Five-year outcomes of self-expanding nitinol stent implantation for chronic total occlusion of the superficial femoral and proximal popliteal artery

Influence of concomitant percutaneous transluminal angioplasty with percutaneous coronary intervention on clinical outcomes of stable lower extremity artery diseases

Concomitant percutaneous transluminal angioplasty (PTA) at the time of percutaneous coronary intervention (PCI) is often performed because lower extremity artery disease (LEAD) commonly coincides with coronary artery disease. We investigated the impact of concomitant PTA on both cardiovascular and limb outcomes in the Korean National Health Insurance Service registry. Among 78,185 patients undergoing PCI, 6563 patients with stable LEAD without limb ischemia were included. After 1:5 propensity score matching was conducted, 279 patients in the PTA + PCI group and 1385 patients in the PCI group were compared. Multivariate Cox proportional hazard models showed that the risk of all-cause death was higher in the PTA + PCI group than in the PCI group, whereas the risks of myocardial infarction, repeat revascularization, stroke, cardiovascular death and bleeding events were not different between the 2 groups. In contrast, the risks of end-stage renal disease and unfavorable limb outcomes were higher in the PTA + PCI group. Mediation analyses revealed that amputation and PTA after discharge significantly mediated the association between concomitant PTA and all-cause death. Concomitant PTA was not associated with an increased risk of cardiovascular events but may increase the risk of all-cause death mediated by unfavorable renal and limb outcomes in patients with stable LEAD.

Angiographic flow velocity predicts lower limb outcomes after endovascular therapy: Application of the frame count method

INTRODUCTION

Several factors related to lesion characteristics and endovascular therapy (EVT) procedures have been reported to affect primary patency after EVT. However, it is unknown why these factors were associated with primary patency. We hypothesized patency failure was related to poor blood flow in affected arteries.

METHODS

This retrospective study included 131 consecutive patients who had received EVT with bare metal stents for peripheral artery disease caused by femoropopliteal artery lesions. Based on the tertile post-EVT flow velocity of the superficial femoral artery (SFA), patients were divided into high (n = 43), middle (n = 44), and low (n = 44) flow velocity groups. Flow velocity was measured using the frame count method. We measured incidence of major adverse limb events (MALE), composed of target lesion revascularization (TLR), non-TLR, and major amputation.

RESULTS

At a median follow-up period of 22.7 months, MALE had occurred in 7 (16.3%), 10 (22.7%), and 29 (65.9%) of patients from the high, middle, and low SFA flow velocity groups, respectively (p < 0.001). Kaplan-Meier analysis showed incidence of MALE was significantly higher in the patients of low SFA flow velocity (log-rank test χ² = 38.8, p < 0.001). Multivariate analysis found low SFA flow velocity to be an independent predictor for MALE (hazard ratio: 4.42; 95% CI: 2.27 to 8.60; p < 0.001) as was ankle-brachial index.

CONCLUSION

Post-EVT SFA flow velocity for femoropopliteal artery lesions treated with bare metal stents is an independent predictor of limb patency. The frame count method for assessing arterial flow velocity is convenient and has potential for wide applications in EVT.

Endovascular Treatment of Long Femoropopliteal Lesions with Contiguous Bare Metal Stents

OBJECTIVES

Recent controversies on the use of drug coated/eluting devices in the arteries of the lower extremities renewed the focus on the evaluation of more conventional techniques. The results of the stenting of short and/or intermediate femoro-popliteal lesions are well known, but little data relate to the endovascular treatment of long femoro-popliteal lesions with contiguous bare metal stents (ETLFBS). The objective of this study was to report our results of ETLFBS.

MATERIAL AND METHODS

Between January 2014 and December 2017, 1233 patients had an infrainguinal angioplasty in our center. The files of patients treated for femoropopliteal lesions longer than 250 mm using extensive stenting with contiguous bare metal stents were reviewed and analyzed. The primary outcome was the 12-month primary patency, defined by the absence of restenosis (≥50%) and/or reintervention on the target lesion. Continuous data were expressed as mean and standard deviation. Survival analysis was carried out according to Kaplan-Meier.

