EFFECT OF PREOPERATIVE HUMAN CHORIONIC-GONADOTROPIN ON INTRAABDOMINALRAT TESTES UNDERGOING STANDARD AND FOWLER-STEPHENS ORCHIOPEXY

Purpose: We attempted to determine whether preoperative human chorioni c gonadotropin (HCG) improves fertility in intra-abdominal rat testes subjected to orchiopexy. Materials and Methods: Newborn male Sprague-D awley rats were made cryptorchid by bilateral gubernaculum excision at age 14 days. Select rats served as controls and underwent sham operat ions. Half of the animals were injected with 10 international units HC G daily from days 14 to 28. On day 28 the animals were divided into gr oup 1-6 that underwent sham operation with or without HCG, group 2-6 w ith cryptorchidism with or without HCG, group 3-22 that underwent stan dard orchiopexy with or without HCG and group 4-22 that underwent Fowl er-Stephens orchiopexy with or without HCG. Contralateral orchiectomy was performed simultaneously. On day 65 each male rat was mated with 2 female rats for 3 ovulatory cycles. Results: Mean testicular weight w as markedly decreased in cryptorchid compared to sham operated testes (87.2 versus 344 mg./100 gm. body weight). Mean testicular weight was similar after standard and Fowler-Stephens orchiopexy. HCG enhanced me an testicular weight after sham operation, standard orchiopexy and Fow ler-Stephens orchiopexy (403 versus 344, 193 versus 176 and 194 versus 175 mg./100 gm. body weight, respectively) but these differences were not statistically significant. Fertility was present in all 6 sham op erated, 0 of the 6 cryptorchid, 1 of the 11 standard orchiopexy and 1 of the 8 Fowler-Stephens orchiopexy rats. Of the HCG treated animals 2 of the 8 that underwent Fowler-Stephens orchiopexy and 1 of the 8 tha t underwent standard orchiopexy were fertile. Mean weight of the teste s associated with pregnancy was significantly greater than those not a ssociated with pregnancy (p < 0.001). Conclusions: The intra-abdominal rat testis has limited fertility potential after orchiopexy that is n ot improved with preoperative HCG. After orchiopexy fertility correlat es closely with testicular weight.