Single-incision surgery trocar-site hernia: an updated systematic review meta-analysis with trial sequential analysis by the Minimally Invasive Surgery Synthesis of Interventions Outcomes Network (MISSION)

Single-incision laparoscopic surgery (SILS) is a new technique that aims to minimize abdominal wall trauma and improve cosmesis. Concerns have been raised about the risk of trocar-site hernia following SILS. This study aims to assess the risk of trocar-site hernia following SILS compared to conventional laparoscopic surgery, and investigate whether current evidence is conclusive. We performed a systematic search of MEDLINE, AMED, CINAHL, CENTRAL, and OpenGrey. We considered randomized clinical trials comparing the risk of trocar-site hernia with SILS and conventional laparoscopic surgery. Pooled odds ratios with 95% confidence intervals (CI) were calculated using the Mantel-Haenszel method. Trial sequential analysis using the Land and DeMets method was performed to assess the possibility of type I error and compute the information size. Twenty-three articles reporting a total of 2471 patients were included. SILS was associated with higher odds of trocar-site hernia compared to conventional laparoscopic surgery (odds ratio 2.37, 95% CI 1.25-4.50, p = 0.008). There was no evidence of between-study heterogeneity or small-study effects. The information size was calculated at 1687 patients and the Z-curve crossed the O'Brien-Fleming alpha-spending boundaries at 1137 patients, suggesting that the evidence of higher risk of trocar-site hernia with SILS compared to conventional laparoscopic surgery can be considered conclusive. Single-incision laparoscopic procedures through the umbilicus are associated with a higher risk of trocar-site hernia compared to conventional laparoscopic surgery.