Electrosurgical catheter aned method for vascular applications

Claim 2

An electrosurgical plaque-resolving or tissue-eroding device having a distal end which is insertable within and along the lumen of a blood vessel and .[.manipulated.]. .Iadd.manipulatable .Iaddend.therethrough to a desired position without causing undue trauma where the device is operated to thermally resolve atherosclerotic plaque buildup or erode tissue in the blood vessel to re-establish desired blood flow through the blood vessel or to remove tissue therefrom, said device comprising: an elongate flexible hollow tubular body having a distal end, a proximal end, and a diameter smaller than the diameter of the vessel into which said device is inserted; first passage means within said tubular body for supplying a flushing fluid to the site where plaque or tissue is resolved or eroded; second passage means within said tubular body for evacuating, such as by suction, debris at the site of resolving plaque or eroding tissue from the site; a hollow tip member mounted at said distal end of said flexible hollow tubular body; an electrode adjacent to and in operative association with said hollow tip member for resolving plaque or eroding tissue, said tip member being beveled or rounded at the distal end of said device; means for supplying a high-frequency electrical current to said electrode for cutting tissue or coagulating body fluid; and means for sensing, from time to time, the amount of plaque or tissue at the site in the blood vessel.

Claim 3

The device of claim 1 wherein said hollow tip member is an electrode.

Claim 4

The device of claim 2 wherein said hollow tip member is made of stainless steel.

Claim 5

The device of claim 2 wherein said electrode has the shape of a stove pipe hat having its top removed, with the brim shaped portion of said electrode being at the distal end of said device.

Claim 6

The device of claim 2 wherein said electrode is an unobstructed ring electrode positioned within said first passage means of the hollow tip member, a distal end of said ring electrode being flush with the end of said tip member.

Claim 7

The device of claim 2 wherein said electrode has the shape of a hollow mushroom including a head which is situated at the distal end of the device.

Claim 8

The device of claim 2 including an electrical insulator which has a high temperature melting point and which connects said tip member electrode to said tubular body.

Claim 9

The device of claim 7 including a ring electrode between said electrical insulator and said tubular body to form said device as a bipolar device.

Claim 10

The device of claim 7 wherein said insulator is made of a material selected from the group consisting of glass, ceramic, fluorocarbon polymers, polyimide polymers and polyphenylene sulfide.

Claim 11

The device of claim 7 wherein said insulator has an inwardly stepped formation and said electrode is cup shaped, with a portion of its bottom removed, and is attached to a distal end of said electrical insulator with the cup walls surrounding said stepped formation.

Claim 12

The device of claim 1 wherein said electrode is covered with an ultra thin layer of insulation on the surface thereof which contacts the plaque or tissue buildup.

Claim 13

The device of claim 1 wherein said hollow tubular body is made of silicone rubber.

Claim 14

The device of claim 1 wherein said hollow tubular body is made of polyurethane.

Claim 15

The device of claim 1 wherein said hollow tubular body is made of polytetrafluoroethylene.

Claim 16

The device of claim 1 wherein said hollow tubular body is made of a polymeric substance capable of resisting softening during resolving.

Claim 17

The device of claim 1 wherein said hollow tip member is made of aluminum.

Claim 18

The device of claim 1 wherein said hollow tip member is made of tantalum.

Claim 19

The device of claim 1 wherein said hollow tip member is made of platinum.

Claim 20

The device of claim 1 wherein said high-voltage, high-frequency current supply means is capable of generating a pulsed current waveform having an intermittent group of pulses separated by periods of no current and being adapted for use in a coagulation mode of operation of said device.

Claim 21

The device of claim 19 wherein said pulsed current waveform has high voltage peaks and a low duty cycle.

Claim 22

The device of claim 1 wherein said high-voltage, high-frequency, current supply means is capable of generating a current waveform having a pure sine waveform.

Claim 23

The device of claim 1 wherein said high-voltage is several hundred volts.

Claim 24

The device of claim 1 wherein said high frequency is between 0.5 l and .[.20.]. .Iadd.8 .Iaddend.megahertz.

Claim 25

The device of claim 1 wherein said sensing means further includes radio-opaque dye and X-ray viewing means, said radio-opaque dye being injected into the blood vessel at the site and the X-ray image showing the amount of plaque remaining being displayed on said viewing means.

Claim 26

The device of claim 1 further including a third passage means for carrying at least one conductor.

Claim 27

The device of claim 25 wherein said passage means are arranged with their axes contained within the diameter of said tubular body.

Claim 29

The device of claim 25 wherein said first passage means opens onto a cylindrical side wall surface of said tubular body at a location adjacent said tip member.

