Risk factors for clinical failure after stent graft treatment for femoropopliteal occlusive disease

Covered endovascular reconstruction of the aortic bifurcation: A systematic review aggregated data and individual participant data meta-analysis

BACKGROUND

We investigated the early and midterm efficacy and safety of covered endovascular reconstruction of the aortic bifurcation (CERAB) in the treatment of aortoiliac disease (AID).

METHODS

A systematic search on PubMed, Scopus, and Web of Science for articles published by August 2023 was performed. The primary end points were primary patency and secondary patency.

RESULTS

Eleven retrospective case series, involving 579 patients, were incorporated in the review with 88.9% of the included lesions being categorized as Trans-Atlantic Inter-Society Consensus (TASC) C or D. The pooled primary patency estimates at 12, 24 and 36 months were 94.4% (95% confidence interval [CI], 89.4-99.7), 84.4% (95% CI, 72.3-98.5) and 83.8% (95% CI, 71.4-98.3) respectively. The mean primary patency time, representing the period during which individuals remained event-free, was 51.9 months (95% CI, 43.6-55.4). The pooled 36 months primary patency for studies with a predominantly claudicant patient population (>75% of patients) was 89.4% (95% CI, 78.5-100.0), compared with 71.5% (95% CI, 45.6-100.0) for studies with a mixed population (50% of patients). The pooled 36 months primary patency for studies with a predominantly TASC D patient population (>82% of patients) was 70.4% (95% CI, 46.4-100.0) compared with 91.0% (95% CI, 79.1-100.0) for studies with a more homogenous cohort. The pooled secondary patency estimates at 12, 24, and 36 months were 98.6% (95% CI, 96.2-100.0), 97% (95% CI, 93.1-100.0), and 97% (95% CI, 93.1-100.0), respectively. The pooled technical success, 30-day mortality and 30-day systemic complications estimates were 95.9% (95% CI, 93.7- 97.4), 1.9% (95% CI, 1.0-3.5), and 6.4% (95% CI, 4.4-9.1), respectively. The pooled intraoperative and postoperative 30-day CERAB-related complications estimates were 7.3% (95% CI, 2.0-23.0) and 4.2% (95% CI, 0.7-21.0), respectively. The pooled major amputation and target lesion reinterventions by the end of follow-up were 1.9% (95% CI, 1.0-3.4) and 13.9% (95% CI, 9.9-19.2), respectively. The pooled access site complication estimate was 11.7% (95% CI, 5.9-21.7).

CONCLUSIONS

Although this review has showcased the safety and feasibility of the CERAB technique in treating AID, it has also highlighted the necessity for a close and prolonged follow-up period extending beyond 1 year. Moreover, the favorable secondary patency estimates predominantly attained via endovascular reinterventions emphasize a potentially advantageous characteristic of the CERAB technique, particularly valuable when addressing late-stage AID disease or anatomically complex lesions.

Revascularization for claudication: Changing the natural history of a benign disease!

OBJECTIVE

The benign natural history of intermittent claudication was first documented in 1960 and has been reconfirmed in several subsequent studies. Excellent outcomes in patients with intermittent claudication can be achieved with exercise therapy and optimal medical management. Professional society guidelines have clearly stated that revascularization procedures should be performed only in patients with incapacitating claudication who have failed conservative therapy. Despite these guidelines, revascularization procedures, primarily percutaneous interventions, have been increasingly utilized in patients with claudication. Many of these patients are not even offered an attempt at medical therapy, and those who are often do not undergo a full course of treatment. Many studies document significant reintervention rates following revascularization, which are associated with increased rates of acute and chronic limb ischemia that may result in significant rates of amputation. The objectives of this study were to compare outcomes of conservative therapy to those seen in patients undergoing revascularization procedures and to determine the impact of revascularization on the natural history of claudication.

METHODS

Google Scholar and PubMed were searched for manuscripts on the conservative management of claudication and for those reporting outcomes following revascularization for claudication.

