U.S. patent application number 10/365458 was filed with the patent office on 2003-07-03 for stent for arterialization of the coronary sinus and retrograde perfusion of the myocardium.
Invention is credited to Martin, Eric C..
Application Number | 20030125798 10/365458 |
Document ID | / |
Family ID | 25168400 |
Filed Date | 2003-07-03 |
United States Patent
Application |
20030125798 |
Kind Code |
A1 |
Martin, Eric C. |
July 3, 2003 |
Stent for arterialization of the coronary sinus and retrograde
perfusion of the myocardium
Abstract
The present invention concerns a novel stent and a method for
communicating oxygenated blood directly from the left ventricle to
the coronary sinus to provide retrograde perfusion to the
myocardium. The stent is placed substantially within the coronary
sinus with its trailing end protruding into the right atrium and
the leading end protruding into the left ventricle. The stent has a
smaller passageway at or near the trailing (right ventricular) end
and at or near the leading (left ventricle) end, and has a covering
at the trailing end. The smaller passageway and the cover at the
trailing end to promote retrograde flow into the venous system of
the hear and specifically the myocardium of the left ventricle and
to reduce a significant left-to-right shunt.
Inventors: |
Martin, Eric C.; (Croton On
Hudson, NY) |
Correspondence
Address: |
John J. Yim
Milbank, Tweed, Hadley & McCloy LLP
1825 Eye Street, N.W., #1100
Washington
DC
20006
US
|
Family ID: |
25168400 |
Appl. No.: |
10/365458 |
Filed: |
February 13, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10365458 |
Feb 13, 2003 |
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09796528 |
Mar 2, 2001 |
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6562066 |
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Current U.S.
Class: |
623/1.13 ;
128/898; 623/1.3 |
Current CPC
Class: |
A61F 2250/0039 20130101;
A61B 2017/00252 20130101; A61F 2/82 20130101; A61F 2/07 20130101;
A61F 2250/0037 20130101; A61F 2/2493 20130101 |
Class at
Publication: |
623/1.13 ;
128/898; 623/1.3 |
International
Class: |
A61F 002/06 |
Claims
1. A stent for supplying oxygenated blood to heart tissue
retrogradely through the coronary sinus comprising: a tubular
member having a leading end and a trailing end and a passageway
therethrough, said tubular member having one or more interstices
therein, said tubular member having a constriction at or near the
leading end and a constriction at or near the trailing end, and
said tubular member surrounded by a cover at or near the trailing
end.
2. The stent according to claim 1, wherein the cross sectional area
of the constriction at or near the trailing end controls the amount
of blood flow into the right atrium.
3. The stent according to claim 1, wherein the cross sectional area
of the constriction at or near the trailing end provides retrograde
perfusion while maintaining an appropriate pressure within the
coronary sinus
4. The stent of claim 3, wherein said appropriate pressure is
approximately 50 mm Hg.
5. The stent according to claim 1, wherein the diameter of the
constriction at or near the trailing end is from about 1 mm to
about 6 mm.
6. The stent according to claim 1, wherein the diameter of the
constriction at or near the trailing end is from about 2 mm to
about 4 mm.
7. The stent according to claim 1, wherein the cross sectional area
of the constriction at or near the leading end controls the amount
of blood flowing into the stent.
8. The stent according to claim 1, wherein the diameter of the
constriction at or near the leading end is from about 1 mm to about
6 mm.
9. The stent according to claim 1, wherein the diameter of the
constriction at or near the leading end is from about 2 mm to about
5 mm.
10. The stent according to claim 1, wherein the diameter of the
constrictions at or near the leading and the trailing ends are from
about 1 mm to about 6 mm.
11. The stent according to claim 1, wherein the diameter of the
constrictions at or near the leading and the trailing ends are from
about 2 mm to about 5 mm.
12. The stent according to claim 1, wherein said tubular member
expands cross sectionally.
13. The stent according to claim 12, wherein said tubular member
compresses cross sectionally.
14. The stent according to claim 1, wherein said tubular member is
flexible to allow bending.
15. The stent according to claim 1, wherein said stent has a mesh
construction.
16. The stent according to claim 1, wherein said stent has a coiled
construction.
17. The stent according to claim 1, wherein the diameter of the
stent does not exceed from about 6 mm to about 15 mm.
18. The stent according to claim 1, wherein said cover surrounds
from about 0.5 cm to about 4 cm of the tubular member at or near
the trailing end.
19. The stent according to claim 1, wherein said cover surrounds
from about 1 cm to about 3 cm of the tubular member at or near the
trailing end.
