Combined angioplasty and intravascular radiotherapy method and apparatus

An apparatus for localized intravascular radiotherapy of a blood vessel comprising:

• a catheter, said catheter comprising a flexible elongate member having a proximal end and a distal end, said elongate member being sized and of sufficient flexibility to be introducible into a patient's body through a cardiovascular lumen until the distal end is disposed at a target area within the blood vessel, said elongate member further including a hole extending longitudinally therethrough from substantially the proximal end thereof defining an inflation lumen;
• a balloon having an interior chamber, said balloon being secured to the distal end of said elongate member with said interior chamber in fluid communication with said inflation lumen;
• a containment membrane surrounding said balloon to retain fluid leaking from said balloon in the event of rupture thereof;
• and
• means for introducing a fluid containing a radioactive material into said inflation lumen to fill the interior chamber of said balloon for exposure of said target area to said radioactive material, and for withdrawing said fluid after an effective dose of radiation has been delivered to the blood vessel wall in said target area.

A method of relieving a stenosis and preventing restenosis of a selected portion of a blood vessel in a patient comprising the steps of:

• selecting a catheter comprising a flexible elongate member having a proximal end and a distal end, said catheter including an angioplasty balloon and an intravascular radiotherapy (IRT) treatment balloon secured to said distal end, said IRT treatment balloon comprising an inflatable balloon substantially surrounding said angioplasty balloon, said catheter being sized and of sufficient flexibility for introduction into the selected portion of the blood vessel;
• advancing said catheter along a cardiovascular lumen of the patient until said IRT treatment balloon is disposed in the selected portion of the blood vessel;
• inflating said angioplasty balloon through a first lumen in said catheter having an opening adjacent the proximal end thereof and communicating with said angioplasty balloon, sufficiently to relieve a stenosed region of said blood vessel;
• at least partially deflating said angioplasty balloon through said first lumen in the catheter after relieving said stenosed region;
• inflating said IRT treatment balloon with a liquid containing a radioactive material through a second lumen in said catheter having an opening adjacent the proximal end thereof and communicating with said IRT treatment balloon;
• maintaining said IRT treatment balloon inflated with said liquid for a predetermined period of time sufficient to deliver an effective dose of radiation to the blood vessel wall in the selected portion of the blood vessel;
• withdrawing said liquid from said IRT treatment balloon through said second lumen in the catheter immediately after said predetermined period of time has elapsed to allow said IRT treatment balloon to collapse, and substantially fully deflating said angioplasty balloon if only partially deflated previously;
• and
• withdrawing said catheter from the patient.

A method of relieving a stenosis and preventing restenosis of a selected portion of a blood vessel in a patient comprising:

• selecting a catheter comprising a flexible elongate member having a distal end with a balloon secured adjacent the distal end and a flexible containment membrane surrounding said balloon to prevent leakage through the balloon from entering the blood vessel, said catheter being sized and of sufficient flexibility for introduction into the selected portion of the blood vessel;
• advancing said catheter along a vascular lumen of the patient until said balloon is disposed in the selected portion of the blood vessel;
• inflating said balloon with fluid to compress a stenosed region of the blood vessel wall along said selected portion of said blood vessel;
• withdrawing said fluid from said balloon and, while maintaining the balloon substantially in place along the selected portion of the blood vessel, inflating said balloon with a radioactive liquid;
• maintaining said balloon inflated with said radioactive liquid for a predetermined period of time sufficient to deliver an effective dose of radiation to the blood vessel wall in the selected portion of the blood vessel;
• withdrawing said radioactive liquid from said balloon immediately after said predetermined period of time has elapsed to cease irradiation of the blood vessel wall and to allow said balloon to collapse;
• preventing the radioactive liquid from entering the blood vessel by containing any liquid that leaks through the balloon within the containment membrane;
• and
• thereafter withdrawing said catheter from the patient.