vasectomy

vasectomy is the operation to sterilize the male by dividing the vas deferens on both sides, and thus to interrupt the passage of sperm.

Vasectomy has been known for some hundred years — the first operation performed specifically for the purpose of sterilization took place in Indiana in 1899. It was initially believed that by suppressing the sperm-making functions of the testes, an increase in the sex hormone could be brought about, producing improvements in physical health and sexual vigour. This led to its practice as a ‘rejuvenation’ operation, known as the ‘Steinach’ operation after the Viennese professor whose laboratory experiments led to this conclusion. The numbers of men who underwent this operation in the hopes of increasing their sexual powers cannot be known, but Kenneth Walker, the British expert in male sexual disorders, believed that ‘uncritical and unprincipled medical men’ widely exploited this belief during the 1920s. He himself was sceptical of its benefit in increasing sexual power, attributing any apparent improvement to suggestion.

As a means of contraception, the operation was also, of course, much easier to perform and less drastic than the equivalent operation on the female. However, in spite of the publicity the operation gained in connection with rejuvenation, for many years it was confused in both the lay and the medical mind with castration. The very legality of such a ‘mutilating operation’ was in question.

It increased in popularity as a method of contraception during the 1960s, particularly for couples who had completed their families and were reluctant for the wife to continue taking the Pill for an indefinite period. Unlike female sterilization, it tends to be the choice of couples who share responsibility for fertility control.

There are currently various different operative techniques but the method that is gaining popularity is the ‘no scalpel’ method invented by Professor Li Shungqiang of Sichuan Reproductive Health Institute, Chengdu, Sichuan, P R China, and worldwide this method is now the most commonly used. It is a very minimal technique using specially designed instruments which enable the vas to be divided through a small puncture wound; the ends are then separated by a bit of tissue. It is interesting to note that Professor Li started life as a neurosurgeon but during the cultural revolution he was redirected to work in family planning. Many lesser men would have become very depressed but he immediately set about devising new operations, culminating in his no scalpel technique. It has now been used on hundreds of thousands of men and probably no other living surgeon has influenced the lives of more men.

A question that is commonly asked is ‘Where do the sperm go after vasectomy?’ The sperm-producing cells are in the seminiferous tubules inside the testicle and sperm exit from the top of the testicle into a softer area, the epididymis. The epididymis to a certain extent acts as a filter, and abnormal sperm and debris associated with cell division are cleared from the ejaculate. After vasectomy the whole sperm production has to be absorbed through the epididymis: an exaggeration of its normal function. Seminal fluid continues to be produced normally by the prostate gland and seminal vesicles.

The effect on subsequent sex-life appears to be beneficial in the majority of cases, in spite of the concern often expressed that it may have a deleterious effect on virility (harking back to the old association with castration) — commonly, increased sexual satisfaction and libido has been reported (perhaps substantiating Steinach, or merely reflecting the release from fear of conception). However, this is more likely to occur when the man has deliberately chosen to undertake vasectomy, unlike the case of the Indian men who were persuaded into vasectomy, in return for portable radios, during a drive to reduce the population problem of the subcontinent.

In recent years there has been some concern about the safety of vasectomy. It has been shown that there is no association between vasectomy and heart attacks or vasectomy and testicular cancer, although there have been worries about both. There is still some concern about the association between vasectomy and prostate cancer, but it seems very likely that this apparent association is because of the introduction of new methods to diagnose prostate cancer, and the way statistics are collected, rather than any cause and effect.

Vasectomy is highly reliable provided that an additional method of contraception is employed during the first weeks following the operation, during which live sperm may still be present in the seminal fluid.

The major disadvantage is that it cannot readily be reversed: even with recent developments in microsurgery, the operation to reunite the severed vasa deferens reopens them in 80–90% of cases, but the success rate in terms of achieving pregnancy is at best only 50%. There have been attempts at temporary, reversible blocking or clipping of the tubes, but so far these have failed to achieve a degree of reliability in any way comparable with the permanent operation.

There is a very small late failure rate (approximately 1 in 2000), but vasectomy remains surer than female sterilization. The only more certain method of contraception is complete abstinence.

Tim Hargreave, and Lesley A. Hall

See also contraception; sterilization.