Risk factors for chronic pain after inguinal hernia repair

INTRODUCTION Chronic postoperative pain after inguinal hernia repair has an incidence of 0.7-36.7%. This study aimed to look for any relationship between patients presenting with severe pain at initial presentation or a past history of chronic pain conditions and the development of severe chronic pain following inguinal hernia repair. PATIENTS AND METHODS This was a retrospective study in which 24 patients referred to a chronic pain clinic following inguinal hernia repair were compared with 24 age- and sex-matched controls. Hospital notes were reviewed for the severity of presenting pain and a past history of chronic pain. RESULTS Average age was 55.4 years. In the chronic postoperative pain group, 14 (58%) presented with severe pain versus 3 (13%) in the pain-free group. Twelve (50%) of the chronic postoperative pain group had a past history of chronic pain conditions versus none of the pain-free group. Both of these factors showed a significant (P < 0.005) association with severe chronic pain postoperatively. CONCLUSIONS Patients with severe pain at presentation or with a past history of chronic pain conditions are at increased risk of severe chronic pain after inguinal hernia repair. A prospective study is needed to quantify any increased risk, although this would need to be of significant size.