extending from the
distal end of the guide tube to a side port 158. The bore receives
the guide wire 52 as shown to permit the guide tube 154 to slide on
the guide wire 52. The guide tube 154 further has a lumen 155 for
receiving the device 30 and the introducer. A delivery slot 162 is
proximal to the side port 158 and communicates with the lumen 155.
Hence, when the guide tube is within the coronary sinus, the
introducer may push the device through the lumen 155 and out the
delivery slot 162 into the coronary sinus for deployment. As will
be appreciated by those skilled in the art, the lumen 155 and bore
157 may communicate to form a single lumen. The side port 158 may
then communicate with the single lumen in the same manner as shown
in FIG. 3.
[0047] The introducer 156 need not be received by the guide wire 52
in this embodiment. Hence, the introducer 156 need not be slotted
as shown in FIG. 3 and preferably takes the form of an elongated
coil.
[0048] As can thus be seen from the foregoing, the present
invention provides a new and improved assembly and method for
treating mitral regurgitation. The device may be rapidly deployed
with only percutaneous techniques. Further, the mitral valve
therapy device may be implanted in a manner which avoids the
crossover point of the circumflex artery and coronary sinus.
Lastly, the effectiveness of the therapy may be immediately deduced
during the implant procedure.
[0049] While particular embodiments of the present invention have
been shown and described, modifications may be made, and it is
therefore intended in the appended claims to cover all such changes
and modifications which fall within the true spirit and scope of
the invention.
* * * * *