Endovascular device for hyperthermia and angioplasty and method for using the same
First Claim
1. An apparatus for hyperthermic treatment of tissue comprising:
- a catheter having a longitudinal lumen;
an elongated member having a distal and proximal end, said distal end adapted to be positioned proximate to said tissue and thermally coupled thereto, said elongated member telescopically disposed in said lumen of said catheter; and
a ohmic heating element disposed on said elongated member at or proximate to said distal end, said ohmic heating element adapted to be in direct contact with fluid normally flowing to said tissue so that said tissue is subjected to a controlled amount of heat at a selected temperature for a selected amount of time,wherein said tissue is supplied with fluid by a vessel having a vascular wall; and
a radially extensible cage structure for selectively maintaining said ohmic heating element in a spaced apart relationship from said vascular wall, andwherein said elongated member is variably coupled to said catheter so that an action applied to said elongated member is adapted to reversibly longitudinally elongate or contract at least a distal portion of said catheter and thereby to reversibly and radially extend or contract said cage structure.
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Accused Products
Abstract
Hyperthermic treatment of tissue such as cancer tumors, is realized by providing an ohmic heating element on the distal tip of a catheter endovascularly inserted upstream of the tissue. Electrical power is provided to the element for a selected time and degree to raise the temperature of blood to a thermally mediating level such as 42° C., but not to heat the blood so that distal tissues downstream are adversely affected. The element comprises a helical coil heater disposed proximate to the end of a catheter and within an expandable cage. The cage can be selectively deployed by expanding it to maintain the coil out of contact with the vessel walls while still allowing free blood flow. Alternatively a guidewire within an expandable cage can be disposed within the same catheter wherein the heating coil has been wound onto the guidewire or the guidewire is uninsulated at that portion within the cage serves as an electrode to directly heat the blood. Angioplasty without blood flow blockage is realized by expanding a cage instead of a balloon on the catheter. The cage can be selectively expanded by withdrawal of a guidewire temporarily coupled to the catheter tip. The cage can widen the narrowed vascular lumen while still allowing free blood flow and/or contrast agent, and it avoids the risk of balloon deflation failure. The expandable cage can be detachable and implantable as a stent.
241 Citations
5 Claims
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1. An apparatus for hyperthermic treatment of tissue comprising:
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a catheter having a longitudinal lumen; an elongated member having a distal and proximal end, said distal end adapted to be positioned proximate to said tissue and thermally coupled thereto, said elongated member telescopically disposed in said lumen of said catheter; and a ohmic heating element disposed on said elongated member at or proximate to said distal end, said ohmic heating element adapted to be in direct contact with fluid normally flowing to said tissue so that said tissue is subjected to a controlled amount of heat at a selected temperature for a selected amount of time, wherein said tissue is supplied with fluid by a vessel having a vascular wall; and
a radially extensible cage structure for selectively maintaining said ohmic heating element in a spaced apart relationship from said vascular wall, andwherein said elongated member is variably coupled to said catheter so that an action applied to said elongated member is adapted to reversibly longitudinally elongate or contract at least a distal portion of said catheter and thereby to reversibly and radially extend or contract said cage structure. - View Dependent Claims (2, 3)
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4. A method for hyperthermically treating tissue comprising:
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providing a catheter having a longitudinal lumen; providing an elongated member with a ohmic heating element included within a distal portion of said elongated member, said elongated member telescopically disposed in said lumen of said catheter; disposing said distal portion of said elongated member proximate to tissue to be treated at a position thermally coupled to said tissue through fluid flow thereto; maintaining said distal portion of said elongated member out of contact with surrounding tissue except for said fluid flowing by said distal portion of said elongated member; and selectively providing power to said ohmic heating element to heat fluid flowing by said ohmic heating element to said tissue to be treated, wherein said tissue is supplied with fluid by a vessel having a vascular wall; and
a radially extensible cage structure for selectively maintaining said ohmic heating element in a spaced apart relationship from said vascular wall when said power is provided to said ohmic heating element, andwherein said elongated member is variably coupled to said catheter and further comprising applying an action to said elongated member to reversibly longitudinally elongate or contract at least a distal portion of said catheter and thereby to reversibly and radially extend or contract said cage structure.
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5. A method for hyperthermically treating tissue comprising:
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providing a elongated member having a proximal end with a ohmic heating element included within a distal portion of said elongated member; disposing said distal portion of said elongated member proximate to tissue to be treated at a position thermally coupled to said tissue through fluid flow thereto; maintaining said distal portion of said elongated member out of contact with surrounding tissue except for said fluid flowing by said distal portion of said elongated member; and selectively providing power to said ohmic heating element to heat fluid flowing by said ohmic heating element to said tissue to be treated, where maintaining said distal portion of said elongated member out of contact with surrounding tissue except for said fluid flowing by said distal portion of said elongated member comprises deploying an expandable cage around said ohmic heating element, where deploying an expandable cage around said ohmic heating element comprises longitudinally drawing a distal portion of said elongated member toward said proximal end of said elongated member to shorten said expandable cage thereby radially extending said expandable cage deployed about said ohmic heating element without substantially radially extending said ohmic heating element.
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Specification