System and method of use for revascularizing stenotic bypass grafts and other blood vessels

Claim 2

An intravascular system for opening a lumen in an occluded blood vessel portion of a living being's vascular system, the occluded blood vessel portion being occluded by an occlusive material, said system comprising an instrument and debris extraction means, said instrument having an exterior surface and a working head and being arranged to be located within the being's vascular system, whereupon a passageway is established outside said exterior surface of said instrument and within the being's vascular system, said working head being arranged to operate on the occlusive material in the interior of the occluded blood vessel portion to open a lumen therein for the flow of blood therethrough, whereupon some debris may be produced from the occlusive material by the operation of said working head, said debris extraction means introducing an infusate liquid at a first flow rate adjacent said working head and withdrawing said liquid at a second and higher flow rate through said passageway to create a differential flow adjacent said working head, whereupon debris produced by the operation of said working head is withdrawn through said passageway by said differential flow for collection remote from the occluded vessel portion and is prevented from flowing into any upstream blood vessel or downstream blood vessel.

Claim 3

The intravascular system of claim 1 wherein the first and second flow rates are adjustable.

Claim 4

The intravascular system of claim 1 wherein said system establishes a vortex flow that circulates locally adjacent the working head.

Claim 5

The intravascular system of claim 3 wherein said working head comprises an impeller which establishes said vortex flow adjacent said working head.

Claim 6

The intravascular system of claim 4 wherein said impeller is a rotary member and wherein debris produced by the operation of said working head is in the form of particles which are carried by said vortex flow into repeated engagement with said impeller to reduce the size of such particles.

Claim 7

The intravascular system of claim 4 wherein said impeller is located within a shroud, said shroud having at least one opening through which said vortex flow passes.

Claim 8

The intravascular system of claim 1 wherein said working head is arranged to mechanically engage the occlusive material to open the lumen therein.

Claim 9

The intravascular system of claim 7 wherein said working head is an impacting member.

Claim 10

The intravascular system of claim 8 wherein said working head is a rotary member.

Claim 11

The intravascular system of claim 9 additionally comprising a flexible drive shaft coupled to said working head for effecting the rotation of said working head at a high rate of speed.

Claim 12

The intravascular system of claim 10 additionally comprising motor means for effecting the rotation of said flexible drive shaft.

Claim 13

The intravascular system of claim 1 wherein said instrument is arranged to introduce said infusate liquid at said first flow rate adjacent said working head.

Claim 14

The intravascular system of claim 12 wherein the first and second flow rates are adjustable.

Claim 15

The intravascular system of claim 12 wherein said instrument is arranged to be located within said catheter to form said passageway between said instrument and said catheter, said infusate liquid and the debris therein being withdrawn from the occluded blood vessel through said passageway.

Claim 16

The intravascular system of claim 14 wherein said debris extraction means comprises first pump means coupled to said instrument for establishing said first flow rate and second pump means coupled to said catheter for establishing said second flow rate.

Claim 17

The intravascular system of claim 12 wherein said system establishes a vortex flow that circulates locally adjacent the working head.

Claim 18

The intravascular system of claim 12 wherein said working head is a rotary member.

Claim 19

The intravascular system of claim 17 wherein said rotary member comprises an impeller which establishes a vortex flow that circulates locally adjacent the working head.

Claim 20

The intravascular system of claim 12 wherein said debris extraction means includes means for correlating said first and second flow rates to each other.

Claim 21

The intravascular system of claim 19 wherein said means for correlating enables said each of said first and second flow rates to be adjustable.

Claim 22

The intravascular system of claim 1 additionally comprising hydrodynamic steering means for steering said working head.

Claim 23

The intravascular system of claim 21 wherein said hydrodynamic steering means comprises a portion of said instrument and is located adjacent the working head, said instrument being arranged to be rotated about its central longitudinal axis to bring said hydrodynamic steering means to a desired orientation with respect to the central longitudinal axis of the blood vessel in which said instrument is located.

Claim 24

The intravascular system of claim 22 wherein said instrument has a distal end portion at which said working head is located and wherein said hydrodynamic steering means produces an unbalanced flow of fluid with respect to said instrument to propel said distal end portion of said instrument laterally of the central longitudinal axis of the blood vessel in which it is located.

Claim 25

The intravascular system of claim 23 wherein said instrument comprises a rotating working head located within a shroud, said shroud including at least one side directed window therein, said window forming at least one port of said hydrodynamic steering means.

Claim 26

The intravascular system of claim 24 wherein said rotary working head is arranged to impact the occlusive material to produce the lumen therethrough.

Claim 27

The intravascular system of claim 25 wherein said rotary working head is arranged to impact the occlusive material to produce the lumen therethrough.

Claim 28

The intravascular system of claim 26 wherein said instrument is arranged to be rotated about its central longitudinal axis to bring said window to a desired orientation with respect to the central longitudinal axis of the blood vessel in which said instrument is located.

Claim 29

The intravascular system of claim 25 wherein said instrument is arranged to be rotated about its central longitudinal axis to bring said window to a desired orientation with respect to the central longitudinal axis of the blood vessel in which said instrument is located.

Claim 30

The intravascular system of claim 21 wherein said instrument has a distal end portion at which said working head is located and wherein said hydrodynamic steering means produces an unbalanced flow of fluid with respect to said instrument to propel said distal end portion of said instrument laterally of the central longitudinal axis of the blood vessel in which it is located.

