Infectious Aortitis Following Peripheral Angiographic Catheterization

Abstract

Infectious aortitis and mycotic aneurysms are rare but potentially fatal conditions that often present with nonspecific symptoms, delaying diagnosis and treatment. The growing use of endovascular interventions has introduced new pathways for infection, particularly in high-risk individuals with vascular implants. We report the case of a 67-year-old man with coronary artery disease who developed persistent lower back pain and systemic symptoms following peripheral angiographic catheterization and covered iliac stent implantation. Blood cultures repeatedly grew Staphylococcus lugdunensis (S. lugdunensis), a virulent coagulase-negative staphylococcus known for its biofilm-forming capacity. CT angiography and 18F-fluorodeoxyglucose (FDG) PET-CT revealed an infected aortic pseudoaneurysm with perivascular inflammation, consistent with infectious aortitis and device-related infection. Despite targeted intravenous antibiotics, bacteremia persisted, indicating failure of conservative management. Surgical intervention was planned but ultimately declined by the patient, who deteriorated and passed away shortly after discharge. This case highlights a rare instance of S. lugdunensis-associated infectious aortitis arising from a covered iliac stent. The persistent bacteremia despite appropriate antibiotic therapy strongly suggests biofilm-mediated infection, underscoring the limitations of medical therapy alone in managing device-associated infections. PET-CT proved instrumental in detecting metabolically active infection when anatomical imaging was inconclusive. Clinicians should maintain a high index of suspicion for infectious aortitis in patients with vascular implants presenting with systemic symptoms and persistent bacteremia. Early use of PET-CT and timely multidisciplinary evaluation are essential for diagnosis and management. This report adds to the limited literature on peripheral stent-associated infections, particularly those caused by S. lugdunensis, and underscores the need for heightened post-procedural vigilance in similar cases.

Keywords: false aneurysm; infectious aortitis; percutaneous coronary intervention complications; sepsis; staphylococcus lugdunensis.

Figure 1. Abdominal aorta at the iliac bifurcation level and both common iliac arteries in their proximal segments

Concentric perivascular hypodense soft tissue thickening is observed, reaching up to 6 mm at its thickest point, which was not seen in the previous examination. This may represent perivascular hematoma or aortitis, but infectious phlegmon is also a possibility in this patient. The stent is noted in the left common iliac artery. Contrast filling within the stent lumen is normal at this level; however, immediately at the iliac bifurcation level, near the origin of the left common iliac artery, a 21x12 mm contrast-filled pouch is seen posteriorly, suggestive of an endoleak with secondary pseudoaneurysm. L: left; R: right

Figure 2. A full-body 18F-fluorodeoxyglucose (18F-FDG) PET-CT revealed increased perivascular thickening and FDG uptake (maximum standard unit value (SUVmax) 9.17) along the distal abdominal aorta and common iliac arteries, with inflammatory involvement of the anterior L4-L5 vertebrae and disc. A hypermetabolic (SUVmax 7.51) 10 mm inter-aortocaval lymph node was also detected.