124: DETERMINING SEVERITY OF ESOPHAGEAL ANASTOMOTIC LEAK IN PATIENTS AFTER ESOPHAGECTOMY: DEVELOPMENT OF THE SEAL SCORE.

Background and aim Anastomotic leakage (AL) is a common and severe complication after esophagectomy, but it is largely unknown how to assess leakage severity at the time of diagnosis. We aimed to develop the Severity of Esophageal Anastomotic Leak (SEAL) score, a tool to predict leakage severity at the time of diagnosis. Methods The TENTACLE—Esophagus study is an international retrospective cohort study, in which 1509 patients with AL after esophagectomy between 2011 and 2019 were included in 71 centers from 20 countries. Potential predictors of mortality were patient parameters at diagnosis (e.g. diet at diagnosis, organ failure) and leakage parameters (e.g. fluid collections, gastric tube condition, leakage circumference). Primary outcome was 90-day mortality. Logistic regression was used to develop the SEAL score, comprising four grades of leakage severity (i.e. mild, moderate, severe and critical). Severity grade cut-offs were predefined and based on the individually predicted risk of 90-day mortality: 0–5%, 5–15%, 15–25% and 25–100%, respectively. Internal validation was performed by bootstrapping. The study protocol is accessible at www.tentaclestudy.com. Results The 90-day mortality rate in the included 1509 patients was 11.7%. The model had good discrimination (c-index 0.77; 95%CI 0.73–0.82) and calibration (calibration intercept 0.00; 95%CI -0.17– 0.17; calibration slope 1.14; 95%CI 0.95–1.33) after internal validation. The model classified 25.9% leakage patients as mild, 50.6% as moderate, 13.1% as severe and 10.4% as critical. The in-hospital, 30-day, 90-day and 180-day mortality rates, length of (ICU) stay, time to leak healing, Comprehensive Complication Index and Esophageal Complication Consensus Group classification worsened statistically significantly with higher classes of AL severity. Conclusion Anastomotic leakage is a severe complication with a 90-day mortality rate of 11.7%. The Severity of Esophageal Anastomotic Leak (SEAL) score is a tool which combines 12 patient and leak parameters at time of leak diagnosis and comprises four classes of leakage severity based on individual predictions of mortality. The SEAL score is instrumental in understanding AL severity in clinical practice and may be used to correct for leakage severity when assessing the efficacy of different treatments of AL after esophagectomy. [ABSTRACT FROM AUTHOR]