POSSUM and P-POSSUM: Predictors of Morbidity and Mortality in Laparoscopic Roux-En-Y Gastric Bypass?

Background: Evidence to support the use of Physiological and Operative Severity Score for the enumeration of Mortality and morbidity (POSSUM) and Portsmouth-POSSUM (P-POSSUM) to predict outcomes in bariatric surgery is sparse. Objectives: The aim of this study is prospectively evaluate their usefulness in laparoscopic gastric bypass. Setting: University Hospital Methods: All patients undergoing primary laparoscopic gastric bypass between November/14 and September/15 in our institution were included. POSSUM and P-POSSUM scores were applied preoperatively. The observed to expect ratios for morbidity and mortality at 30 days after surgery were calculated. Chi-square and binomial tests were used to compare observed and expected outcomes. A p-value <0.05 was considered significant. Results: Ninety-four patients (76 female) were included, mean age of 45.5years, 66 patients were ASA 2. Mean BMI was 43.9Kg/m2. Estimated morbidity by POSSUM score was 24.1%. Estimated mortality was 4.4% by POSSUM, 1.0% by P-POSSUM. Observed morbidity was 23.4%. No patient died. Both scores resulted in over predicted outcomes. In contrast to P-POSSUM, POSSUM expected outcomes were statistically different from the ones observed. Conclusion: POSSUM was not a good predictor of morbidity and mortality in the sample. The use of these scores in bariatric surgery has to be careful. These results should be assessed further in larger, multicenter, studies.