Changes in Gastric Volume and Their Implications for Weight Loss after Laparoscopic Sleeve Gastrectomy

Laparoscopic sleeve gastrectomy (LSG) is a relatively new surgical technique for the treatment of morbid obesity. It is unclear whether the volume of the gastric remnant can expand after surgery as a result of intraluminal pressure maintained over time. If this were the case, the increased volume could affect weight loss and the improvement in comorbidities. This study aims to assess the evolution of residual gastric volume (RGV) during the first year after LSG and its relationship with weight loss.

We conducted a prospective study of 112 patients who underwent LSG from February 2009 to December 2013. In order to measure the RGV after surgery, all patients were evaluated radiologically by an esophagogastroduodenal (EGD) transit at 1 and 12 postoperative months.

All patients showed a significant reduction in BMI compared with the preoperative measurement (33.48 ± 5.78 vs. 50.54 ± 6.69 kg/m²; p < 0.001). Increased RGV was observed when comparing the results obtained by EGD transit at 1 (68.39 ± 25.89 cm³) and 12 postoperative months (122.58 ± 38.76 cm³; p < 0.001). There was no association between increase in gastric volume and weight loss at 1-year follow-up (r = 0.01; p = 0.910).

The volume of the gastric remnant increased significantly during the first year after LSG. However, this increase was not associated with weight loss. Further prospective research with longer follow-up periods is needed to confirm or contrast the present results.