An expandable transluminal atherectomy catheter

Claim 2

An atherectomy catheter for use in the removal of arterial stenotic plaque from an artery, comprising: a guide wire (32) which can be passed through said arterial stenotic plaque; an atherectomy catheter (22) having an expanded plaque excising means (24) at its distal end and which can be advanced into the artery over said guide wire with said excising means at a first and smaller diameter, said excising means being subsequently expandable in the artery to a second and larger diameter prior to the excising of the stenotic plaque from the artery; means for axially moving said atherectomy catheter and said excising means in the expandable state through the said arterial plaque so that the plaque excising means separates the plaque from the artery; means for removing the separated plaque from the artery through the catheter; and means for expanding the plaque excising means (24) after insertion into the artery but before advancement through the arterial plaque, and for subsequently collapsing the plaque excising means (24) after removal of the arterial, thereby to permit the removal of the atherectomy catheter from the artery; characterised in that the plaque excising means (24) extend forwardly from the distal end of the atherectomy catheter in the direction of insertion into the artery and are operated, in the expanded state, by further advancement of the atherectomy catheter and the associated plaque excising means into the stenotic plaque in that same direction.

Claim 3

A catheter according to claim 1, wherein the plaque excising means (24) are expandable within the artery by means of a radially outwardly applied spring bias, and wherein the means for expanding and collapsing the plaque excising means (24).comprise a sheathing catheter (40) coaxial with and located about the atherectomy catheter (22), the sheathing catheter and the atherectomy catheter being axially slidable one with respect to the other, whereby during insertion and withdrawal of the atherectomy catheter into the artery along said guide wire (32) the plaque excising means (24) are retracted in a collapsed state against said spring bias within the distal end of the sheathing catheter (40), and following which insertion the sheathing catheter (40) can be retracted relative to the atherectomy catheter (22) to permit the radial expansion of the plaque excising means (24) under said spring bias.

Claim 4

A catheter according to claim 2, wherein the plaque excising means (24) comprise a plurality of radially spaced, arcuately bowed, spring blades projecting axially from the distal end of the atherectomy catheter (22) and held in a collapsed condition during insertion and withdrawal of the catheter into the artery by retraction within the distal end of the sleeve catheter (40).

Claim 5

A catheter according to claim 1, 2 or 3, wherein the plaque excising means (24) comprise a plurality of blades projecting axially from the distal end of the atherectomy catheter (22) and provided with either a cutting edge (24a) or grinding surface (24d), for excision or grinding away of the stenotic plaque, or both.

Claim 6

A catheter according to any one of claims 1 to 4, wherein the atherectomy catheter (22) is a torque transmitting catheter and rotary drive means (60) are provided connected or connectable to the proximal end of the atherectomy catheter to drive the catheter, after insertion into the artery, and its associated plaque excising means (24), when in its expanded state, thereby to effect the removal of the stenotic plaque from the artery.

Claim 7

A catheter according to any one of claims 1 to 5, wherein the plaque removing means comprise a means (75) for applying suction to the proximal end of the atherectomy catheter (22) to remove separated arterial stenotic plaque through the atherectomy catheter as the excising means is advanced through the arterial stenotic plaque.

Claim 8

A catheter according to any one of claims 1 to 6, further comprising means (76) for injecting a flushing or other solution into the artery at the distal end of the atherectomy catheter to flush said separated stenotic plaque from the artery, or for other purposes, e.g. as a contrast medium.

Claim 9

A catheter according to claim 7, wherein the guide wire (32) is hollow and said flushing or other solution is injected into the artery through the guide wire.

Claim 10

A catheter according to any one of claims 1 to 8, wherein the guide wire (32) is hollow and comprises an inflatable balloon (34) at its distal end which is in fluid communication with the proximal end of said guide wire, and means (76) are provided for inflating the balloon (34) after insertion of the atherectomy catheter into the artery thereby to block said artery downstream from said atherectomy catheter to prevent separated stenotic plaque from flowing downstream in said artery during the atherectomy procedure.