Claim 30

The device of claim 25 wherein said first passage means extends through said tip .[.memeber.]. .Iadd.member .Iaddend.and opens onto a front end surface of said tip member.

Claim 31

The device of claim 25 including a second electrode at the distal end of said tubular body.

Claim 32

The device of claim 30 wherein said tip member is made of a relatively high temperature resistance insulative material, said first electrode is mounted in said tip member and has an electrode surface on the distal end thereof, and said second electrode is a ring or sleeve electrode on said tubular body and located adjacent but rearwardly of said tip member.

Claim 33

The device of claim 30 wherein said tip member is made of a relatively high temperature resistance insulative material, and said first and second electrodes are semi-cylindrical in shape and are positioned .[.with said tip member.]. facing each other across the axis of said tip member.

Claim 34

The device of claim 30 including a fourth passage means for carrying a second wire conductor therein for connection to said second electrode.

Claim 35

The device of claim 25 including a trident structure at the proximal end of said tubular body, said trident structure having three legs each of which has a passageway communicating individually with a respective one of said passage means in said tubular body.

Claim 36

The device of claim 25 including a stiffening wire which extends through said first passageway for stiffening said tubular body.

Claim 37

The device of claim 1 including a collar at said distal end of said device, said collar having a bore therein and a countersunk formation in said bore, a front flat surface and an outer generally cylindrical surface.Iadd., .Iaddend.said electrode being fully received within said countersunk formation.Iadd., .Iaddend.having a bore therethrough which mates with and is flush with said bore of said collar, and having an annular front surface which is flush with said front surface of said collar, and said collar being beveled or rounded between the front surface and the outer surface.

Claim 38

The device of claim 1 wherein said sensing means includes means coupled to said electrode for measuring the impedance between said electrode through the plaque or tissue buildup and a current return path, the impedance measured being directly related to the amount of plaque or tissue buildup at the site.

Claim 39

The device of claim 37 wherein said impedance measuring means include means for supplying a low voltage DC current to said electrode for making the impedance measurement.

Claim 40

A cardiovascular thermal ablation device having a distal portion which is insertable into and along a lumen of a blood vessel to a desired position against an area of atherosclerotic plaque buildup or like obstruction within the lumen of the vessel without undue trauma, said device having means for thermally resolving the area of obstruction within the vessel and having means for removing resolved tissue from the area of thermal ablation, said device further comprising an elongate flexible hollow tubular body having a distal end and a proximal end; a hollow tip member mounted at said distal end of said flexible hollow tubular body; at least one electrode adjacent to and in operative association with said hollow tip member for resolving plaque or eroding tissue; said tip member being beveled or rounded at said distal end of said device; means for supplying electrical current to said electrode; means for sensing, between periods of application of electrical current to said electrode, the amount of plaque or tissue remaining to obstruct the site in the blood vessel by measuring the impedance of the plaque .[.of.]. .Iadd.or .Iaddend.tissue; means for supplying fluid to, or for supplying suction from, the site including at least one channel extending through said flexible hollow tubular body and tip member, and said device having at least one further channel, at least one wire conductor in said further channel extending proximally from said at least one electrode to said proximal end of said device and means for connecting said conductor to a source of .Iadd.high frequency .Iaddend.electrical current. .Iadd.40. An electrosurgical plaque-eroding device having a distal end which is insertable within and along the lumen of a blood vessel and manipulatable therethrough without causing undue trauma to a desired position where the device is operated to thermally erode atherosclerotic plaque buildup in the blood vessel to reestablish desired blood flow through the blood vessel, said device comprising: an elongate flexible hollow tubular body having an inner lumen, a distal end, a proximal end, and an outer diameter smaller than the diameter of the vessel into which said device is inserted; a hollow tip member mounted at said distal end of said flexible hollow tubular body, having a distal end and a proximal end, and having an axial passageway therethrough communicating said tip member distal end with said lumen of said hollow tubular body; means for withdrawing material which collects at said tip member distal end; means for supplying flushing fluid to said tip member distal end; an electrode assembly adjacent to and in operative association with said hollow tip member and including first and second electrodes for thermally eroding plaque, said tip member being beveled or rounded at the distal end of said device to facilitate insertion thereof into a blood vessel, and means for supplying a high-frequency electrical current to said electrodes for cutting plaque,

