Endovascular stenting for vertebral artery stenosis

Vertebral Artery Interventions: A Comprehensive Updated Review

Patients with posterior circulation ischemia due to vertebral artery stenosis account for 20 to 25% of ischemic strokes and have an increased risk of recurrent stroke. In patients treated with medical therapy alone, the risk of recurrence is particularly increased in the first few weeks after symptoms occur, with an annual stroke rate of 10 to 15%. Additionally, obstructive disease of the vertebrobasilar system carries a worse prognosis, with a 30% mortality at 2-years if managed medically without additional surgical or endovascular intervention. Percutaneous transluminal angioplasty and stenting of symptomatic vertebral artery stenosis are promising options widely used in clinical practice with good technical results; however, the improved clinical outcome has been examined in various clinical trials without a sufficient sample size to conclusively determine whether stenting is better than medical therapy. Surgical revascularization is an alternative approach for the treatment of symptomatic vertebral artery stenosis that carries a 10-20% mortality rate. Despite the advances in medical therapy and endovascular and surgical options, symptomatic vertebral artery stenosis continues to impose a high risk of stroke recurrence with associated high morbidity and mortality. This review aims to provide a focused update on the percutaneous treatment of vertebral artery stenosis, its appropriate diagnostic approach, and advances in medical therapies.

Vertebral Artery Stenosis: A Narrative Review

Vertebral artery stenosis (VAS) is the cause of approximately 20% of ischemic strokes in the posterior circulation. There are several causes of vertebral artery stenosis, including atherosclerosis, calcification, dissections, fibromuscular dysplasia, giant cell arteritis, neurofibromatosis type 1, and bony compressions. The most common cause of VAS is atherosclerosis which is derived from the macrophage-induced oxidation of low-density lipoproteins (LDLs), alongside the accumulation of cholesterol. Calcification of the vertebral artery occurs when there is excess calcium and phosphate deposition in the vessel. Dissection of the vertebral artery can lead to the formation of a hematoma causing stenosis of the vertebral artery. Fibromuscular dysplasia can result in stenosis due to the deposition of collagen fibers in the tunica media, intima, or adventitia. Giant cell arteritis, an autoimmune disorder, causes inflammation of the internal elastic membrane resulting in eventual stenosis of the artery. Neurofibromatosis type 1, an autosomal dominant disorder, results in the stenosis of the vertebral artery due to the altered function of neurofibromin. Mechanical compression of the vertebral artery by bone can also cause stenosis of the vertebral artery. Digital subtraction angiography (DSA) is considered the current gold standard in diagnosing vertebral artery stenosis; however, its associated morbidity and mortality have led to increased use of non-invasive techniques such as duplex ultrasonography (DUS), computed tomography angiography (CTA), and magnetic resonance angiography (MRA). Currently, asymptomatic and symptomatic vertebral artery stenoses are treated by risk factor modification and medical treatment. However, it is recommended that surgical (endarterectomy, reconstruction, and decompression) and endovascular (balloon coronary, bare-metal, and drug-eluting stents) treatments are also used for symptomatic vertebral artery stenosis.

Vertebral artery stenosis

Symptomatic vertebral artery stenosis is associated with high risk of early recurrent stroke. Vertebral artery stenosis can be treated with angioplasty and stenting with good technical results. In this review we outline the framework for the diagnosis and management of vertebral artery disease with focus on the emerging benefits of angiography and endovascular interventions.

Validation and comparison of drug eluting stent to bare metal stent for restenosis rates following vertebral artery ostium stenting: A single-center real-world study

BACKGROUND AND PURPOSE

While drug-eluting stents (DES) have been widely applicated in coronary stenosis, uncertainty persists concerning the relative performance and clinical benefit in patients undergoing vertebral artery stenting when compared with a bare metal stent (BMS). We sought to compare in-stent restenosis (ISR) rates of DES and BMS in the treatment of vertebral artery ostium (VAO) stenosis.

MATERIALS AND METHODS

This study analyzed a single-center prospective cohort. Over 1.5-year period (January 2014-June 2015), 137 consecutive patients underwent VAO stenting involving deployment of 76 DES and 74 BMS. Patient demographics, comorbidities, stenosis severity, stent diameters and lengths, periprocedural complications, imaging and duplex ultrasonography follow-up and recurrent symptoms were assessed.

RESULTS

Technical success was achieved in all patients. Mean VAO stenosis at presentation were 82.4 ± 7.2% in the DES group and 83.3 ± 7.5% in the BMS group and were reduced to 12.5 ± 4.5% and 11.3 ± 4.0%. Mean stent diameter was 3.53 ± 0.40 mm in DES and 5.05 ± 0.40 mm in BMS (p < 0.0001). Mean follow-up was 12.3 months for DES and 11.7 months for BMS. The use of DES was associated with significant lower ISR rates compared with BMS (18.4% vs. 31.1%; OR = 2.628, p = 0.021). Recurrent symptoms rates were similar in DES vs. BMS (2.6% vs 2.7%, p = 0.680). Stent type and stent diameter were independent risk factors for ISR (P = 0.026).