RESULTS

Despite early improvement in claudication symptoms following revascularization, multiple studies have demonstrated that long-term outcomes following revascularization are often no better than those obtained with conservative therapy. High reintervention rates (up to 43% for tibial atherectomies) result in high rates of both acute and chronic limb ischemia as compared with those patients undergoing medical therapy. In addition, amputation rates as high as 11% on long-term follow-up are seen in patients undergoing early revascularization. These patients also have a higher incidence of adverse cardiovascular events such as myocardial infarctions compared with patients treated medically.

CONCLUSIONS

Revascularization procedures negatively impact the natural history of claudication often resulting in multiple interventions, an increase in the incidence of acute and chronic limb ischemia, and an increased risk of amputation. Accordingly, informed consent requires that all patients undergoing early revascularization must be appraised of the potential negative impact of revascularization on the natural history of claudication.

Endovascular bypass as a strategy for long femoropopliteal lesions

INTRODUCTION

Endovascular treatment has become the predominant treatment modality for femoropopliteal lesions. In longer and more complex lesions advanced technology is often required to improve results, with the endovascular bypass being one of them.

EVIDENCE ACQUISITION

A systematic review of the literature was performed to determine the clinical and technical outcomes of the latest generation endoprosthesis, with heparin bioactive surface and contoured proximal edge.

EVIDENCE SYNTHESIS

13 articles were enrolled: 3 randomized controlled trials, 4 prospective multicenter trials and 6 retrospective studies. The VIASTAR trial showed that the endoprosthesis has a better two-year primary patency compared to bare metal stenting, especially in long lesions (62% vs. 27%, P=0.004). The SUPERB trial showed that the endoprosthesis had similar results compared to bypass surgery, albeit with less complications (31% vs. 55%, P=0.048). The RELINE study showed that treatment with an endoprosthesis had a better one-year primary patency compared to balloon angioplasty for in-stent restenosis (75% vs. 28%, P<0.001). In the cohort studies one-year patency rates ranged from 61% to 86% for primary patency, from 65% to 92% for primary assisted patency, and from 83% to 95% for secondary patency.

CONCLUSIONS

For long femoropopliteal lesions, the heparin-bonded endoprosthesis is related to better outcomes compared to bare nitinol stents, and comparable outcomes as with the femoropopliteal bypass, but with less complications. There is a wide range in primary patency rates, with consistent high secondary patency rates. The endovascular bypass can be considered an appropriate strategy in these patients.

Long term clinical outcomes of portal vein stenting for symptomatic portal vein stenosis after pancreaticoduodenectomy

Gastrointestinal bleeding caused by portal vein (PV) stenosis is serious complication after pancreaticoduodenectomy (PD) The purpose of this study is to reveal the long-term clinical outcomes of PV stenting for symptomatic PV stenosis and risk factors of stent related complication.Fifteen patients who underwent portal vein stenting for symptomatic PV stenosis after PD between 2000 and 2018 were retrospectively reviewed. The whole cohort was divided into 9 patients with benign stenosis group (Group-B) and 6 patients with recurrence group (Group-R).The median follow up period was 17.0 (interquartile range 12.0-38.0) months. The technical success rate and clinical success rate was revealed at 93.3% and 86.7%. The primary patency rate of stents was 79.4% and mean patency period was 14.0 (4.0-28.0) months. There was significant difference in time to stenosis and proportion of anticoagulation treatment between 2 groups [2.0 (1.0-4.0) months vs 18.5 (2.5-50.3) months, P  = .035 and 100% vs 50%, P  = .044. In univariable analysis, stent diameter was found to have a significant correlation with stent occlusion (P  = .036).PV stenting was found to be feasible and safe in the treatment of symptomatic PV stenosis from a long term point of view.

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.

Clinical Impact of Stent Graft Thrombosis in Femoropopliteal Arterial Lesions

OBJECTIVES

This study sought to elucidate the clinical impact and prognosis of stent graft (SG) thrombosis.

