Atherectomy catheter and RF cutting method
First Claim
1. A device for removing atheromas from a body lumen;
- including;
an elongate catheter having a proximal end and a distal end, a catheter wall defining a compartment within the catheter near the distal end, and an window through the catheter wall to allow entry into the compartment;
an electrically conductive tissue cutting element;
a carrier mounted movably relative to the catheter, for supporting the cutting element proximate the window for a controlled movement thereof along and adjacent the window; and
a heating means for generating an electrical current in the cutting element to heat the cutting element at least to a selected temperature above normal body temperature, and for maintaining the cutting element at least at said selected temperature during said controlled movement;
wherein the catheter is flexible and maneuverable to locate the distal tip of the catheter within a body lumen and to place the window against a tissue wall segment of the body lumen to acquire tissue within the compartment, and the cutting element, when so heated and undergoing the controlled movement, severs the acquired tissue and heats tissue adjacent the cutting element while severing.
1 Assignment
0 Petitions
Accused Products
Abstract
An atherectomy device includes a catheter with a window at its distal tip for admitting tissue into a catheter compartment. A cylindrical cartridge in the compartment has a cutting edge that supports an electrically conductive cutting element, e.g. a band or wire. The cutting element and adjacent tissue can be heated to a selected temperature by generating an electrical current through the cutting element. The catheter is maneuverable to position its distal end near a lesion in an artery. The catheter incorporates a dilatation balloon or other feature to urge the catheter against the lesion, so that at least part of the lesion enters the compartment through the window. Then, the cartridge is manipulated from the catheter'"'"'s proximal end to move the cutting edge across the window, severing the acquired tissue. According to alternative embodiments, the cartridge is either rotated or moved axially relative to the catheter, in either event closing the catheter window when the cut is complete. Further alternatives involve either placing an indifferent electrode on the patient and providing an RF signal via a single conductor to the cutting element for ohmic heating, or providing an RF (or a DC) current through the cutting element and two separate conductors for direct resistive heating of the cutting element.
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Citations
30 Claims
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1. A device for removing atheromas from a body lumen;
- including;
an elongate catheter having a proximal end and a distal end, a catheter wall defining a compartment within the catheter near the distal end, and an window through the catheter wall to allow entry into the compartment; an electrically conductive tissue cutting element; a carrier mounted movably relative to the catheter, for supporting the cutting element proximate the window for a controlled movement thereof along and adjacent the window; and a heating means for generating an electrical current in the cutting element to heat the cutting element at least to a selected temperature above normal body temperature, and for maintaining the cutting element at least at said selected temperature during said controlled movement; wherein the catheter is flexible and maneuverable to locate the distal tip of the catheter within a body lumen and to place the window against a tissue wall segment of the body lumen to acquire tissue within the compartment, and the cutting element, when so heated and undergoing the controlled movement, severs the acquired tissue and heats tissue adjacent the cutting element while severing. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
- including;
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19. A device for removing unwanted tissue from a body lumen;
- including;
an elongate catheter having a proximal end and a distal end, a catheter wall defining a compartment within the catheter near the distal end, and a window through the catheter wall to allow entry into the compartment; a cartridge mounted movably within the compartment, said cartridge having a cartridge wall, a cartridge opening for receiving tissue into the cartridge, and a cutting edge along the cartridge opening; a control means coupled to the cartridge and operable to selectively position and move the cartridge within the compartment, for providing a controlled movement of the cutting edge along and adjacent the window; and a heating means for heating the cutting edge at least to a selected temperature above normal body temperature, and for maintaining the cutting element at least at said selected temperature during said controlled movement; wherein the catheter is flexible and maneuverable to locate the distal end of the catheter within a body lumen and to place the window against a tissue wall segment to acquire tissue within the compartment, and the cutting edge, when undergoing the controlled movement, severs the acquired tissue and heats adjacent tissue while severing; and wherein said control means is operable to move the cartridge between an open position for permitting entry into the compartment via the window, and a closed position in which the cartridge wall closes the window. - View Dependent Claims (20, 21, 22, 23, 24, 25)
- including;
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26. A process for removing tissue from a body lumen;
- including;
providing, near a distal end of an elongate catheter, a compartment and a window to the compartment through a catheter wall of the catheter, and an electrically conductive tissue cutting element mounted to the catheter for a controlled movement of the cutting element adjacent and along the window; inserting the catheter into a body lumen, and guiding the catheter to position the window against a tissue wall segment of the body lumen, thus to cause tissue to enter the compartment via the window and occupy the compartment; heating the cutting element heat adjacent tissue and to at least to a selected temperature above normal body temperature, and causing the cutting element while so heated to undergo said controlled movement, thereby to sever the tissue occupying the compartment. - View Dependent Claims (27, 28, 29, 30)
- including;
Specification