Should occult contralateral inguinal hernias be repaired during unilateral TAPP? A systematic review and single-arm meta-analysis.

Abstract

Aim: Occult inguinal hernias (OIH) are frequently detected during laparoscopic repair of unilateral inguinal hernias due to direct visualization of the contralateral groin. However, the optimal management of these asymptomatic defects remains debated. This systematic review and single-arm meta-analysis aimed to evaluate the clinical characteristics and postoperative outcomes of contralateral OIH repaired during transabdominal preperitoneal (TAPP) repair.

Methods: A systematic review was conducted following PRISMA guidelines. PubMed, Embase, and Scopus were searched from inception to February 2026 for studies including adult patients undergoing TAPP repair with intraoperative identification of contralateral OIH. Due to heterogeneous reporting and inconsistent measures of dispersion, comparative meta-analysis was not feasible. A single-arm meta-analysis was therefore performed only on patients undergoing contralateral OIH repair. Data were synthesized with random-effects models for dichotomous outcomes. Continuous variables were pooled using inverse-variance methods. Weighted pooled estimates were calculated for baseline characteristics.

Results: Five retrospective cohort studies published between 2018 and 2025 were included, comprising 4,485 total patients, of whom 873 (19.5%) had occult inguinal hernias identified intraoperatively and subsequently repaired. The majority of repairs were performed using laparoscopy, with robotic approach reported in two studies. Mean patient age was 52.6 ± 14.0 years, mean BMI was 23.4 ± 3.9 kg/m², and > 90% of patients were male. Operative time ranged from 90.3 ± 30.9 to 132 ± 44.1 min, with a pooled mean of 116.9 min (95% CI 59.6-174.2) under a random-effects model (I² = 97.2%). Overall postoperative complications were reported in four studies, totaling 39 events among 819 patients (4.7%), with a pooled complication rate of 13% (95% CI 6-26%; I² = 31%). Surgical site infections (SSI) were rare, with 4 events among 873 patients (0.4%), corresponding to a pooled SSI rate of 1% (95% CI 1-2%; I² = 0%). Surgical site occurrences (SSO) were reported in 32 of 819 patients (3.6%), with a pooled rate of 12% (95% CI 4-29%; I² = 46.7%). Recurrence was reported in one study, with 9 cases (2.2%) during a mean follow-up of 30 months, and no reoperations or mortality were reported.

Conclusion: Occult inguinal hernias are identified in approximately one in five patients undergoing minimally invasive inguinal hernia repair. Repair of these defects during TAPP appears safe, with low surgical site infection rates, low complication rates, and no reported mortality or reoperation across available studies. Although contralateral repair may modestly increase operative time and short-term postoperative burden, it may reduce the likelihood of future symptomatic hernia development and the need for a second operation. Substantial heterogeneity and limited long-term recurrence data highlight the need for prospective studies to better define the role of routine contralateral exploration and repair.