Abstract Body (Do not enter title and authors here): Background
Aortic root pseudoaneurysm is a rare but life-threatening complication of cardiac surgery or infective endocarditis. Early diagnosis and surgical repair are vital due to rupture, embolization, and hemodynamic compromise risks. We present a case of pseudoaneurysm formation following bicuspid aortic valve (BAV) endocarditis and root reconstruction.

Case Summary
A 70-year-old male with chronic back pain and benign prostatic hyperplasia presented with acute-on-chronic back pain, fever, and signs of sepsis. Blood cultures grew oxacillin-sensitive Staphylococcus aureus. Initial transesophageal echocardiography (TEE) showed reduced ejection fraction (EF 30–35%), severely calcified BAV with moderate insufficiency, but no vegetations. Coronary angiography revealed non-obstructive disease. He was treated with IV antibiotics and discharged to inpatient rehabilitation.

Soon after, he re-presented with neurological deficits. Imaging revealed a right middle cerebral artery infarct and left occipital hemorrhage, suspected due to septic emboli or ruptured mycotic aneurysm. Repeat TEE showed severe aortic regurgitation, leaflet perforation, and perivalvular abscess. Emergent surgery included aortic valve replacement, abscess debridement, pericardial patch aortic root reconstruction, and anterior mitral leaflet repair. Pathology confirmed active endocarditis with vegetations and abscesses. Postoperative TEE showed a stable prosthesis and improved EF (40–45%). He completed antibiotics and was discharged home.

TEE done at a routine follow-up three years later revealed an echogenic sinus of Valsalva structure with a >1.2 cm wide neck communicating with the ascending aorta—findings consistent with pseudoaneurysm from pericardial patch dehiscence. Redo sternotomy and a modified Bentall procedure were performed, including explantation of the bioprosthesis, root and valve replacement with a bioprosthetic conduit, ascending aorta replacement, and coronary reimplantation. The procedure was successful with preserved cardiac function and clinical improvement.

Discussion
This case illustrates the severe sequelae of BAV endocarditis, including late pseudoaneurysm formation post-reconstruction. Contributing factors may include persistent infection, mechanical stress, and impaired healing. Given the significant mortality risk of rupture, early detection, prompt surgical intervention, and ongoing multidisciplinary surveillance are essential for optimal management.