An absorbable artificial vas deferens for vasovasotomy

An absorbable artificial vas deferens is being developed in order to improve the relativley poor conception rates of vasovasotomy. The capillary device which is 0.4 mm I.D. by 0.7 mm O.D. and 15 mm long vas made from 3 absorbable polymers: starch, collagen, and a copolyester of lactide and glycolide. Preliminary evaluation of the device was made by implantation in the guinea pig was deferens immediately following vasectomy. Absorption of the starch and the copolyester occurred within 2-4 wks after implantation, whereas collagen required 3 mos and sometimes longer. Gross and histological examination showed little or no adverse effect on the tissues of the vas deferens, epididymes and testes. Active spermatogenesis continued in most cases and sperm count and motility remained essentially unchanged. Breeding studies with males implanted with the device for 5 mos have resulted in 12/13 prrgnancies with starch, 19/19 pregnancies with the copolyester and 9/11 pregnancies with collagen.