Unfolding balloon catheter for proximal embolus protection
Devices, systems and methods for removing foreign bodies within a body lumen are disclosed. An unfolding balloon catheter may include an elongated shaft having an intussuscepting balloon that can be actuated within a body lumen to capture and retrieve an intravascular device. The balloon may be configured to radially and/or axially expand when inflated, enveloping the intravascular device. In certain embodiments, the balloon may be formed by folding the ends of a distensible member inwardly, and then bonding the ends of the distensible member to the elongated shaft to form an expandable sleeve. An adhesive layer located along a portion of the elongated shaft may be used to temporarily secure the balloon to the elongated shaft.
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The present invention relates generally to the field of intravascular devices. More specifically, the present invention pertains to catheter devices for proximal embolus protection within a body lumen.
BACKGROUND OF THE INVENTIONEmbolectomy devices such as inflatable catheters and clot pullers are used in a variety of applications to remove blood clots or other foreign bodies from a blood vessel such as an artery or vein. The formation of thrombus within the vessel may partially block or totally occlude the flow of blood through the vessel, preventing the flow of blood downstream to vital locations within the body. Such thrombolytic events may also be exacerbated by atherosclerosis, a vascular disease that causes the vessels to become tortuous and narrowed. The tortuousness or narrowness of the vessel may, in certain circumstances, lead to the formation of atherosclerotic plaque, which can cause further complications in the body.
In embolectomy procedures for removing such blood clots from the body, a delivery catheter or sheath is typically inserted percutaneously into the body (e.g. via the femoral, jugular or antecubital veins) and advanced to a target site within the body containing the clot. To ascertain the precise location of the blood clot within the body, radiopaque die may be injected into the body permitting the occluded blood vessel to be radiographically visualized with the aid of a fluoroscope. A Fogarty catheter or other suitable delivery device may be used to transport the embolectomy device in a collapsed position distal the site of the clot. The embolectomy device is then withdrawn from within the delivery device, causing the device to expand within the vessel. The embolectomy device may then be urged in the proximal direction to remove the clot from the vessel wall. A wire basket, coil, membrane or other collector element can be used to capture the clot as it is dislodged from the vessel wall. Once entrained within the collector element, the embolectomy device and captured blood clot are then loaded into a retrieval device and withdrawn from the patient's body.
In certain applications, the removal of the foreign object within the vessel may cause emboli to migrate upstream and enter other branching passageways within the body. To prevent migration of emboli upstream, it may be necessary to temporarily impede or obstruct the flow of blood proximal the therapeutic site while retrieving the embolectomy device.
SUMMARY OF THE INVENTIONThe present invention pertains to catheter devices for proximal embolus protection within a body lumen. An unfolding balloon catheter in accordance with an exemplary embodiment of the present invention includes an intussuscepting balloon disposed about the distal section of an elongated shaft. An inflation lumen extending through a portion of the elongated shaft may be configured to deliver pressurized fluid through an orifice in the external wall of the elongated shaft to the interior of the intussuscepting balloon.
The intussuscepting balloon may be configured to radially expand to partially or fully occlude the body lumen proximal the intravascular device. The intussuscepting balloon may be formed by folding the ends of a distensible member inwardly, and then securing the ends of the distensible member to the elongated shaft to form an expandable sleeve. An adhesive layer located about a portion of the elongated shaft may be used to temporarily secure a portion of the intussuscepting balloon to the outer periphery of the elongated shaft. In use, pressurized fluid can be delivered through the inflation lumen to inflate the balloon within the vessel. Once the pressure within the expandable sleeve reaches a pre-defined level, the balloon may be configured to unfold along the adhesive layer and envelope the intravascular device. In certain embodiments, a retrieval lumen operatively coupled to a vacuum source may be employed to aspirate the intravascular device and/or foreign object at least in part into the catheter.
BRIEF DESCRIPTION OF THE DRAWINGS
The following description should be read with reference to the drawings, in which like elements in different drawings are numbered in like fashion. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. Although examples of construction, dimensions, and materials are illustrated for the various elements, those skilled in the art will recognize that many of the examples provided have suitable alternatives that may be utilized.