BACKGROUND

The VIABAHN SG offers a favorable outcome in long peripheral artery occlusive disease (PAOD) lesions in the femoropopliteal artery. One concern after SG deployment is the incidence of stent thrombosis and consequent acute limb ischemia (ALI).

METHODS

In this retrospective multicenter study, we collected the clinical data of PAOD patients treated with VIABAHN SG who subsequently experienced SG thrombosis. The clinical symptoms of SG thrombosis, patency after reintervention, and predictors of loss of patency after reintervention were examined.

RESULTS

VIABAHN SGs were used for 1,215 patients; SG thrombosis occurred in 159 (13%) patients at a median of 6.4 months (interquartile range: 2.8 to 13.5 months) after SG implantation; 21 (13%) patients presented with ALI. A total of 131 (82%) patients underwent reintervention for SG thrombosis, whereas 2 (1%) underwent primary major amputation and the remaining 26 (16%) were treated conservatively. The patency rate 1 year after reintervention, freedom from major adverse limb events, and limb salvage after reintervention were 54.9%, 73.6%, and 92.5%, respectively. Critical limb-threatening ischemia at SG implantation and ALI presentation at SG thrombosis were positively associated with an increased risk of rethrombosis, whereas distal stent diameter was negatively associated with the risk of rethrombosis.

CONCLUSIONS

SG thrombosis is associated with a considerable risk of ALI, but the risk of primary major amputation was not high. Clinical outcomes after reinterventions for thrombosed SGs were suboptimal.

Patients with failed femoropopliteal covered stents are more likely to present with acute limb ischemia than those with failed femoropopliteal bare metal stents

OBJECTIVE

Covered stents (CS) to treat superficial femoral artery (SFA) occlusive disease have become more common. However, concerns about patients presenting with acute limb ischemia (ALI) after failure due to coverage of important collaterals have been raised. Herein, we determine if CS are associated with ALI after failure.

METHODS

Vascular Quality Initiative peripheral vascular intervention and infrainguinal bypass datasets were queried from 2010 to 2020 for patients who underwent SFA stenting with a bare metal stent (BMS) or CS and who also had a subsequent ipsilateral SFA endovascular reintervention or bypass recorded in the Vascular Quality Initiative. The initial SFA stenting procedure will be referred to as the index procedure and the subsequent procedure will be referred to as the reintervention. Patients with aneurysmal pathology, prior infrainguinal bypass, and ALI at the index procedure were excluded. Patients with pre-index inflow/outflow procedures were not excluded. The primary outcome was ALI at reintervention. Other outcomes included higher degree of ischemia (claudication vs rest pain vs tissue loss vs ALI) and reoperative factors. Predictors of the primary outcome were determined with multivariable logistic regression. The index treatment length and pre-index ankle-brachial index were forced into the model.

RESULTS

There were 3721 patients: 3338 with index BMS, 383 with index CS. The mean patients age was 66.3 ± 11.0 years and 59.2% were male. Baseline covariates were similar between the groups; during the index procedure, more patients with BMS underwent plain balloon angioplasty (68.7% vs 62.1%; P = .001) and had shorter total index treatment length (median, 15.0 cm [interquartile range, 10.0-25.0 cm] vs 20.0 cm [interquartile range, 12.0-30.0 cm]; P < .001). At reintervention, ALI was the presenting symptom for 12.0% of the CS cohort vs 6.3% of the BMS cohort (P < .001). More patients with an index CS underwent major amputation at the time of reintervention (2.6% vs 1.0%; P = .006). Reinterventions for the patients with a CS more often used bypass, pharmacologic thrombolysis, and mechanical thrombolysis. CS at the index procedure was a predictor of ALI at reintervention (odds ratio, 1.87; 95% confidence interval, 1.31-2.65; P = .001) while controlling for age, time difference between procedures, body mass index, chronic obstructive pulmonary disorder, preoperative anticoagulation and antiplatelet, prior carotid intervention and major amputation, index procedure fluoroscopy time and treatment length, and pre-index ankle-brachial index.

