VASCULAR SYSTEM TREATING METHOD AND APPARATUS

摘要

This invention is an apparatus and method for delivering a treating element (22), such as a radiation source, through a catheter (60) to a desired site in a vascular system of a patient, such as a coronary artery, for inhibiting the formation of scar tissue such as may occur in restenosis following balloon angioplasty. The apparatus includes an elongate flexible catheter tube (20) having proximal and distal portions, with a lumen (202) extending therebetween, and a diameter sufficiently small for insertion into the patient's vascular system. One or more treating elements (22), such as a capsule or pellet containing radioactive material, is positionable within the lumen and movable between the proximal and distal end portions under the force of a liquid flowing through the lumen. The catheter comprises a first elongated tube having a lumen sized to slidingly receive the treating element, and a second elongated tube coaxial with and spaced apart from the first elongated tube, the second elongated tube extending beyond the distal end of the first elongated tube and having a barrier located in the second tube beyond the end of the first tube to close the second tube and block further distal movement of the treating element, the space between the first elongated tube and the second elongated tube defining afluid return lumen.