This study investigated the impact of preoperative interventions (calorie restriction and exercise) on postoperative weight loss in LSG. Preoperative weight loss of ≥ 8% after preoperative intervention was related to 25% ≤ %TWL at 1 year postoperatively.
Sleeve gastrectomy, which removes 80% of the stomach along the greater curvature but maintains the intestinal anatomy, has been gaining popularity. It is a definitive procedure for the treatment of morbid obesity and obesity-related diseases. The number of sleeve gastrectomy cases has been increasing in several countries [12–14]. In addition, sleeve gastrectomy is successfully and safely performed via laparoscopy in 99.7% of the cases [15].
The resolution rates of obesity-related diseases such as T2DM, HT, HL, and SAS in LSG were 58.6%, 38.8%, 63%, and 91.2%, respectively [16].
Regarding the predictor of postoperative weight loss after LSG, Seki et al. reported that the %EWL was significantly lower in the super morbid obesity group (preoperative BMI ≥ 50 kg/m2) than in the mild obesity group (preoperative BMI < 35 kg/m2) and the reference group (35 ≤ preoperative BMI < 50) [17]. However, the preoperative BMI did not correlate with postoperative weight loss in our study. Pekkarinen T et al. reported that a larger preoperative weight loss predicted less postoperative weight loss for the next 2 years [18]. Moreover, the extent of preoperative weight loss statistically affects postoperative weight loss [19]. Therefore, preoperative weight loss remains controversial. Regarding preoperative calorie restriction, a preoperative diet using immune-nutrition formulas reportedly achieves preoperative weight loss, lower postoperative pain, and lower CRP and liver enzyme levels in LSG than high-protein formulas or a regular diet despite having similar caloric intake [10].
In our department, calorie restriction by nutritional support and exercise were offered for patients with obesity who would undergo LSG. Our program shows effective preoperative weight loss and skeletal muscle maintenance. However, patients with both visceral obesity and sarcopenia have a higher complication rate after surgery for colorectal cancer [20]. Sarcopenia and fatty infiltration of the muscle (myosteatosis) are reportedly independent predictors of worse survival in stage I–III colorectal cancer, and owing to their combined effect, oncologic survival has been greatly reduced [21]. Therefore, obesity and sarcopenia are associated with difficulty in performing surgical procedures, postoperative complications, and poor postoperative oncological outcomes. Hence, the preoperative intervention for obesity and sarcopenia is crucial for improving short- and long-term surgical outcomes.
There were some limitations in our study that should be acknowledged. These include its retrospective nature and single-institution design, as well as its small sample size.