Non-penetrating mesh fixation may reduce pain and hematoma risk in laparoscopic groin hernia repair.

Rationale Groin hernia is a common condition, and the only curative treatment is an operation where laparoscopic groin hernia repair is the recommended choice. During laparoscopic repair, a mesh is placed in the groin, which many surgeons choose to fixate, but the best fixation method regarding chronic pain and recurrence has not been established. Theoretically, non‐penetrating mesh fixation (glue or self‐adhesive mesh) could result in a lower risk of chronic pain, while penetrating mesh fixation (tacks, staples, and sutures) could give a reduced risk of recurrence. Objectives To assess the benefits and harms of penetrating versus non‐penetrating mesh fixation in adults undergoing laparoscopic groin hernia repair. Search methods We searched CENTRAL, MEDLINE Ovid, Embase Ovid, ClinicalTrials.gov, and the WHO International Clinical Trial Registry Platform. Additionally, we performed reference checking, forward and backward citation searching, and contacted study authors to identify eligible studies. The latest search date was 14 November 2024. Eligibility criteria We included randomised controlled trials (RCTs) that compared non‐penetrating (glue or self‐adhesive mesh) with penetrating (tacks, staples, and sutures) mesh fixation in laparoscopic groin hernia repair in adults. Outcomes The critical outcomes were chronic pain measured ≥ 6 months postoperatively and recurrence assessed ≥ 12 months postoperatively. Other important outcomes were acute pain, haematoma, mesh infection, serious vascular intraoperative events, operative time, and convalescence. Risk of bias We used the RoB 2 tool to assess the risk of bias for chronic pain (dichotomous and continuous), recurrence, acute pain (dichotomous and continuous), haematoma, mesh infection, serious vascular intraoperative events, operative time, and convalescence (both dichotomous and continuous). Synthesis methods We synthesised results for each outcome using meta‐analysis where possible by applying a random‐effects model, calculating the risk ratio (RR) using the Mantel‐Haenszel method for dichotomous data and calculating the mean difference (MD) using the inverse‐variance method for continuous data, along with 95% confidence intervals (CIs). Where this was not possible due to the nature of the data, we synthesised the results narratively. We used GRADE to assess the certainty of evidence for each outcome. Included studies We included 35 RCTs with 4329 participants. The studies randomised 2028 participants to non‐penetrating mesh fixation and 2301 participants to penetrating mesh fixation, with a median sample size of 82 (range 30 to 600 participants). The mean or median age ranged from 37 to 66 years, and the majority (94%) were men. In general, the operated hernias were primary unilateral inguinal hernias. Most of the non‐penetrating mesh fixation was fibrin sealant and cyanoacrylate glue, and most of the penetrating mesh fixation was permanent staples, permanent tacks, or absorbable tacks. Synthesis of results RoB 2 assessment Regarding the overall risk of bias, most of the outcomes had some concerns or a high risk of bias. This was mostly due to missing information regarding the randomisation process, insufficient reporting of missing outcome data, or both. GRADE We assessed the certainty of evidence to be very low for most outcomes. This was mainly due to high or unclear risk of bias or due to imprecision because of few events, a wide confidence interval, or a small population. Critical outcomes Non‐penetrating mesh fixation may result in little to no difference in the risk of chronic pain (RR 0.62, 95% CI 0.35 to 1.07; I² = 9%; 7 studies, 553 participants; very low‐certainty evidence) and recurrence (RR 0.75, 95% CI 0.33 to 1.67; I² = 0%; 15 studies, 2165 participants; very low‐certainty evidence), but the evidence is very uncertain. Non‐penetrating mesh fixation may reduce the level of chronic pain (continuous), but the evidence is very uncertain (MD −0.34, 95% CI −0.56 to −0.11; I² = 98%; 7 studies, 639 participants; very low‐certainty evidence). Important outcomes Non‐penetrating mesh fixation may have little to no effect on the risk of acute pain (dichotomous) (RR 0.93, 95% CI 0.50 to 1.73; I² = 56%; 2 studies, 218 participants; very low‐certainty evidence). Non‐penetrating mesh fixation may reduce the level of acute pain (continuous) (MD −0.90, 95% CI −1.31 to −0.49; I² = 98%; 16 studies, 1611 participants; very low‐certainty evidence), the risk of haematoma (RR 0.43, 95% CI 0.24 to 0.78; I² = 0%; 19 studies, 2560 participants; very low‐certainty evidence), convalescence (RR 1.49, 95% CI 1.10 to 2.01; I² = 94%; 9 studies, 1116 participants; very low‐certainty evidence), and the length of convalescence (MD −0.81, 95% CI −1.38 to −0.23; I² = 80%; 7 studies, 589 participants; very low‐certainty evidence), but the evidence is very uncertain. Non‐penetrating mesh fixation may have little to no effect on the risk of mesh infection (RR 0.34, 95% CI 0.01 to 8.23; I² not applicable; 5 studies, 1128 participants; very low‐certainty evidence) and operative time (MD −0.26, 95% CI −3.11 to 2.59; I² = 94%; 20 studies, 1800 participants; very low‐certainty evidence), but the evidence is very uncertain. Lastly, non‐penetrating mesh fixation may result in little to no difference in serious vascular intraoperative events (RR 0.18, 95% CI 0.02 to 1.57; I² = 0%; 9 studies, 1289 participants; low‐certainty evidence). Authors' conclusions There may be little to no difference between non‐penetrating and penetrating mesh fixation regarding the risk of chronic pain (dichotomous), recurrence, acute pain (dichotomous), mesh infections, and operative time, but the evidence is very uncertain. Non‐penetrating mesh fixation may result in little to no difference in serious vascular intraoperative events. While the evidence is very uncertain, non‐penetrating mesh fixation may slightly reduce the level of chronic pain (continuous), the level of acute pain (continuous), and the risk of haematoma, and shorten convalescence (dichotomous and continuous). Overall, this review demonstrated little to no difference in clinically important outcomes between penetrating and non‐penetrating mesh fixation in laparoscopic groin hernia repair in adults, based on low‐ to very low‐certainty evidence. Funding This Cochrane review had no dedicated funding. Registration Protocol available via DOI: 10.1002/14651858.CD016122. PICOs PICOs Population Intervention Comparison Outcome