Long-term complications and side effects of bariatric surgery: a systematic review

Background and objective: Bariatric surgery is a procedure that has gained popularity in the last decades as a treatment for obesity and is generally regarded as safe and effective in the short term, though the complications on the long term have been poorly described. We aim to review studies with long term follow-up reporting complications after a bariatric procedure. Method: A search was conducted on the data bases MEDLINE, EBSCO, Cochrane Library, and Google Scholar, and also scanning through references list in publications. We included cohort studies and clinical trials published from January 1st 2014 to April 15th 2017 with a follow up ≥ 5 years, retention rate above 50%, written in the following languages; English, Spanish, or Portuguese. We conducted qualitative bias assessment and analysis of heterogeneity. Result: Only four studies met the inclusion criteria, all of them were conducted with different bariatric procedures (vertical sleeve gastrectomy, laparoscopic sleeve gastrectomy, laparoscopic adjustable gastric banding, and billiopancreatic diversion with or without duodenal shift). Study design, outcome assessment, and complication definition were highly heterogeneous. The most frequent long term complications were gastroesophageal reflux disease, several nutritional deficits, incisional hernias, and failure to weight loss. Conclusions: There is insufficient evidence to ensure the quantity and severity of long-term complications of bariatric surgery.