Claim 41

A cardiovascular thermal ablation device having a distal portion which is insertable into and along a lumen of a blood vessel to a desired position against an area of atherosclerotic plaque buildup or like obstruction within the lumen of the vessel without undue trauma, said device having means for thermally resolving the area of obstruction within the vessel and having means for removing resolved tissue from the area of thermal ablation, said device further comprising an elongate flexible hollow tubular body having a distal end and a proximal end; a hollow tip member mounted at said distal end of said flexible hollow tubular body; at least one electrode adjacent to and in operative association with said hollow tip member for resolving plaque or eroding tissue; said tip member being beveled or rounded at said distal end of said device; means for supplying electrical current to said electrode; means for sensing, between periods of application of electrical current to said electrode, the amount of plaque or tissue remaining to obstruct the site in the blood vessel by measuring the impedance of the plaque .[.of.]. .Iadd.or .Iaddend.tissue; means for supplying fluid to, or for supplying suction from, the site including at least one channel extending through said flexible hollow tubular body and tip member, and said device having at least one further channel, at least one wire conductor in said further channel extending proximally from said at least one electrode to said proximal end of said device and means for connecting said conductor to a source of .Iadd.high frequency .Iaddend.electrical current. .Iadd.40. An electrosurgical plaque-eroding device having a distal end which is insertable within and along the lumen of a blood vessel and manipulatable therethrough without causing undue trauma to a desired position where the device is operated to thermally erode atherosclerotic plaque buildup in the blood vessel to reestablish desired blood flow through the blood vessel, said device comprising: an elongate flexible hollow tubular body having an inner lumen, a distal end, a proximal end, and an outer diameter smaller than the diameter of the vessel into which said device is inserted; a hollow tip member mounted at said distal end of said flexible hollow tubular body, having a distal end and a proximal end, and having an axial passageway therethrough communicating said tip member distal end with said lumen of said hollow tubular body; means for withdrawing material which collects at said tip member distal end; means for supplying flushing fluid to said tip member distal end; an electrode assembly adjacent to and in operative association with said hollow tip member and including first and second electrodes for thermally eroding plaque, said tip member being beveled or rounded at the distal end of said device to facilitate insertion thereof into a blood vessel, and means for supplying a high-frequency electrical current to said electrodes for cutting plaque,

Claim 42

which high frequency can extend up to 20 megahertz. .Iaddend. .Iadd.41. The electrosurgical plaque-eroding device of claim 40 wherein said means for withdrawing material which collects at said tip member distal end and said means for supplying flushing fluid to said tip member distal end are both defined by the inner lumen of the tubular body and the axial passageway through the hollow tip member which provide passage means for withdrawing material which collects at said tip member distal end and for supplying flushing fluid to said tip member distal end. .Iaddend.

Claim 43

.Iadd. A cardiovascular thermal ablation device having a distal portion which is insertable into and along a lumen of a blood vessel without causing undue trauma to a desired position against an area of atherosclerotic plaque buildup or like obstruction within the lumen of the vessel, said device having means for thermally resolving the area of obstruction within the vessel, said device further comprising an elongate flexible hollow tubular body having an inner lumen, a distal end and a proximal end; a hollow tip member mounted to said distal end of said flexible hollow tubular body having a distal end and a proximal end, and having an axial passageway therethrough communicating said tip member distal end with said lumen of said hollow tubular body; means for withdrawing material which collects at said tip member distal end; means for supplying flushing fluid to said tip member distal end; said means for thermally eroding plaque including an electrode assembly adjacent to and in operative association with said hollow tip member and including two electrodes for eroding plaque; said tip member being beveled or rounded at said distal end of said device; means for supplying high frequency electrical current to said electrodes, which high frequency can extend up to 20 megahertz; and means for sensing, between periods of application of electrical current to said electrodes, the amount of plaque remaining at said position by measuring the impedance through the plaque between said

Claim 44

.Iadd. A cardiovascular thermal ablation device having a distal portion which is insertable into and along a lumen of a blood vessel without causing undue trauma to a desired position against an area of atherosclerotic plaque buildup or like obstruction within the lumen of the vessel, said device having means for thermally resolving the area of obstruction within the vessel, said device further comprising an elongate flexible hollow tubular body having an inner lumen, a distal end and a proximal end; a hollow tip member mounted to said distal end of said flexible hollow tubular body having a distal end and a proximal end, and having an axial passageway therethrough communicating said tip member distal end with said lumen of said hollow tubular body; means for withdrawing material which collects at said tip member distal end; means for supplying flushing fluid to said tip member distal end; said means for thermally eroding plaque including an electrode assembly adjacent to and in operative association with said hollow tip member and including two electrodes for eroding plaque; said tip member being beveled or rounded at said distal end of said device; means for supplying high frequency electrical current to said electrodes, which high frequency can extend up to 20 megahertz; and means for sensing, between periods of application of electrical current to said electrodes, the amount of plaque remaining at said position by measuring the impedance through the plaque between said

