WO2002085092A2

WO2002085092A2 - Angioplasty device and method

Info

Publication number: WO2002085092A2
Application number: PCT/US2002/011999
Authority: WO
Inventors: T. Anthony Don Michael
Original assignee: Don Michael T Anthony
Priority date: 2001-04-16
Filing date: 2002-04-16
Publication date: 2002-10-31
Also published as: AU2002309575A1; WO2002085092A3

Abstract

Apparatus and method for carrying out an angioplasty procedure while preventing the occurrence of embolisms, the apparatus being composed of: a catheter (2); an angioplasty balloon (14) carried by the catheter (2) at a first location spaced from the distal end of the catheter (2); a blocking balloon (16) carried by the catheter (2) at a second location between the first location and the distal end; a sheath (40) surrounding the catheter (2), the sheath (40) being dimensioned to slide over the angioplasty balloon (14) when it is deflated; and a suction unit (48) connected to the proximal end of the sheath (40) for producing a suction force that is effective at the distal end of the sheath (40). The catheter (2) contains not more than three lumens (4, 6, 8).

Description

ANGIOPLASTY DEVICE AND METHOD

BACKGROUND OF THE INVENTION [0001] The present invention relates to devices for performing medical treatments in blood vessels, and particularly relates to balloon catheters used to treat, and remove, obstructions in blood vessels. The invention is particularly concerned with preventing the occurrence of embolisms incident to such treatments.

[0002] When performing an angioplasty treatment, it is important to be able to remove from the blood vessel debris produced during the treatment. If such debris is allowed to remain, it will circulate with blood flow and can create embolisms downstream of the treatment site. It is also desirable, and frequently essential, to maintain a flow of blood downstream of the treatment site. However, prior art systems for achieving all of these objectives require the use of a catheter having a complicated structure, including a large number of lumens, and which is thus difficult to fabricate.

BRIEF SUMMARY OF THE INVENTION [0003] The present invention allows all of the above capabilities to be provided by a system that includes a catheter having a simpler structure than prior art catheters. The catheter is constructed to be inserted into a blood vessel, is provided with not more than three axially extending lumens, and carries at least one balloon or other device for blocking the blood vessel and an angioplasty balloon. The system further includes a sheath that surrounds the catheter and that provides a path for removing debris by suction.

BRIEF DESCRIPTION OF THE DRAWING [ 0004 ] The Figure is a partly cross-sectional view of a preferred embodiment of a system according to the invention DETAILED DESCRIPTION OF THE INVENTION [0005] A preferred embodiment of a system according to the invention is shown in the Figure. This system is composed essentially of a catheter 2 fabricated to have three lumens 4, 6 and 8, and carrying an angioplasty balloon 14 and a high compliance blocking balloon 16.

[0006] Catheter 2 has a distal end, which is the end shown in the Figure, that will be inserted to extend in the direction 20 of blood flow in a blood vessel. [0007] Lumen 4 extends the length of catheter 2 and serves as a guide wire lumen as well as a blood bypass flow lumen. To enable lumen 4 to function as a blood bypass flow lumen, catheter 2 is provided with one or more lateral passages 24 that are located in the region of catheter 2 that is between balloons 14 and 16 and that extend from the exterior of catheter 2 to lumen 4. Thus, passages 24 and the part of lumen 4 that extends from passages 24 to the distal end of catheter 2 form a blood bypass flow channel, at least when balloon 14 is at least partially deflated and balloon 16 is inflated. [0008] According to an optional feature of the invention, passages 24 may be covered by a filter screen 26 that may be cylindrically molded around the outer surface of catheter 2 between balloons 14 and 16. Screen 26 preferably has an orifice size of 100 μm and can be made of nitinol or stainless steel. Filter 26, if needed, serves to prevent debris produced by the angioplasty procedure from migrating into lumen 4 and then downstream of catheter 2.

[0009] Lumens 6 and 8 extend from a conventional manifold (not shown) at the proximal end (not shown) of catheter 2 to respective ones of balloons 14 and 16 for supplying inflation fluid thereto.

[0010] Angioplasty balloon 14 may be equipped with a stent 30 that will be automatically deployed at the end of the angioplasty procedure, as a result of expansion of balloon 14. Stent 30 may carry, as being impregnated with, a treatment agent, such as a gene delivery agent, that will diffuse into the blood vessel wall after the stent has been deployed.

[0011] The system further includes a guide catheter 40, ^■ whose distal end is shown in the Figure, that is disposed around catheter 2. The proximal end (not shown) of guide catheter 40 may be coupled to the above-mentioned manifold.

[0012] In one exemplary embodiment, catheter 2 may be 4 to 4.5 French (F) in size and guide catheter may be 6 F in size. Lumens 4, 6 and 8 and the, or each, lateral passage 24 will be dimensioned according to principles known in the art to produce the requisite bypass blood flow mass rate.

[0013] An angioplasty procedure using the apparatus described above may be performed as follows: [0014] 1) First, a guide wire 44 is advanced in the direction 20 of blood flow into the blood vessel where an angioplasty is to be performed.

[0015] 2) Catheters 2 and 40 are advanced in direction 20 over guide wire 44 to positions where angioplasty balloon 14 is aligned with the region of the blood vessel that is to be dilated. As a result, balloon 16 is located downstream of that region. Catheter 2 and 40 can be advanced over guide wire 44 in either order.