The dimensions and general configuration of the balloon catheter 10 may vary depending on such factors as the location of the body to be traversed, the size of the target vessel, and the type of intravascular device to be retrieved. In applications involving the removal of blood clots using clot pullers or embolic protection filters, for example, the retrieval lumen 22 may include an inside diameter in the range of about 0.016 to 0.022 inches, although other sizes may be employed, as desired. In certain embodiments, the balloon catheter 10 may be configured similar to a microcatheter or guide catheter, allowing the catheter 10 to be used to both deliver and retrieve the intravascular device within the body. Although the illustrative elongated shaft 12 depicted in
The elongated shaft 12 may be fabricated from polymeric and/or metallic materials using known PVS catheter techniques in the art. Examples of suitable materials may include, for example, stainless steel, nickel-titanium alloy, polyethylene terapthalate (PET), polytetraflouroethylene (PTFE), polyurethane, fluorinated ethylene propylene (FEP), polypropylene (PP), polyvinylchloride (PVC), polyether-ether ketone (PEEK), polyimide, polyester, polyamide, elastomeric polyamides, block polyamide/ethers, polyether block amide (PEBAX), and polyetherimide (PEI).
In certain embodiments, all or portions of balloon catheter 10 may include a lubricious coating. For example, as shown in
Balloon catheter 10, or portions thereof, may also be coated, plated, wrapped or surrounded by, doped with, or otherwise include a radiopaque material. Radiopaque materials are understood to be materials capable of producing a relatively bright image on a fluoroscopic monitor or other imaging device, allowing the physician to determine the location of the balloon catheter 10 within the body. Some examples of radiopaque materials may include metals such as gold, platinum, palladium, tantalum, tungsten alloy, or materials loaded with a radiopaque filler such as barium sulfate, powdered tantalum, powdered tungsten, bismuth oxide, and the like.
In a deflated position depicted in
In certain embodiments, the intussuscepting balloon 36 may be formed by a folding process, wherein a proximal portion 50 of the distensible member 42 is folded inwardly such that the distensible member 42 is relatively slack at the proximal portion 50 when deflated. The distal portion 52 of the distensible member 42, in turn, may be relatively taut such that the distensible member 42 does not extend distally beyond the distal end 26 of the elongated shaft 12 in the deflated position. As shown in
As shown in
The amount and direction of expansion of the intussuscepting balloon 36 can also be controlled by the type of materials employed. In certain embodiments, for example, a non-compliant material may be used to limit the amount of expansion of the intussuscepting balloon 36 to a pre-defined size. In other embodiments, a compliant material may be employed, allowing further expansion of the intussuscepting balloon 36, if desired. In one exemplary embodiment, the intussuscepting balloon 36 may comprise a multiple-layered construction wherein the inner layer of the balloon 36 is generally thicker than the outer layer, biasing the balloon 36 to expand radially when inflated.
The inflation lumen 20 may be fluidly coupled to a source of pressurized fluid that can be used to selectively inflate or deflate the intussuscepting balloon 36. An orifice 60 formed through the external wall 14 of the elongated shaft 12 adjacent the inflation lumen 20 fluidly connects the interior 34 of the intussuscepting balloon 36 with the inflation lumen 20. The amount of inflation or deflation can be controlled using a pressure valve or other suitable mechanism connected to the proximal section of the elongated shaft 12. A radiopaque coating or material on the intussuscepting balloon 36 can be used to fluoroscopically monitor the amount of radial and/or axial expansion that has occurred within the body, if desired.
The retrieval lumen 22 may be operatively connected to a vacuum source to provide suction at the distal end 26 of the elongated shaft 12 to aspirate the intravascular device and any emboli into the balloon catheter 10. The flared region 32 of the retrieval lumen 22 may be configured to receive all or part of the intravascular device therein. In the illustrative embodiment depicted in
Referring now to
As shown in
As the pressure within the interior 34 of the intussuscepting balloon 36 increases, the radial force will eventually exceed the bonding force of the adhesive layer 58. When this occurs, the intussuscepting balloon 36 unfolds and begins to envelope the proximal portion of the clot puller 62, as shown in
Inflation of the balloon catheter 10 may be accomplished at any time during the embolectomy procedure. Thus, while the step of inflating the balloon catheter 10 in
The intussuscepting balloon 36 can be configured to fully appose the vessel wall, temporarily restricting the flow of blood within the vessel, or can be configured to occlude only a portion of the vessel, as desired. In certain embodiments, the portion of the intussuscepting balloon 36 that contacts and engages the walls of the vessel may include one or more cutting edges or blades configured to remove the blood clot C from the vessel wall. The cutting edges or blades may be placed circumferentially about the outer periphery of the intussuscepting balloon 36, and can be configured to engage the vessel wall when the balloon 36 is axially expanded within the blood vessel V. Alternatively, or in addition, the cutting edges or blades may be placed longitudinally along the length of the intussuscepting balloon 36, and can be configured to engage the vessel wall by rotation of the elongated shaft 12 within the blood vessel V.
