Fatal invasive fungal infection morphologically consistent with aspergillosis accompanied by vascular graft infection and marked eosinophilia after thoracic endovascular aneurysm repair.

Fungal vascular graft infection is rare and difficult to diagnose, particularly when caused by filamentous fungi morphologically consistent with Aspergillus species. A Japanese man in his 60s who had undergone thoracic endovascular aneurysm repair for a saccular aortic arch aneurysm 2 months earlier was referred to our hospital with marked eosinophilia and left renal infarction. Contrast-enhanced computed tomography showed graft thrombosis. Repeated blood cultures were negative, and extensive evaluation did not identify a definitive cause of eosinophilia. On hospital day 17, he developed rapidly progressive respiratory failure. Despite systemic glucocorticoid therapy, invasive mechanical ventilation, and continuous hemodiafiltration, his condition deteriorated. Repeat computed tomography showed progression of graft thrombosis with near-complete obstruction of the descending aorta, and he died on hospital day 22. Autopsy revealed invasive septate hyphae with acute-angle branching in the aortic wall around the stent graft, adjacent lung, mesenteric vessels, and portal vein, which is consistent with disseminated invasive filamentous fungal infection morphologically suggestive of Aspergillus species. Molecular identification was unsuccessful, and other hyaline molds could not be completely excluded. This case highlights the importance of considering fungal vascular graft infection in patients with unexplained fever, embolic events, and progressive graft thrombosis after endovascular repair, even when blood cultures are negative. Marked eosinophilia was also present, but its relationship with invasive fungal infection could not be determined. Rather than serving as a diagnostic clue, the eosinophilia prompted an extensive alternative workup that may have diverted attention from vascular graft infection.