Catheter having a funnel-shaped occlusion balloon of uniform thickness and methods of manufacture
Methods and apparatus are provided for removing emboli during an angioplasty, stenting or surgical procedure comprising a catheter having a funnel-shaped occlusion balloon of uniform thickness disposed on a distal end of the catheter. The occlusion balloon is fused to the distal end so that it provides a substantially seamless flow transition into a working lumen of the catheter. Additionally, a distal edge of the occlusion balloon is configured to be in close proximity with an inner wall of a vessel to facilitate blood flow into the catheter and efficiently remove emboli.
The present application is divisional application of Ser. No. 10/187,058 filed Jun. 27, 2002, which is a continuation-in-part of U.S. patent application Ser. No. 09/418,727, filed Oct. 15, 1999, which is a continuation-in-part of U.S. patent application Ser. No. 09/333,074, filed Jun. 14, 1999, now U.S. Pat. No. 6,206,868, which is a continuation-in-part of International Application PCT/US99/05469, filed Mar. 12, 1999, which is a continuation-in-part of U.S. patent application Ser. No. 09/078,263, filed May 13, 1998.
FIELD OF THE INVENTIONThis invention relates to apparatus and methods for removing emboli during vascular interventions. More particularly, the apparatus and methods of the present invention provide a catheter having an occlusion balloon of uniform thickness that facilitates retrograde flow and removes emboli from a treatment vessel via a funnel-shaped taper of the occlusion balloon.
BACKGROUND OF THE INVENTIONToday there is a growing need to provide controlled access and vessel management during such procedures as stenting, atherectomy and angioplasty. Generally during these procedures there is a high opportunity for the release of embolic material. The emboli may travel downstream from the occlusion, lodging deep within the vascular bed and causing ischemia. The resulting ischemia may pose a serious threat to the health or life of a patient if the blockage forms in a critical area, such as the heart, lungs, or brain.
Several previously known apparatus and methods attempt to remove emboli formed during endovascular procedures by aspirating the emboli out of the vessel of interest using a catheter having an occlusion balloon. These previously known occlusion balloons, however, have various drawbacks, including variability in deployment of the balloon to the desired shape, inefficiency in removing emboli, and/or high cost and complicated processes associated with manufacturing the balloon.
In applicant's co-pending U.S. patent application Ser. No. 09/418,727, filed Oct. 15, 1999, which is incorporated herein by reference in its entirety, applicant describes the use of a bell or pear-shaped occlusion balloon disposed on the distal end of an arterial catheter. The occlusion balloon comprises a compliant material having a variable thickness along its length to provide a bell-shape when inflated. The balloon is affixed to distal end of the catheter so that a distal portion of the balloon extends beyond the distal end of the catheter to provide an atraumatic tip or bumper for the catheter.
The balloon of that catheter may be formed using previously known techniques, such as varying the thickness of the balloon wall to achieve the preferred bell-shape in the deployed position. Such processes, however, can lead to variability in the final product due to the manufacturing process. Because variable thickness balloons present greater difficulties during manufacture than balloons having uniform wall thickness, the cost of such balloons may be higher.
In view of the foregoing limitations of previously known devices, it would be desirable to provide an apparatus for removing emboli from a vessel comprising an occlusion balloon of uniform thickness to enhance manufacturability of the occlusion balloon.
It also would be desirable to provide an apparatus for removing emboli from a vessel comprising an occlusion balloon of uniform thickness to reduce manufacturing cost and enhance product yield.
It further would be desirable to provide an apparatus for removing emboli from a vessel comprising a catheter having an occlusion balloon of uniform thickness that facilitates retrograde flow and efficiently removes emboli.
SUMMARY OF THE INVENTIONIn view of the foregoing, it is an object of this invention to provide an apparatus for removing emboli from a vessel comprising an occlusion balloon of uniform thickness to enhance manufacturability of the occlusion balloon.
It also is an object of the present invention to provide an apparatus for removing emboli from a vessel comprising an occlusion balloon of uniform thickness to reduce manufacturing cost and enhance product yield.
It further is an object of the present invention to provide an apparatus for removing emboli from a vessel comprising a catheter having an occlusion balloon of uniform thickness that facilitates retrograde flow and efficiently removes emboli.
The foregoing objects of the present invention are accomplished by providing interventional apparatus comprising a catheter having proximal and distal ends, a working lumen extending therethrough and an occlusion balloon having proximal and distal ends disposed on the distal end of the catheter. The occlusion balloon has a contracted state suitable for insertion into a vessel and a deployed state configured to occlude antegrade flow in the vessel.
In a preferred embodiment, the catheter comprises an inner layer covered with a layer of flat stainless steel wire braid and a polymer cover. A distal section of the occlusion balloon is melt-bonded to a distalmost end of the inner layer and, optionally, to a distalmost end of the polymer cover to form a substantially seamless transition into the working lumen of the catheter. The proximal end of the occlusion balloon is everted and affixed to the polymer cover to form an inflation chamber between the polymer cover and the balloon.
