Introduction: Bariatric surgery is currently the only validated treatment option for obesity that provides significant and long-term weight loss. Even though initially performed with open techniques, the vast majority of bariatric procedures are nowadays performed using minimally invasive surgery (MIS). The objective of the present systematic review was to compare postoperative outcomes after open and MIS bariatric procedures.

Methods: A systematic search of MEDLINE, EMBASE, PUBMED, Web of Science and Cochrane databases was performed to identify studies comparing open and MIS bariatric surgery among adult patients. The primary outcome was the rate of 30-day postoperative complications. Secondary outcomes included operative times, conversion to open surgery, length of hospital stay (LOS), readmissions and reoperations.

Results: A total of 35 studies were included, reporting on 82’843 participants who underwent open and 152’398 participants who underwent MIS bariatric surgery. The overall early postoperative complication rate was 21.9% (18’175/82’843) in the open group and 18.2% (27’767/152’398) in the MIS group (p<0.0001). The rate of early severe complications was 2.4% in the open group and 1.1% in the MIS group (OR 2.17, 95% CI 1.61-2.91, p<0.0001). Rates of individual postoperative complications were all lower among MIS patients in the pooled and subgroup analyses, except for a comparable rate of hemorrhagic complications. Participants who underwent open surgery had higher mortality, reoperation and readmission rates and a longer LOS.

Conclusion: Postoperative outcomes were significantly better after MIS compared to open bariatric surgery. These findings support the use of MIS as the gold-standard for bariatric procedures.