Effect of resected gastric volume on weight loss after sleeve gastrectomy: A retrospective clinical study

BACKGROUND Obesity is a major global health concern associated with increased morbidity and mortality. Sleeve gastrectomy is an effective bariatric surgery; however, the impact of resected gastric volume (RGV) on postoperative weight loss remains controversial. AIM To evaluate the effect of RGV on weight loss and body mass index (BMI) changes in patients undergoing sleeve gastrectomy. METHODS This retrospective study included 49 patients. Preoperative and postoperative body weight and BMI (at 6 months and 12 months after surgery) were recorded. RGV was calculated using the ellipsoid formula based on the specimen’s length, width, and thickness measurements. Statistical analyses included parametric tests, repeated-measures one-way analysis of variance, Bonferroni post-hoc tests, and Pearson correlation analysis. RESULTS Both body weight and BMI significantly decreased over time (weight: F = 951.34, P < 0.01, η2 = 0.95; BMI: F = 345.97, P < 0.01, η2 = 0.88). A positive and statistically significant correlation was found between preoperative body weight and RGV (r = 0.285, P < 0.05). However, no significant associations were identified between RGV and weight or BMI at 6 months and 12 months. CONCLUSION RGV correlated with preoperative weight but not with postoperative outcomes, indicating that weight loss after sleeve gastrectomy is a multifactorial process and influenced by hormonal, metabolic, and lifestyle factors.