Laser-assisted demucosalized gastrocystoplasty with autoaugmentation in a canine model

Objectives. Laser-assisted autoaugmentation gastrocystoplasty has been performed successfully. Experiments were performed to determine the optimal laser for tissue welding during demucosalized autoaugmentation gastrocystoplasty using both a 1.9-μm diode and a 1.32-μm neodymium:yttrium-aluminum-garnet (Nd:YAG) laser with and without thermal control. Methods. Autoaugmentation gastrocystoplasty was performed on 18 female mongrel dogs. Anastomoses were performed by either suture or laser welding with a 50% human albumin solution. A 1.9-μm diode laser was compared with a 1.32-μm Nd:YAG laser with and without thermal control. In vivo canine bladder capacity measurements were performed both before gastrocystoplasty and at euthanasia. The animals were studied on days 4 and 14. Samples of the anastomotic area from each group were taken to measure tensile strength. Histologic samples were assessed for tissue damage. Results. There was a significant increase in bladder volume in the 4-day group compared with pregastrocystoplasty values. Both the 1.9-μm diode laser and suture control dogs with the 14-day repairs had significantly more tensile strength than their 4-day counterparts. In contrast, no statistical difference was found between the 4 and 14-day 1.32-μm Nd:YAG groups. The suture control group had evidence of minor tissue devitalization at the anastomosis at both 4 and 14 days. The 1.9 and 1.32-μm laser groups both had evidence of tissue devitalization at 4 and 14 days. The 1.32-μm laser group had primarily severe tissue injury. The laser groups at 14 days demonstrated an inflammatory reaction that was localized to the albumin. Conclusions. Demucosalized gastrocystoplasty with autoaugmentation can be safely and successfully performed with a 1.9-μm diode laser without significant differences in tensile strength when compared with suture controls. The 1.32-μm Nd:YAG laser can also be successfully used; however, the long-term results appear to be inferior to the 1.9-μm diode laser.