[0016] 3) Balloon 14 is inflated to block blood flow between catheter 2 and the blood vessel wall, while blood is permitted to flow at a reduced mass flow rate via the blood bypass flow passage 24, 4.

[0017] 4) Balloon 16 is inflated to perform an angioplasty procedure, which includes, if desired, deployment of stent 30. This step can be constituted by any desired angioplasty procedure that results in dilation of the blood vessel wall, with or without application of a stent. Any debris created during this step will tend to collect at the upstream, or proximal, side of balloon 16. Debris is unlikely to enter passages 24 from the region between balloons 14 and 16 because when balloon 14 is expanded after balloon 16 has been expanded, the pressure downstream of balloon 16 will exceed that in the region around catheter 2 and between balloons 14 and 16. This will tend to cause a retrograde, or upstream, flow of blood through lumen 4 from the distal end of catheter 2, resulting in the creation of a positive pressure at the ends of passages 24 that communicate with lumen 4. This pressure will rapidly decrease when balloon 14 is deflated but will serve to force debris by laminar flow against balloon 16. Optional filter 26 may be provided, if desired, to help to assure that debris will not flow in the downstream direction though passages 24 [0018] 5) Balloon 14 is then deflated, at which time additional debris from the angioplasty procedure will be conveyed by blood flowing past balloon 14 to the proximal side of balloon 16 and bypass blood flow is restored through passage 24, 4.

[0019] 6) Simultaneously with, or as soon as possible after, deflation of balloon 14, guide catheter 40 is advanced in direction 20 past balloon 14 until the distal end of guide catheter 40 is proximate to balloon 16. Suction is applied through guide catheter 40 from the proximal end thereof (not shown), e.g. _r by means of a conventional suction source 48 connected through the manifold, to aspirate debris that has collected on the proximal side of balloon 14 and in the region upstream of balloon 14. Suction is preferably started as soon as possible after the start of deflation of balloon 14.

[0020] 7) After suction has been applied for a sufficient time, balloon 14 is deflated and catheters 2 and 40 and guide wire 44 are withdrawn from the blood vessels in any order. The guide wire can have been withdrawn at any time after catheter 2 has been brought to the desired position in the blood vessel. As a result, substantially all debris will be removed from the blood vessel, thereby significantly reducing the possibility of the appearance of embolisms as a result of the treatment procedure.

[0021] The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without undue experimentation and without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. The means, materials, and steps for carrying out various disclosed functions may take a variety of alternative forms without departing from the invention. Thus the expressions "means to..." and "means for...", or any method step language, as may be found in the specification above and/or in the claims below, followed by a functional statement, are intended to define and cover whatever structural, physical, chemical or electrical element or structure, or whatever method step, which may now or in the future exist which carries out the recited function, whether or not precisely equivalent to the embodiment or embodiments disclosed in the specification above, i.e., other means or steps for carrying out the same functions can be used; and it is intended that such expressions be given their broadest interpretation.

Claims

WHAT IS CLAIMED IS:

1. Apparatus for carrying out an angioplasty procedure while preventing the occurrence of embolisms, comprising: a catheter having a distal end and a proximal end; an angioplasty balloon carried by said catheter at a first location spaced from said distal end; a high compliance-blocking balloon carried by said catheter at a second location between said first location and said distal end; a sheath surrounding said catheter and having a distal end facing said distal end of said catheter, said sheath further having a proximal end being dimensioned to slide over said angioplasty balloon at least when said angioplasty balloon is deflated; and suction means connected to said proximal end of said sheath for producing a suction force that is effective at said distal end of said sheath; wherein said catheter contains not more than three lumens, including an angioplasty balloon inflation lumen that extends from said proximal end of said catheter to said angioplasty balloon, a blocking balloon inflation lumen that extends from said proximal end of said catheter to said blocking balloon, and a guide wire lumen that extends from said proximal end of said catheter to said distal end of said catheter.

2. The apparatus of claim 1 wherein said catheter is provided with lateral passages at a third location between said first and second locations for placing a region surrounding said catheter in fluid flow communication with said guide wire lumen.

3. The apparatus of claim 2, further comprising a stent carried by said angioplasty balloon.

4. The apparatus of claim 2, further comprising a filter extending across said lateral passages.

5. The apparatus of claim 1, further comprising a stent carried by said angioplasty balloon.

6. A method for performing an angioplasty procedure while preventing the occurrence of embolisms with the apparatus according to claim 2 comprising; introducing the catheter into a blood vessel that contains an obstruction so that the blocking balloon is downstream, with respect to the direction of blood flow, of the obstruction and the angioplasty balloon is in line with the obstruction; inflating the blocking balloon to block blood flow past the blocking balloon; inflating the angioplasty balloon to dilate the obstruction and the blood vessel; deflating the angioplasty balloon and then advancing the sheath past the angioplasty balloon and operating the suction means to suction debris from a region of the blood vessel upstream of the blocking balloon; and deflating the blocking balloon and withdrawing the catheter and the sheath form the blood vessel.

7. The method of claim 6, wherein the angioplasty balloon carries a stent that is deployed against the blood vessel wall in conjunction with aid step of inflating the angioplasty balloon.