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
Introduction:
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).
Methods:
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.
Results:
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).
Conclusion:
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.