Development of a potentially reversible vas deferens occlusion device and evaluation in primates

A vas deferens occlusion device has been developed and tested in primates. The device consists of two silicone plugs held together by a nylon suture. Implantation of each plug is readily accomplished by making two small puncture holes in the vas deferens and inserting one plug into the lumen toward the epididymis and the other plug toward the seminal vesicles. Implantation is aided by a metal stylus inserted in each plug to give the plug rigidity. The stylus is removed after insertion of the plug into the vas deferens. Two separate primate experiments showed that the device completely prevents sperm transport over a 7-month period. Upon device removal, all of the primates ejaculated spermatozoa again at normal concentrations and motility. These results indicate the potential contraceptive use of the device and encourage its validation in men.