In a review article about current practices in hernia surgery, Volker Schumpelick of The Department of Surgery at the Rhenish-Westphalian Technical University in Germany, the author of a book on hernia operations, and his colleagues point out that the person who developed mesh repair in Europe limits his technique to patients above 50, because of the "unknown long-term fate and side effects of the implanted mesh material (The Lancet, 6 August 1994).

"Indeed, almost nothing is known about the biological compatibility of these materials in the very long term. . . . Since the average life expectancy of patients with hernia repair is more than 20 years, this potential hazard must be considered," they wrote. Schumpelick only recommends mesh when groin ligaments are unusually weak.

The general consensus among doctors is that hernias in all cases requires surgical repair (other than those patients who are terminally ill or very old and frail).

Most people aren't given the truth about leaving well alone, the dangers of which, in some instances, are vastly overplayed with little scientific evidence. To attempt to quantify this risk, a group of surgeons at the University College and Middlesex School of Medicine in London calculated the cumulative probability of strangulation for all hernia cases at their hospital between 1987-89.

The risk of strangulation for groin hernia was 2.8 per cent after three months, rising to 4.5 per cent after two years. However, for femoral hernias, the likelihood of strangulation was 22 per cent at three months, rising to 45 per cent after 21 months.

The probability rate increased fastest during the first three months, suggesting that if you have a new hernia you are at higher risk than someone who has been carrying one around for years (Br J Surg, 78; (10): 1171-3). Schumpelick and his group say that direct hernias particularly broad direct bulges are 10 times less likely to strangulate than indirect hernias.

Doctors also underplay the risks of hernia surgery particularly of repeat operations. Usually the risk of dying from the operation is under 0.01 per cent in elective surgery. This risk rises to 5 per cent in emergency cases and among elderly patients. Other complications include injuries to the nerves and vessels of the spermatic cord, leading to the trapping of a nerve and long-term pain on the upper side and groin and even the back. Another worry is orchitis painful swelling of the testis which in 40 per cent of cases can lead to testicular atrophy.

This complication is rare in first time cases (0.03-0.5 per cent), but

increases by 10 times in recurrent hernia operations (The Lancet, 6 August 1994).

One study showed this complication could be minimized by leaving all

hernia sacs intact, not cutting beyond the tubercle (bulge) of the pelvic bone and using the intra-abdominal wall approach for recurring hernias (Surg Gyn Obstet 1992; 174: 399-402).

!AClive Couldwell

Clive Couldwell frequently writes for the London Times and the Telegraph.