Once enveloped at least in part within the intussuscepting balloon 36, the clot puller 62 and accompanying blood clot C can then be loaded at least in part into the retrieval lumen 22 for removal from the body. In certain embodiments, a vacuum source coupled to the retrieval lumen 22 may be used to provide suction at the distal end 26 of the catheter 10, aspirating the clot puller 62 at least in part into the flared region 32 of retrieval lumen 22, as shown in
Once the unfolding balloon catheter 10 and clot puller 62 have been advanced to the general location of the blood clot C, the physician next engages the unfolding balloon catheter 10 against the blood clot C by urging the catheter 10 forward slightly, or in the alternative retracting the guidewire proximally, causing the balloon catheter 10 to contact the blood clot C. A vacuum source coupled to the retrieval lumen 22 provides suction that can be used to aspirate the blood clot C at least in part into the flared region 32 of the retrieval lumen 22. With the blood clot C held tight against the catheter 10 vis-à-vis the vacuum source, the physician may urge the clot puller 62 in the proximal direction, causing the blood clot C to become severed from the wall of the vessel V and entrained within the clot puller 62, as shown in
To intussuscept the clot puller 62 and blood clot C, fluid may be delivered through the inflation lumen 20 and into the intussuscepting balloon 36, causing the balloon 36 to initially expand in a radial direction within the vessel V. As the pressure within the interior 34 of the balloon 36 continues to increase, the radial force will eventually exceed the bonding force of the adhesive layer 58, causing the balloon 36 to unfold and envelope the proximal portion of the clot puller 62 and blood clot C, as shown in
To intussuscept the blood clot C, fluid may be delivered through the inflation lumen 20 and into the intussuscepting balloon 36, causing the balloon 36 to initially expand in a radial direction within the vessel V, as shown in
Having thus described the several embodiments of the present invention, those of skill in the art will readily appreciate that other embodiments may be made and used which fall within the scope of the claims attached hereto. Numerous advantages of the invention covered by this document have been set forth in the foregoing description. It will be understood that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size and arrangement of parts without exceeding the scope of the invention. While the present invention has been described with respect to the extraction of blood clots during an embolectomy procedure, it should be understood that the present invention may be used in other applications, if desired.
Claims
1. A medical device for retrieving an intravascular device within a body lumen, comprising:
- an elongated shaft having a proximal section and a distal section;
- an inflation lumen extending from the proximal section of the elongated shaft to the distal section of the elongated shaft; and
- an expandable sleeve coupled to the distal section of the elongated shaft and in fluid communication with the inflation lumen, the expandable sleeve configured to unfold along an adhesive layer disposed about a portion of the elongated shaft for retrieving the intravascular device within said body lumen.
2. The medical device of claim 1, further comprising a retrieval lumen extending from the proximal section of the shaft to an opening at the distal end of the elongated shaft.
3. The medical device of claim 2, wherein the retrieval lumen includes a distal flared region.
4. The medical device of claim 2, wherein the retrieval lumen is operatively coupled to a vacuum source.
5. The medical device of claim 2, wherein the retrieval lumen includes a lubricious coating.
6. The medical device of claim 1, wherein the inflation lumen includes an inflation port disposed through an external wall of the elongated shaft.
7. The medical device of claim 1, wherein the inflation lumen is operatively coupled to a pressure source.
8. The medical device of claim 1, wherein the expandable sleeve is configured to unfold along the adhesive layer when inflated to a sufficient pressure.
9. The medical device of claim 1, wherein the expandable sleeve is configured to radially and axially expand to a pre-defined shape when inflated to a sufficient pressure.
10. The medical device of claim 1, wherein the expandable sleeve is formed of a non-compliant material.
11. The medical device of claim 1, wherein the expandable sleeve is formed of a compliant material.
12. The medical device of claim 1, wherein the expandable sleeve is formed at least in part of polyethylene.
13. The medical device of claim 1, wherein the expandable sleeve includes an inner layer and an outer layer.
14. The medical device of claim 13, wherein the inner layer of the expandable sleeve is thinner than the outer layer of the expandable sleeve.
