Non-union of testis and epididymis. Description of an experimental model in the rat. Effect on testicular descent.

Most of the reported anomalies in undescended male gonads involve disruption of continuity in the proximal reproductive tract. In order to study the effect of this anomaly on the testis, an experimental model was developed. 16-day-old Sprague-Dawley rats were operated on. The testes were mobilized through a midline abdominal incision and further dissection was carried out under an operation microscope with 20X magnification. The efferent ducts were dissected free, clamped with a microclip, severed and ligated. The epididymis and testis were separated to the level of the inferior epididymal artery. Following surgery 11 of 35 operated testes (31%) remained in the abdomen while three (9%) descended into the opposite hemiscrotum. One of these atrophied due to torsion. The rest descended normally as did all in the sham-operated group. No surgical complications were seen. At 30-37 days the non-union operated testes were edematous, but no tubular distension was seen. The operative procedure probably involves ligation of lymphatic vessels from the testis as well as ductuli efferentes causing an interstitial edema.