Abstract: A method and apparatus for reducing restenosis of a stenotic region of a blood vessel after performing a dilatation angioplasty treatment is disclosed. The method includes radiating microwave energy from a microwave antenna to kill a medial tissue layer of the blood vessel in the stenotic region. The radiation is applied during or after inflation of dilatation balloon to permanently dilate the stenotic region. When radiation is applied during dilatation of the stenotic region, the dilatation balloon forms a seal against the inner wall surface of the blood vessel to exclude blood in the vessel from contacting the stenotic region. The method preferably further includes cooling the blood circulating in the blood vessel about a shaft of the catheter with cooling fluid circulating within cooling lumens of the catheter and cooling an inner wall surface of the blood vessel in the stenotic region during the application of radiation to the medial cell layer.

Abstract: A system for treatment of a target volume of cancerous tissue comprises a probe carrying a microwave antenna positioned in a body cavity proximate the target volume. At least one energy-emitting element is placed in the target volume. The microwave antenna is energized so that energy emitted from the antenna and the energy-emitting element necroses cancerous tissue in the target volume.

Abstract: Tissue surrounding a bodily conduit, such as a urethra, is thermally treated while preventing restrictions of the bodily conduit due to heat-induced shrinkage of collagen rich tissue surrounding the bodily conduit. A select volume of collagen-containing tissue surrounding the urethra is heated to destroy the tissue and to cause the tissue to be capable of being plastically remodeled into a selected shape. The selected shape is defined while the tissue is heated, and the tissue is allowed to cool while continuing to define the selected shape to cause plastic remodeling of the tissue into the selected shape. The method also includes performing a thermal therapy treatment without causing the surrounding tissue to exceed a collagen transition temperature of the tissue during the heating step of the treatment session.

Abstract: A method of prostate treatment includes the step of inserting into a prostatic portion of urethra an energy emitting device that is connected to an energy source. Energy is delivered to the prostate from the energy emitting device. The amount of energy emitted to prostatic tissue adjacent to a bladder is greater than that emitted to prostatic tissue distant from the bladder.

Abstract: A method of applying microwave energy to cardiac tissue uses a catheter adapted for insertion into a cardiac chamber and which includes a microwave antenna, a cooling lumen structure, and an inflatable cooling balloon. Necrosing levels of microwave energy are delivered from the microwave antenna to diseased cardiac tissue spaced from the catheter. Tissues immediately surrounding the catheter are cooled and microwave energy emitted by the antenna is selectively absorbed by the cooling lumen structure surrounding the antenna. The cooling balloon of the catheter is positioned adjacent the antenna and partially surrounds the cooling lumen structure on one side of the catheter to provide additional cooling capability and additional microwave energy absorption on the side of the catheter opposite the diseased cardiac tissue to prevent unwanted heating of blood within the cardiac chamber.

Abstract: A method for treating an individual with diseased prostatic tissue, such as benign prostatic hyperplasia, includes inserting a catheter into a urethra to position a microwave antenna located within the catheter adjacent a prostatic region of the urethra. A microwave antenna is then driven within a power range for applying microwave energy substantially continuously to prostatic tissue to heat the prostatic tissue surrounding the microwave antenna at a temperature and for a time period sufficient to cause necrosis of the prostatic tissue.

Abstract: An intraurethral catheter includes an microwave antenna and a cooling lumen structure substantially surrounding the antenna. A cooling balloon partially surrounds the cooling lumens on one side of the catheter adjacent the microwave antenna. The cooling balloon improves wall contact between the catheter and a wall of the urethra to improve cooling of the urethra. The cooling balloon communicates with the cooling lumen structure to permit circulation of cooling fluid through the cooling balloon.

Abstract: A method of selectively treating interstitial tissue following microwave thermal therapy includes an intraurethral Foley-type catheter shaft. The catheter shaft contains a microwave antenna which is capable of generating a cylindrically symmetrical thermal pattern in tissue, within which temperatures are capable of exceeding 45.degree. C. The antenna is surrounded by means within the shaft for asymmetrically absorbing electromagnetic energy emitted by the antenna so as to concentrate thermal energy on a first side of the shaft. This asymmetrical absorption alters the thermal pattern generated by the microwave antenna, making it possible to focus microwave thermal therapy toward undesirous tissue and away from healthy tissue. The absorption means is also capable of absorbing heat from adjacent tissue by thermal conduction. Operation of the absorption means upon the conclusion of microwave thermal therapy aids in reducing edema of the treated tissues caused by the elevated temperatures of those tissues.