CONCLUSIONS

In patients undergoing reintervention for failed SFA stents, CS are more likely to present with ALI than those with failed SFA BMS.

Risk Factors for Early and Late Iliac Limb Occlusions of Stent Grafts Extending to the External Iliac Artery after Endovascular Abdominal Aneurysm Repair

BACKGROUND

Iliac limb stent grafting to the external iliac artery (EIA) is a commonly performed procedure in various situation during endovascular abdominal aneurysm repair (EVAR). However, this procedure is associated with a risk of graft occlusion. We evaluated risk factors affecting occlusion among patients who underwent iliac limb stent-graft extension to the EIA.

MATERIALS AND METHODS

We compared occluded limbs with patent limbs during the follow-up period using variables, including anatomical values, demographics, and other factors. Thereafter, we divided the occluded limbs into early and late occlusion subgroups. The main and subgroup analyses used the same variables. Survival analysis was performed to evaluate time-dependent risk factors for late limb occlusion.

RESULTS

From 2007 to 2016, 766 iliac limbs from 383 patients who underwent EVAR were initially included in our analysis. Among them, 134 iliac limbs underwent limb extension to the EIA. The limb extension was a significant risk factor for occlusion (hazard ratio = 6.34, P < 0.001). Occlusion occurred in 10 patients who underwent iliac limb extension. The size of common iliac artery (CIA) was associated with occlusion. The most significant factor was iliac bifurcation diameter (patent vs. occluded limbs, 21.6 ± 7.6 vs. 27.5 ± 9.5 mm, P = 0.005). Subgroup analysis revealed that the CIAs of the early occlusion subgroup were generally more tortuous (1.16 ± 0.33 vs. 1.47 ± 0.25, P = 0.091) and longer (53 ± 24 vs. 74 ± 9, P = 0.01) than those of the patent limb group. In addition, the EIA diameters of the late occlusion subgroup were narrower than those of the patent limb group (10.9 ± 1.6 mm vs. 9.1 ± 0.8 mm, P = 0.011). Using the log-rank test, those patients with an EIA diameter narrower than 10.1 mm had a higher risk for late limb occlusion (log-rank χ² = 5.73, P = 0.017) and the patients who did not take at least a single antiplatelet agent had a significantly higher chance of limb occlusion (log-rank χ² = 11.029, P = 0.001). In addition, the patients who did not take a statin had a higher risk for late limb occlusion (log-rank χ² = 7.41, P = 0.007).

CONCLUSIONS

Among patients who underwent EVAR with iliac limb extension, the CIA length affected early limb occlusion and predisposed patients to vessel injury or stent-graft kinking, and there was the possibility that CIA tortuosity was associated with a higher risk. The late occlusion subgroup had narrower EIAs than the patent limb group. Appropriate antiplatelet and statin therapy is expected to play a key role in the prevention of late limb occlusion after EVAR.

Covered stent versus bare-metal stents for chronic total occluded long complicated femoropopliteal lesions: A 2-year single center review

BACKGROUND

To compare the efficacy, safety, and results of Viabahn versus bare-metal stents (BMS) in chronic total occluded (CTO) long femoropopliteal lesions.

METHODS

From April 2009 to August 2014, a total 97 patients (71.2 ± 9.7, 45-90 years old, 70 males) with occluded femo-ropopliteal lesions underwent Viabahn (55 patients) or BMS (42 patients) implantation. The clinical findings, procedural factors, and overall outcomes were collected and analyzed.

RESULTS

The average lesion length was 22.1 ± 4.8 cm in the Viabahn group and 17.8 ± 3.3 cm in the BMS group. Both groups had a 100% technical success rate. Although there was no difference between the groups in complication, mortality, and major amputation rates, the Viabahn group had a significantly better average post-operative ankle brachial index (ABI) at 1-year and 2-year follow-ups. The Viabahn group also had significantly less in-stent restenosis (ISR) and target lesion revascularization (TLR) compared with the BMS group. Nevertheless, the two groups shared similar 2-year primary patency rates (63.6% vs. 50.0%, p = .178) and 2-year secondary patency rates (85.5% vs. 81.0%, p = .554).