20. The stent according to claim 1, wherein said stent has a cover
surrounding the tubular member at or near the leading end.
21. The stent according to claim 20, wherein said cover surrounds
from about 0.5 cm to about 4 cm of the tubular member at or near
the leading end.
22. The stent according to claim 1, wherein said tubular member
exhibits said constrictions when expanded without additional
mechanism or means.
23. The stent according to claim 22, wherein said constrictions are
woven into the tubular member.
24. The stent according to claim 1, wherein said constrictions are
applied by a constricting material.
25. The stent according to claim 1, wherein said constrictions are
applied by a constricting means.
26. A method for directly supply oxygenated blood from the left
ventricle to heart tissue via the coronary sinus using a stent
comprising: a tubular member having a leading end and a trailing
end and a passageway therethrough, said tubular member having one
or more interstices therein, said tubular member having a
constriction at or near the leading end and a constriction at or
near the trailing end, and said tubular member surrounded by a
cover at or near the trailing end.
27. The method according to claim 26, wherein said stent maintains
an appropriate pressure in the coronary sinus.
28. The method according to claim 26, wherein said tubular member
is positioned substantially within the coronary sinus.
29. The method according to claim 26, wherein the leading end
protrudes into the left ventricle.
30. The method according to claim 26, wherein the trailing end
protrudes into the right atrium.
31. A method for directly supplying oxygenated blood from the left
ventricle to heart tissue via the coronary sinus using the stent of
claim 1 comprising: creating a hole with the wall of the coronary
sinus and the wall of the left ventricle to make an opening between
the left ventricle and the coronary sinus, dilating the hole,
percutaneously delivering and positioning the stent to provide a
fluid passageway between the left ventricle and the coronary sinus.
Description
[0001] This application is a continuation-in-part of copending
application Ser. No. 09/796,528, filed Mar. 2, 2001.
BACKGROUND
[0002] 1. Field of Invention
[0003] The present invention relates to a stent for supplying
oxygenated blood retrogradely to the myocardium via the coronary
sinus. The stent directs blood from the left ventricle to the
coronary sinus through a hole punctured through the wall of the
coronary sinus and the wall of the left ventricle and restricting
the outflow of the coronary sinus directs that blood
retrogradely.
[0004] 2. Description of Related Technology
[0005] Retrograde perfusion using the coronary sinus has long been
known for treating end-stage heart disease. Previous methods among
others attempted to connect the aorta to the coronary sinus using a
jugular vein or an internal mammary artery graft. These methods
were invasive in nature and required open heart surgery.
[0006] U.S. Pat. No. 5,824,071, issued to Nelson et al. in 1998,
discloses an apparatus and method for providing retrograde
perfusion directly from the left ventricle to the coronary sinus.
Nelson requires a pressure sensitive valve that prevents pressure
build-up inside the coronary sinus from rising above 60 mm Hg.
Nelson, however, does not teach how such a valve may be
constructed, and it is unlikely that such a device may be
introduced percutaneously.
[0007] In 2000, Patel et al. conducted experiments for percutaneous
arterialization of the coronary sinus using a stent. See Patel et
al., Percutaneous Transmyocardial Intracardiac Retroperfusion
Shunts: Technical Feasibility in a Canine Model, JVIR 2000,
11:382-390. The stent employed by Patel et al., however, results in
a significant shunt of oxygenating blood from the left ventricle to
the right atrium (hereinafter "left-to-right shunt"). Further,
although Patel recommends using a T or a Y shaped device, technical
problems associated with accurately delivering such a device in
place render the invention difficult. These factors argue for a
simpler device for providing retrograde perfusion to the heart via
the coronary sinus.
SUMMARY OF INVENTION
[0008] It is an object of the present invention to provide a novel
stent and a method for providing oxygenated blood retrogradely from
the left ventricle to the heart tissue through the coronary sinus
without a significant left-to-right shunt.
[0009] In a preferred embodiment, the present invention
contemplates a stent having a leading end and a trailing end and
having a passageway therethrough. After delivery, the body of the
stent is expanded or self expands to fit securely within the
coronary sinus. The leading end of the stent (hereinafter "leading
(LV) end) is positioned in the left ventricle, and the trailing end
(hereinafter "trailing (RA)end") is preferably positioned in the
right atrium.
[0010] The stent preferably has reduced cross sectional areas or
smaller passageways (or constrictions) at or near the leading (LV)
end and the trailing (RA) end as compared to the remainder of the
stent. The size of the passageway decreases or tapers preferably
toward the leading (LV) end and toward the trailing (RA) end.
