S5195 Palliative EUS-Guided Enterocolostomy (EUS-EC) for Management of Malignant Small Bowel Obstruction (MSBO) From Metastatic Gastric Cancer

Introduction: Malignant small bowel obstruction (MSBO) challenges management in advanced GI malignancies. Surgery carries high morbidity, especially with peritoneal carcinomatosis. Endoscopic ultrasound-guided enterocolostomy (EUS-EC) offers minimally invasive palliation when surgery isn't feasible. Case Description: A 55-year-old man with prediabetes presented with abdominal symptoms in 2024. Imaging showed hydronephrosis, misty small bowel, and retroperitoneal lymphadenopathy. A December esophagogastroduodenoscopy/colonoscopy revealed poorly differentiated gastric carcinoma with signet cells and ascending colon obstruction due to extrinsic compression. One month after starting palliative folinic acid, fluorouracil and oxaliplatin, he developed abdominal distension with small bowel dilation and ascites requiring total parenteral nutrition and nasogastric decompression concerning for MSBO. Large volume paracentesis provided temporary relief, but MSBO persisted despite additional chemotherapy cycles. February imaging showed distended small bowel (11 cm) and malignant ascites with peritoneal thickening from which the patient was still symptomatic. Multidisciplinary tumor board deemed chemotherapy ineffective, and the patient was not a surgical candidate. Given ongoing symptoms, the decision was made to proceed with EUS-EC for palliation of MSBO. After a 4.8 L paracentesis, an unprepped lower EUS was performed. A dilated small bowel loop was identified. There was a small amount of intervening ascites, but a suitable window was located to perform EUS-EC. Under both sonographic and fluoroscopic guidance, the small bowel loop was accessed using a 19-gauge needle. Liquid stool was aspirated, then a 15 mm × 10 mm freehand cautery enhanced lumen-apposing metal stent was used to create an enterocolostomy with immediate decompression of the bowel noted endoscopically. Within 24 hours, the nasogastric tube was removed and the patient tolerated clear liquids. On day 3, normal bowel movements resumed, and he was advanced to a pureed diet. Per patient preference, he was transitioned to hospice and passed away 13 days later without recurrence of MSBO. Discussion: This case demonstrates the utility of EUS-EC for palliative MSBO management. With advancing EUS capabilities and increasing gastrointestinal malignancies, more non-surgical candidates will benefit from EUS-EC when conventional stenting isn't possible. Our case highlights the importance of multidisciplinary management and pre-procedural paracentesis prior to EUS-directed therapy.