RESULTS

Overall, 64 patients aged 80 ± 11 years were included, with 49 (76.6%) presenting with critical limb ischemia. Lesions were classified as TASC D in 54.7% of the cases. The length of the lesions was 295 ± 64 mm and 3 ± 1 stents were implanted. The 30-day mortality was null but two patients (3.1%) presented nonvascular major complications. With a follow-up of 27 ± 17 months, 22 patients (34.3%) died including three of vascular causes. The healing of the trophic disorder was obtained in 77.5% of the cases. The rate of amputation was 10.9%. The 6-, 12-, and 24-month primary patency rates were 79.7%, 66.6%, and 60.9%, respectively. The 6-, 12-, and 24-month rates of freedom from target lesion revascularization were 96.3%, 73.9%, and 71.9%, respectively. The 6-, 12-, and 24-month survival rates were 90.3%, 83.6%, and 65.6%, respectively.

CONCLUSIONS

The 12-month primary patency rate of ETLFBS is acceptable. This strategy constitutes an acceptable alternative in patients presenting with critical limb ischemia and a limited life expectancy.

Advances in Revascularization for Peripheral Artery Disease: Revascularization in PAD

Effective revascularization of the patient with peripheral artery disease is about more than the procedure. The approach to the patient with symptom-limiting intermittent claudication or limb-threatening ischemia begins with understanding the population at risk and variation in clinical presentation. The urgency of revascularization varies significantly by presentation; from patients with intermittent claudication who should undergo structured exercise rehabilitation before revascularization (if needed) to those with acute limb ischemia, a medical emergency, who require revascularization within hours. Recent years have seen the rapid development of new tools including wires, catheters, drug-eluting technology, specialized balloons, and biomimetic stents. Open surgical bypass remains an important option for those with advanced disease. The strategy and techniques employed vary by clinical presentation, lesion location, and lesion severity. There is limited level 1 evidence to guide practice, but factors that determine technical success and anatomic durability are largely understood and incorporated into decision-making. Following revascularization, medical therapy to reduce adverse limb outcomes and a surveillance plan should be put in place. There are many hurdles to overcome to improve the efficacy of lower extremity revascularization, such as restenosis, calcification, microvascular disease, silent embolization, and tools for perfusion assessment. This review highlights the current state of revascularization in peripheral artery disease with an eye toward technologies at the cusp, which may significantly impact current practice.

Comparison of ultrasound-guided versus angiography-guided endovascular treatment for femoropopliteal artery occlusive disease

PURPOSE

This study aimed to compare the efficacy of ultrasound-guided and angiography-guided intraluminal approach for femoropopliteal (FP) artery occlusive disease.

METHODS

A retrospective analysis was performed using the data collected regarding patients that underwent endovascular treatment (EVT) for FP artery occlusive disease between January 2010 and April 2018 at two centers. A total of 221 consecutive de novo lesions were analyzed according to the method of recanalization. Propensity score-matched analysis was performed to compare the clinical outcomes of recanalization methods for FP occlusive lesions. The prognostic value was analyzed based on the number of guidewires, wire cross time, distal puncture rate, radiation exposure, the amount of contrast media, primary patency, and clinically driven-target lesion revascularization (CD-TLR) at 1 year.

RESULTS

A total of 44 matched pairs of patients were analyzed after propensity score-matched analysis. The number of guidewires, distal puncture rate, wire passage time, radiation exposure, and the amount of contrast media were significantly lower in the ultrasound-guide group, with 3.4 vs. 4.7, 9.1% vs. 54.5%, 47 min vs. 83 min, 207 mGy vs. 821 mGy, 66 ml vs. 109 ml, respectively (p < .01), but there were no significant differences between the two groups in terms of primary patency and CD-TLR.

CONCLUSIONS

The ultrasound-guided EVT for FP occlusive disease significantly reduced the number of guidewires, wire cross time, the rate of distal puncture, radiation exposure, and the amount of contrast media used.