CONCLUSION

Both Viabahn and BMS were efficient treatments for long femoropopliteal CTO lesions. However, the Viabahn group had significantly improved results compared with the BMS group in TLR and ISR, but the difference was not sufficient enough to result in different primary and secondary patency rates.

Endovascular Management of Right Subclavian Artery Pseudoaneurysm due to War Injury in Adolescent Patient

Today there is a widespread use of endovascular treatment (EVT) for traumatic vascular injuries in adults, but there is lack of evidence of its use in adolescent patients with vascular injuries. With this case, we present successful EVT of 14-year-old adolescent with a right subclavian artery pseudoaneurysm (SAP) due to war injury. SAP was successfully excluded with deployment of 6 × 50 mm flexible, self-expanding covered nitinol stent graft (The GORE® VIABAHN® Endoprosthesis (W.L. Gore & Associates, Flagstaff, AZ)). Patient was discharged from hospital 2 days after the procedure with dual antiplatelet therapy (clopidogrel and aspirin). 3 months after discharge control DUS showed patent stent graft without any residual lesions. As a result, EVT is an alternative approach to treatment of SAP. It is safe, effective, and less invasive therapy for SAP in adults as well as in adolescents. We aim to contribute to the literature with this first case report.

Are drug-coated balloons cost effective for femoropopliteal occlusive disease? A comparison of bare metal stents and uncoated balloons

Aim: To perform a cost–effectiveness analysis to help hospital decision-makers with regard to the use of drug-coated balloons compared with bare metal stents and uncoated balloons for femoropopliteal occlusive disease. Methods: Clinical outcomes were extracted from the results of meta-analyses already published, and cost units are those used in the Quebec healthcare network. The literature review was limited to the last four years to obtain the most recent data. The cost–effectiveness analysis was based on a 2-year perspective, and risk factors of reintervention were considered. Results: The cost–effectiveness analysis indicated that drug-coated balloons were generally more efficient than bare metal stents, particularly for patients with higher risk of reintervention (up to CAD$1686 per patient TASC II C or D). Compared with uncoated balloons, results indicated that drug-coated balloons were more efficient if the reintervention rate associated with uncoated balloons is very high and for patients with higher risk of reintervention (up to CAD$3301 per patient). Conclusion: The higher a patient's risk of reintervention, the higher the savings associated with the use of a drug-coated balloon will be. For patients at lower risk, the uncoated balloon strategy is still recommended as a first choice for endovascular intervention.

How should we manage thrombosis of Viabahn stent-graft? A case report focused on catheter-directed thrombolysis

PURPOSE

To report a case of a thrombosed GORE® VIABAHN® endoprosthesis stent-graft in the femoral artery (SFA) and popliteal artery managed using the pulse-spray technique and complicated by compartment syndrome of the lower leg of the affected limb.

CASE REPORT

A 61-year-old woman with three Viabahn stent grafts relining seven bare-metal stents in her right SFA and popliteal artery visited our hospital with complaint of recurrent lifestyle-limiting claudication of right leg. Angiography and intravascular ultrasound showed complete intra-stent obstruction by thrombus from the proximal right SFA to the proximal popliteal artery. Catheter-directed thrombolysis using pulse-spray technique followed by mechanical thrombectomy was performed. Despite successful recanalization, unfortunately, compartment syndrome developed on her right leg on the following day and fasciotomy was performed.

CONCLUSION

The larger thrombus burden in Viabahn stent-grafts and its unique physicochemical properties increases the risk for distal embolic complications and potential poor clinical outcomes.

Clinical Outcomes after Endovascular Treatment Failure in Patients with Femoropopliteal Occlusive Disease

BACKGROUND

To analyze the clinical impact derived from endovascular treatment failure on patients with femoropopliteal occlusive disease (FPOD) regarding their preoperative clinical stage.

