Impact of Body Mass Index on Major Complications, Multiple Complications, In-hospital Mortality, and Failure to Rescue After Esophagectomy for Esophageal Cancer

To examine the association of BMI with mortality and related outcomes after oncologic esophagectomy.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.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.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/m 2 ), severe underweight (<16.0 kg/m 2 ), mild/moderate underweight (16.0-18.4 kg/m 2 ), and obese (≥27.5 kg/m 2 )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).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.