Case Report of an Infectious Aortic Aneurysm Following Intravesical Bacillus Calmette‐Guérin Therapy After Transurethral Resection of a Bladder Tumor

Introduction: Intravesical Bacillus Calmette-Guérin (BCG) therapy is an established treatment for non-muscle-invasive bladder cancer. Although systemic BCG infection is rare, infectious aortic aneurysm is a potentially fatal complication. Case Presentation: BCG infection. Despite antituberculosis therapy, aneurysmal rupture with abscess progression occurred, necessitating prosthetic graft replacement with omental flap coverage. The patient recovered without recurrence after prolonged therapy. Conclusion: BCG-related infectious aortic aneurysm may develop even in the absence of fever or marked inflammatory response. Clinicians should suspect and consider early CT evaluation in patients with a history of intravesical BCG therapy when unexplained retroperitoneal or vascular abnormalities are identified, regardless of inflammatory status.