787. THE CHALLENGE OF GASTRO-ESOPHAGEAL ONCOLOGICAL SURGERY AFTER BARIATRIC PROCEDURES: EXPERIENCE OF A REFERRAL HIGH-VOLUME UPPER GI SURGICAL CENTER

Background The effectiveness of bariatric surgery for weight loss in morbidly obese patients has been well established and it's becoming more common as many surgeons are trained to perform them safely, even in older patients. Obesity is associated with reflux and hormonal imbalances that increase the risk of Barrett's esophagus, esophageal adenocarcinoma and gastric cancer. Bariatric procedures alter gastric anatomy, vascularization and lymphatic drainage and render subsequent upper gastrointestinal surgery for malignancies a technical challenge, that will present more and more in the future. We present laparoscopic sleeve gastrectomy, gastric bypass and gastric banding conversion to oncological respective surgeries. Methods We retrospectively reviewed the medical records of our referral high-volume center for upper gastrointestinal surgery and identified patients who underwent upper gastrointestinal oncologic surgery from January 1998 to May 2024. We selected all patients who had previously undergone bariatric surgery (laparoscopic sleeve gastrectomy, laparoscopic gastric bypass, gastric banding, or other less common procedures). Three patients met our criteria, and we recorded: demographic characteristics, surgical technique, oncologic surgical outcome, postoperative complications, long-term complications, and oncologic follow-up. Results A hybrid IvorLewis esophagectomy was performed years after a sleeve gastrectomy for distal esophageal adenocarcinoma. The sleeve was used for gastric pull-up, adequately vascularized by the right gastroepiploic artery as demonstrated by intraoperative indocyanine green. A patient developed adenocarcinoma of the cardia after Roux-en-Y gastric bypass, infiltrating the gastric pouch, the gastric remnant and liver S2. After neoadjuvant chemotherapy, an open Ivor-Lewis esophagectomy was performed using the gastric remnant for a pull-up. In a third patient, a locally advanced adenocarcinoma of the stomach developed after gastric banding. After neoadjuvant chemotherapy, an open total gastrectomy with Roux-en-Y esophagojejunostomy was performed. Conclusion We report three cases of successful esophago-gastric oncological surgery in patients with altered anatomy and vascularization due to previous bariatric surgery, without major postoperative complications or mortality. Oncologic benchmarks for both esophageal and gastric surgery were met as a high lymph node yield and oncologic margins were maintained. Our heterogeneous series suggests that sleeve gastrectomy, gastric bypass, and gastric banding surgery can be successfully converted to resective surgeries after a metachronous neoplasia diagnosis in high-volume upper gastrointestinal centers. These and similar modified reconstructive techniques are likely to be used in the future as metabolic surgery and esophago-gastric cancer are increasing.