Drug-Coated Balloon Treatment for Femoropopliteal Artery Disease: The Chronic Total Occlusion Cohort in the IN.PACT Global Study

OBJECTIVES

This study evaluated the 12-month safety and effectiveness of a paclitaxel drug-coated balloon for treatment of intermittent claudication or rest pain in subjects with femoropopliteal chronic total occlusions (CTO).

BACKGROUND

CTOs are difficult to treat, and the optimal intervention remains to be determined.

METHODS

The IN.PACT Global Study is an international single-arm study that enrolled 1,535 patients with symptomatic femoropopliteal artery disease. The study contains prospectively defined cohorts with prospectively planned imaging analyses, including a CTO (≥5 cm) cohort in which subjects underwent duplex ultrasonography analyzed by an independent core laboratory. The primary safety endpoint was a composite of freedom from device- and procedure-related mortality through 30 days, and freedom from major target limb amputation and target vessel revascularization through 12 months. An independent Clinical Events Committee adjudicated all adverse events. The primary effectiveness endpoint was primary patency at 12 months, defined as freedom from clinically driven target lesion revascularization and freedom from restenosis.

RESULTS

The CTO imaging cohort had 126 subjects with 127 lesions (mean lesion length 22.83 ± 9.76 cm). Primary patency by Kaplan-Meier estimate was 85.3% through 12 months. Provisional stenting was performed in 46.8% of lesions. The primary safety composite endpoint was achieved by 88.7% of subjects. There were no device- or procedure-related deaths through 30 days or major target limb amputations through 12 months.

CONCLUSIONS

The paclitaxel drug-coated balloon was safe and highly effective at 12 months after treatment of subjects with CTO ≥5 cm in the femoropopliteal arteries. (IN.PACT Global Clinical Study; NCT01609296).

Clinical Significance of Endothelin-1 And C Reaction Protein in Restenosis After the Intervention of Lower Extremity Arteriosclerosis Obliterans

OBJECTIVE

This study aims to investigate the role of endothelin-1 (ET-1) and C-reactive protein (CRP) in restenosis after intervention of lower extremity arteriosclerosis obliterans.

METHODS

The present prospective observational study included a total of 251 patients with arteriosclerosis obliterans in the lower extremity. All patients were treated with balloon dilatation, stent-assisted angioplasty or balloon dilatation, and stent-assisted angioplasty. Furthermore, these patients received a CTA examination at one and three months after surgery. The serum ET-1 and CRP levels were determined using a commercial enzyme-linked immunosorbent assay (ELISA).

RESULTS

In non-restenosis patients, both the CRP and ET-1 levels were significantly upregulated after surgery, reached a peak level at one week, and decreased at one month after surgery. However, for restenosis patients, the serum ET-1 and CRP levels did not decrease to the baseline at one and three months after surgery, but were remarkably higher than the levels for non-restenosis patients. Serum ET-1 levels were positively correlated with serum CRP levels at both one and three months after surgery. Both ET-1 and CRP levels after one week and one month, and CRP at three days, one week, one month and three months after surgery were risk factors for restenosis after intervention surgery of arteriosclerosis obliterans.

CONCLUSION

Both serum ET-1 and CRP levels were elevated after one and three months of intervention for lower extremity arteriosclerosis obliterans in patients with restenosis. These might be the risk factors for restenosis of lower extremity arteriosclerosis obliterans patients.

Morphologic Changes of the Femoropopliteal Arterial Segment with Knee Flexion after Endovascular Therapy

Objective: The purpose of this study is to investigate morphologic changes of the femoropopliteal arterial segment (FPAS) with knee flexion after endovascular therapy (EVT).

Methods: From July 2012 to January 2015, EVT was performed on 12 limbs in 12 consecutive patients who had obliterative lesions in the FPAS. After the implantation of nitinol stents, angiography was performed with the knee in both extension and flexion to investigate morphologic changes of the FPAS.

