Laser-induced thermal occlusion of berry aneurysms: initial experimental results.

An intravascular laser-catheter technique was used to occlude 12 experimental berry aneurysms, ranging in size from 4 X 3 mm to 8 X 6 mm (length X width), while the patency of adjacent arteries was preserved. A small steel cap on the end of an optical fiber was fluoroscopically positioned within the aneurysm. The cap was rapidly heated by the optical transmission of laser energy. This produced a thermal tissue reaction within the aneurysm, resulting in its occlusion. After treatment, the steel cap was detached atraumatically from the fiber and left as a permanent implant within the occluded aneurysm. This method has an advantage over the use of a bare-ended intravascular optical fiber because the steel cap provides a uniform distribution of thermal energy, thereby reducing the risk of unexpected perforation during treatment. The radiologic and histologic results of using this laser-catheter system were evaluated 1-21 weeks after treatment.