Methods of repair and risk for reoperation in Swedish hernia surgery from 1992 to 1996

Difficulties in obtaining and analysing outcome measures in hernia surgery may be an obstacle to necessary progress in non-specialized hospitals. Against this background a voluntary register was initiated in 1992 with the aim of describing and evaluating hernia surgery in participating units.

Prospective registration of all hernia operations carried out in participating hospitals was undertaken using identification codes specific for each individual. Repair technique, complications, day surgery, type of anaesthesia, and reoperation for recurrence were recorded. Actuarial analysis was used to determine the cumulative incidence of reoperation. Relative risk for reoperation was estimated by the Cox proportional hazards model.

The number of participating hospitals and registered operations increased from eight and 1689 respectively in 1992 to 21 and 4056 in 1996. The use of mesh increased from 7 per cent of all operations in 1992 to 51 per cent in 1996. The proportion of operations done for recurrent hernia remained constant at 16-17 per cent throughout the 5-year study period. For all 12542 herniorrhaphies registered, the cumulative incidence of reoperation at 2 years was 3 (95 per cent confidence interval 3-4) per cent. Postoperative complications, recurrent hernia, direct hernia and absorbable suture were associated with increased risk of reoperation for recurrence. An increased incidence of reoperation, although not statistically significant, was noted for conventional open repairs (Bassini, McVay, Marcy and others) versus the Shouldice technique.

In this prospective audit an increasing use of mesh was observed for open and laparoscopic surgery, especially for bilateral and recurrent hernia operations. Reoperation rates decreased significantly between 1992 and 1995.