Introduction: The volume of the gastric reservoir (VGR) after sleeve gastrectomy influences weight loss in the short-term, but long-term results are scarce. The aim was to analyze the correlation between the VGR and weight loss at 5 years of follow-up.
Methods: It is a prospective observational study of 50 patients undergoing sleeve gastrectomy (SG) from February 2009 to December 2013. An upper gastrointestinal series was performed at 1 month and at 1 and 5 years after surgery. A composite formula was used for VGR estimation. Weight loss-related data included the following: body mass index (BMI), percentage of excess weight loss (%EWL), and percentage of excess BMI loss (%EBMIL) at 1 month and at 1 and 5 years. Uni- and multivariate analyses were carried out to determine other factors that might influence long-term weight loss results.
Results: The %EWL at 1 year was 74.5(63.8-86) vs. 55.5(47-74.3) at 5 years (p < 0.001). The VGR 1 month after surgery was 114.9 (90.5-168.3) mL. The VGR increased from 216.7 (155.1-278.6) to 367.5 (273-560.3) mL (p < 0.001) at 1 and 5 years. Although a significant inverse correlation was observed between VGR and BMI, %EWL, and %EBMIL at 1 year, it disappeared at 5 years. In the multivariate analysis, the main factor to predict worse weight results at 5 years was a pre-surgical BMI ≥ 50 kg/m2.
Conclusion: The VGR increased progressively during the study period. Although an inverse relationship between VGR and weight was found at 1 year, this correlation did not remain at 5 years. A preoperative BMI ≥ 50 kg/m2 is the main predictive factor of poor weight outcomes.
Keywords: Excess weight loss; Sleeve gastrectomy; gastric volume; long-term results..