S1210 Weight Loss Outcomes in Bariatric Surgery Based on Pre-Operative Gastric Emptying: A Retrospective Study

Abstract

INTRODUCTION: The obesity epidemic is predicted to impact half of the United States population within the next decade. Bariatric surgery, including laparoscopic sleeve gastrectomy (LSG) and Roux-en-Y gastric bypass (RYGB), is the most effective option for severe obesity, with dramatic weight loss results and often complete resolution of comorbid conditions. Many possible reasons for the effectiveness of bariatric surgery exist, with alterations in gastric motility as one of these explanations. Our aim was to determine the interaction between pre-operative gastric emptying rate and the metabolic outcomes after bariatric surgery. METHODS: We conducted an IRB approved retrospective study at a tertiary medical center. Patients were included if they had a BMI above 34, were between the ages of 18–70, had undergone either LSG or RYGB, and had nuclear medicine gastric emptying scintigraphy (GET) completed prior to surgery. Patients with gastric or small bowel surgery prior to their weight loss surgery were excluded. Data on weight, HbA1C, and GI symptoms at 0, 6, and 12 months from the time of surgery were extracted from the medical record. Data was analyzed using the t-test with P < 0.05 considered significant. RESULTS: Seventy patients were identified with 32 meeting full inclusion criteria. Patients averaged 50 years old, and 90% were female; 87.5% were Caucasian and 9% were African American. Four-hour GET, showed 68.8% of patients had normal gastric emptying, 3% had rapid emptying, and 28% had delayed emptying. At 12 months, patients with normal 4-hour GET had an average decrease in BMI of 28.1% compared to 31.1% in patients with delayed emptying (P = 0.375). Absolute change in HbA1C at 12 months was -0.2 in patients with normal GET compared to -0.8 in patients with delayed GET (P = 0.085). Subgroup analysis comparing mild, moderate, and severe delayed emptying also resulted in no difference in weight loss after operations. CONCLUSION: The results of this retrospective analysis indicate that differences in gastric emptying prior to surgery do not impact metabolic outcomes after bariatric surgery. However, more patients with rapid gastric emptying need to be studied given its link to obesity and the physiologic changes to gastric emptying associated with weight loss surgery. Comparing LSG and RYGB in relation to GET may be an additional consideration for future study.