Accordingly, as blood flows through the small passageway of the
leading (LV) end, the passageway broadens in cross sectional area
toward the midsection of the stent and decreases again toward the
small passageway of the training (RA) end.
[0011] The smaller passageways (or constrictions) at or near the
leading (LV) end and the trailing (RA) end of the stent operate to
control the amount of blood flowing into and out of the coronary
sinus. The size of the passageway of the constriction at the
leading (LV) end controls the amount of inflow into the coronary
sinus.
[0012] The cover surrounding the stent at the trailing (RA) end
directs blood flow through the passageway at the trailing (RA) end,
and the size of the passageway of the constriction at or near the
trailing (RA) end controls the amount of outflow into the right
atrium. They also control the retrograde flow of oxygenated blood
to the myocardium. The stent preferably forms a friction fit with
the lumen of the coronary sinus.
[0013] The stent is expandable cross-sectionally, and preferably
compressible cross-sectionally. For example, a stent may be fit
within a catheter for delivery. After percutaneous delivery into
its desired position, the stent may self expand to form a friction
fit within the coronary sinus. If a stent does not self expand, it
may be expanded using a balloon as known in the art or other
suitable mechanism. Once expanded, such a stent may or may not be
further compressible cross sectionally. The present invention also
contemplates materials well known in the art, including but not
limited to stainless steel, nitinol, or plastic. The stent is also
made of a flexible material as known in the art that allows bending
without forming a kink.
[0014] The present invention also contemplates a percutaneous
method for delivering and placing a stent of the present invention
to allow blood flow from the left ventricle to the coronary sinus.
A hole punctured percutaneously through the wall of the coronary
sinus and the wall of the left ventricle creates a passageway for
blood flow between the left ventricle and the coronary sinus. The
hole is dilated using a balloon as known in the art. After the
stent is delivered and positioned between the left ventricle and
the right atrium, the sheath of the catheter is removed to expose
the stent. Preferably, the stent forms a friction fit with the
interior wall of the coronary sinus as it expands. The trailing
(RA) end preferably but not necessarily protrudes through the
coronary ostium and extends into the right atrium. The leading (LV)
end protrudes through the hole in the wall of the coronary sinus
and the wall of the left ventricle to extend into the left
ventricle.
[0015] In the present invention, the smaller passageway and the
cover of the trailing (RA) end restrict blood flow into the right
atrium. With the increased pressure inside the coronary sinus,
blood flows out through the open interstices of the stent
retrogradely to perfuse the myocardium.
[0016] Some amount of blood flow into the right atrium through the
coronary ostium, however, is necessary to control the pressure in
the coronary sinus. The cross sectional area (or diameter) of the
passageway at the trailing (RA) end (or constriction) should be
large enough to prevent the coronary sinus pressure from rising
above a suitable pressure, preferably about 50 mm Hg, while
reducing a significant amount of left-to-right shunt. A suitable
pressure limit avoids damage to the venous system draining into the
coronary sinus while effectively providing retrograde perfusion. An
optional covering at the leading (LV) end of the stent will help
direct blood through the constriction at the leading (LV) end.
[0017] Thus, the present invention overcomes the difficulty in the
prior art with an elegant and simple stent that retrogradely
supplies oxygenated blood to the myocardium while decreasing the
shunting of oxygenated blood from the left ventricle to the right
atrium.
BRIEF DESCRIPTION OF THE FIGURES
[0018] FIG. 1 shows a preferred embodiment of a stent having a
wire-mesh construction and the cross sectional area of the stent
tapering toward the leading (LV) end and toward the trailing (RA)
end, with a covering around the trailing (RA) end.
[0019] FIG. 2 shows the stent of FIG. 1 in place in a schematic
diagram of the human heart.
[0020] FIG. 3 shows an alternative embodiment of a stent comprising
a coiled-type construction.
[0021] FIG. 4 shows an alternative embodiment of a stent having
flaring ends with constrictions near the trailing end and the
leading end.
DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
[0022] A preferred embodiment of a stent contemplated in the
present invention is illustrated in FIG. 1. An object of the
invention is to provide a novel stent 101 which may be placed
percutaneously to communicate oxygenated blood from the left
ventricle to the coronary sinus. The stent 101 generally comprises
a tubular member having a leading (LV) end 105 and a trailing (RA)
end 109 and having an axial passageway therethrough.