Claim 31

The intravascular system of claim 29 wherein said instrument comprises a rotating working head located within a shroud, said shroud including at least one side directed window therein, said window forming at least one port of said hydrodynamic steering means.

Claim 32

The apparatus of claim 1 wherein said system additionally comprises a tubular member arranged for introduction into the being's vascular system adjacent the occluded blood vessel portion, said instrument being arranged to be disposed within said tubular member to establish said passageway between said tubular member and said instrument.

Claim 33

The apparatus of claim 31 wherein said tubular member is arranged to introduce and guide said working head of said instrument to a position adjacent the occlusive material.

Claim 34

An intravascular system for opening a lumen in an occluded blood vessel portion of a living being's vascular system, said occluded blood vessel portion being occluded by an occlusive material, said system comprising an instrument, a catheter and debris extraction means, said instrument including a working head, said instrument being located within said catheter, said working head being arranged to operate on the occlusive material in the interior of the occluded blood vessel portion to open a lumen therein for the flow of blood therethrough, whereupon some debris may be produced from the occlusive material by the operation of said working head, said debris extraction means including debris removal means coupled to said catheter, said debris extraction means being arranged for introducing an infusate liquid through said instrument at a first flow rate to a position adjacent said working head, said debris extraction being also being arranged for withdrawing said liquid at a second and higher flow rate to create a differential flow adjacent said working head, whereupon debris produced by the operation of said working head is withdrawn by said differential flow for collection remote from the occluded vessel portion and is prevented from flowing into any upstream blood vessel or downstream blood vessel, said infusate liquid and the debris therein being withdrawn from the occluded blood vessel portion through said passageway under the influence of said debris removal means.

Claim 35

An intravascular system for opening a lumen in an occluded blood vessel portion of a living being's vascular system, said occluded blood vessel portion being occluded by an occlusive material, said system comprising an instrument, a catheter and debris extraction means, said instrument including a working head, said instrument being located within said catheter, said working head being arranged to operate on the occlusive material in the interior of the occluded blood vessel portion to open a lumen therein for the flow of blood therethrough, whereupon some debris may be produced from the occlusive material by the operation of said working head, said debris extraction means including debris removal means coupled to said catheter, said debris extraction means being arranged for introducing an infusate liquid through said instrument at a first flow rate to a position adjacent said working head, said debris extraction being also being arranged for withdrawing said liquid at a second and higher flow rate to create a differential flow adjacent said working head, whereupon debris produced by the operation of said working head is withdrawn by said differential flow for collection remote from the occluded vessel portion and is prevented from flowing into any upstream blood vessel or downstream blood vessel, said infusate liquid and the debris therein being withdrawn from the occluded blood vessel portion through said passageway under the influence of said debris removal means.

Claim 36

The intravascular system of claim 33 wherein said catheter comprises a guide catheter.

Claim 37

The intravascular system of claim 33 wherein said catheter comprises an introducer sheath.

Claim 38

The intravascular system of claim 33 wherein the first and second flow rates are correlated to each other.

Claim 39

The intravascular system of claim 36 wherein said first and second flow rates are adjustable.

Claim 40

The intravascular system of claim 33 wherein said debris extraction means comprises first pump means coupled to said instrument for establishing said first flow rate and wherein said debris removal means comprises second pump means for establishing said second flow rate.

Claim 41

The intravascular system of claim 38 wherein said first and second pump means are each positive displacement pumps.

Claim 42

The intravascular system of claim 33 wherein said instrument and said catheter are each sufficiently flexible to be passed longitudinally through a portion of the vascular system so that said working head is located adjacent the occluded blood vessel portion.

Claim 45

The method of claim 41 wherein said differential flow prevents debris produced by the operation of said working head from flowing into either the first blood vessel portion or the second blood vessel portion.

Claim 46

The method of claim 42 wherein said occluded blood vessel portion comprises a bypass graft.

Claim 47

The method of claim 43 wherein the bypass graft is a coronary bypass graft, wherein said living being's vascular system includes an aorta, and wherein the first vessel portion comprises the aorta.

Claim 48

The method of claim 43 wherein said living being's vascular system includes a femoral artery and wherein the occluded blood vessel portion comprises a portion of the femoral artery.

Claim 49

The method of claim 45 wherein said living being's vascular system includes a profunda femoris and wherein the first blood vessel portion comprises the profunda femoris.

Claim 50

The method of claim 41 additionally comprising: (d) establishing a vortex flow that circulates locally adjacent said working head.

Claim 51

The method of claim 41 wherein said working head is arranged to engage the occlusive material to open the lumen therein.

Claim 52

The method of claim 48 wherein said working head is a rotary member which is rotated to cause to repeatedly engage the occlusive material to open the lumen therein.

Claim 53

The method of claim 49 wherein the repeated engagement causes portions of the occlusive material to be removed to produce the lumen therethrough.

Claim 54

The method of claim 49 wherein said repeated engagement comprises repeated impacting of the occlusive material, to break portions of the occlusive material away to produce the lumen.

Claim 55

The method of claim 50 additionally comprising: (d) establishing a vortex flow that circulates locally adjacent said working head.

Claim 56

The method of claim 50 wherein said vortex flow carries removed portion of the occlusive material into repeated engagement with said working.