[Significance of preoperative weight loss for perioperative metabolic adaptation and surgical risk in patients with tumors of the upper gastrointestinal tract].

Body composition and energy expenditure were investigated before and 10-14 days after surgery in 44 patients with upper gastrointestinal cancer (23 esophageal and 21 gastric cancer) in order to assess the impact of preoperative weight loss on metabolic adaptation to the surgical trauma and on postoperative complications. Patients were divided in three groups with I: 0-5%, II: 5-10% and III: greater than 10% preoperative weight loss related to the usual body weight. 50% of the patients presented with no or just minor weight loss. Even in case of weight loss greater than 10% no decrease below the ideal body weight was observed. Body cell mass and fat mass were significantly (p less than 0.05) reduced in group III when compared with I. Since energy expenditure and substrate oxidation rates were rather normal in most patients weight loss was considered to be due to tumor related stenosis and dysphagia. More than 50% of the energy requirements were gained from fat oxidation. General criteria of malnutrition were not fulfilled. Perioperative weight loss was lowest (1.6 +/- 4.9 kg) in patients of group III related to group I (2.9 +/- 1.7 kg) and II (5.0 +/- 6.9 kg). Similar elevation of energy expenditure and lipid oxidation with concomitant reduction in glucose oxidation was observed in all groups of patients. This led to a similar decrease of body cell mass. Independent of preoperative weight loss major complications occurred in 8 cases--pneumonia in 6 and leakage of the anastomosis in 2 patients; no patient died. From this study can be concluded that with regard to perioperative weight loss the metabolic response to surgical trauma is adequate even in patients with marked preoperative weight loss. These patients remain compensated and preoperative weight loss is without major effect on postoperative complication rate.