Prevention of vesicovaginal fistulas after laparoscopic hysterectomy with electrosurgical cystotomy in female mongrel dogs

Objective Using a previously described animal model, we sought to compare 3 methods of double-layer cystotomy repair to each other and to single-layer repair in the prevention of vesicovaginal fistula formation. Study design Twenty-four female mongrels, which were divided into 3 groups, underwent laparoscopic hysterectomy followed by monopolar electrosurgical cystotomy. Group 1 had simple 2-layer cystotomy repair with interrupted 2-0 polyglactin sutures; group 2 had resection of tissue 5 mm beyond the visible electrosurgical burn margin followed by 2-layer closure, and group 3 had interposition of an omental flap after 2-layer closure. Animals were killed at least 27 days after the operation, and a careful evaluation for vesicovaginal fistulas was undertaken by retrograde bladder filling. Group results were compared with one another and to a historic control group of 8 dogs that had undergone cystotomy repair with single-layer closure. Results All groups were similar in preoperative and necropsy weight. Bladder perforation occurred in 1 dog in group 1 on postoperative day 3; necropsy revealed perforation in the area of electrosurgical thermal spread with intact sutures. No vesicovaginal fistulas were noted in any of the study dogs (0/23 dogs; 95% CI, 0-12.7%) compared with 2 of 8 dogs (25%) that underwent single-layer closure (95% CI, 0-55%; P = .06). Conclusion Double-layer repair appears to be superior to single-layer repair for the prevention of vesicovaginal fistulas after monopolar cystotomy. The benefit of electrosurgical burn margin excision or omental flap interposition remains unclear, but both are accomplished easily with little risk and may play a role in fistula prevention