System and Method of Use for Revascularizing Stenotic Bypass Grafts and Other Blood Vessels

Claim 2

1 . A system for removing occlusive material from an occluded blood vessel portion of a living being's vascular system, comprising: an elongated flexible tubular body member having a free end adapted to be delivered intravascularly to the occluded blood vessel portion and deliver a jet of infusate liquid into said vessel to dislodge particles of said occlusive material; an infusate pump for delivering said infusate liquid to said occluded blood vessel portion at an infusate flow rate; and an aspiration pump for aspirating infusate liquid, blood and dislodged particles from the occluded blood vessel portion at an aspiration flow rate; wherein said aspiration flow rate is greater than said infusate flow rate and said infusate and aspiration pumps are simultaneously operable to create a differential flow rate in said occluded blood vessel portion and thereby prevent particles of occlusive material from flowing into any upstream blood vessel or downstream blood vessel in said living being's vascular system.

Claim 3

2 . The system according to claim 1 , further comprising a guide catheter.

Claim 4

3 . The system according to claim 1 , further comprising a collection vessel located outside the body of said living being.

Claim 5

4 . The system according to claim 1 , wherein the aspiration flow rate is in the range of 5 to 100 ml per minute.

Claim 6

5 . The system according to claim 1 , wherein the aspiration flow rate exceeds the infusion flow rate by between 5 and 50 percent.

Claim 7

6 . The system according to claim 1 , wherein said aspiration flow rate and said infusion flow rates are variable.

Claim 8

7 . The system according to claim 1 , wherein said infusate and aspiration pumps are piston pumps.

Claim 9

8 . The system according to claim 1 , wherein said infusate and aspiration pumps are peristaltic pumps.

Claim 10

9 . The system according to claim 1 , wherein said elongated flexible tubular body is adapted to direct said jet of liquid laterally toward the wall of said blood vessel.

Claim 11

10 . The system according to claim 1 , wherein said aspiration flow rate and said infusion flow rate are coordinated, so that a change in one flow rate automatically results in a proportional change in the other flow rate.

Claim 12

11 . The system according to claim 1 , further comprising an electrical controller for controlling said infusate flow rate and said aspiration flow rate.

Claim 13

12 . The system according to claim 11 , wherein said controller automatically coordinates said aspiration flow rate and said infusion flow rate, so that a change in one flow rate automatically results in a proportional change in the other flow rate.

Claim 14

13 . A method for removing occlusive material from an occluded blood vessel portion of a living being's vascular system, comprising: providing a system comprising: (i) an elongated flexible tubular body member having a free end adapted to be delivered intravascularly to the occluded blood vessel portion and deliver a jet of infusate liquid into said vessel to dislodge particles of said occlusive material; (ii) an infusate pump for delivering said infusate liquid, at an infusate flow rate; and (iii) an aspiration pump for aspirating infusate liquid, blood and occlusive material from the occluded blood vessel portion at an aspiration flow rate; simultaneously aspirating infusate liquid, blood and dislodged particles from the occluded blood vessel portion at an aspiration flow rate that is greater than said infusate flow rate to create a differential flow rate in said occluded blood vessel portion and thereby prevent particles of occlusive material from flowing into any upstream blood vessel or downstream blood vessel in said living being's vascular system.

Claim 15

13 . A method for removing occlusive material from an occluded blood vessel portion of a living being's vascular system, comprising: providing a system comprising: (i) an elongated flexible tubular body member having a free end adapted to be delivered intravascularly to the occluded blood vessel portion and deliver a jet of infusate liquid into said vessel to dislodge particles of said occlusive material; (ii) an infusate pump for delivering said infusate liquid, at an infusate flow rate; and (iii) an aspiration pump for aspirating infusate liquid, blood and occlusive material from the occluded blood vessel portion at an aspiration flow rate; simultaneously aspirating infusate liquid, blood and dislodged particles from the occluded blood vessel portion at an aspiration flow rate that is greater than said infusate flow rate to create a differential flow rate in said occluded blood vessel portion and thereby prevent particles of occlusive material from flowing into any upstream blood vessel or downstream blood vessel in said living being's vascular system.