METHODS

Retrospective review for primary endovascular procedures for FPOD from 2008 to 2013. Primary end point included clinical deterioration defined as acute limb ischemia (ALI) or clinical worsening by, at least, one Rutherford's classification category, related to procedure's failure (restenosis >70% or occlusion).

RESULTS

Ninety procedures were analyzed in 85 patients, 87.8% operated due to critical limb ischemia. The lesion treated was classified as Trans-Atlantic Inter-Society Consensus (TASC)-A/B in 76.7%, with a mean length of 98.5 ± 54 mm. Covered stent graft (SG) was used in 31.1% of the cases. Median follow-up was 14.5 months and treatment failure occurred in 33.3% of cases (n = 30, 9 restenosis and 21 occlusions). Clinical worsening was assessed in 40% of treatment failures and 6 of 21 (28.6%) presented as ALI. Twenty-two major adverse limb events (MALEs) were recorded and 8 major amputations. Regarding the type of stent, more occlusions were recorded on patients treated with SG compared with bare metal stent (39.3% vs. 16%; P = 0.02). However, no differences were found between groups regarding clinical worsening attributable to treatment failure (HR, 1.33; CI 95%, 0.5-3.5; P = 0.5). On multivariate analysis, TASC-C/D lesions (HR, 5.5; CI 95%, 2.3-13.3; P < 0.001) and female sex (HR, 4.9; CI 95%, 1.9-12.5; P = 0.001) behaved as significant predictors for failure and dual-antiplatelet therapy as a protective factor (HR, 0.3; CI 95%, 0.3-0.13; P = 0.03). No predictors were obtained regarding clinical worsening and occurrence of MALEs in our series.

CONCLUSIONS

Patients with failure of endovascular procedures on FPOD appeared with clinical worsening in a no negligible number of cases in our sample regarding their preoperative clinical situation. Thus, we believe that endovascular treatment should be carefully deliberated.

Society for Vascular Surgery practice guidelines for atherosclerotic occlusive disease of the lower extremities: management of asymptomatic disease and claudication

Peripheral arterial disease (PAD) continues to grow in global prevalence and consumes an increasing amount of resources in the United States health care system. Overall rates of intervention for PAD have been rising steadily in recent years. Changing demographics, evolution of technologies, and an expanding database of outcomes studies are primary forces influencing clinical decision making in PAD. The management of PAD is multidisciplinary, involving primary care physicians and vascular specialists with varying expertise in diagnostic and treatment modalities. PAD represents a broad spectrum of disease from asymptomatic through severe limb ischemia. The Society for Vascular Surgery Lower Extremity Practice Guidelines committee reviewed the evidence supporting clinical care in the treatment of asymptomatic PAD and intermittent claudication (IC). The committee made specific practice recommendations using the GRADE (Grades of Recommendation Assessment, Development and Evaluation) system. There are limited Level I data available for many of the critical questions in the field, demonstrating the urgent need for comparative effectiveness research in PAD. Emphasis is placed on risk factor modification, medical therapies, and broader use of exercise programs to improve cardiovascular health and functional performance. Screening for PAD appears of unproven benefit at present. Revascularization for IC is an appropriate therapy for selected patients with disabling symptoms, after a careful risk-benefit analysis. Treatment should be individualized based on comorbid conditions, degree of functional impairment, and anatomic factors. Invasive treatments for IC should provide predictable functional improvements with reasonable durability. A minimum threshold of a >50% likelihood of sustained efficacy for at least 2 years is suggested as a benchmark. Anatomic patency (freedom from restenosis) is considered a prerequisite for sustained efficacy of revascularization in IC. Endovascular approaches are favored for most candidates with aortoiliac disease and for selected patients with femoropopliteal disease in whom anatomic durability is expected to meet this minimum threshold. Conversely, caution is warranted in the use of interventions for IC in anatomic settings where durability is limited (extensive calcification, small-caliber arteries, diffuse infrainguinal disease, poor runoff). Surgical bypass may be a preferred strategy in good-risk patients with these disease patterns or in those with prior endovascular failures. Common femoral artery disease should be treated surgically, and saphenous vein is the preferred conduit for infrainguinal bypass grafting. Patients who undergo invasive treatments for IC should be monitored regularly in a surveillance program to record subjective improvements, assess risk factors, optimize compliance with cardioprotective medications, and monitor hemodynamic and patency status.

