Body composition and post-operative outcomes after minimally-invasive esophagectomy

<h2>Abstract</h2><h3>Objective</h3> Esophagectomy is a complex operation associated with significant morbidity for fit patients. Risk calculation is essential to guide pre-operative patient selection. This study used CT-derived body composition measures and age to develop a model for the prediction of postoperative mortality after minimally-invasive esophagectomy. <h3>Methods</h3> Patients who underwent minimally-invasive esophagectomy from 2010-2022 were identified. Preoperative CT scans at the L3-vertebral level were analyzed to calculate skeletal muscle gauge (SMG) as the product of skeletal muscle index and density. Patient demographics, clinical characteristics, and outcomes were collected. Patients were grouped based on SMG (low muscle=bottom quartile vs normal muscle=top 3 quartiles) and age (≥75 vs <75 years). Ninety-day postoperative mortality was compared between risk groups. <h3>Results</h3> Of 399 patients<b>,</b> mean age was 62.8 years. Anastomotic leak occurred in 8.3%, pneumonia in 17.0%, discharge to home in 81.5% and 90-day mortality in 5.5%. Ninety-day mortality by risk group showed 1.8% mortality for patients <75 years with normal muscle (n=281), 10% mortality for patients <75 years with low muscle (n=72), 5.6% mortality for patients ≥75 years with normal muscle (n=18), and 32% mortality among patients ≥75 years with low muscle (n=28). <h3>Conclusions</h3> Low-risk patients (<75 years with normal muscle), which comprised 70% of our study cohort, had favorable outcomes with 1.8% 90-day postoperative mortality. Contrastingly, patients ≥75 years with low muscle measures were at high risk with 32% mortality. Predictive models including SMG and age can identify high-risk groups and predict postoperative mortality after minimally-invasive esophagectomy.