Laser assisted vascular welding with real time temperature control

Background and Objective Previous studies in laser assisted vascular welding have been limited by the lack of a reliable end point for tissue fusion. As a means of improving the reproductibility of laser assisted repairs, a system incorporating real time temperature monitoring and closed loop feedback was used. Study Design/Materials and Methods The system consisted of a direct view infrared thermometer for monitoring the laser heated spot, a 1.9 μm diode laser, and a microprocessor for data acquisition and feedback control of the laser power to maintain a constant tissue temperature. Rat aortas were welded under constant surface temperature conditions. Results In vivo temperature stability of ±2°C was achieved over a temperature range of 70–90°C pertinent to welding small vessels. When welds were completed using the feedback system to maintain the tissue temperature at 80°C, the acute success rate was 100% and the burst pressure was 290 ± 70 mmHg. Conclusion These studies demonstrate that the use of real time monitoring and feedback control results in improved consistency for vascular tissue welding. © 1996 Wiley‐Liss, Inc.