To close a large(more than 3cm diameter) malignant gastro-colonic fistula in a case of advanced pancreatic malignancy with previous attempts of closure using through the scope clips and over the scope (OTSC) clips unsuccessful. Moreover, comorbidities,advanced age and metastatic disease made surgical closure options very high risk in this case

After multidisciplinary discussion, a cardiac septal occluder device was chosen, typically used by interventional cardiologist for atrial septal defect (ASD) closure, as a salvage endoscopic procedure. A 36mm ASD occluder device– the largest size commercially available was selected. To ensure accurate orientation and optimal device positioning, simultaneous dual-endoscope technique was employed. A gastroscope was introduced through the stomach, and the colonoscope was advanced up to the defect at splenic flexure. This allowed both luminal openings to be visualized simultaneously. Under bidirectional endoscopic visualization and fluoroscopic guidance, the delivery system of 36mm ASD occluder device was advanced across the fistula tract through the gastric side into the colonic lumen. The distal (colonic) disc was first deployed, followed by gentle retraction to appose it against the colonic wall. Subsequently, the proximal (gastric) disc was released ensuring complete coverage of the fistulous orifice. The device was carefully observed to secure the site with good approximation and no immediate bleeding or leak was seen. Post-procedure fluoroscopy and barium study confirmed no contrast leak across the closure site. The patient tolerated the procedure well without any immediate complications

Over subsequent weeks, patient showed a marked clinical improvement with cessation of feculent vomiting, resolution of diarrhea, and gradual improvement in appetite. During 8 weeks of follow-up, patient maintained stable body weight, resumed normal oral nutrition, and remained asymptomatic. A repeat imaging at 8 weeks confirmed persistent closure of fistula with the device in situ with no evidence of leak or migration. Patient continued to receive supportive oncological care and nutritional supplementation

This case demonstrates that endoscopic deployment of a large (36mm) atrial septal occluder device can achieve closure even in malignant gastro-colonic fistulas where conventional approaches fail. It exemplifies the expanding frontier of interventional endoscopy through creative adaptation of cardiovascular technologies for complex gastroenterology pathologies. For patients unfit for the surgery, this approach offers an effective, safe, and minimally invasive palliative solution that can restore nutrition, and further improve quality of life. Continued innovation and structure clinical evaluation will define the precise role of these devices in future gastrointestinal oncology practice