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.

Vessel Patency and Associated Factors of Drug-Coated Balloon for Femoropopliteal Lesion

Background Although clinical trials have reported favorable outcomes after drug-coated balloon (DCB) therapy for femoropopliteal lesions, their real-world performance and predictors have not been well evaluated. This study aimed to elucidate 1-year freedom from restenosis and to explore the associated factors after a DCB for femoropopliteal lesions in clinical settings. Methods and Results This multicenter, prospective cohort registered 3165 de novo or restenotic femoropopliteallesions (mean lesion length, 13.5±9.3 cm; chronic total occlusion, 25.9%; severe calcification, 14.6%) that underwent successful DCB (Lutonix [24.2%] and IN.PACT Admiral [75.8%]) treatment between March 2018 and December 2019. Patency was assessed at 12±2 months. The primary outcome measure was 1-year freedom from restenosis and its associated factors. Bailout stenting was performed in 3.5% of patients. The postprocedural slow flow phenomenon was observed in 3.9% of patients. During a median follow-up of 14.2 months, 811 patients experienced restenosis. The Kaplan-Meier estimate of freedom from restenosis was 84.5% at 12 months (79.7% at 14 months). Focal, tandem, diffuse, and occlusive restenosis accounted for 37.4%, 9.8%, 18.9%, and 33.9%, respectively. Freedom from target lesion revascularization was 91.5% at 12 months. Risk factors independently associated with 1-year restenosis were a history of revascularization, smaller distal reference vessel diameter, severe calcification, chronic total occlusion, low-dose DCB, and residual stenosis. Conclusions The 1-year clinical outcomes after DCB use for femoropopliteal lesions in real-world practice was favorable. The additive risk factors were associated with a lower rate of freedom from restenosis

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

Polymer-Based Drug-Eluting Stent Treatment Extends the Time to Reintervention for Patients With Symptomatic Femoropopliteal Artery Disease: Clinical Evidence and Potential Economic Value

Aim: Use long-term follow-up data from the IMPERIAL study to determine whether drug-eluting polymer-based nitinol stent treatment can delay the time to repeat intervention for femoropopliteal artery disease and how such a delay may result in cost savings in a value-based episode of care. Patients & methods: The IMPERIAL randomized controlled trial was an international study of a paclitaxel-eluting polymer-coated stent (Eluvia, Boston Scientific, MA, USA) versus a polymer-free paclitaxel-coated stent (Zilver PTX, Cook Corporation, IN, USA) for treating lesions of the femoropopliteal arterial segment. Study patients (n = 465) had symptomatic lower limb ischemia. Safety and efficacy assessments were performed through 5 years. Mean time to first reintervention was calculated in post-hoc analysis for patients who underwent a clinically driven target lesion revascularization (CD-TLR) through 3 or 5 years following the index procedure. To simulate potential cost savings associated with differential CD-TLR burden over time, a cost-avoidance analysis using input parameters from IMPERIAL and US 100% Medicare standard analytical files was developed. Results: Among patients with a first CD-TLR through 3 years of follow-up, mean time to reintervention was 5.5 months longer (difference 166 days, 95% CI: 51, 282 days; p = 0.0058) for patients treated with Eluvia (n = 56) than for those treated with Zilver PTX (n = 30). Through the 5-year study follow-up period, CD-TLR rates were 29.3% (68/232) for Eluvia and 34.2% (39/114) for Zilver PTX (p = 0.3540) and mean time to first reintervention exceeded 2 years for patients treated with Eluvia at 737 days versus 645 days for the Zilver PTX group (difference 92 days, 95% CI: -85, 269 days; p = 0.3099). Simulated savings considering reinterventions occurring over 1 and 5 years following initial use of Eluvia over Zilver PTX were US $1,395,635 and US$1,531,795, respectively, when IMPERIAL CD-TLR rates were extrapolated to 1000 patients. Conclusion: IMPERIAL data suggest initial treatment with Eluvia extends the time patients spend without undergoing reintervention. This extension may be associated with cost savings in relevant time frames