[0023] According to the present embodiment, the stent 101 has
relatively smaller passageways or smaller cross sectional areas (or
constrictions) at or near the leading (LV) end 105 and the trailing
(RA) end 109 as compared to the rest of the stent 101. Thus, the
cross sectional area (or the diameter) of the stent 101 tapers
toward or near the leading (LV) end 105 and the trailing (RA) end
109. The cross sectional area (or diameter) enlarges toward the
midsection of the stent 101 and decreases toward the trailing (RA)
end 109. The diameter may be constant substantially in the mid
section of the stent. The stent 101 at the trailing (RA) end 109 is
preferably surrounded with a cover 120 made of suitable material.
The stent 101 at the leading (LV) end may also be surrounded with a
cover (not pictured).
[0024] The smaller passageway (or constricition) and the cover at
the trailing (RA) end 109 help to direct blood retrogradely and to
prevent a significant amount of left-to-right shunt. The smaller
passageway of the leading end 105 controls the amount of blood
entering the coronary sinus from the left ventricle. Increasing the
size of the passageway at the leading end increases the amount of
blood flow, and decreasing the size of the passageway decreases the
amount of blood flow. As the stent 101 expands to fit securely
within the coronary sinus, the cover 120 directs blood flow towards
the passageway at the trailing (RA) end 109. By restricting flow
into the right atrium, the increased pressure inside the coronary
sinus promotes the blood to flow retrogradely to the heart
tissue.
[0025] A number of suitable commercially available stents having
the desired characteristics may be employed in practicing the
present invention. Generally, the stent 101 has a wire-mesh
construction with one or more interstices 113. Numerous variations
in wire mesh designs and weave configurations are known in the art.
The stent is preferably woven or designed to exhibit the
constrictions upon expansion. In other embodiments, open
architecture stents as known in the art may be employed. As seen in
FIG. 3, the stent 401 may also have a coiled construction with
multiple interstices 413. The stent 401 in FIG. 3 also has a
leading (LV) end 405 and a trailing (RA) end 409, with the stent
401 tapering toward the leading (LV) end 405 and toward the
trailing (RA) and 409.
[0026] The stent 101 should also be made of a flexible material
that can withstand bending without kinking. The stent 101 should
maintain a fluid passageway therethrough to allow sufficient blood
flow. The stent 101 may be made of a variety of commercially
available materials. Metallic stents as well as non-metallic stents
as known in the art may be used in the construction of the stent
101. Non-metallic stents, for example, may be made of a suitable
plastic material. In a preferred embodiment, the stent 101 is made
of surgical-grade stainless steel or nitinol.
[0027] Referring now to FIG. 2, the stent 101 of FIG. 2 is
positioned in a schematic diagram of the human heart 200. The heart
200 generally comprises a left ventricle 202, a left atrium 206, a
right ventricle 222, and a right atrium 210. The left ventricle 202
is primarily responsible for delivery of oxygenated blood to the
body. The left atrium 206 receives the oxygenated blood from the
lungs, which is then delivered to the left ventricle 202. The right
atrium 210 is primarily responsible for receiving the deoxygenated
blood from the body. The deoxygenated blood then flows into the
right ventricle 222 before being sent to the lungs for
oxygenation.
[0028] After perfusing the heart, the deoxygenated blood normally
drains through the coronary sinus 218 into the right atrium 210.
The coronary ostium 226 separates the right atrium 210 and the
coronary sinus 218.
[0029] To place the stent, a hole 220 is first punctured
percutaneously through the wall of the coronary sinus 218 and the
wall of the left ventricle 202 under fluoroscopic control using a
needle and a stiff guide. Access is preferably from the internal
jugular vein but may also be from the femoral vein. The hole 220 is
then widened using a balloon as known in the art or by some other
suitable method. In a preferred embodiment, a catheter encasing the
compressed stent 101 is introduced and placed into position before
removing the sheath to expose the stent 101. The method used by
Patel et al., may be employed in delivering the stent according to
the present invention. Patel et al., Percutaneous Transmyocardial
Intracardiac Retroperfusion Shunts: Technical Feasibility in a
Canine Model, JVIR 2000, 11:382-290. Patel et al. modifies the
stent delivery method as described by Rosch et al. in Rosch et al.,
Coaxial Catheter-Needle System for Transjugular Portal Vein
Entrance, JVIR, Volume 4, No. 1. pp. 145-147, 1993. The stent may
also be marked with appropriate platinum markers to aid
fluoroscopic placement.
[0030] Referring again to FIG. 1, the stent 101 preferably has
variable cross sectional area or diameter along the tubular member.
