In vivo CO₂ laser rat urinary bladder welding with silver halide fiberoptic radiometric temperature control

Laser welding has been used for connecting various tissues in the body. In urology such welding has the advantage of forming an immediate watertight seal. We have developed a fiberoptic system that makes it possible to monitor and control the temperature of the tissue during welding. In previous work we demonstrated that this system could be successfully used to weld punctures in the urinary bladder of rats. It was found that optimal welding was obtained at a temperature of 55°C. In this work we used the same system for welding of large openings (cystotomy) in the urinary bladder of rats. In early experiments we used stay sutures and decompressing catheters. It was later found that complete closure can be obtained with CO₂ laser welding alone. This work demonstrates the feasibility of using temperature-controlled laser welding as an efficient surgical tool.