Vasectomy risks and benefits

Once you’ve made up your mind that you never want to have any more children, a very reliable form of contraception is a vasectomy. However, one precaution: to reduce the risk of your vasectomy failing, make sure the doctor who does yours is qualified and has a lot of experience.

When done correctly by an experienced doctor, as few as one in 2,000 vasectomies fail to do their job - preventing you from ejaculating sperm when you have an orgasm, thus preventing pregnancy.

How it works

To understand how a vasectomy works, you need to understand a bit of your own anatomy. Sperm are made in your testes and stored in an adjacent sac, called the epididymis. From there they travel, whipping their tails, through a 38 cm tube called the vas deferens. Inside your abdomen, the vas connects with the semen-producing prostate gland and seminal vesicles adjacent to the bladder.

This is the launching pad for the male contribution to reproduction. If the sperm don’t get to the pad, there’s still blast-off but it’s the unmanned version - no sperm astronauts to couple with the ova in her space.

To perform a vasectomy, the surgeon first kneads the scrotum until he can feel the vas deferens, a process something like a man trying to find the tie-string after it has retracted into the waistband of his tracksuit trousers. After finding it, the doctor pokes a hole (the best surgeons use a needle rather than a scalpel) in the scrotum and uses tiny clamps to pull out a short length of vas deferens.

Vasectomy technique

Surgeons have used a variety of techniques to cut, inactivate and close the two ends of the vas deferens. One technique is called “intraluminal cauterisation with fascial interposition”.  With this technique, the surgeon slices the vas deferens in two and scars the inside - or lumina - of one tube with a heated needle. Then the surgeon pulls up the fascia - tissue surrounding the tube - and clamps or sutures it over the tube end.

Sewing up the tube prevents “recanalisation”, which can occur when microscopic channels grow between the severed ends of the vas deferens. When that happens, sperm can find their way through these micro-channels and into the semen.

One review of 14,000 men who’d had various types of vasectomy reported six conceptions among their partners, but as many as 10% of men in some surveys have significant amounts of sperm in their semen a few months after a vasectomy.

Dr Michel Labrecque, a professor of family medicine at Laval University in Quebec and one of the world’s authorities on the procedure, recalls that earlier in his career, when he clipped each end of the vas and did not cauterise it, up to one in 300 of his patients got their partners pregnant.

“With the technique I’m using now, it went down to one in 7,000,” he says. “I redo one vasectomy per year at the most. With interposition, you are putting tissues between the two cut ends, so it’s like a double zip lock.”

“Ultimately, the experience of the surgeon performing the vasectomy is the most important factor in achieving success with minimal complications,” says Ninaad Awsare, a urology researcher in the UK.