The vulnerability of the vas deferens.

Transection of the vas deferens is considered a disaster, but other manipulations may have unpredictable and hitherto undocumented effects. In order to delineate the structural changes in the vas deferens after operative manipulation, 40 Wistar rats (300-500 g) were divided into four groups and subjected to four different operative manipulations (grasping with fingers, nontoothed Adson forceps, bulldog vascular clamp, clamping with "mosquito" hemostat). Histologic studies performed at 6 wk postmanipulation demonstrated a variable intra- and transmural inflammatory reaction in all groups. Thirty percent of the specimens grasped by the forceps showed disruption of the muscle wall. One-hundred percent of the specimens clamped by the hemostat showed mural disruption and marked inflammatory reaction; in addition 30% had an associated abscess. Therefore all manipulation of the vas deferens should be minimized to avoid triggering inflammation and secondary obstruction. Grasping with a nontoothed forceps results in appreciable damage. Clamping with a hemostat is as serious as complete transection.