Is the presence of an inguinal hernia enough to justify repair

O'Dwyer and colleagues present the results of a randomized trial evaluating observation as an option for the treatment of inguinal hernia.1 The results of the larger U.S. trial comparing observation to open repair (WW trial) were reported a few months ago.2 Although the trials are similar in design and in results, the conclusions drawn are quite different. The conclusions from the WW trial were: “Watchful waiting is an acceptable option for men with minimally symptomatic inguinal hernias” and “Delaying surgical repair until symptoms increase is safe because acute hernia incarcerations occur rarely.” O'Dwyer and coinvestigators conclude: “Repair of an asymptomatic inguinal hernia does not affect the rate of long-term chronic pain and may be beneficial of patients in improving overall health and reducing potential serious morbidity.” These conflicting interpretations beg further exploration of the similarities and differences of the 2 trials. Both trials used pain as a primary outcome measure. Both trials also tracked and reported crossover rates. The O'Dwyer trial was limited to men over age 55 with “asymptomatic hernias,” whereas the WW trial enrolled men as young as 18 years with asymptomatic or minimally symptomatic hernias. Although nearly a third of the patients in the WW trial were over age 65, these differences in inclusion criteria resulted in a higher mean age of subjects in the O'Dwyer study (nearly 13 years older than the patients in the WW trial). The higher rate of postoperative cardiovascular complications in the O'Dwyer study could be accounted for by this difference in age. In the O'Dwyer trial, 2 patients (1% overall, both were originally assigned to observation but crossed over to repair) had postoperative cardiovascular complications; whereas in the WW trial, 2 patients (0.1% overall) experienced this type of complication. Both trials found that there was no difference between groups in pain scores (primary outcome measure) at any time. Both trials also found that the groups experienced similar changes in the SF-36, except “change in health” in the O'Dwyer trial, which showed more improvement in the operation group (this specific measure was not used in the WW trial). Importantly, the rate of hernia accident (acute incarceration or strangulation) was very low in both trials (0.3% in WW trial, 1% in O'Dwyer trial). While both trials attempted to enroll patients whose hernias were asymptomatic or minimally symptomatic, the subjects in the O'Dwyer trial had median pain scores at baseline of 2.0 mm in both groups. Interestingly, this is the same value the authors later state was used to indicate pain at rest, despite an inclusion criterion of “no pain at rest.” The patients in the O'Dwyer trial may have been more symptomatic at baseline than originally thought, perhaps accounting for the higher than expected crossover rate. Similarly, in the WW trial, the patients who crossed over to repair had higher pain scores at baseline. In the WW trial, the crossover rate from observation to repair at 2 years was 23% and continued at a rate of 4% per year until the close of the trial at 4.5 years. Twenty percent of the observation patients in the O'Dwyer trial crossed over to repair by 1 year; by 15 months, 26% had received repair. In the WW trial, there did not appear to be a “penalty for delaying repair until the hernia was more symptomatic.” In the O'Dwyer trial, 2 patients experienced significant postoperative cardiovascular morbidity, leading them to conclude that “Repair of an asymptomatic hernia. may be beneficial to patients in improving overall health and reducing potentially serious morbidity.” The authors presume that the serious complications suffered by the 2 patients might have been avoided by operating on the patients at the time they presented, rather than some time later (the trial observation period was 1 year). Unfortunately, their trial was not designed to test that hypothesis. Between these 2 randomized trials, more than 400 men were followed for their asymptomatic or minimally symptomatic hernias. Several conclusions can be drawn when taking the results of these 2 trials together. First, the rate of acute incarceration and strangulation is very low. The risk of this complication should not be the sole indication for repair of the hernia. Second, patients who have pain benefit from repair; however, many patients experience pain after hernia repair; and in some patients, this is new or worse pain than before their operation. Preoperative discussions with patients should include disclosure of this risk. Third, delaying repair appears safe, although major life-threatening complications can occur in any patient undergoing even a simple operation. An alternative conclusion to that of O'Dwyer and colleagues would be that the safest course in a patient with significant comorbidities is not to repair an asymptomatic hernia.