Very late intrastent thrombotic occlusion caused by neoatherosclerosis after bare-metal stent implantation in the superficial femoral artery: Insight from histopathological findings

Abstract

A 58-year-old male with gangrene in his left 1^st digit due to critical limb ischemia had undergone endovascular therapy for chronic total occlusion of the left superficial femoral artery using bare-metal stents (BMSs). Angiography revealed in-stent occlusion of the BMS site when he was referred to our hospital with a recurrent ulcer at 7 years after stent implantation. As catheter-directed thrombolysis with urokinase was not effective, surgical thrombectomy was performed. His ankle-brachial index improved, and the ulcer was completely healed after thrombectomy. Pathological evaluation of the retrieved thrombi showed that it consisted of a massive erythrocyte, abundant fibrin precipitation, and fragments of atherosclerotic plaques, such as foamy macrophages and ghost images thought to be cholesterol crystals. These findings suggested that the neoatherosclerotic changes in the neointima gradually occurred in the stented segment, and neointimal disruption potentially caused the intrastent thrombotic occlusion. <Learning Objective: Although endovascular treatment for peripheral artery disease has gained widespread acceptance, in-stent occlusion (ISO) remain a serious concern after stent implantation. However, the mechanism of ISO has not been well elucidated. In this case, the histopathological findings suggested that neoatherosclerotic changes in the neointima occurred in the lower limb arteries and the disruption of in-stent neoatherosclerosis after bare metal stent implantation may cause intrastent thrombotic occlusion.>.

Keywords: Endovascular therapy; In-stent occlusion; Neoatherosclerosis; Pathology; Superficial femoral artery.