Claim 45

two electrodes. .Iaddend. .Iadd.43. The electrosurgical plaque-eroding device of claim 42 wherein said means for withdrawing material which collects at said tip member distal end and said means for supplying flushing fluid to said tip member distal end are both defined by the inner lumen of the tubular body and the axial passageway through the hollow tip member which provide passage means for withdrawing material which collects at said tip member distal end and for supplying flushing fluid to said tip

Claim 46

member distal end. .Iaddend. .Iadd.44. An elongate electrosurgical plaque-eroding device having a distal end which is insertable within, through and long the lumen of a blood vessel without causing undue trauma to the blood vessel to a desired position where the device is operated to thermally erode atherosclerotic plaque buildup in the blood vessel to re-establish desired blood flow through the blood vessel, said device comprising: an elongate flexible body having an inner lumen, a distal end, a proximal end, and an outer diameter smaller than the diameter of the vessel into which said device is inserted; a tip section at said distal end of said elongate flexible body having a distal end and a proximal end, and having an axial passageway therethrough communicating said tip section distal end with said lumen of said hollow tubular body; means for withdrawing material which collects at said tip section distal end; means for supplying flushing fluid to said tip section distal end; an electrode assembly adjacent to and in operative association with said tip section and including first and second electrodes for thermally eroding plaque, said tip section being rounded at the distal end of said device to facilitate insertion thereof into a blood vessel, and means coupled to said electrodes for supplying a high-frequency electrical current to said electrodes for cutting through said plaque, which high frequency can

Claim 47

member distal end. .Iaddend. .Iadd.44. An elongate electrosurgical plaque-eroding device having a distal end which is insertable within, through and long the lumen of a blood vessel without causing undue trauma to the blood vessel to a desired position where the device is operated to thermally erode atherosclerotic plaque buildup in the blood vessel to re-establish desired blood flow through the blood vessel, said device comprising: an elongate flexible body having an inner lumen, a distal end, a proximal end, and an outer diameter smaller than the diameter of the vessel into which said device is inserted; a tip section at said distal end of said elongate flexible body having a distal end and a proximal end, and having an axial passageway therethrough communicating said tip section distal end with said lumen of said hollow tubular body; means for withdrawing material which collects at said tip section distal end; means for supplying flushing fluid to said tip section distal end; an electrode assembly adjacent to and in operative association with said tip section and including first and second electrodes for thermally eroding plaque, said tip section being rounded at the distal end of said device to facilitate insertion thereof into a blood vessel, and means coupled to said electrodes for supplying a high-frequency electrical current to said electrodes for cutting through said plaque, which high frequency can

Claim 48

extend up to 20 megahertz. .Iaddend. .Iadd.45. The electrosurgical plaque-eroding device of claim 44 wherein said means for withdrawing material which collects at said tip section distal end and said means for supplying flushing fluid to said tip section distal end are both defined by the inner lumen of the tubular body and the axial passageway through the hollow tip section which provide passage means for withdrawing material which collects at said tip section distal end and for supplying

Claim 49

flushing fluid to said tip section distal end. .Iaddend. .Iadd.46. A cardiovascular thermal ablation device having a distal portion which is insertable into and along a lumen of a blood vessel without causing undue trauma to a desired position against an area of atherosclerotic plaque buildup or like obstruction within the lumen of the vessel, said device having means for thermally resolving the area of obstruction within the vessel, said device further comprising an elongate flexible body having an inner lumen, a distal end and a proximal end; a tip section at said distal end of said elongate flexible body having a distal end and a proximal end, and having an axial passageway therethrough communicating said tip section distal end with said lumen of said hollow tubular body; means for withdrawing material which collects at said tip section distal end; means for supplying flushing fluid to said tip section distal end; said means for thermally eroding plaque including an electrode assembly adjacent to and in operative association with said distal end of said device; means coupled to said electrodes for supplying high frequency electrical current to said electrodes, which high frequency can be up to 20 megahertz; and means for sensing, between periods of application of electrical current to said electrodes, the amount of plaque remaining at said position by measuring the impedance through the plaque between said two electrodes. .Iaddend. .Iadd.47. The electrosurgical plaque-eroding device of claim 46 wherein said means for withdrawing material which collects at said tip section distal end and said means for supplying flushing fluid to said tip section distal end are both defined by the inner lumen of the tubular body and the axial passageway through the hollow tip section which provide passage means for withdrawing material which collects at said tip section distal end and for supplying flushing fluid to said tip section distal end. .Iaddend.