Appendix interposition in the treatment of severe posterior urethral injuries.

The aim of this study was to investigate the applicability of the Mitrofanoff principle in the treatment of severe posterior urethral injuries and determine the feasibility of this technique with its early and late postoperative results. A total of 27 New Zealand rabbits (12 male and 15 female) was used (mean weight 2,272 +/- 343 gm.). Using general anesthesia the proximal part of the posterior urethra was transected completely and a 1 cm. segment was excised. A 2 cm. segment of appendix with its intact vascular pedicle was meticulously mobilized and anastomosed to the proximal and distal site of the urethra. Excretory urograms, voiding cystourethrograms, urodynamic investigation and histopathological examination were performed postoperatively. The fertility of the male rabbits was examined in the late postoperative period as well. These results were compared with those of a control group. There was no problem concerning voiding patterns in the pedicled appendiceal flap group. Excretory urograms revealed a properly functioning urinary system. Voiding cystourethrograms showed a normal bladder capacity and voiding pattern, and an intact urethra. Urodynamic analysis was within normal limits except for a decrease in bladder volume. An intact urethral lumen without any strictures or fibrosis was demonstrated histopathologically. No calculus, mucus formation or urinary tract infection was observed in the late postoperative period. Fertility problems were noted in male rabbits. This animal experiment suggested that the pedicled appendiceal flap technique could be used for the treatment of severe forms of posterior urethral injuries.