incidence of VTE. However, the optimal approach and duration of these interventions after bariatric surgery remains unclear Objective: Our goal is to evaluate safety and efficacy of an extended VTE prophylaxes model in a bariatric surgery patient population. Methods: We conducted a retrospective cohort study comparing patients treated with conventional VTE prophylaxis (January 2007- February 2012) to those undergoing extended VTE prophylaxis (February 2012- January 2017) of patients who underwent laparo- scopic primary bariatric surgery. In February 2012 we introduced an extended VTE prophylaxes protocol. We identified 4,268 patients who underwent bariatric surgery during the study period. Patients were excluded for the following reasons; revisional surgery (n¼376), open procedure (n¼930), did not receive pre and/or post anticoagulation (n¼363), preoperatively on therapeutic anticoagulation (n¼342), or patients with moderate/severe liver disease (n¼1). A total of 2,256 were included in the study; 1,106 patients in the conventional therapy group and 1,150 patients in the extended group. We compared the perioperative outcomes of extended VTE prophylaxis against conven- tional therapy. The primary outcome measured post-operative VTE events. Secondary outcomes included bleeding complications, 30-day mortality, morbidity, re-operations, and readmissions. Conventional therapy included mechanical calf compression, preoperative 30mg subcutaneous dose of low molecular weight heparin prior to surgery, and prophylactic dose low molecular weight heparin while inpatient starting on post-operative day one. The extended VTE prophylaxes protocol includes the same pre-operative and in hospital prophylaxis in addition to chemical VTE prophylaxis as an outpatient for 10 and 28-day models based on pre-operative risk factors. Results: There were no significant difference in VTE events between the two groups (Conventional n¼0, Extended n¼2; p¼0.5) No deep venous thrombosis events were documented in either group. There was no significant difference in rate of bleeding complications between the two groups (Conventional n¼11, Extended n¼9; p¼0.591). There was no difference in the 30-day mortality (Conventional n¼1, Extended n¼1; p 0.999). There was no significant difference in the readmissions after initiating the extended VTE protocol (Conventional n¼63, Extended n¼79; p 0.251). There was no significant difference in re-operations (Conventional n¼37, Extended n¼50; p 0.216) Conclusions: Pulmonary embolism remains the primary cause of perioperative mortality following bariatric surgery. Our study demonstrates extended VTE prophylaxis regimen in a bariatric surgery patient population is safe and feasible. A523 BARIATRIC SURGERY IS SAFE IN PATIENTS ON IMMUNOSUPPRESSIVE AGENTS Salvatore Docimo 1 ; Aurora Pryor 1 ; Andrew Bates 1 ; Nabeel Obeid 2 ; Mark Talamini 1 ; Dino Spaniolas; 1 Stony Brook Medicine, Stony Brook NY; 2 Stony Brook Medicine, Rego Park NY Introduction: As studies continue to demonstrate both the effective- ness and safety of bariatric surgery, weight loss procedures are more commonly being performed in high-risk cohorts. Patients with chronic disease processes requiring immunosuppressive therapy are one such group. The aim of this study was to compare the perioperative safety of immunosuppressed patients undergoing sleeve gastrectomy (LSG) and roux-en-y gastric bypass (LRYGB) procedures. Methods: Using the Metabolic and Bariatric Surgery Accredita- tion and Quality Improvement Program (MBSAQIP) public use file for 2015, patients on chronic immunosuppressive medications undergoing LSG and LRYGB were identified. Baseline patient demographics and characteristics were assessed and comparisons of 30-day outcomes were performed. Post-operative events were assessed as a composite outcome (complication or reoperation or readmission). Analyses were performed in SPSS Statistics version 25 for Windows (IBM Corp; Armonk, NY). All p values are 2-tailed with a set at 0.05. Odds ratios (OR) with 95% confidence intervals are reported. Results: We identified 1,998 patients who underwent RYGB (n¼522) or SG (n¼1476) while on chronic immunosuppression. Mean age and BMI were 48.53±11.19 years and 45.56±8.19 kg/m 2 for the entire surgery group, respectively. There were four (0.2%) deaths, 16 (0.8%) anastomotic/staple line leaks and 95 (4.8%) complications in this cohort. RYGB patients were more likely to experience a 30-day post-operative event (16.5% vs. 8.5%, po0.001), complication (8.4% vs 3.5%, po0.001), re-operation (3.3% vs 1.4%, p¼o.oo6), and intervention (5.2% vs. 1.8%, po0.001) compared to SG. After controlling for differences in other baseline characteristics, SG was independently associated with lower rate of postoperative events (OR 0.51, 95 CI 0.377-0.694). There was no significant difference in leak rate, 30 day readmission rate, 30 day mortality rate, pulmonary embolism (PE) rate, or myocardial infarction (MI) rate between the two groups. Discussion: Bariatric surgery in patients on chronic immunosuppres- sive medications is being performed with minimal perioperative morbidity and mortality. However, less post-operative events, such as 30-day post-operative re-operation or intervention, are to be expected when utilizing SG over RYGB for this patient population. A524 LAPAROSCOPIC SLEEVE GASTRECTOMY VERSUS LAPAROSCOPIC ROUX-EN-Y GASTRIC BYPASS: SINGLE CENTER EXPERIENCE WITH 4 YEARS FOLLOW UP Joseph Noto 1 ; Maher El Chaar 2 ; Leonardo Claros 3 ; Jill Stoltzfus 1 ; 1 St. Luke’s University Hospital, Allentown Pennsylvania; 2 St. Luke’s University Hospital; 3 St. Luke’s University Hospital, Allentown PA Background: Laparoscopic Sleeve gastrectomy (LSG) and Laparoscopic Roux-en-Y Gastric Bypass (LRYGB) are the two most commonly performed bariatric procedures in the United States. We previously reported our experience comparing LSG to LRYGB at two years. The purpose of this study is to compare LSG and LRYGB up to four years postoperatively at a single accredited center. Methods: We performed a retrospective analysis of prospectively collected data on patients undergoing LSG and LRYGB between January 2009 and November 2011. LSG was performed with a 36 Fr bougie starting 4 cm from the pylorus, while LRYGB was performed with a 25-mm circular stapler in an antecolic antegastric fashion. Primary outcomes included hospital length of stay, 30-day and overall complications, 30-day readmissions, 30-day reopera- tion rates, operative times and % Excess Weight Loss (%EWL) at 3, 6, 12, 24, 36, and 48 monthspostoperatively. Additionally, LSG patients were stratified based on their initial Body Mass Index 2017 Quickshot Abstracts / Surgery for Obesity and Related Diseases 13 (2017) S52–S65 S62