Six RCTs (510 patients) were included in the review. Sample sizes ranged from 50 to 155 patients. Three RCTs reported adequate sequence generation, and two trials reported allocation concealment. Blinding of participants was reported in one trial. Losses to follow-up were not reported in two trials. Follow-up periods ranged from 12 to 24 months.
There were statistically significant benefits observed with laparoscopic surgery compared with open bariatric surgery with reductions in risk of wound infection (RR 0.21, 95% CI 0.07 to 0.65, Ι²=0%, six RCTs) and incisional hernia (RR 0.11, 95% CI 0.03 to 0.35, Ι²=0%, six RCTs). There were no significant differences observed between the groups for the risks of re-operation, anastomotic leak, and all-cause mortality. There was no significant heterogeneity reported for any outcome.
The mean length of hospital stay ranged from three to six days in the laparoscopic surgery group and from four to eight days in the open bariatric surgery group, but there was insufficient data to perform a meta-analysis. Mean changes in body mass index ranged from -11.6 to -15.0 points in the laparoscopic group and -10.6 points to -15.5 points in the open bariatric surgery group (four RCTs). The mean weight loss ranged from 35 to 39kg in the laparoscopic group and from 34 to 41kg in the open bariatric surgery group (two RCTs).
There was no evidence of publication bias for the outcomes of reoperation, wound infection, incisional hernia or anastomotic leak.