Chronic occlusion of the rabbit Fallopian tube with silicone polymer

Investigators have previously reported good retention, antifertility efficacy, and good retrievability with no adverse tissue reactions in rabbit oviducts occluded with silicone rubber for 55 days. The present study attempts to determine the long-term effects of this silicone polymer system installed into the oviducts of 12 New Zealand White rabbits for 7 months. 9 rabbits had both oviducts occluded while 3 had only one oviduct treated. All animals were visualized by X-rays and were mated an average of six times over the experimental period. Oviduct tissue was examined with light and scanning electron microscopy. There was no evidence of inflammation, distortion, or tissue irritation. Good retention and antifertility efficacy were exhibited.