CONCLUSION

Our results suggest superior efficacy of deploying DES for the treatment of VAO stenosis with lower ISR rates as compared to BMS, but do not support significant differences in periprocedural risk and recurrent symptoms rate.

Angioplasty Using Drug-Coated Balloons in Ostial Vertebral Artery Stenosis

BACKGROUND

Ostial vertebral artery stenosis (OVAS) is a relevant cause of acute ischemic posterior circulation stroke. Percutaneous trans-luminal angioplasty (PTA) might offer a promising treatment modality, but restenosis rate is high. So far, little is known about recanalization using drug-coated balloons (DCB) in OVAS. We aimed to show feasibility and safety of DCB-PTA in OVAS.

METHODS

Retrospective, monocenter case series of 12 patients with ostial vertebral artery stenosis (≥50%) treated with PTA using a drug-coated balloon.

RESULTS

Median age was 69.5 years (IQR 57-78.5) with a female rate of 41%. Patients were treated either with a SeQuent Please NEO or Neuro Elutax SV DEB. Median preinterventional stenosis degree was 75% (IQR 70-85) with a median lesion length of 4.5 mm (IQR 4-7.5). Median postinterventional stenosis degree was 40% (IQR 27-50). All treated vessels remained patent. No major complications such as dissection, vessel perforation, hemorrhage, or ischemic events occurred. Moreover, we did not detect any restenosis during a median follow-up period of 6.1 months. The clinical outcome was excellent with median mRS scale of 0 (IQR 0-1).

CONCLUSIONS

PTA using drug-coated balloons is feasible and safe in patients with ostial vertebral artery stenosis.

Successful Endovascular Bailout Strategy for Retained Accunet Embolic Protection Device During Vertebral Artery Stenting

Introduction: Vertebral artery stenosis can lead to posterior circulation TIAs and stroke. Stenting is often performed to treat symptomatic vertebral artery stenosis. As with carotid stenting, embolic protection devices (EPD) are increasingly used when stenting a vertebral artery stenosis. In general, EPDs may rarely become detached or retained in the circulation during stent revascularization. We discuss a 77-year-old male with a history of cerebral atherosclerosis and prior left occipital lobe and right insular infarcts who presented with increasing left sided weakness and was found to have severe stenosis of the proximal left vertebral artery. We report the only known case and successful endovascular bailout for an irretrievable EPD occurring during vertebral artery stenting.

Methods: Systematic reviews of the medical literature were performed using PubMed and multiple combinations of keywords to search for irretrievable EPDs in either the carotid or vertebral arteries. The bibliographies of the results were used to identify additional publications until this process was exhausted.

Results: No prior reports were found for retained or detached vertebral artery EPD. A total of six cases were found where an EPD was lost in the carotid circulation. In three of the cases, a carotid arteriotomy was required to retrieve the EPD. In two other cases, diagnostic catheters were used to retrieve the EPD. In our case, an EverFlex Biliary Stent was used to flatten the irretrievable EPD into the vertebral artery wall while preserving robust vertebral artery perfusion. 21-month clinical and 16-month imaging follow-up demonstrated durable vertebral artery patency and no ischemic symptoms.

Conclusion: Successful bailout strategy for a retained vertebral artery EPD during stenting may be achieved with a self-expanding stent. The resultant revascularization remained durable and without clinical sequelae.

Comparison of hemodynamic changes and prognosis between stenting and standardized medical treatment in patients with symptomatic moderate to severe vertebral artery origin stenosis

This study aimed to compare the clinical efficacy of stenting compared with standardized medical treatment in patients with moderate to severe vertebral artery origin stenosis (VAOS).Patients diagnosed with moderate to severe VAOS and indicated to undergo vertebral artery stenting were enrolled. Patients were divided into stenting group and standardized medical treatment group. All patients underwent transcranial Doppler (TCD) before and after treatment. Incidence of new cerebral infarction, transient ischemic attack (TIA), improvement of clinical symptoms, and National Institutes of Health Stroke Scale (NIHSS) score were observed.A total of 98 patients were enrolled. Vertebral artery stenting implant was accepted by 43 patients. Two weeks after treatment, the NIHSS score in the stenting group decreased significantly compared to that in the standardized medical treatment group. The modified Rankin Scale (mRS) score in the stenting group at three months was significantly lower than that in the medical treatment group (P = .044). The extent of vascular stenosis in the stent group decreased significantly (76.5 ± 10.0% vs. 13.7 ± 5.9%, t = 35.878, P = .000). The adverse events occurred in 9 (16.4%) patients in the medical treatment group and 5 (11.6%) in the stenting group (P = .506). There was one case with new cerebral infarction in the stenting group, whereas the medical treatment group showed 1 case with TIA and three with new cerebral infarction during follow-up after 3 months. The peak systolic velocity (PSV), end diastolic velocity (EDV), pulsatility index (PI) of stenosis vertebral artery, and PSV of basilar artery were significantly higher in the stent group than those in the standardized medical group (P < .05).Stenting for VAOS, rather than standardized medical treatment, can effectively relieve vascular stenosis, alter vertebral-basilar artery hemodynamics, and improve neurological function, with low perioperative complications.

