An 80-year-old woman presented with epigastric pain. Contrast-enhanced computed tomography (CECT) revealed a suspected mycotic aneurysm near the celiac axis. Empirical antibiotic therapy was initiated, resulting in decreased inflammatory markers. However, follow-up CECT on day 10 showed progressive aneurysmal enlargement. Surgical intervention was performed via midline laparotomy, with visceral debranching using a Y-graft from the left common iliac artery to the superior mesenteric and common hepatic arteries. This was followed by thoracic endovascular aortic repair (TEVAR). Given the patient’s advanced age and frailty, hybrid repair with abdominal debranching TEVAR was considered a less invasive alternative to conventional thoracoabdominal aortic replacement.