Impact of Body Mass Index on Major Complications, Multiple Complications, In-hospital Mortality, and Failure to Rescue After Esophagectomy for Esophageal Cancer: A Nationwide Inpatient Database Study in Japan

Objective: To examine the association of BMI with mortality and related outcomes after oncologic esophagectomy. Summary Background Data: Previous studies showed that high BMI was a risk factor for anastomotic leakage and low BMI was a risk factor for respiratory complications after esophagectomy. However, the association between BMI and in-hospital mortality after oncologic esophagectomy remains unclear. Methods: Data for patients who underwent esophagectomy for esophageal cancer between July 2010 and March 2019 were extracted from a Japanese nationwide inpatient database. Multivariate regression analyses and restricted cubic spline analyses were used to investigate the associations between BMI and short-term outcomes, adjusting for potential confounders. Results: Among 39,406 eligible patients, in-hospital mortality, major complications, and multiple complications (≥2 major complications) occurred in 1069 (2.7%), 14,824 (37.6%), and 3621 (9.2%), respectively. Compared with normal weight (18.5-22.9 kg/m²), severe underweight (<16.0 kg/m²), mild/moderate underweight (16.0-18.4 kg/m²), and obese (â ‰¥27.5 kg/m²)were significantly associated with higher in-hospital mortality [odds ratio 2.20 (95% confidence interval 1.65-2.94), 1.25 (1.01-1.49), and 1.48 (1.05-2.09), respectively]. BMI showed U-shaped dose-response associations with mortality, major complications, and multiple complications. BMI also showed a reverse J-shaped association with failure to rescue (death after major complications). Conclusions: Both high BMI and low BMI were associated with mortality, major complications and multiple complications after esophagectomy for esophageal cancer. Patients with low BMI were more likely to die once a major complication occurred. The present results can assist with risk stratification in patients undergoing oncologic esophagectomy.