Vasectomy part 2: What is Vasectomy: What is a vasectomy? Vasectomy is surgery a man may choose to have if he does not want to father any more children. It is lasting (permanent) male birth control. During the surgery, 2 tubes called the vas deferens are cut and sealed. The vas deferens carry sperm from testicles to the urethra. The urethra is the tube inside the penis. Once they are cut, sperm can't get into the semen or out of the body. The testes still make sperm, but the sperm die and are ab