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

AbstractA 76-year-old man presented with right critical limb ischemia. An angiography revealed right SFA occlusion. Therefore, two paclitaxel-eluting stents (Zilver PTXs 6.0mm×120mm 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.

1-Year Results of the ZEPHYR Registry (Zilver PTX for the Femoral Artery and Proximal Popliteal Artery) Predictors of Restenosis

AbstractObjectivesThis study sought to assess the rate and predictors of 1-year restenosis after drug-eluting stent implantation for femoropopliteal (FP) lesions in patients with peripheral arterial disease.BackgroundZilver PTX, a paclitaxel-eluting stent for FP lesions, provides superior outcomes to angioplasty and bare-metal stents in clinical trials. However, its real-world outcomes and the associated features remain unclear.MethodsThis was a prospective multicenter study enrolling 831 FP lesions (797 limbs, 690 patients) treated by Zilver PTX implantation. The primary endpoint was 1-year restenosis. Secondary endpoints included major adverse limb event and stent thrombosis.ResultsMean lesion length was 17 ± 10 cm. One-year restenosis, major adverse limb event, and stent thrombosis rates were 37%, 22%, and 2%, respectively. The generalized linear mixed model showed that lesion length ≥16 cm assessed by angiography and distal external elastic membrane area ≤27 mm2 and minimum stent area ≤12 mm2 assessed by intravascular ultrasound were independent risk factors for restenosis. One-year restenosis rates were 15% in cases with none of these risk factors and 50% in those with ≥2 risk factors.ConclusionsThe current study demonstrated 1-year real-world outcomes after drug-eluting stent treatment for FP lesions, including challenging ones in clinical practice. Lesion length, external elastic membrane area, and minimum stent area were independent predictors for restenosis. (Zilver PTX for the Femoral Artery and Proximal Popliteal Artery—Prospective Multicenter Registry [ZEPHYR]; UMIN000008433