A young woman with traumatic vertebral artery occlusion: a case report

Vertebral artery occlusion (VAO) may result from closed head or neck trauma and can be lifethreatening due to brain-stem and cerebellar infarction. CT angiography is recommended as a screening diagnostic tool in selected patients after blunt cervical trauma. A 24-year-old woman was admitted to our emergency department with left hemiplegia two days after motor vehicle collision. Final diagnosis of occlusion of the right vertebral artery was made in CT angiography. She was treated with anticoagulant for 4 days then discharged with 5/5 muscle forces. She was advised to continue warfarin and atorvastatin for her after discharge.

Arterial occlusions increase the risk of in-stent restenosis after vertebral artery ostium stenting

OBJECTIVE

The study was designed to investigate if vascular occlusion in the internal carotid artery (ICA) or the contralateral vertebral artery (VA) contribute to developing in-stent restenosis (ISR) in patients with vertebral artery ostium stenosis (VAOS).

METHODS

420 consecutive patients treated with VAOS stents (from a population of 8145 patients with VAOS) from January 2013 to December 2014 were analyzed in this retrospective study; 216 with drug eluted stents and 204 with bare metal stents. Based on pre-stent DSA findings, patients were divided into four groups: both carotid and vertebral arteries patent (PAT), ICA occlusion (ICA-OCC), contralateral VA occlusion (CVA-OCC), and combined occlusions (C-OCC). The incidence of ISR (stenosis >50%) was compared between groups using Cox regression analysis.

RESULTS

Of the 420 patients, the mean incidence of ISR was 36.4%, with a median 12 months of follow-up (IQR 3-12). Logistic regression analysis showed that drug eluting stent had less ISR than bare metal stent (OR=0.38, 95% CI 0.19 to 0.75, P=0.01). Cox regression analysis showed that CVA-OCC (HR=1.63, P=0.02) and C-OCC (HR=3.30, P=0.001) were risk factors for ISR but not ICA-OCC (P=0.31). In the CVA-OCC and C-OCC groups, in-stent peak systolic velocity (PSV) ≥140 cm/s, 1 day after successful stenting, was associated with subsequent development of ISR (OR=2.81, 95% CI 1.06 to 7.43, P=0.04).

CONCLUSION

Contralateral VA occlusion at the time of stenting increased the risk of ISR, especially if stent PSV on day 1 was >140 cm/s. Bare metal stents had more ISR than drug eluting stents.

Clinical outcomes and influencing factors of in-stent restenosis after stenting for symptomatic stenosis of the vertebral V1 segment

OBJECTIVE

The objective of this study was to evaluate 30-day and long-term clinical outcomes and influencing factors of in-stent restenosis (ISR) after stenting for symptomatic stenosis of the vertebral V1 segment.

METHODS

The clinical and follow-up data of 301 consecutive patients (mean age, 64 ± 8 years; 252 men) with symptomatic V1 stenosis who underwent stenting at the Fuwai Hospital between January 2010 and June 2016 were collected retrospectively. The 30-day and long-term follow-up of stroke and death after stenting and the recurrence of symptoms, ISR, and repeated revascularization were assessed.

RESULTS

Technical success was 100%. The mean stenosis of lesions was reduced from 82.8% ± 7.6% to 4.4% ± 4.0% immediately after 312 stents (165 bare-metal stents [BMSs] and 147 drug-eluting stents) were implanted. The overall risk of combined any stroke and death was 1.0% (3/301) within 30 days after stenting. The rates of freedom from any stroke and death were 98.2%, 96.8%, and 91.4% at 1 year, 3 years, and 5 years, respectively. After a mean follow-up of 2.9 ± 1.5 years, 46 (15.8%) patients developed ISR, of whom 19 (6.5%) were symptomatic. Twenty-two (7.6%) patients with ISR underwent repeated revascularization. The primary and assisted patency rates were 90.0% and 95.4%, 82.6% and 90.3%, and 80.3% and 87.9% at 1 year, 3 years, and 5 years, respectively. BMS (hazard ratio, 2.02; 95% confidence interval, 1.01-4.06; P < .05) and diabetes (hazard ratio, 1.87; 95% confidence interval, 1.04-3.37; P = .04) were independently associated with an increased risk of ISR.

