Abstract Body (Do not enter title and authors here): Introduction: Ascending aortic pseudoaneurysms are mostly related to either surgery or non-surgical trauma. Any pseudoaneurysm arising from graft anastomoses, regardless of size or location, must be repaired due to the potential for catastrophic rupture. Traditional surgical intervention has a high mortality rate, but percutaneous treatment has emerged as an alternative. We present such a case of pseudoaneurysm treated by percutaneous intervention using a 6-mm Amplatzer device. Case: A 77-year-old female with a history of type A aortic dissection s/p emergent repair with a 32 mm tube graft one year ago presented with chest pain radiating to her back. Initial vital signs showed a BP of 185/105, SaO2 98% on RA, 98.3 F, HR 98 bpm, and RR 24/min. A chest CT scan suggested a pseudoaneurysm at the proximal anastomotic site of the aortic graft (Figs. 1A and B). Serial troponin and EKGs were unremarkable for acute ischemia. Multiple quaternary centers declined intervention due to the high risk of redo sternotomy for open repair and patient frailty. After multidisciplinary discussions, it was felt that percutaneous closure with an Amplatzer device was possible without coronary obstruction. In the catheterization lab, a TEE probe was placed to visualize the pseudoaneurysm of the ascending aorta (Fig. 1C). Angiography showed the aneurysm coming off the posterior aorta just above the noncoronary cusp, with the neck measuring ~6 mm (Fig. 1D). The aneurysm was successfully engaged using an 8-French sheath and an 8-French AL1. Based on measurements from the TEE and the angiogram, a 6 mm ASO device was used. After device deployment and release, aortograms showed that the pseudoaneurysm was excluded (Fig. 1H). Assessment with TEE and CTA showed no residual flow in the pseudoaneurysm (Fig. 1 E–G). Conclusion: Using an atrial septal occluder, endovascular intervention may be a safe and effective alternative to surgery for treating the ascending aortic pseudoaneurysm, especially in patients with a high prohibitive surgical risk. Longitudinal follow-ups are needed to comment on long-term mortality benefits for these individuals.