Results: On angiography, the distal end of the implanted stent was placed at various distances (5–10 cm in two cases, 10–15 cm in nine cases, and 15–20 cm in one case) above the knee joint line with the knee in extension. In all cases, although the popliteal artery was highly bent with the knee in flexion, the FPAS morphology was highly variable. However, the most proximal bending point of the FPAS was about 10 cm above the knee joint line. In one case, the artery was occluded at the distal part of the stent 16 months later, probably due to EVT.

Conclusion: In EVT of the FPAS, it is important to consider the characteristics and position of the stent to prevent complications.

Balloon Angioplasty Versus Bailout Stenting for Isolated Chronic Total Occlusions in the Popliteal Artery

Aims:

Stenting of the popliteal artery (PA) is generally considered inappropriate due to the high mechanical stress and bending of the artery during knee flexion. Nevertheless, vessel recoil remains problematic following angioplasty procedure for chronic total occlusions (CTOs) and adjunctive stenting may be required. The purpose of this study is to compare balloon angioplasty alone versus bailout stenting for isolated CTO of the PA.

Materials and Methods:

Between March 2012 and October 2016, 43 patients were treated with percutaneous transluminal angioplasty with balloon alone (PTA, n = 16) or bailout stenting percutaneous transluminal angioplasty and stenting (PTAS, n = 27) for de novo CTO of PA. There was no statistically significant difference between both groups with regard to patient demographics and lesions characteristics (calcification severity and lesion length). The median lesion lengths were 67 mm (39.5-78.5) in the PTA group and 94 mm (50-114) in the PTAS group ( p = 0.14). The primary outcome measure was primary patency; secondary outcomes were technical success, primary assisted patency, major amputation, and increased Rutherford classification.

Results:

Technical success rate was 37% and 96.3% in the PTA and PTAS groups, respectively. There was no statistical difference in 12-month primary patency rate (65.8% versus 58.7%; p = 0.15) and primary assisted patency at 12 months (75.2 versus 69.2; p = 0.47) between the 2 groups. Freedom from target lesion revascularization at 12 months was not significantly different, with 85.7% and 81.6% ( p = 0.2) in the PTA and PTAS groups, respectively. One amputation occurred in the PTA group.

Conclusion:

This small cohort suggests that stenting as a bailout procedure in CTO of the PA provides similar results to successful balloon angioplasty. Stenting should only be performed after suboptimal balloon angioplasty with vessel recoil. Due to the large lost to follow-up, strong evidence of a therapy over the other cannot be formulated. Larger studies with longer and stronger follow-up are needed to confirm those results.

Nitinol Self-Expanding Stents for the Superficial Femoral Artery

The superficial femoral artery is a complex artery subject to a unique set of biomechanical loading conditions in its course through the leg. Plain balloon angioplasty and balloon-expandable stents had unacceptably high rates of restenosis, necessitating target vessel revascularization. Nitinol alloy is well suited to provide the strength and flexibility needed of stents to withstand the external forces posed by the environment of the superficial femoral artery. Advances in stent technology with the addition of a slow-releasing antiproliferative agent and changes in scaffold design have shown promise in reducing the rates of stent fracture and in-stent restenosis.

Extent of Vascular Remodeling Is Dependent on the Balance Between Estrogen Receptor α and G-Protein–Coupled Estrogen Receptor

Estrogens are important regulators of cardiovascular function. Some of estrogen’s cardiovascular effects are mediated by a G-protein–coupled receptor mechanism, namely, G-protein–coupled estrogen receptor (GPER). Estradiol-mediated regulation of vascular cell programmed cell death reflects the balance of the opposing actions of GPER versus estrogen receptor α (ERα). However, the significance of these opposing actions on the regulation of vascular smooth muscle cell proliferation or migration in vitro is unclear, and the significance in vivo is unknown. To determine the effects of GPER activation in vitro, we studied rat aortic vascular smooth muscle cells maintained in primary culture. GPER was reintroduced using adenoviral gene transfer. Both estradiol and G1, a GPER agonist, inhibited both proliferation and cell migration effects that were blocked by the GPER antagonist, G15. To determine the importance of the GPER-ERα balance in regulating vascular remodeling in a rat model of carotid ligation, we studied the effects of upregulation of GPER expression versus downregulation of ERα. Reintroduction of GPER significantly attenuated the extent of medial hypertrophy and attenuated the extent of CD45 labeling. Downregulation of ERα expression comparably attenuated the extent of medial hypertrophy and inflammation after carotid ligation. These studies demonstrate that the balance between GPER and ERα regulates vascular remodeling. Receptor-specific modulation of estrogen’s effects may be an important new approach in modifying vascular remodeling in both acute settings like vascular injury and perhaps in longer term regulation like in hypertension.

