Use of the Obesity Surgery Mortality Risk Score to Predict Complications of Laparoscopic Bariatric Surgery

This study aimed to evaluate the role of the Obesity Surgery Mortality Risk Score (OS-MRS) to predict the risk of post-operative adverse events, in addition to death, from any laparoscopic bariatric procedure.

The OS-MRS was applied to consecutive patients at a single hospital during October 2008–September 2009. The composite end point comprised one or more of the following adverse events: mortality, re-intervention, re-admission to hospital, venous thromboemobolism, or blood transfusion.

There were 381 patients (men, 19%). The median age was 43 years (range, 19–67 years), with 42% patients aged ≥45 years. The median weight was 126 kg (75–295 kg) and median BMI 46 kg/m² (30–84 kg/m²); 37% had BMI ≥50 kg/m². Twenty-seven percent of patients had hypertension and 3% had a past history of venous thromboembolism. The OS-MRS classes were A (60.1%), B (35.9%), or C (4.0%). Operations comprised adjustable gastric band (37%), Roux-en-Y gastric bypass (54%), sleeve gastrectomy (8%), or biliopancreatic diversion (1%). Of the operations, 1.6% were revisional procedures. An adverse outcome occurred in 19 patients, with distribution in 3.5% of class A patients, 5.8% of class B, and 20.0% of class C (A vs. B, P = 0.451; A vs. C, P = 0.002; B vs. C, P = 0.025). There was one death: OS-MRS class C. On multivariate analysis, OS-MRS (class C vs. A or B; Odds Ratio [OR], 4; P = 0.050) and type of operation (band vs. bypass or sleeve; OR, 9.2; P = 0.033) were independently predictive of the composite end point.

OS-MRS and type of the bariatric operation are independently predictive of the risk of post-operative adverse events.