In the deployed state, the occlusion balloon is configured to extend distal of the catheter and provides a funnel-shaped transition into the working lumen of the catheter. A distal edge of the occlusion balloon is configured to be in close proximity with an inner wall of a vessel to facilitate retrograde flow into the working lumen of the catheter and efficiently remove emboli. Additionally, because the occlusion balloon of the present invention comprises a uniform thickness, the balloon may be more reliable, easier to manufacture and more cost-effective than an occlusion balloon having a variable thickness along its length.
Preferred methods of making and using the apparatus of the present invention also are disclosed.
BRIEF DESCRIPTION OF THE DRAWINGSFurther features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments, in which:
Referring to
As described hereinabove, the variable thickness characteristic of occlusion balloon 20, which is used to deploy the balloon to the preferred bell-shape, presents certain manufacturing challenges. In particular, manufacturing a balloon having a variable wall thickness can lead to reduced yield due to variability of the manufacturing process. Additionally, a variable thickness balloon may be difficult to manufacture and may have a higher cost relative to a balloon having a uniform thickness.
Referring now to
Occlusion balloon 42 comprises a uniform thickness material having a contracted state suitable for insertion into a vessel and a deployed state in which occlusion balloon 42 occludes antegrade flow in the vessel. In the deployed state, occlusion balloon 42 comprises distal taper 66 that is configured to provide a funnel-shaped transition into working lumen 58 so that blood flows in a non-turbulent fashion from a treated vessel into catheter 41. Additionally, distal edge 68 is configured to be in close proximity with an inner wall of a vessel to facilitate blood flow into catheter 41 and efficiently remove emboli.
Catheter 41 preferably comprises inner layer 60 of low-friction polymeric material, such as polytetrafluoroethylene (“PTFE”), covered with a layer of flat stainless steel wire braid 61 and polymer cover 62 (e.g., polyurethane, polyethylene, or PEBAX), as shown in
Apparatus 40 preferably further includes proximal hemostatic port 43, e.g., a Touhy-Borst connector, inflation port 44, and blood outlet port 48. Inflation port 44 is coupled to inflation lumen 63, which in turn is coupled to occlusion balloon 42. Proximal hemostatic port 43 and working lumen 58 of catheter 41 are sized to permit interventional devices, such as angioplasty balloon catheters, atherectomy devices and stent delivery systems to be advanced through the working lumen when a guidewire (not shown) is positioned within the working lumen.
Blood outlet port 48, which is in fluid communication with working lumen 58, may be coupled to an external aspiration device, e.g., a syringe, to cause blood flow distal of occlusion balloon 42 to flow into working lumen 58. Alternatively, in a preferred embodiment, blood outlet port 48 may be coupled to a venous return catheter to form an arterial-venous shunt suitable for providing retrograde flow in a treatment vessel. This aspiration embodiment comprising an arterial-venous shunt is described in detail in applicant's commonly-assigned, above-incorporated U.S. patent application Ser. No. 09/418,727.
Referring now to
In a preferred method of manufacture, distal end 50 of occlusion balloon 42 is positioned atop polymer cover 62 near the distal end of catheter 41 and just distal of opening 70 of polymer cover 62, as shown in
In a next manufacturing step, distal section 51 of occlusion balloon 42, which is situated just proximal of distal end 50, is melt-bonded to at least one polymeric layer of catheter 41. Specifically, in a preferred embodiment, distal section 51 of occlusion balloon 42 is melt-bonded to distalmost end 85 of inner layer 60 and, optionally, to distalmost end 87 of polymer cover 62 to form fusion joint 67, as shown in
Proximal end 52 of occlusion balloon 42 then is everted so that it extends proximally and radially outward from catheter 41, as shown in
The fusion of occlusion balloon 42 to catheter 41 at fusion joint 67 and subsequent eversion of the balloon creates substantially seamless transition 72 into working lumen 58, as shown in
Referring now to
Distal edge 68 is defined as a section of occlusion balloon 42 that is formed between central section 75 and distal taper 66. In the deployed state, distal edge 68 is configured to be in close proximity with an inner wall of vessel V to facilitate blood flow into working lumen 58 and efficiently remove emboli.
Distal taper 66 provides a funnel-shaped flow transition from distal edge 68 into working lumen 58. Additionally, as described hereinabove, fusion joint 67 provides substantially seamless transition 72 from occlusion balloon 42 into working lumen 58 due to the melt-bond between balloon 42 and inner layer 60 of catheter 41.
Referring now to
Aspiration may be provided through working lumen 58 via blood outlet port 48 using an external aspiration device, e.g., a syringe, or alternatively using a venous return catheter to form an arterial-venous shunt, as described hereinabove.
An interventional instrument, such as conventional angioplasty balloon catheter 80 having balloon 82, may be loaded through hemostatic port 43 and working lumen 58 and positioned within stenosis S, preferably via guidewire 83. Hemostatic port 43 is closed and the angioplasty balloon is actuated to disrupt stenosis S. As seen in
Occlusion balloon 42 provides a substantially uniform funnel-shaped transition from an inner wall of vessel V into working lumen 58 of catheter 41. Distal edge 68, which is configured to be in close proximity with an inner wall of vessel V, facilitates flow into working lumen 58 and efficiently removes emboli. Additionally, the funnel-shaped transition provided by distal taper 66 and substantially seamless transition 72 into the working lumen via fusion joint 67 improves retrograde flow dynamics into working lumen 58.
