INTRODUCTION: Endoscopic cryotherapy for the treatment of premalignant and malignant conditions has been demonstrated to be an effective tool in esophageal malignancy. However, there is concern for perforation from gas production during cryotherapy. Here we describe the use of a biliary dilation balloon to prevent distal gas accumulation in Roux-en-Y anatomy. CASE DESCRIPTION/METHODS: This is a case of a 77-year-old male with history of total gastrectomy with Roux-en-Y esophagojejunostomy for remote history of gastric leiomyosarcoma and locally advanced esophageal cancer. Two years prior he underwent Endoscopic Submucosal Dissection (ESD) of an esophageal nodule previously biopsied positively for adenocarcinoma. One year ago a surveillance EGD/EUS with biopsy showed no evidence of residual disease at the ESD site. Repeat surveillance EGD/EUS early this year identified thickening of subepithelial layers with a 6mm hypoechoic lesion at the level of the ESD scar. A hybrid ESD and endoscopic mucosal resection (EMR) technique was performed to remove the nodule. Pathology showed invasive poorly differentiated adenocarcinoma with the deeper cauterized margin involved. Endoscopic cryoablation was planned for the remaining margins. Close examination of the ESD defect using EGD and EUS showed no evidence of recurrence. Cryotherapy was then prepared with the insertion of a biliary dilation balloon via a nasal trumpet. The balloon was endoscopically guided to the jejunum distal to the esophagojejunal anastomosis and inflated to prevent distal leakage of cooling gases. A decompression tube was placed in the esophagus proximal to the treatment area. Using the cryocatheter, 3 treatments of liquid nitrogen at -190⁰ C were sprayed over the ESD scar to achieve uniform white frost, each treatment lasting 30 seconds with 60 seconds of defrost time between. Throughout the treatment, suction was provided via the decompression tube and the abdomen was palpated without significant distention. The patient tolerated the procedure well without complication and was discharged home. DISCUSSION: Gas by-products are produced during cryotherapy, which in the case of a patient with a Roux-en-Y, causes substantial risk for perforation. With a distally inflated biliary dilation balloon, gas is prevented from accumulating in the small intestine where it may be difficult to suction, reducing the risk of perforation. This technique may be applied to similar cases where perforation risk is elevated.