Obesity Surgery Mortality Risk Score: Can we Go Beyond Mortality Prediction?

Abstract

Introduction: High morbidity and low mortality has been linked to bariatric surgery. The Obesity surgery mortality risk score (OS-MRS) is a validated scale for mortality risk assessment. The aim of this study was to evaluate if OS-MRS scale can also be used as a predictor of postoperative complications in obese patients submitted to primary laparoscopic gastric bypass. Methods: Retrospective study including all patients submitted to primary laparoscopic gastric bypass between January and December 2014. The OS-MRS scale was applied preoperatively, and postoperative to access morbidity and mortality at 30 and 90 days. Complications were classified according to Clavien-Dindo's grades (I to V). The association between different OSMRS classes and the occurrence of adverse events was analyzed. Results: 85 patients were included and classified as class A (n=33; 38.8%), class B (n=48; 56.5%) and class C (n=4; 4.7%). No mortality cases were registered. The morbidity rate at 30 days was 23.5% (n=20), and 25.9% at 90 days (n=22). The complications rate in each of OS-MRS subgroups, was 9.1% in class A (both at 30 and 90 days), 31.3% and 35.4% in class B (at 30 and 90 days respectively), and 50% in class C (both at 30 and 90 days). There was a statistically significant independent relationship between OS-MRS scale, ASA physical status and the risk of developing pulmonary embolism, both at 30 and 90 postoperative days. Patients from classes B and C showed a greater risk of complications when compared to class A (at 30 days, OR 4.9, 95% IC: 1.3-18.2; p=0.019 and at 90 days, OR 5.8, 95% IC: 1.5-21.4; p=0.009). Conclusion: There is increasing evidence that OS-MRS scale is a useful tool to predict morbidity after gastric laparoscopic bypass in morbidly obese patients.