Advantageously, because the present invention utilizes an occlusion balloon having a uniform thickness and relies on pre-molding of the occlusion balloon to obtain the desired deployed shape, a variable thickness occlusion balloon is not required. As noted hereinabove, use of an occlusion balloon having a uniform thickness provides several advantages, including enhanced manufacture, reduced cost and increased reliability.
While preferred illustrative embodiments of the invention are described above, it will be apparent to one skilled in the art that various changes and modifications may be made. The appended claims are intended to cover all such changes and modifications that fall within the true spirit and scope of the invention.
Claims
1. Apparatus for removing emboli from a vessel during an interventional procedure, the apparatus comprising:
- a catheter having proximal and distal ends, a working lumen extending therethrough; and
- an occlusion balloon having a distal end affixed to an interior surface of the working lumen and a proximal end everted to surround, and affixed to, a portion of the catheter proximal of the distal end of the catheter disposed on the distal end of the catheter, the occlusion balloon having a contracted state suitable for insertion into a vessel and a deployed state configured to occlude antegrade flow in the vessel,
- wherein the occlusion balloon comprises a wall having a substantially uniform thickness along its length, and in the deployed state, provides a funnel-shaped transition into the working lumen.
2. The apparatus of claim 1 wherein the working lumen has an interior polymer cover.
3. The apparatus of claim 2 wherein the distal end of the occlusion balloon is fused to the interior polymer cover.
4. The apparatus of claim 3 wherein the distal end of the occlusion balloon is adhesively bonded to the interior polymer cover.
5. The apparatus of claim 3 wherein the occlusion balloon further comprises a distal section situated just proximal of the distal end, wherein the distal section of the occlusion balloon is fused to a distalmost end of the interior polymer cover.
6. The apparatus of claim 5 wherein an exterior surface of the catheter comprises an exterior polymer cover.
7. The apparatus of claim 5 wherein the proximal end of the occlusion balloon is fused to the exterior polymer cover.
8. The apparatus of claim 7 wherein the proximal end of the occlusion balloon is affixed to the exterior polymer cover at a distance between about 10-20 mm proximal of the distal end of the catheter.
9. The apparatus of claim 7 wherein the proximal end of the occlusion balloon is adhesively bonded to the exterior polymer cover.
10. The apparatus of claim 2 further comprising an inflation lumen disposed within the exterior polymer cover that is in fluid communication with the occlusion balloon.
11. The apparatus of claim 2 further comprising a radiopaque marker band disposed at the distal end of the catheter.
12. The apparatus of claim 11 wherein the catheter comprises a wire braid disposed between the interior polymer cover and the exterior polymer cover, the apparatus further comprising a radiopaque marker band disposed between the wire braid and exterior polymer cover.
13. The apparatus of claim 1 wherein the occlusion balloon further comprises a proximal taper in the deployed state.
14. The apparatus of claim 1 further comprising a blood outlet port coupled to the proximal end of the catheter.
15. A method of manufacturing an emboli catheter for use in an interventional procedure, the method comprising:
- providing a catheter having an exterior surface, proximal and distal ends and a working lumen extending therethrough having an interior surface;
- providing an occlusion balloon having first and second ends and a uniform thickness therebetween;
- affixing a first end of the occlusion balloon to the interior surface of the working lumen;
- everting the second end of the occlusion balloon over the distal end of the catheter so that the second end is disposed surrounding the catheter at a position proximal of the distal end; and
- affixing the second end of the occlusion balloon to the exterior surface of the catheter at the location proximal of the distal end.
16. The method of claim 15 wherein the interior surface of the working lumen comprises an interior polymer cover, and affixing the first end of the occlusion balloon to the interior surface of the working lumen comprises fusing the first end to the interior polymer cover.
17. The method of claim 15 wherein the interior surface of the working lumen comprises an interior polymer cover, and affixing the first end of the occlusion balloon to the interior surface of the working lumen comprises adhesively bonding the first end to the interior polymer cover.
18. The method of claim 15 wherein the exterior surface of the catheter comprises an exterior polymer cover, and affixing the second end of the occlusion balloon to the exterior surface of the catheter comprises fusing the second end to the exterior polymer cover.
19. The method of claim 15 wherein the exterior surface of the catheter comprises an exterior polymer cover, and affixing the second end of the occlusion balloon to the exterior surface of the catheter comprises adhesively bonding the second end to the exterior polymer cover.
20. The method of claim 15 wherein providing a catheter further comprises providing a catheter having a radiopaque marker band disposed on the catheter adjacent to the distal end.
Type: Application
Filed: Oct 21, 2005
Publication Date: Feb 23, 2006
Inventors: Hung Vo (Sacramento, CA), Rainier Betelia (San Jose, CA)
Application Number: 11/256,121
International Classification: A61M 29/00 (20060101);