Comparison of surgical outcomes between laparoscopic percutaneous extracorporeal closure (LPEC) and open repair for pediatric inguinal hernia by propensity score methods and log-rank test analysis

Background Despite a number of studies comparing laparoscopic inguinal hernia repair (LH) and open herniorrhaphy (OH), the putative advantage of LH remains controversial due to a paucity of firm evidence. We hypothesized that LH has both advantages and disadvantages compared to OH and sought to clarify them by comprehensively analyzing the retrospective data using the combination of multiple statistical methods. Methods Operative data for inguinal hernia during the period from February 1999 to December 2019 were examined. The patients were assigned into two groups according to the surgical procedure: laparoscopic percutaneous extraperitoneal closure (LPEC, n = 2410) and OH ( n = 2038). Operative and anesthesia times and incidence of postoperative complications were evaluated using the propensity score methods and log-rank test. Results In comparison with OH, operative time of LPEC was longer for unilateral repair (21.59 ± 8.1 min vs 18.01 ± 8.0 min; p < 0.001) and shorter for bilateral repairs (28.55 ± 10.1 min vs 33.23 ± 11.7 min; p < 0.001), while anesthesia times were longer for both unilateral repair (57.67 ± 10.1 min vs 40.62 ± 11.9 min; p < 0.001) and bilateral repairs (65.95 ± 12.5 min vs 56.35 ± 15.1 min; p < 0.001). LPEC significantly reduced the risk of metachronous contralateral hernia (MCLH) (0.52% vs 9.29%; p < 0.001), but the recurrence rate was higher (0.21% vs 0.04%; p = 0.002) than OH. Orchiectomy due to testicular atrophy or torsion was required in 3 cases of OH (0.19%), whereas it was not seen in LPEC. Conclusions LPEC had a less risk of MCLH and testicular complications but was associated with a higher recurrence rate and longer anesthesia time. Propensity scoring techniques can enhance the robustness of retrospective comparisons between groups over several years of data collection, which is frequently required in pediatric surgery studies.