A Four-Year Silence: Late-Onset Stent-Graft Endocarditis Due to Rare Enterobacter hormaechei Diagnosed via Transesophageal Echocardiography

Stent-graft infection (SGI) after thoracic endovascular aortic repair (TEVAR) is a rare but life-threatening complication. We report a case of a male patient who presented four years after TEVAR with systemic sepsis. At admission, laboratory investigations revealed a marked inflammatory response with a C-reactive protein (CRP) level of 212 mg/dL and a procalcitonin level of 23.30 progression. Diagnostic workup identified multidrug-resistant (MDR) Enterobacter hormaechei bacteremia. While transthoracic imaging was inconclusive, transesophageal echocardiography (TEE) confirmed a 6.6 x 5 mm mobile, fibrillar vegetation on the luminal surface of the aortic stent-graft, accompanied by severe aortic regurgitation. Following susceptibility results, the initial trimethoprim/sulfamethoxazole treatment was discontinued, and targeted intravenous gentamicin was initiated. Following the switch to gentamicin, a prompt therapeutic response was achieved, and inflammatory markers showed a significant downward trend. After multidisciplinary evaluation with the cardiovascular surgery department, a conservative management approach was adopted due to high operative risk. The patient remains under stable clinical follow-up. This case underscores the diagnostic necessity of TEE and the importance of targeted aminoglycosides in managing late-onset MDR prosthetic infections, especially when surgical intervention is not feasible.