15. The medical device of claim 13, wherein the expandable sleeve includes cutting means.
16. The medical device of claim 15, wherein said cutting means comprises at least one cutting blade or edge.
17. The medical device of claim 1, wherein said intravascular device is a clot puller.
18. A medical device for retrieving an intravascular device within a body lumen while preventing proximal embolus flow, comprising:
- an elongated shaft having a proximal section, a distal section., and an external wall;
- an inflation lumen extending from the proximal section of the elongated shaft to the distal section of the elongated shaft, the inflation lumen including an inflation port disposed through the external wall of the elongated shaft;
- an expandable sleeve coupled to the distal section of the elongated shaft and in fluid communication with the inflation lumen, the expandable sleeve configured to unfold along an adhesive layer disposed about a portion of the elongated shaft for retrieving the intravascular device within said body lumen; and
- a retrieval lumen extending from the proximal section of the shaft to an opening at the distal end of the shaft.
19. The medical device of claim 18, wherein the retrieval lumen includes a distal flared region.
20. The medical device of claim 18, wherein the retrieval lumen is operatively coupled to a vacuum source.
21. The medical device of claim 18, wherein the retrieval lumen includes a lubricious coating.
22. The medical device of claim 18, wherein the inflation lumen is operatively coupled to a pressure source.
23. The medical device of claim 18, wherein the expandable sleeve is configured to unfold along the adhesive layer when inflated to a sufficient pressure.
24. The medical device of claim 18, wherein the expandable sleeve is configured to radially and axially expand to a pre-defined shape when inflated to a sufficient pressure.
25. The medical device of claim 18, wherein the expandable sleeve is formed of a non-compliant material.
26. The medical device of claim 18, wherein the expandable sleeve is formed of a compliant material.
27. The medical device of claim 18, wherein the expandable sleeve is formed at least in part of polyethylene.
28. The medical device of claim 18, wherein the expandable sleeve includes an inner layer and an outer layer.
29. The medical device of claim 28, wherein the inner layer of the expandable sleeve is thinner than the outer layer of the expandable sleeve.
30. The medical device of claim 28, wherein the expandable sleeve includes cutting means.
31. The medical device of claim 30, wherein said cutting means comprises at least one cutting blade or edge.
32. The medical device of claim 18, wherein said intravascular device is a clot puller.
33. A system for retrieving a blood clot disposed at a target site within a blood vessel, comprising:
- an intravascular device configured to engage the blood clot adjacent the target site; and
- a balloon catheter configured to intussuscept the intravascular device and blood clot while limiting the proximal flow of blood within the blood vessel, the balloon catheter comprising an elongated shaft having a proximal section and a distal section, an inflation lumen extending from the proximal section of the elongated shaft to the distal section of the elongated shaft, a retrieval lumen configured to receive at least part of the intravascular device, and an expandable sleeve disposed about the distal section of the elongated shaft and in fluid communication with the inflation lumen.
34. The system of claim 33, wherein the expandable sleeve is configured to unfold distally when inflated.
35. The system of claim 33, wherein the expandable sleeve is configured to unfold distally along an adhesive layer disposed about a portion of the elongated shaft.
36. The system of claim 33, wherein the expandable sleeve is configured to radially and axially expand to a pre-defined shape when inflated.
37. A method of retrieving a foreign object from a target site within a body lumen, comprising the steps of:
- providing an intussuscepting balloon catheter comprising an elongated shaft having a proximal section and a distal section, an inflation lumen, a retrieval lumen, and an expandable sleeve coupled to the distal section of the elongated shaft and in fluid communication with the inflation lumen;
- advancing the intussuscepting balloon to the target site;
- inflating the expandable sleeve; and
- intussuscepting the foreign object within the expandable sleeve.
38. The method of claim 37, further comprising the step of engaging an intravascular device at the target site.
39. The method of claim 38, wherein the step of engaging the intravascular device at the target site is performed prior to the step of inflating the expandable sleeve.
40. The method of claim 38, wherein the step of engaging the intravascular device at the target site is performed during the step of inflating the expandable sleeve.
41. The method of claim 38, further comprising the step of retrieving the intravascular device at least in part within the retrieval lumen.