Claim 11

A catheter according to claim 9, wherein the distal end of the guide wire (32) is provided with at least one discharge port (32a) upstream of the balloon (34), but downstream of the plaque cutting means (24), whereby fluid injected through the hollow guide wire (32) by the inflation means (76) serves the dual purpose of inflating the balloon and providing a flushing or other solution to the artery downstream of the distal end of the atherectomy catheter for flushing separated plaque from the artery, or for other purposes, e.g. as a contrast medium.

Claim 12

An atherectomy catheter for use in the removal of arterial stenotic plaque from an artery, comprising; a guide wire (32) which can be passed through said arterial stenotic plaque; an atherectomy catheter (22) having an expandable plaque excising means (24) at its distal end and which can be advanced into the artery on said guide wire with said excising means at a first and smaller diameter, said excising means subsequently being expandable in the artery to a second and larger diameter prior to the excising of the stenotic plaque from the artery; means for axially moving the atherectomy catheter and said excising means in its expanded state through the arterial plaque so that the plaque excising means separates the plaque from the artery; means (75) for removing separated plaque from the artery by suction through the catheter (22); and means for expanding-the plaque excising means (24) after insertion through the arterial plaque, and for subsequently collapsing the plaque excising means (24) after removal of the plaque thereby to permit the removal of the atherectomy catheter from the artery, characterised in that: a) the plaque excising means (24) extend forwardly from the distal end of the atherectomy catheter in the direction of insertion into the artery and are operated, in the expanded state, by the further advancement of the atherectomy catheter and the associated plaque excising means into the stenotic plaque in that same direction, b) the guide wire (32) is hollow and comprises an inflatable balloon (34) at its distal end, and c) means (76) are provided for inflation of the balloon after insertion of the guide wire (32) through the arterial plaque, thereby to block the artery downstream from the distal end of the atherectomy catheter on the opposite side of the arterial plaque to that which is being excised by the plaque excising means, and prevent separated plaque from flowing downstream in said artery during the atherectomy procedure.

Claim 13

An atherectomy catheter for use in the removal of arterial stenotic plaque from an artery, comprising; a guide wire (32) which can be passed through said arterial stenotic plaque; an atherectomy catheter (22) having an expandable plaque excising means (24) at its distal end and which can be advanced into the artery on said guide wire with said excising means at a first and smaller diameter, said excising means subsequently being expandable in the artery to a second and larger diameter prior to the excising of the stenotic plaque from the artery; means for axially moving the atherectomy catheter and said excising means in its expanded state through the arterial plaque so that the plaque excising means separates the plaque from the artery; means (75) for removing separated plaque from the artery by suction through the catheter (22); and means for expanding-the plaque excising means (24) after insertion through the arterial plaque, and for subsequently collapsing the plaque excising means (24) after removal of the plaque thereby to permit the removal of the atherectomy catheter from the artery, characterised in that: a) the plaque excising means (24) extend forwardly from the distal end of the atherectomy catheter in the direction of insertion into the artery and are operated, in the expanded state, by the further advancement of the atherectomy catheter and the associated plaque excising means into the stenotic plaque in that same direction, b) the guide wire (32) is hollow and comprises an inflatable balloon (34) at its distal end, and c) means (76) are provided for inflation of the balloon after insertion of the guide wire (32) through the arterial plaque, thereby to block the artery downstream from the distal end of the atherectomy catheter on the opposite side of the arterial plaque to that which is being excised by the plaque excising means, and prevent separated plaque from flowing downstream in said artery during the atherectomy procedure.

Claim 14

A catheter according to claim 10, wherein the distal end of the guide wire (32) is provided with at least one discharge port (32a) upstream of the balloon (34), but downstream of the plaque cutting means (24), whereby fluid injection through the hollow guide wire (32) by the inflation means (76) serves the dual purpose of inflating the balloon and providing a flushing or other solution6to the artery downstream of the distal end of the atherectomy catheter for flushing separated plaque from the artery, or for other purposes, e.g. as a contrast medium.