Vasectomy (Image 4 of 11). Surgeon pulling a loop of the vas deferens through a cut in the scrotum during a vasectomy, the male sterilization operation. The surgeon is using forceps. In a vasectomy, the vas deferentia, the two ducts that carry sperm from either testis into the penis' urethral duct, are partly pulled through incisions and cut. The cut ends are then tightly closed with ligatures before they are replaced. This stops sperm from being ejected at ejaculation, providing a method of contraception that is nearly 100% efficient. The whole procedure takes about 20 minutes under local anaesthetic. This sequence runs from image M860/193-203.