Critical limb ischemia and the diseased popliteal artery

The unique anatomical location and particular biomechanical factors affecting the popliteal artery provide a challenge to determine the proper endovascular, surgical, or combined intervention for patients with critical limb ischemia who often require prompt management in the presence of severe lifestyle-limiting symptoms or of the risk of limb loss or both. Herein, we provide an overview and practical guide for endovascular management of popliteal artery disease in the setting of critical limb ischemia.

Outcomes of covered versus bare-metal balloon-expandable stents for aortoiliac occlusive disease

OBJECTIVE

Randomized trials and retrospective data suggest that covered balloon-expandable (CBE) stents have better short-term patency compared with balloon-expandable bare-metal stents (BMSs) in the treatment of iliac artery disease. This study evaluated midterm outcomes of BMSs vs CBE stents placed in the common iliac artery (CIA) for aortoiliac occlusive disease.

METHODS

All endovascular interventions for symptomatic peripheral arterial occlusive disease performed at a single institution from 2006 to 2012 were reviewed. Patients undergoing stent placement in the CIA segment were included in the analysis. Demographic data, TransAtlantic Inter-Society Consensus (TASC) classification, stent type, patency, and limb reinterventions were compared.

RESULTS

For treatment of de novo distal aorta or CIA stenosis, 254 procedures were performed in 162 patients. BMSs were used in 190 arteries; CBE stents were used in 64 arteries. There was no difference in age, gender, or TASC classification between the two groups. Mean follow-up was 22 ± 16 months. Primary patency, assisted patency, and secondary patency were significantly better in the BMS group. CIAs treated with covered stents were more likely at 1 year or longer to require repeated intervention (hazard ratio, 2.5; 95% confidence interval, 1.2-5.3; P = .009). TASC classification did not predict need for reintervention in either group. Multivariate analysis revealed dual antiplatelet therapy to be the only other factor to affect patency during long-term follow-up.

CONCLUSIONS

In this study, BMSs had significantly better patency compared with CBE stents for treatment of aortoiliac occlusive disease. A randomized trial comparing patency as well as restenosis rates with long-term follow-up is needed to determine if there is any benefit from use of covered stents in the aortoiliac segment.

Midterm outcomes of stent placement for long-segment iliac artery chronic total occlusions: a retrospective evaluation in a single institution

PURPOSE

To assess the clinical and patency results of stent placement for long-segment iliac artery chronic total occlusions (CTOs).

MATERIALS AND METHODS

A retrospective analysis of 217 patients (141 men and 76 women; mean age, 76.6 y; 256 limbs) with long-segment (>5 cm) iliac artery CTOs treated with stent placement was conducted in a single institution from January 2005 to July 2011. Demographics, clinical presentation, classification, comorbidity, ankle-brachial index (ABI) before and after treatment, technical success, patency, and complications were recorded at follow-up. The approach was initial access from the left brachial artery or the contralateral femoral artery.

RESULTS

According to the TransAtlantic Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II) classification, 27 patients were type B, 143 were type C, and 47 were type D. Clinical presentation was recorded according to the Rutherford-Becker classification: 35 patients presented with stage 3; 108, with stage 4; 53, with stage 5; and 21, with stage 6. Technical success was 96.5% (247 of 256). Periprocedural in-stent thrombosis occurred in nine patients and was treated successfully with catheter-directed thrombolysis. ABI increased from 0.36±0.16 (range, 0-0.57) before the procedure to 0.79±0.24 (range, 0.56-1.12) after the procedure. The mean duration of follow-up was 25.4 months (range, 1-72 months). The primary, primary assisted, and secondary patency of the iliac artery was 95.1%, 98.4%, and 99.2% at 1 year and 91.9%, 95.6%, and 97.5% at 2 years, respectively. Major complications were encountered in 17 (6.6%) patients, and minor complications occurred in 12 (4.7%) patients.

