Pathological findings of late stent thrombosis after paclitaxel-eluting stent implantation for superficial femoral artery disease.

A 76-year-old man presented with right critical limb ischemia. An angiography revealed right SFA occlusion. Therefore, two paclitaxel-eluting stents (Zilver PTXs 6.0 mm × 120 mm stents; Cook Medical, Bloomington, Indiana) were placed, which promoted good blood flow. Follow-up angiography at 6 months also showed no restenosis. However, 10 months later, the patient suddenly visited with acute-onset pain in the right leg. Computed tomography showed the acute occlusion at the stented SFA. Eventually, above-knee amputation was performed due to the poor general condition and progressive limb ischemia. As the pathological finding, heterogeneous neointima formation at the stented site was mainly found. Although neointimal layer consisting of smooth muscle cell (SMC) was partly observed, necrotic tissue was evident in the remaining portion. At the necrotic tissue site, the majority of the components of the material covered by the stent strut were fibrin deposits. The findings of regenerative endothelial cells were not observed at the luminal surface. Nuclei of medial SMCs were also lost between the arterial media and the stent strut. Late stent thrombosis after paclitaxel-eluting stenting for SFA lesion has not been sufficiently evaluated. Here, we report a case of late stent thrombosis with a review including pathological findings. <Learning objective: We reported that a 76-year-old man received paclitaxel-eluting stent for femoropopliteal disease. Ten months later, stent thrombosis was occurred and above-knee amputation was performed. As the pathological finding, heterogeneous neointima formation was mainly found and the regenerative endothelial cells were not observed. Our report suggested that delayed healing and uncovered strut caused by paclitaxel-exposure resulted in late stent thrombosis.>.