P1.207. Reduced Risk of Postoperative Chyle Leak in Patients With Obesity After Esophagectomy for Esophageal Cancer - a Nationwide Cohort Study

Abstract

Esophageal Cancer: Surgical Treatment of Esophageal Cancer – early outcomes and complications Esophagectomy is a cornerstone in the treatment of esophageal cancer. Although postoperative chyle leak (PCL) is uncommon, it is clinically important due to its associated morbidity and often challenging management. This study aimed to investigate risk factors for PCL and associations with survival in a nationwide cohort. All patients with esophageal cancer, registered in the Swedish National Registry for Esophageal and Gastric Cancer (NREV) between 2006 and 2025, were included. The study represents an updated analysis of PCL in NREV, including an expanded cohort with extended follow-up. Directed acyclic graphs (DAGs) were used to identify confounders and guide covariate selection. Missing data for key variables were handled with multiple imputation. Variables associated with PCL were analyzed with adjusted multivariable logistic regression, and estimates were pooled according to Rubin’s rules. Overall and adjusted survival were assessed with the Kaplan–Meier method and Cox proportional hazards regression. A total of 3,182 patients with esophageal cancer undergoing esophagectomy were included. PCL occurred in 97 patients (3.0%), of whom 57 (58.8%) required interventional radiology or surgical management. Patients with PCL had a longer median hospital stay compared with those without PCL (23 vs. 14 days, p <0.001). In multivariable logistic regression, overweight patients (BMI >25) and patients with obesity (BMI >30) had a significantly lower risk of PCL (OR 0.60 [95% CI 0.37–0.98]; OR 0.43 [95% CI 0.21–0.88], respectively). Neoadjuvant chemo- or chemoradiotherapy was associated with an increased risk of PCL (OR 2.92 [95% CI 1.47–5.81]). There was no significant association between PCL and overall survival. PCL is a clinically important complication after esophagectomy, prolonging hospitalization and often requiring reintervention. Overweight patients and patients with obesity appear to have a lower risk of PCL, possibly due to a reduced risk of accidental thoracic duct injury in an adipose mediastinum. Neoadjuvant treatment was associated with an increased risk of PCL. In contemporary clinical practice, PCL does not appear to compromise long-term survival. Further studies on preventive strategies and perioperative management are warranted.