Abstract
A 20-year-old male chimpanzee (Pan troglodytes) was presented with a history of amputation of the distal 2 cm of the penis by a conspecific 4 years previously. Since this injury, a progressively enlarging swelling of the ventral penis was observed which was approximately 2 cm diameter at the time of presentation. The animal demonstrated progressively more severe dysuria and, by the time of presentation, urination was a slow stream accompanied by prolonged abdominal straining. Endoscopy revealed a urethral diverticulum, and this was opened by transurethral “unroofing” which was performed using a human pediatric resectoscope.1 Unfortunately, postoperative infection of the surgery site caused extensive necrosis. Subsequent loss of the majority of the penis occurred and a perineal urethrostomy was required to allow urination.
Perineal urethrostomy was achieved using the procedure described for humans following total penectomy,2 although compared with human surgery, a relatively longer length of urethra was required to pass through the deep layer of subcutaneous fibrofatty tissue of the chimpanzee perineum. Recovery was uneventful and despite some narrowing of the meatus, no further treatment was required for the following 18 months. At this time, stenosis caused an apparently acute onset urethral obstruction that was successfully managed by atraumatic dilatation using a fine bougie (filliform) and connecting progressively wider bougies (followers, and van-Buran sounds). Obstruction due to insertion of a piece of straw into the meatus was observed after 24 months and suspected on several subsequent occasions. The development of polyp-like outgrowths of the distal urethra caused obstruction after 26 months.
Re-examination using endoscopy and dilatation are currently performed every 3–6 months. To the authors’ knowledge, neither a urethral diverticulum nor perineal urethrostomy have been reported previously in a nonhuman primate.
LITERATURE CITED
1. Fåhræus, B. 1991. Diverticula of the male anterior urethra: symptoms, diagnosis and treatment. Scand. J. Urol. Nephrol. Suppl. 138: 221–225.
2. Donat, S.M., P.J. Cozzi, and H.W. Herr. 2002. Surgery of penile and urethral carcinoma. In: Welsh, P.C. (ed.). Campbell’s Urology, 3rd ed., Saunders, Philadelphia, Pennsylvania. Pp. 2985–2986.