E449: Post-Gastrectomy Weight Loss in the Modern Era

Patients who undergo gastrectomy for any indication can expect significant postoperative weight loss. Limited data are available on longitudinal post-gastrectomy weight loss and risk factors for weight loss in the modern era.

Methods:

Retrospective review of patients who underwent distal (DG), subtotal (SG), or total gastrectomy (TG) at a single institution from 2012 to 2022. Weights recorded approximately each month in the first 36 months from surgery were collected. Underweight was defined as BMI < 18.5, normal weight as BMI 18.5-24.9, overweight as BMI 25-29.9, and obesity as BMI >30. Associations of percent maximum weight loss with clinical characteristics were examined using linear model techniques, both before and after adjustment for baseline BMI. 

Results:

In total, 208 patients were identified; 114 (55%) underwent TG with Roux-en-Y reconstruction, 65 (31%) SG with Roux-en-Y reconstruction, and 29 (14%) DG with Billroth II reconstruction. Before surgery, four patients (1.9%) were underweight, 76 (37%) normal weight, 72 (35%) overweight, and 56 (27%) were obese. The median preoperative BMI was 26.2 overall; 27.2 for TG, 25.3 for SG, and 26.0 for DG (p=0.12). The majority of weight loss in all groups occurred in the first 6 months from surgery. Slow weight gain happened after 9 months following SG and DG and after 15 months following TG (Figure). The mean maximum percentage weight loss ³6 months from surgery was 22% after TG, 14% after SG, and 10% after DG (p< 0.001). After TG, mean maximum weight loss was 19% in normal weight patients, 21% in overweight patients, and 27% in obese patients (p< 0.001). The median preoperative BMI for patients undergoing TG was 27.2 and the median BMI 36 months from surgery was 22.2. Following TG, 23 patients (20%), who previously were normal weight or overweight/obese, met BMI criteria for underweight, with 20 of those (87%) still underweight at last follow-up (median follow-up 24 months). After adjusting for preoperative BMI, increased weight loss after TG was associated with younger age, female sex, and minimally-invasive approach (p< 0.05) but not with TNM stage or postoperative complications (p >0.05). Additionally, feeding jejunostomy tube placement was associated with slightly less mean maximum weight loss following TG (21% versus 23%, p=0.002).

Conclusions:

Weight loss after gastrectomy is influenced by age, sex, preoperative BMI, and type of gastrectomy.  Feeding jejunostomy tube placement decreases weight loss after TG and should be selectively considered in patients at high risk for significant weight loss and malnutrition.