Incidence and Predictors of In-stent Re-Stenosis in the Superficial Femoral Artery: Evaluation of Long-Term Outcomes by Color Duplex Ultrasound

This study aimed to investigate the incidence and predictors of in-stent re-stenosis (ISR) for nitinol stents in the superficial femoral artery (SFA) by color duplex ultrasound (CDU). In total, 235 patients undergoing SFA stenting were included in the present study. The cumulative ISR rates at 3, 6, 12, 24 and 36 mo post-procedure were 5.4%, 24.0%, 49.0%, 61.5% and 71.5%, respectively. The markedly low peak systolic velocity of the popliteal artery (PSV2) post-operation was inversely correlated with the ISR. The threshold for ≥50% re-stenosis was PSV2 ≤ 63 cm/s with 86.6% sensitivity and 90.5% specificity. With regard to re-occlusion, the PSV2 was ≤40 cm/s with 98.1% sensitivity and 93.4% specificity. Cox regression analysis indicated that the cumulative stent length, diabetes, and pre-stent stenosis level were independent risk factors of ISR. In conclusion, the ISR incidence after SFA stenting is relatively high and CDU follow-up is a feasible method for evaluating ISR.

Application of rotational atherectomy for a calcified superficial femoral artery lesion

A 78-year-old man on dialysis with a history of femoro-popliteal bypass grafting of his right superficial femoral artery was presented with a recurrence of intermittent claudication. Angiography revealed new heavily calcified stenosis located distal to the anastomosis of the graft. A guide wire was crossed the lesion, however, a balloon catheter could not pass. Rotational atherectomy with Rotablator enabled the balloon to cross the lesion with full dilatation. Due to residual stenosis and dissection, a stent was implanted. Final angiogram showed no residual stenosis with TIMI 3 flow. The patient remained free of symptoms during the 1-year follow-up.

Shared and additional risk factors for decrease of toe-brachial index compared to ankle-brachial index in Japanese patients with diabetes mellitus

OBJECTIVE

Some diabetic patients have a low toe-brachial index (TBI) despite their normal ankle-brachial index (ABI). We statistically investigated whether the impact of risk factors on TBI would be different compared to ABI.

RESEARCH DESIGN AND METHODS

We used a database of 1738 limbs of consecutive 869 Japanese diabetic patients whose ABI and TBI were simultaneously evaluated. We developed a common regression model to ABI and TBI by extending the linear mixed model, and statistically detected the difference in the impact of risk factors between the two indices.

RESULTS

Sex, smoking, proteinuria, hypertension, and history of stroke and coronary artery disease were common independent risk factors for the decrease of ABI and TBI; their impacts on ABI and TBI were not significantly different. On the other hand, the impact of age, diabetic duration, and body mass index was significantly different between the two indices (all p < 0.05). Age and body mass index were significantly associated with TBI but not with ABI. Diabetic duration had a significant impact both on TBI and ABI, but the impact on TBI was significantly greater than that on ABI (β = -0.144 vs. -0.087; p < 0.05). In the population with normal ABI, patients with these risk factors had a higher prevalence of decreased TBI.

CONCLUSIONS

The risk factors for the decrease of ABI and TBI were not identical in Japanese diabetic patients. Age, diabetic duration and body mass index were associated with reduced TBI in patients with normal ABI.