LASER VASCULAR ANASTOMOSIS - PRELIMINARY EVALUATION OF A NEW ANASTOMOTIC TECHNIQUE

Laser vascular anastomosis (laser welding) is a developing technique that employs the thermal effect of laser energy to achieve fusion of apposed vessel edges. The authors have attempted to establish a definitive technique by an investigation of the physical properties of laser welds. Porcine coronary arteriotomies were repaired in vitro by two different laser wavelengths (Argon [488/514 nm] and Nd:YAG [1064 nm]) and by use of chromophore dyes to enhance energy absorption at the anastomosis. Anastomatic bursting strength was measured directly by means of saline infusion and vessel constriction (caused by diffusion of heat from the weld) assessed by a constant-pressure flow rate model. Histologic techniques were also employed to estimate the degree of thermal damage to the vessel. In all these respects optimal results were obtained by the Argon laser and use of the chromophore Basic Fuchsin. These repairs all burst at greater than 200 mmHg and were minimally constricted. Thermal tissue damage was accurately confined to the anastomotic site. This technique will, therefore, be employed in future studies.