Groin hernia surgery: a systematic review

An extensive volume of clinical research has been undertaken on the use of surgery for groin hernias. For many years there has been a large number of different methods of repairing hernias and, with the introduction of laparoscopic surgery, this has increased further. It is uncertain which method is the best in terms of safety and effectiveness.

This review was undertaken to compare the outcomes following different surgical procedures to treat groin hernias in adults. It sought answers to six questions: 1)Which method of surgery (including open procedures and laparoscopic surgery) is the safest and most effective for inguinal hernia repair? 2) Is local anaesthesia a safe and effective alternative to general anaesthesia? 3) Is there a difference in outcome between specialist and non-specialist surgeons? 4) Is day-case as safe and effective as inpatient surgery? 5) Is synchronous bilateral hernia repair as safe and effective as delayed repair? 6) Which method of surgery is the safest and most effective for femoral hernia repair?

The primary measure of effectiveness used was the proportion of hernia repairs in which there was a recurrence. Secondary outcome measures included complications, post-operative pain, wound infection, time to return to normal activities and/or return to work. A systematic search of the literature (up to February 1996) was undertaken using a variety of approaches. the methodological quality of all prospective comparative studies (45 randomised trials and 26 non-randomised trials/prospective cohort studies) was assessed using a standard checklist.

Some of the variation in findings from different studies is likely to be due to methodological differences rather than differences in the effectiveness of the surgical procedures. The main methodological shortcomings of the studies that have been performed are: lack of agreed method for assessing severity of hernias; failure to take confounding into account in non-randomised studies; variation in length of follow-up; poor external validity; lack of objective measures of outcome; and inadequate statistical power. These problems severely limit the conclusions that can be drawn from the literature.