03.08 Does 3 Nerve Identification and Preservation Reduce Pain during Open Inguinal Hernia Repair?

E. George1, M. A. Olson2, S. Renshaw1, B. Poulose1  1The Ohio State University Wexner Medical Center, Department Of Surgery, Columbus, OHIO, USA 2Weill Cornell Medical College, Department Of Population Health Sciences, New York, NY, USA

The rates of chronic groin pain (CGP) after open inguinal hernia repair are reported between 18-51%. Previous literature has implicated nerve damage to be a significant factor and has increased awareness of proper nerve identification. However, the relative contribution of nerve management to CGP continues to emerge. Recent guidelines emphasize three-nerve recognition and handling (particularly iliohypogastric, ilioinguinal and genital branches of genitofemoral nerves) to minimize CGP. We sought to identify whether a strategy of three nerve identification (3N) and preservation results in decreased pain 6 months after open anterior inguinal hernia repair compared to two common strategies of nerve management: ilioinguinal nerve identification alone (1N) or two nerve identification (2N).

We identified adult patients undergoing elective open anterior repair of unilateral inguinal hernias within the Abdominal Core Health Quality Collaborative (ACHQC). Six-month postoperative pain was defined using the pain domain of the EuraHS Quality of Life tool (range 0-30 with higher values indicating higher pain). A proportional odds model was used to estimate odds ratios and expected mean differences in 6 month pain for nerve management while adjusting for the logit of propensity score, baseline EuraHS pain score, and baseline confounders identified a-priori.

Between 2017-2021, 4451 patients were identified (358 (3N), 1731 (1N) and 2362 (2N) consisting mostly of White Non-Hispanic males (84%) over the age of 60, followed by African American males (8%) for both 3N and 1N groups and Hispanic males (9%) for 2N. The mean body mass index for each group was 26kg/m2. Academic centers identified all three nerves more often than ilioinguinal or two nerve identification methods. Median 6-month postoperative pain scores were 0 [IQR 0-2] for all nerve management groups (p = 0.51 3N vs 1N and 3N vs 2N). There was no evidence of a difference in the odds of higher 6 month pain scores in nerve management methods after adjustment (3N vs 1N OR: 0.95; 95% CI 0.36-1.95, 3N vs 2N OR: 1.00; 95% CI 0.50-1.85).

While guidelines emphasize three nerve identification and preservation, the three nerve management strategies evaluated did not result in statistically significant differences in pain 6 months after operation. These findings suggest that nerve manipulation alone may not contribute as significant a role in CGP after open inguinal hernia repair compared to other factors.