Study of Eso-SPONGE for Treating Leaks After Upper Gastrointestinal Surgery

Inclusion Criteria 1. Confirmed Type II anastomotic leaks in the esophagus or stomach * Type I: Leak requiring no change in treatment * Type II: Leak requiring intervention but not surgery * Type III: Leak requiring surgical intervention 2. Subject has an anastomotic leak in the esophagus or stomach that is endoscopically accessible within the range of the overtube length. 3. Subject is eligible for endoscopic intervention. 4. Subject has a transmural defect of at least 2 cm in diameter in the esophagus or stomach. 5. Subject understands the trial requirements and is willing and able to comply with the study procedures, all protocol-required follow up evaluations and provide written informed consent to participate in the study. 6. Investigator decision that EVT is the most suitable treatment of the available treatment options. Exclusion Criteria: 1. Subject is under 18 years of age. 2. Potentially vulnerable subject, including, but not limited to pregnant women. 3. Subject has undergone EVT or other similar interventions for the current leak. 4. Subject had upper gastrointestinal surgery resulting in the leak more than 60 days prior to the planned study procedure. 5. Subject has any necrotic tissue that would require endoscopic debridement prior to Eso-SPONGETM placement. 6. Subject has known contraindication for EVT as per the Investigator Brochure (IB) 7. Subject is currently enrolled in another investigational study that would directly interfere with the current study, without prior written approval from the sponsor.