Method and apparatus for dilating blood vessels

• US 4,723,549 A
• Filed: 09/18/1986
• Issued: 02/09/1988
• Est. Priority Date: 09/18/1986
• Status: Expired due to Term

• Current Assignee: Endotex Interventional Systems Incorporated (Boston Scientific Corporation), AngioGuard, Inc. (Cardinal Health, Inc.)
• Original Assignee: Mark H. Wholey, Mark L. Nagurka, Robert S. Katz
• Inventors: Wholey, Mark H., Katz, Robert S., Nagurka, Mark L.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US06/908,988
• Time in Patent Office: 509 Days
• Field of Search: 604/101, 604/105, 128/341-345, 128/348.1, 128/328, 128/325
• US Class Current: 606/194
• CPC Class Codes: A61B 17/221 Gripping devices in the form of loops or baskets for gripping calculi or similar types of obstructions surgical snare instruments A61B17/32056
• CPC Class Codes: A61F 2002/018 made from tubes or sheets of material, e.g. by etching or laser-cutting
• CPC Class Codes: A61F 2230/0006 circular
• CPC Class Codes: A61F 2230/008 paraboloidal
• CPC Class Codes: A61F 2250/0003 having an inflatable pocket filled with fluid, e.g. liquid or gas
• CPC Class Codes: A61M 25/104 used for angioplasty

Abstract

A catheter for dilating occluded or stenotic blood vessels includes a collapsible filter device disposed between a dilating balloon and the distal end of the catheter. The collapsible filter device comprises a plurality of resilient ribs secured to the catheter at or adjacent the distal end thereof and extending generally axially toward the dilating balloon. Inflation of a filter balloon extends the ribs outward against the vessel wall to stretch filter material secured to the ribs across the vessel to form a cup shaped trap for fragments of a stenosis loosened by the dilating balloon. Upon deflation of the filter balloon, the resilient ribs retract against the catheter to retain the trapped fragments during withdrawal of the catheter. In the preferred embodiment, the ends of the ribs projecting generally toward the dilating balloon are secured to a ring which slides along the catheter. In use, the filter is extended and then the dilating balloon is inflated. Blood flow established by deflation of the dilating balloon carries stenosis fragments into the filter.

Claims

1. Apparatus for dilating occluded and stenotic blood vessels comprising:

an elongated flexible catheter the distal end of which is insertable into said blood vessel;

a dilating balloon affixed to the catheter at a location spaced from the distal end of the catheter;

means for selectively introducing a pressurized fluid into the dilating balloon to inflate it against a stenosis and thereby dilate the vessel; and

for withdrawing said fluid to deflate the dilating balloon;

a collapsible filter device attached to the catheter between the dilating balloon and the distal end of the catheter which filter is extendable outward against the wall of the blood vessel to trap fragments of the stenosis broken by inflation of the dilating balloon while allowing passage of blood therethrough, and retractable along the catheter to retain the trapped fragments of the stenosis while the catheter is withdrawn from the blood vessel, said filter device comprising a plurality of ribs resiliently biased inward along the catheter angularly spaced around the catheter and extending generally axially along the catheter in the direction of the dilating balloon, and filter material bridging said ribs; and

means for extending and retracting the filter device to selectively urge said ribs outward against the walls of the blood vessel to spread the filter material across the blood vessel, said means comprising a filter balloon disposed between the catheter and said resilient ribs, and a filter balloon lumen in said catheter through which fluid is selectively supplied to inflate the filter balloon and thereby extend said filter and through which fluid is withdrawn to deflate the filter balloon and thereby retract the filter, the diameter of said filter balloon when inflated being less than the diameter of the blood vessel.

2. The apparatus of claim 1 wherein the ends of the resilient ribs extending toward the dilating balloon are secured to a ring slidable along the catheter as the ribs are extended and retracted by inflation and deflation of the filter balloon, said filter material only bridging said ribs between the distal ends of the ribs and about a midportion of the ribs which bears against the vessel wall.

