Technical frontiers for the vascular surgeon: laser anastomotic welding and angioscopy-assisted intraluminal instrumentation.

Innovations in therapy for peripheral vascular disease include laser vessel welding and angioscopy-assisted intraluminal laser instrumentation. Vascular tissue fusion by laser occurs at energy levels lower than those required to coagulate or vaporize. CO2, argon, and Nd:YAG (1.06 micron) lasers have all been reported to fuse anastomoses in microvessels, but adequate welding of larger veins and arteries (3 to 8 mm in diameter) has only been accomplished with the argon laser. Laser welds heal comparably to sutured wounds but do not have the chronic foreign body reaction and disorientation of elastin and collagen associated with sutures. Preliminary evidence suggests that argon laser-welded anastomoses have less intimal hyperplasia than sutured anastomoses. Laser welding may also be a useful adjunct for sealing intimal flaps during endarterectomy. Additional work is needed to determine the mechanism, optimal parameters, and wavelengths required for vascular tissue fusion by laser. Direct application of laser light intraluminally has thus far been associated with a high incidence of vessel perforation. Angioscopy-assisted delivery of a metal hot-tip probe shows promise for angioplasty of occluded medium-sized arteries and for valvulotomy in in situ vein bypasses.