RESUMO
BACKGROUND: Preoperative nutritional status and body structure affect short-term prognosis in patients undergoing major oncologic surgery. Bioimpedance vectorial analysis (BIVA) is a reliable tool to assess body composition. Low BIVA-derived phase angle (PA) indicates a decline of cell membrane integrity and function. The aim was to study the association between perioperative PA variations and postoperative morbidity following major oncologic upper-GI surgery. PATIENTS AND METHODS: Between 2019 and 2022 we prospectively performed BIVA in patients undergoing surgical resection for pancreatic, hepatic, and gastric malignancies on the day before surgery and on postoperative day (POD) 1. Malnutrition was defined as per the Global Leadership Initiative on Malnutrition criteria. The PA variation (ΔPA) between POD1 and preoperatively was considered as a marker for morbidity. Uni and multivariable logistic regression models were applied. RESULTS: Overall, 542 patients with a mean age of 64.6 years were analyzed, 279 (51.5%) underwent pancreatic, 201 (37.1%) underwent hepatobiliary, and 62 (11.4%) underwent gastric resections. The prevalence of preoperative malnutrition was 16.6%. The overall morbidity rate was 53.3%, 59% in those with ΔPA < -0.5 versus 46% when ΔPA ≥ -0.5. Age [odds ratio (OR) 1.11; 95% confidence interval (CI) (1.00; 1.22)], pancreatic resections [OR 2.27; 95% CI (1.24; 4.18)], estimated blood loss (OR 1.20; 95% CI (1.03; 1.39)], malnutrition [OR 1.77; 95% CI (1.27; 2.45)], and ΔPA [OR 1.59; 95% CI (1.54; 1.65)] were independently associated with postoperative complications in the multivariate analysis. CONCLUSIONS: Patients with preoperative malnutrition were significantly more likely to develop postoperative morbidity. Moreover, a decrease in PA on POD1 was independently associated with a 13% increase in the absolute risk of complications. Whether proactive interventions may reduce the downward shift of PA and the complication rate need further investigation.
