Single-incision laparoscopic surgery through the umbilicus is associated with a higher incidence of trocar-site hernia than conventional laparoscopy: a meta-analysis of randomized controlled trials.

Single-incision laparoscopic surgery has been developed with the objective to reduce surgical trauma, decrease associated surgical stress and to improve cosmetic outcome. However, concerns have been raised regarding the risk of trocar-site hernia following this approach. Previous meta-analyses have suggested a trend toward higher hernia rates, but have failed to demonstrate a significant difference between single-incision and conventional laparoscopic surgery.

Medline, AMED, CINAHL and CENTRAL were searched up to May 2014. Randomized controlled trials comparing single-incision and conventional laparoscopic surgery were considered for inclusion. Studies with patients aged less than 18 years and those reporting on robotic surgery were disregarded. Pooled odds ratios with 95% confidence intervals were calculated to measure the comparative risk of trocar-site hernia following single-incision and conventional laparoscopic surgery.

Nineteen randomized trials encompassing 1705 patients were included. Trocar-site hernia occurred in 2.2% of patients in the single-incision group and in 0.7% of patients in the conventional laparoscopic surgery group (odds ratio 2.26, 95% confidence interval 1.00-5.08, p = 0.05). Sensitivity analysis of quality randomized trials validated the outcome estimates of the primary analysis. There was no heterogeneity among studies (I2 = 0%) and no evidence of publication bias.

Single-incision laparoscopic surgery involving entry into the peritoneal cavity through the umbilicus is associated with a slightly higher risk of trocar-site hernia than conventional laparoscopy. Its effect on long-term morbidity and quality of life is a matter for further investigation.