3. Apparatus for dilating occluded and stenotic blood vessels comprising;

an elongated flexible catheter the distal end of which is insertable in the blood vessel to be dilated;

a dilating balloon affixed to the catheter at a location spaced from said distal end;

a first lumen extending along the catheter to the dilating balloon for supplying a fluid to inflate said dilating balloon;

a plurality of resilient ribs angularly spaced around and secured at one end to the catheter adjacent the distal end thereof, said resilient ribs being pivotable from a stowed position wherein they extend generally axially along the catheter toward the dilating balloon and an extended position wherein they pivot outward against the walls of the blood vessel;

a filter fabric spanning the ribs to trap fragments of a stenosis broken loose by the dilating balloon while permitting the passage of blood therethrough when said ribs are extended, and to retain said fragments of the stenosis as the ribs return to the stowed position;

a filter balloon disposed between the ribs and the catheter; and

a second lumen extending along the catheter to the filter balloon for selectively supplying a fluid to the filter balloon to inflate the balloon and pivot the ribs outward into contact with the blood vessel wall, said filter balloon even when inflated being smaller in diameter than the extended ribs.

4. The apparatus of claim 3 wherein said resilient ribs are each secured at an end extending toward the dilating balloon to a ring slidable along the catheter as said ribs pivot between the stowed position and the extended position, wherein said filter balloon is disposed adjacent said one end of the ribs to cause said resilient ribs to bow outward between the ends into contact with the wall of the blood vessel, and wherein said filter material spans said ribs between the one end and about where the bowed ribs contact the wall of the blood vessel.

5. The apparatus of claim 3 includiing a bypass lumen in said catheter for bypassing blood flow past the dilating balloon.

6. The apparatus of claim 5 wherein said bypass lumen extends from a point in the catheter on the proximal side of said dilating balloon to the distal end of the catheter.

7. A filter device to be mounted on a balloon catheter downstream of a dilating balloon to trap fragments of a stenosis dislodged by dilation, comprising:

a plurality of resilient ribs angularly spaced around the catheter and formed to extend along the catheter toward the dilating balloon in a stowed position;

means for securing the ends of the ribs remote from the dilating balloon in a stowed position;

a toroidal filter balloon mounted on the catheter adjacent the secured ends of the ribs and radially between the catheter and the ribs;

means for supplying fluid to said filter balloon to inflate the balloon and pivot the ribs radially outward to an extended position in contact with the wall of the blood vessel;

said filter balloon even when inflated being smaller in diameter than the extended ribs; and

filter material spanning said ribs to form a cup shaped trap for fragments of the stenosis.

8. The filter device of claim 7 including a ring secured to the ends of said ribs toward the dilating ballon, said ring being slidable along the catheter as the ribs are extended and retracted by inflation and deflation of the filter balloon.

9. A method of dilating occluded and stenotic blood vessels:

inserting a catheter into the blood vessel to align adjacent a stenosis in the blood vessel a dilating balloon carried by the catheter;

expanding a collapsible filter carried by the catheter distal to the dilating balloon to filter fluid in the blood vessel passing therethrough;

inflating the dilating balloon to dilate the blood vessel by pressing radially outward on the stenosis;

deflating the dilating balloon and trapping in the filter fragments of the stenosis broken loose by dilation as blood flows through the dilated blood vessel;

retracting the filter radially inward to retain the trapped fragments of the stenosis; and

withdrawing the catheter from the blood vessel and with it the fragments of the stenosis.

10. The method of 9 including providing a filter having a plurality of resilient ribs angularly spaced around the catheter and biased generally axially therealong toward the dilating balloon with filter material bridging the ribs and with a filter balloon disposed between the resilient ribs and said catheter and wherein said step of extending the filter comprises injecting fluid into the filter balloon to press the resilient ribs outward against the walls of the blood vessel and wherein the step of retracting the filter comprises withdrawing fluid from the filter balloon so that the resilient ribs retract against the catheter to retain the fragments of the stenosis.