Analysis of Gastric Physiology After Laparoscopic Sleeve Gastrectomy (LSG) With or Without Antral Preservation in Relation to Metabolic Response: a Randomised Study

Laparoscopic sleeve gastrectomy is one of the most common techniques in bariatric surgery, but there is no consensus on the optimal distance from the pylorus to start the gastric transection. The aim of this study is to determine the differences in gastric emptying, gastric distension and metabolic response between two starting distances. This is a prospective randomised study of 60 patients (30 patients with the section at 3 cm and 30 patients at 8 cm from the pylorus). We calculate at 6 and 12 months from surgery gastric emptying by scintigraphy (T1/2 min), gastric volume by CT scan (cc) and metabolic response by blood sample analysis (glucose, HbA1c, insulin, HOMA-IR, GLP-1, GIP and C-peptide). Gastric emptying increases the speed significantly in both groups but is greater in the 3-cm group (p < 0.05). Dividing groups into type 2 diabetic patients and non-diabetic patients, the speed in non-diabetic patients is significantly higher for the 3-cm group. Residual volume increases significantly in both groups, and there are no differences between them. One year after surgery, there are significant improvements in the hyperinsulinaemia in the patients of the 3-cm group with respect to the 8-cm group, but only in diabetic patients. No differences between groups are found regarding changes in GLP-1 or GIP. Gastric emptying is faster in patients with antrum resection. The distance does not influence the gastric emptying of diabetic patients. Other mechanisms may explain metabolic response besides GLP-1 and its association with improvements in diabetes via gastric emptying.