E. Hernandez1,2, D. Athanasiadis1,2, A. Christodoulides3, L. Petrucciani3, V. C. Osuji3, D. Stefanidis1,2 1Indiana University School Of Medicine,Department Of Bariatric And Minimally Invasive Surgery,Indianapolis, IN, USA 2Indiana University School Of Medicine,Department Of Surgery,Indianapolis, IN, USA 3Indiana University School Of Medicine,Indianapolis, IN, USA
Introduction:
Accurate prediction of patient outcomes after bariatric surgery is desirable for the counseling of patients seeking surgical weight loss. In August of 2019, the American College of Surgeons and the American Society for Metabolic and Bariatric Surgery released the MBSAQIP Bariatric Surgical Risk/Benefit calculator, an online tool that can predict bariatric surgery outcomes based on preoperative patient characteristics. The aim of our study was to assess the accuracy of this Risk/Benefit calculator in predicting our patients’ outcomes following bariatric surgery.
Methods:
Patients who underwent primary laparoscopic Roux-en-Y gastric bypass (LRYGB) or laparoscopic sleeve gastrectomy (LSG) at our institution between 2012 and 2019 were included in this study. Patient characteristics such as age, sex, BMI, race, functional status, ASA, comorbidities at baseline, 30-day reintervention and reoperation rates, weight loss (expressed as difference in BMI, ΔBMI), and comorbidity resolution for diabetes mellitus II (DM-II), hypertension (HTN), hyperlipidemia (HLD), and obstructive sleep apnea (OSA) 1 year after surgery were retrieved from our prospectively maintained database. Preoperative patient data were entered into the Risk/Benefit calculator and predicted postoperative outcomes recorded for each individual patient. To assess the tools’ accuracy, we compared actual outcomes of these patients with calculator predicted outcomes using sample t-test. Subgroup analysis based on operation type was also performed. A p-value of <0.05 was considered significant. Analysis was performed using SPSS statistical software, Version 26.0 (SPSS Inc., Armonk, NY).
Results:
During the study period 1455 patients had undergone a primary bariatric operation, of which 789 (54%) had follow up for at least 1 year (312 – 40% LRYGB and 477 – 60% LSG). There was no difference between the predicted and actual ΔBMI for LSG after one year (p=0.19) and a small difference (ΔBMI difference= 0.97) for LRYGB (p<0.001). Comorbidity resolution was overestimated by the calculator for HTN, DM-II, OSA, and HLD ranging from 9%-17% for LSG and 17%-26% for LRYBG (p<0.001 for all). There was no difference in risk estimate for 30- day reoperation or reintervention for LSG but a minor underestimation for LRYGB (1.3%-1.7%, p<0.001)
Conclusion:
The MBSAQIP Bariatric Surgical Risk/Benefit calculator is an accurate predictor of 1-year weight loss and 30-day reoperation and reintervention in our patient sample. Comorbidity resolution, however, appears to be overestimated by the calculator. Bariatric surgeons should incorporate this calculator in the preoperative counseling of their patients and be aware of its limitations.