The diameter of the passageway at the trailing (RA) end 109 is
preferably from about 1 mm to about 6 mm, and more preferably from
about 2 mm to about 4 mm. Likewise, the diameter of the passageway
at the leading (LV) end 105 is preferably from about 1 mm to about
6 mm, and more preferably from about 2 mm to about 4 mm. The
diameter increases from the leading (LV) end 105 to the midsection
of the stent and decreases again toward the trailing (RA) end 109.
The diameter in the middle portion of the stent may also be
constant or may vary. The largest diameter of the stent 101 is
preferably from about 6 mm to about 15 mm. The passageway therefore
may taper or constrict toward each constriction at or near each end
109 or 105.
[0031] Referring now to FIG. 2, the stent 101 is positioned as
follows. The stent 101 is positioned to fit substantially within
the coronary sinus 218 to preferably form a friction fit. The
leading (LV) end 105 of the stent 101 protrudes through the hole
220 and extends into the left ventricle 202. The leading (LV) end
105 extends preferably from about 2 mm to about 10 mm into the left
ventricle 202. The trailing (RA) end 109 of the stent 101
preferably protrudes past the coronary ostium 226 into the right
atrium 210. The trailing (RA) end 109 protrudes preferably from
about 2 mm to about 10 mm into the right atrium 210. In other
embodiments, the trailing (RA) end may be within the coronary
sinus. An optional cover (not shown) may also be placed around the
leading (LV) end 105 to guarantee the inflow cross sectional area
or to guarantee that blood will flow through the constriction at
the leading (LV) end.
[0032] As discussed, a cover 120 surrounds the stent 101 near the
trailing (RA) end 109. As blood flows toward the right atrium 210,
the cover directs the blood into the stent through the passageway
or constriction at or near the trailing (RA) end 109, then to the
right atrium 210. Thus, the cover 120 helps in controlling the
amount of blood flow through the coronary ostium 226. The cover 120
is preferably made of a number of commercially available materials,
such as PET, PTFE, etc. The cover 120 preferably covers from about
0.5 cm to about 4 cm of the trailing end 109 of the stent 101 and
more preferably from about 1 cm to about 3 cm of the trailing (RA)
end 109 of the stent 101. Blood flowing from the left ventricle 202
into the coronary sinus 218 is also directed through the uncovered
interstices 113 in the stent 101 to provide retrograde perfusion to
the myocardium because of the increased coronary sinus pressure
caused by the small passageway at the trailing (RA) end.
[0033] Blood flowing through the coronary ostium 226 is also
controlled by controlling the size of the passageway or
constriction at or near the leading (LV) end 105. If the flow rate
through the passageway at the trailing (RA) end 109 into the right
atrium is too great, the heart tissue would not adequately be
perfused and there would be a large left-to-right shunt. If,
however, the size of the passageway at the trailing (RA) end 109 is
too small, pressure build up within the coronary sinus 218 would
damage the venous system being perfused retrogradely. Preferably,
the pressure within the coronary sinus should not exceed a suitable
pressure range to avoid damage to the coronary sinus venous system.
For example, the pressure should not exceed approximately 50 mm Hg.
Thus, the passageway at the trailing (RA) end 109 should be large
enough to prevent excess pressure build up, but restrictive enough
to allow the heart to be supplied with oxygenated blood.
[0034] Coronary sinus pressure may also be controlled by
controlling the amount of blood flowing from the left ventricle 202
into the coronary sinus 218. Thus, the size of the passageway at
the leading (LV) end 105 may be controlled in relation to the size
of the passageway at the trailing (RA) end 109 to provide efficient
retrograde perfusion of heart tissue without excessive pressure
build up.
[0035] In an alternative embodiment, as seen in FIG. 4, the
smallest diameters or constrictions of the stent 501 are not at the
leading (LV) end 505 and the trailing (RA) end 509, but preferably
approximately 5 mm to about 2 cm from the leading (LV) end 505 and
the trailing (RA) end 509. Thus, the stent would have one or two
flaring ends. The smallest cross sectional areas would be at
constrictions 520 and 522, which are near the leading (LV) end 505
and the trailing (RA) end 509, respectively.
[0036] In some embodiments, a stent having a constant cross
sectional area throughout its length is constricted at or near the
ends so that the cross sectional areas at the constrictions are
limited. Such constrictions may be woven into the stent design or
applied by constricting material or other materials and/or mean as
known in the art, e.g., using suture, band, wire, or tape. In other
embodiments, the cover itself may limit the cross sectional area of
the stent.
* * * * *