Presurgical factors influencing weight loss in obese patients after undergoing laparoscopic sleeve gastrectomya predictive model of postsurgical results

Resum

Introduction Laparoscopic Sleeve Gastrectomy (LSG) is the most performed bariatric surgery in the United States. It leads to significant comorbidity resolution and weight loss. Factors that can predict the amount of surgical weight loss at long-term follow-up are still not well understood. The aim of our study is to analyze the preoperative factors that could predict weight loss after LSG. Methods We retrospectively reviewed all patients that underwent LSG for bariatric purposes from 2004 to 2016. Data was collected on demographics, preoperative comorbidities, and weight on follow up visits after surgery up to December 2017. The cohort was divided into 2 groups (before and after 2015). A statistical model was created using the first group to determine the effect of multiple preoperative variables on weight loss. Statistical models to predict BMI Loss and % Excess Weight Loss (% EWL) were fit using generalized least squares techniques with an autoregressive-type correlation structure assumed. A validation test was performed using the second group of patients.   Results A total 1,617 patients and 10,631 weight measurements at follow up were included in the study. Females represented 67 % of the cohort (n= 1079), 53 % of the cohort was white, the average preoperative age of 48 years and the average BMI of 42 Kg/m2. Overall prevalence of arterial hypertension was 53%, Type II diabetes was 48%, sleep apnea 43%, Gastroesophageal reflux disease 36%, Depression 18% and hypercholesterolemia 17%. Group 1 includes 1,166 patients. We calculate the predicted impact of each of the multiple measured variables on a statistical model on the overall weight- loss up to 10 years of follow-up with the other preoperative variables held fixed. Younger age, Males, non-white race, Diagnosis of Arterial Hypertension, Type II Diabetes Mellitus, Gastroesophageal reflux disease, Sleep Apnea and higher Preoperative BMI were found to have a significant independent impact on weight loss over time, this impact being variable depending on the time of the BMI measurement. Group 2 includes 451 patients and was used to validate the statistical predictive models with good fitting. The effect of each preoperative variable on estimated weight loss can be measure individually or collectively using a web integration system. Conclusion Multiple preoperative variables can be used to estimate in detail surgical weight loss after Laparoscopic Sleeve Gastrectomy