Claim 16

14 . The method according to claim 13 , wherein the infusate liquid contains a therapeutic drug.

Claim 17

15 . The method according to claim 13 , wherein the infusate liquid contains a contrast medium.

Claim 18

16 . The method according to claim 13 , wherein the aspiration flow rate is in the range of 5 to 100 ml per minute.

Claim 19

17 . The method according to claim 13 , wherein the aspiration flow rate exceeds the infusion flow rate by between 5 and 50 percent.

Claim 20

18 . The method according to claim 13 , wherein said aspiration flow rate and said infusion flow rates are variable.

Claim 21

19 . The method according to claim 13 , wherein said aspiration flow rate and said infusion flow rate are coordinated, so that a change in one flow rate automatically results in a proportional change in the other flow rate.

Claim 22

20 . The method according to claim 13 , wherein said system further comprises an electrical controller for controlling said infusate flow rate and said aspiration flow rate.

Claim 23

21 . The method according to claim 20 , wherein said controller automatically coordinates said aspiration flow rate and said infusion flow rate, so that a change in one flow rate automatically results in a proportional change in the other flow rate.

Claim 24

22 . The method according to claim 13 , wherein said infusate and aspiration pumps are piston pumps.

Claim 25

23 . The method according to claim 13 , wherein said infusate and aspiration pumps are peristaltic pumps.

Claim 26

24 . The method according to claim 13 , wherein said elongated flexible tubular body is adapted to direct said jet of liquid laterally toward the wall of said blood vessel.

Claim 27

25 . A system for removing occlusive material from a blood vessel portion of a living being's vascular system comprising: an elongated flexible tubular body member adapted to be delivered intravascularly to the occluded portion of a blood vessel; an infusate pump for delivery an infusate liquid at an infusate flow rate into said blood vessel; and an aspiration pump for aspirating said infusate liquid and said occlusive material at an aspiration flow rate, wherein said infusate flow rate is less than said aspiration flow rate, and wherein said rates serve to prevent embolization of said occlusive material in the living being's vascular system.

Claim 28

25 . A system for removing occlusive material from a blood vessel portion of a living being's vascular system comprising: an elongated flexible tubular body member adapted to be delivered intravascularly to the occluded portion of a blood vessel; an infusate pump for delivery an infusate liquid at an infusate flow rate into said blood vessel; and an aspiration pump for aspirating said infusate liquid and said occlusive material at an aspiration flow rate, wherein said infusate flow rate is less than said aspiration flow rate, and wherein said rates serve to prevent embolization of said occlusive material in the living being's vascular system.

Claim 29

26 . The system of claim 25 wherein said tubular body member is arranged to deliver said infusate liquid in the form of a liquid jet that serves to dislodge particles of said occlusive material to open the lumen.

Claim 30

27 . The system of claim 26 wherein said tubular body member comprises a working head arranged to dislodge particles of said occlusive material.

Claim 31

28 . The system of claim 27 wherein said working head is arranged to deliver said infusate liquid in the form of a jet.

Claim 32

29 . The system of claim 25 wherein said infusate comprises at least one of a contrast medium, a drug, or an oxygenated fluid.

Claim 33

30 . The system of claim 29 , wherein the drug is heparin or urokinase.

Claim 34

31 . The system of claim 25 wherein said tubular body member is arranged to act on the occlusive material to produce debris.

Claim 35

32 . The system of claim 31 wherein said tubular body member comprises an atherectomy device or a thrombolectomy device.

Claim 36

33 . The system of claim 25 wherein said infusate flow rate and said aspiration flow rate are coordinated, such that a change in one flow rate automatically causes a proportional change in the other flow rate.

Claim 37

34 . The system of claim 33 further comprising a mechanical linkage between said infusate pump and said aspiration pump.