Bladder welding in rats using controlled temperature CO₂ laser system

The promising clinical potential for laser welding of tissues has generated a growing interest in this field. An improved laser welding system was constructed in this work. It was based on IR transmitting AgClBr fibers for laser power delivery and for temperature control. The fiberoptic system was used to transmit CO₂ laser power for tissue heating and for non contact (radiometric) temperature monitoring and control. Bladder opening (cystotomy) was performed in 38 rats and 33 of the animals underwent laser welding. In 5 rats (control group) the bladder wound was closed with one layer continuous 6-0 dexon sutures. The rats were sacrificed on days 2, 10 and 30 for histological study. The temperature control of the upper tissue surface was set at 70 ± 5°C. Bladder closure using laser welding was successful in 31/33 (94%) of the animals. The quality of the weld was examined immediately after the operation, revealing a water tight closure of the bladder wall. The histological examination showed an excellent welding and healing of the tissue. These results demonstrate the potential of temperature controlled CO₂ laser welding.