Do postoperative complications correlate to chronic pain following inguinal hernia repair? A prospective cohort study from the Swedish Hernia Register.

Purpose: To analyse if postoperative complications constitute a predictor for the risk of developing long-term groin pain.

Methods: Population-based prospective cohort study of 30,659 patients operated for inguinal hernia 2015-2017 included in the Swedish Hernia Register. Registered post-operative complications were categorised into hematomas, surgical site infections, seromas, urinary tract complications, and acute post-operative pain. A questionnaire enquiring about groin pain was distributed to all patients 1 year after surgery. Multivariable logistic regression analysis was used to find any association between postoperative complications and reported level of pain 1 year after surgery.

Results: The response rate was 64.5%. In total 19,773 eligible participants responded to the questionnaire, whereof 73.4% had undergone open anterior mesh repair and 26.6% had undergone endo-laparoscopic mesh repair. Registered postoperative complications were: 750 hematomas (2.3%), 516 surgical site infections (1.6%), 395 seromas (1.2%), 1216 urinary tract complications (3.7%), and 520 hernia repairs with acute post-operative pain (1.6%). Among patients who had undergone open anterior mesh repair, an association between persistent pain and hematomas (OR 2.03, CI 1.30-3.18), surgical site infections (OR 2.18, CI 1.27-3.73) and acute post-operative pain (OR 7.46, CI 4.02-13.87) was seen. Analysis of patients with endo-laparoscopic repair showed an association between persistent pain and acute post-operative pain (OR 9.35, CI 3.18-27.48).

Conclusion: Acute postoperative pain was a strong predictor for persistent pain following both open anterior and endo-laparoscopic hernia repair. Surgical site infection and hematoma were predictors for persistent pain following open anterior hernia repair, although the rate of reported postoperative complications was low.