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Abstract

Apparatus and methods are provided for relieving a stenosed region of a blood vessel such as a coronary using a single catheter that relieves the angioplasty by conventional means and then delivers an easily controllable inherently uniform dosage of radiation to the walls of a blood vessel for preventing restenosis after angioplasty. An embodiment of the apparatus comprises a catheter having an angioplasty balloon that is inflatable with a liquid containing a suspended radioactive material such as .sup.125 I or .sup.32 P. The balloon is surrounded by a membrane to capture the radioactive liquid in the event the balloon ruptures. The catheter is advanced through the patient until the balloon is disposed in the stenosed region of the blood vessel. The stenosed region is relieved using the angioplasty balloon, after which the angioplasty balloon is emptied and re-filled with the radioactive liquid, which expands the balloon to engage the walls of the blood vessel thereby providing an inherently uniform dosage of radiation to the blood vessel walls. Another embodiment of the apparatus comprises a catheter having an angioplasty balloon surrounded by a radiotherapy treatment balloon that is separately inflatable with a radioactive liquid. The stenosed region is relieved using the inner angioplasty balloon after which the radiotherapy treatment balloon is filled with the radioactive liquid. An additional containment balloon outside the radiotherapy treatment balloon may also be provided to prevent loss of radioactive liquid in the event the treatment balloon ruptures. The angioplasty balloon may be partly filled during the radiation treatment to minimize the volume of radioactive liquid necessary to achieve the desired dosage.

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First Claim