Infective Endocarditis Following Coil Embolization for a Visceral Pseudoaneurysm: A Case Report

Endovascular coil embolization is an effective, minimally invasive technique used to treat visceral pseudoaneurysms. Although rare, post-procedural infections such as bacteremia and infective endocarditis (IE) can occur, particularly in patients with underlying malignancy, valvular abnormalities, or immunosuppression. Early recognition and intervention are critical to preventing serious complications. A 52-year-old male with a history of renal cell carcinoma (post left nephrectomy) and a known heart murmur presented to the hospital with worsening left-sided abdominal pain. Imaging revealed multiple visceral pseudoaneurysms involving the hepatic, splenic, and mesenteric arteries. He underwent successful coil and glue embolization. Further workup with transesophageal echocardiography (TEE) revealed severe mitral regurgitation with vegetations and a flail posterior mitral leaflet. Blood cultures obtained after the embolization procedure were positive for Streptococcus mutans, confirming IE, and the patient subsequently underwent mitral valve replacement and pacemaker implantation at a cardiac hospital. He completed intravenous antibiotic therapy and was discharged in stable condition. Eighteen-month follow-up imaging showed evolving splenic infarcts without evidence of visceral pseudoaneurysms. This case highlights a rare but serious complication of coil embolization. While the causal link cannot be definitively confirmed, the sequence of events and known mechanisms of post-procedural bacteremia support a strong association. Factors such as the introduction of foreign material, ischemia-induced tissue vulnerability, and the presence of underlying malignancy may increase the risk of hematogenous bacterial seeding. Streptococcus mutans, though classically associated with dental flora, can exhibit invasive potential in vulnerable hosts. Cancer patients face elevated risks due to frequent vascular instrumentation and immunosuppressive treatments. High-risk patients may benefit from close post-procedural monitoring and early infectious workup. This case highlights the importance of species-level identification and clinical vigilance in preventing delayed diagnosis and complications.