42. The method of claim 41, wherein the retrieval lumen is operatively coupled to a vacuum source.
43. The method of claim 42, wherein said retrieval step is accomplished at least in part by aspiration.
44. The method of claim 41, wherein said retrieval step is accomplished at least in part by retracting the guidewire proximally while holding the intussuscepting balloon catheter stationary.
45. The method of claim 37, wherein the step of inflating the expandable sleeve comprises:
- inflating the expandable sleeve to a first state, causing the expandable sleeve to radially expand and distend the body lumen; and
- continuing to inflate the expandable sleeve to a second state, causing the expandable sleeve to unfold and expand distally.
46. A method of retrieving a foreign object from a target site within a body lumen, comprising the steps of:
- providing an intravascular device coupled to the distal portion of a guidewire;
- providing an intussuscepting balloon catheter comprising an elongated shaft having a proximal section and a distal section, an inflation lumen, a retrieval lumen, and an expandable sleeve coupled to the distal section of the elongated shaft and in fluid communication with the inflation lumen;
- advancing the guidewire and intravascular device to the target site;
- engaging the intravascular device at the target site;
- advancing the intussuscepting balloon catheter along the guidewire to a location adjacent the intravascular device;
- inflating the expandable sleeve; and
- intussuscepting the foreign object and at least part of the intravascular device within the expandable sleeve; and
- retrieving the intravascular device at least in part within the retrieval lumen.
47. The method of claim 46, wherein the step of engaging the intravascular device at the target site is performed prior to the step of inflating the expandable sleeve.
48. The method of claim 46, wherein the step of engaging the intravascular device at the target site is performed during the step of inflating the expandable sleeve.
49. The method of claim 46, further comprising the step of retrieving the intravascular device at least in part within the retrieval lumen.
50. The method of claim 46, wherein the retrieval lumen is operatively coupled to a vacuum source.
51. The method of claim 50, wherein said retrieval step is accomplished at least in part by aspiration.
52. The method of claim 49, wherein said retrieval step is accomplished at least in part by retracting the guidewire proximally while holding the intussuscepting balloon catheter stationary.
53. The method of claim 46, wherein the step of inflating the expandable sleeve comprises:
- inflating the expandable sleeve to a first state, causing the expandable sleeve to radially expand and distend the body lumen; and
- continuing to inflate the expandable sleeve to a second state, causing the expandable sleeve to unfold and expand distally.
54. A method of retrieving a foreign object from a target site within a body lumen, comprising the steps of:
- providing an intravascular device coupled to the distal portion of a guidewire;
- providing an intussuscepting balloon catheter comprising an elongated shaft having a proximal section and a distal section, an inflation lumen, a retrieval lumen, and an expandable sleeve coupled to the distal section of the elongated shaft and in fluid communication with the inflation lumen;
- advancing the guidewire and intravascular device to the target site;
- engaging the intravascular device at the target site;
- advancing the intussuscepting balloon catheter along the guidewire to a location adjacent the intravascular device;
- inflating the expandable sleeve to a first state, causing the expandable sleeve to radially expand and distend the body lumen; and
- continuing to inflate the expandable sleeve to a second state, causing the expandable sleeve to unfold and expand distally;
- intussuscepting the foreign object and at least part of the intravascular device within the expandable sleeve; and
- retrieving the intravascular device at least in part within the retrieval lumen.
55. A method of retrieving a foreign object from a target site within a body lumen, comprising the steps of:
- providing an intussuscepting balloon catheter comprising an elongated shaft having a proximal section and a distal section, an inflation lumen, a retrieval lumen, and an expandable sleeve coupled to the distal section of the elongated shaft and in fluid communication with the inflation lumen;
- providing a vacuum source in fluid communication with the retrieval lumen;
- advancing the intussuscepting balloon catheter along a guidewire to the target site;
- activating the vacuum source to aspirate the foreign object at least in part within the retrieval lumen;
- inflating the expandable sleeve; and
- intussuscepting the foreign object within the expandable sleeve.
Type: Application
Filed: Oct 21, 2003
Publication Date: Apr 21, 2005
Applicant:
Inventors: Ajitkumar Nair (Fremont, CA), Kamal Ramzipoor (Fremont, CA), Tra Ngo (San Jose, CA), Hieu Nguyen (San Jose, CA), Maggie Le (San Jose, CA)
Application Number: 10/690,004