332. OUTCOMES OF SALVAGE SURGERY FOR ESOPHAGEAL CARCINOMA: A NATIONWIDE COHORT STUDY

Abstract Background Compared to a standard resection, salvage esophagectomy is a more complex procedure and associated with increased postoperative morbidity and mortality. This study aimed to investigate short-term outcomes of salvage surgery for esophageal carcinoma and the influence of hospital volume and baseline characteristics on outcomes. Methods All patients undergoing esophagectomy for esophageal cancer registered in the Dutch Upper Gastrointestinal Cancer Audit (DUCA) between 2012-2022 in the Netherlands were included. Patients were classified as salvage or non-salvage by registering surgeons. The definition was: surgery after definitive chemoradiotherapy. Postoperative mortality (30-day/-in-hospital) and morbidity were compared between salvage and non-salvage patients using multilevel logistic regression analyses. Hospital variation in the use of salvage esophagectomy was investigated using funnel plots. The influence of annual hospital volume (<40->40) and annual salvage volume (<6->6) on outcomes of salvage patients were investigated. Using backward elimination, relevant baseline characteristics influencing outcomes after salvage surgery were identified. Results Between 2012-2022, 7,749 patients underwent esophagectomy, of whom 251 (3%) underwent salvage resection, varying from 0%-8% of esophagectomies between centers. Salvage surgery was associated with an increased risk of 30-day/in-hospital mortality (11% vs. 3%; OR:3.65; 95%CI:2.38-5.61) and severe complications (43% vs. 28%; OR:1.81; 95%CI:1.40-2.34). Salvage patients treated in high-volume esophagectomy centers (>40) had a decreased risk of 30-day/in-hospital mortality compared to low-volume centers (9% vs. 19%; OR:0.42; 95%CI:0.18-0.99), with no relation found between annual salvage volume and outcome. Certain baseline characteristics, foremost men, elderly (>75 years) and squamous cell carcinomas, were associated with worse short-term outcomes of salvage surgery. Conclusion Salvage surgery for esophageal carcinoma is infrequently but increasingly performed in the Netherlands, with wide hospital variation in its use. Salvage surgery is associated with worse short-term outcomes when compared with non-salvage esophagectomy. Outcomes after salvage surgery were favorable in high-volume esophagectomy centers, suggesting a volume-outcome relationship for salvage surgery.