CONCLUSIONS

These data suggest that stent placement is an effective, safe, and feasible method for treating long-segment iliac artery CTOs.

Adventitial nab-rapamycin injection reduces porcine femoral artery luminal stenosis induced by balloon angioplasty via inhibition of medial proliferation and adventitial inflammation

BACKGROUND

Endovascular interventions on peripheral arteries are limited by high rates of restenosis. Our hypothesis was that adventitial injection of rapamycin nanoparticles would be safe and reduce luminal stenosis in a porcine femoral artery balloon angioplasty model.

METHODS AND RESULTS

Eighteen juvenile male crossbred swine were included. Single-injury (40%-60% femoral artery balloon overstretch injury; n=2) and double-injury models (endothelial denudation injury 2 weeks before a 20%-30% overstretch injury; n=2) were compared. The double-injury model produced significantly more luminal stenosis at 28 days, P=0.002, and no difference in medial fibrosis or inflammation. Four pigs were randomized to the double-injury model and adventitial injection of saline (n=2) or 500 μg of nanoparticle albumin-bound rapamycin (nab-rapamycin; n=2) with an endovascular microinfusion catheter. There was 100% procedural success and no difference in endothelial regeneration. At 28 days, nab-rapamycin led to significant reductions in luminal stenosis, 17% (interquartile range, 12%-35%) versus 10% (interquartile range, 8.3%-14%), P=0.001, medial cell proliferation, P<0.001, and fibrosis, P<0.001. There were significantly fewer adventitial leukocytes at 3 days, P<0.001, but no difference at 28 days. Pharmacokinetic analysis (single-injury model) found rapamycin concentrations 1500× higher in perivascular tissues than in blood at 1 hour. Perivascular rapamycin persisted ≥8 days and was not detectable at 28 days.

CONCLUSIONS

Adventitial nab-rapamycin injection was safe and significantly reduced luminal stenosis in a porcine femoral artery balloon angioplasty model. Observed reductions in early adventitial leukocyte infiltration and late medial cell proliferation and fibrosis suggest an immunosuppressive and antiproliferative mechanism. An intraluminal microinfusion catheter for adventitial injection represents an alternative to stent- or balloon-based local drug delivery.

Oleic acid increases synthesis and secretion of VEGF in rat vascular smooth muscle cells: role of oxidative stress and impairment in obesity

Obesity is characterized by poor collateral vessel formation, a process involving vascular endothelial growth factor (VEGF) action on vascular smooth muscle cells (VSMC). Free fatty acids are involved in the pathogenesis of obesity vascular complications, and we have aimed to clarify whether oleic acid (OA) enhances VEGF synthesis/secretion in VSMC, and whether this effect is impaired in obesity. In cultured aortic VSMC from lean and obese Zucker rats (LZR and OZR, respectively) we measured the influence of OA on VEGF-A synthesis/secretion, signaling molecules and reactive oxygen species (ROS). In VSMC from LZR we found the following: (a) OA increases VEGF-A synthesis/secretion by a mechanism blunted by inhibitors of Akt, mTOR, ERK-1/2, PKC-beta, NADPH-oxidase and mitochondrial electron transport chain complex; (b) OA activates the above mentioned signaling pathways and increases ROS; (c) OA-induced activation of PKC-beta enhances oxidative stress, which activates signaling pathways responsible for the increased VEGF synthesis/secretion. In VSMC from OZR, which present enhanced baseline oxidative stress, the above mentioned actions of OA on VEGF-A, signaling pathways and ROS are impaired: this impairment is reproduced in VSMC from LZR by incubation with hydrogen peroxide. Thus, in OZR chronically elevated oxidative stress causes a resistance to the action on VEGF that OA exerts in LZR by increasing ROS.