Reintervention or mortality within 90 days of bariatric surgery: population-based cohort study

Background Bariatric surgery carries a risk of severe postoperative complications, sometimes leading to reinterventions or even death. The incidence and risk factors for reintervention and death within 90 days after bariatric surgery are unclear, and were examined in this study. Methods This population-based cohort study included all patients who underwent bariatric surgery in one of the five Nordic countries between 1980 and 2012. Data on surgical and endoscopic procedures, diagnoses and mortality were retrieved from national high-quality and complete registries. Multivariable Cox regression analysis was used to calculate hazard ratios (HRs), adjusted for country, age, sex, co-morbidity, type of surgery and approach, year and hospital volume of bariatric surgery. Results Of 49 977 patients, 1111 (2 center dot 2 per cent) had a reintervention and 95 (0 center dot 2 per cent) died within 90 days of bariatric surgery. Risk factors for the composite outcome reintervention/mortality were older age (HR 1 center dot 65, 95 per cent c.i. 1 center dot 36 to 2 center dot 01, for age at least 50 years versus less than 30 years) and co-morbidity (HR 2 center dot 66, 1 center dot 53 to 4 center dot 62, for Charlson co-morbidity index score 2 or more versus 0). The risk of reintervention/mortality was decreased for vertical banded gastroplasty compared with gastric bypass (HR 0 center dot 37, 0 center dot 28 to 0 center dot 48) and more recent surgery (HR 0 center dot 51, 0 center dot 39 to 0 center dot 67, for procedures undertaken in 2010 or later versus before 2000). Sex, surgical approach (laparoscopic versus open) and hospital volume did not influence risk of reintervention/mortality, but laparoscopic surgery was associated with a lower risk of 90-day mortality (HR 0 center dot 29, 0 center dot 16 to 0 center dot 53). Conclusion Reintervention and death were uncommon events within 90 days of bariatric surgery even in this unselected nationwide cohort from five countries. Older patients with co-morbidities have an increased relative risk of these outcomes.