Failure of the Obesity Surgery Mortality Risk Score (OS-MRS) to Predict Postoperative Complications After Bariatric Surgery. A Single-Center Series and Systematic Review

The obesity surgery mortality risk score (OS-MRS) was developed to determine the risk of postoperative mortality in patients undergoing bariatric surgery. The aim of the present study is to assess the utility of this score for preventing the risk of postoperative complications from bariatric surgery. Prospective study of 321 patients undergoing bariatric surgery to whom the OS-MRS was applied. Postoperative complications were classified according to the Clavien-Dindo system. The relation between the OS-MRS and the appearance of complications and mortality was analyzed. A Medline/Embase search was conducted using bariatric surgery, mortality, and complications as key words. Studies using the OS-MRS to predict morbidity and mortality were included. Of the 321 patients, 303 (94.3%) underwent gastric bypass and the remaining 18 (5.6%) a sleeve gastrectomy. The OS-MRS classified 178 patients as class A (55.5%), 129 as class B (40.2%), and 14 as class C (4.4%). According to the Clavien-Dindo system, 10.4% of the complications were >= III. There was one death (class B). No significant association was found between the OS-MRS and the rate of complications. In our study, the OS-MRS is not correlated with the appearance of early complications or mortality. Future studies must focus on systems for predicting the appearance and severity of postoperative complications classified according to the Clavien-Dindo system, and not only on mortality.