Sutureless microvascular anastomosis using the THC:YAG laser: A preliminary report

Laser anastomosis of the rat carotid artery was performed using a new midinfrared laser, the pulsed thulium‐holmium‐chromium:YAG (THC:YAG) laser (2.15 μm). Solid silicone stents made stay sutures unnecessary for coaptation of vessel edges during laser bonding. Grossly, the laser anastomoses displayed minimal thermal distortion of the vessel contour and no tissue carbonization. Of the 30 anastomoses performed, 27 were patent and 3 had separation of the weld shortly after the approximator clamp was released. Mean anastomotic time was 4 min 48 sec. Mean bursting pressure for the 9 vessels tested was 400 mm Hg. Thrombosis did not occur at any time during our examination of these anastomoses. Fusion of collagen fibers in the media was confirmed histologically. Unlike the CO2 laser, the THC:YAG is transmissible through flexible silica fibers, which greatly facilitates delivery of the laser in a microsurgical operative field. The THC:YAG provides shallower absorption depth than Nd:YAG and argon lasers but somewhat deeper tissue penetration than CO2. For microvessels, this intermediate absorption results in full‐thickness fusion of the media, with minimal thermal damage to vascular tissue adjacent to the anastomosis.