CONCLUSIONS

Percutaneous stent placement for symptomatic V1 stenosis is safe and associated with a good long-term patency rate. BMS and diabetes are independent predictive factors of ISR.

A systematic classification of the vertebral artery variable origin: clinical and surgical implications

Several congenital anomalies regarding the right (RVA) and left (LVA) vertebral artery have been described. The current paper aims to perform a systematic literature review of the variable vertebral artery (VA) origin from the aortic arch (AOA) and its branches. The incidence of these variants and the ensuing AOA branching pattern are highlighted. Atypical origin cases were found more commonly unilaterally, while LVA presented the majority of the aberrancies. The LVA emersion from the AOA (3.6%) and the RVA from the right common carotid artery (RCCA) (0.14%) were the commonest origin variations. Aberrant RVA origin as last branch of the AOA is very rare. Eighteen cases (0.12%) with an aberrant right subclavian artery (ARSCA) were found. Among them, the RVA originated from the RCCA and right subclavian artery in 94.4 and 5.6%, respectively. Sporadic cases had an AOA origin bilaterally; RVA and LVA had a double origin in 0.027 and 0.11%, respectively. A dual origin was detected in 0.0069%, bilaterally. The atypical VA origin may coexist with: (i) an ARSCA, (ii) a common origin of brachiocephalic artery and left common carotid artery (the misnomer bovine arch) and (iii) a bicarotid trunk. The aberrant VA origin favors hemodynamic alterations, predisposing to cerebrovascular disorders and intracranial aneurysm formation. Detailed information of VA variants is crucial for both endovascular interventionists and diagnostic radiologists involved in the treatment of patients with cerebrovascular disease. Such information may prove useful to minimize the risk of VA injury in several procedures.

Technical factors affecting outcomes following endovascular treatment of posterior circulation atherosclerotic lesions

Background

Atherosclerotic disease of the vertebrobasilar system causes significant morbidity and mortality. All lesions require aggressive medical management, but the role of endovascular interventions remains unsettled. This study examines such endovascular interventions for vertebrobasilar atherosclerosis.

Methods

Retrospective review was performed of prospectively maintained procedure logs at three hospitals with comprehensive neurointerventional services. Patients with angiographically-proven stenosis undergoing elective stent placement were selected for analysis of demographic factors, lesion characteristics, and treatment details. Multivariate analysis was performed to evaluate for associations with ischemic stroke, death, and functional status as measured by modified Rankin scale at multiple intervals.

Results

One hundred and twenty-three lesions were treated in 110 patients. A total of 43 (58.1%) lesions caused stroke, while 66 (89.2%) caused transient ischemic attacks (TIAs). Forty lesions (32.5%) were at the vertebral origin; 97 (60.2%) were intracranial. A total of 112 (91.1%) were treated successfully. 4 (3.3%) of 10 (8.1%) procedural complications were symptomatic. Intracranial lesions were associated with death at 1 and 2 years (OR 24.91, P < 0.001) and mRS >2 at last contact (OR 12.83, P < 0.001). Stenting treatment with conjunctive angioplasty had lower rates of death (OR 0.303, P = 0.046) and mRS >2 at last contact (OR 0.234, P = 0.018) when angioplasty was performed with a device other than that packaged with the stent.

Conclusion

Endovascular treatment of vertebrobasilar atherosclerosis can be performed safely, particularly for vertebral origin lesions. Higher rates of technical failure and complication may be acceptable for certain intracranial lesions due to their refractory nature and the morbidity caused by such lesions. Treatment should be tailored to features of each individual lesion.

[Brainstem auditory evoked potentials in neurophysiological assessment of brain stem dysfunction in patients with atherostenosis of vertebral arteries]

AIM

To assess brain stem dysfunction in patients with hemodynamically significant stenosis of vertebral arteries (VA) using short latency brainstem auditory evoked potentials (BAEP).

MATERIAL AND METHODS

The study group included 50 patients (mean age 64±6 years) with hemodynamically significant extracranial VA stenosis.

RESULTS

Patients with hemodynamically significant extracranial VA stenosis had BAEP abnormalities including the elongation of interpeak intervals I-V and peak V latency as well as the reduction of peak I amplitude. After transluminal balloon angioplasty with stenting of VA stenoses, there was a shortening of peak V latency compared to the preoperative period that reflected the improvement of brain stem conductive functions.

CONCLUSION

Atherostenosis of vertebral arteries is characterized by the signs of brain stem dysfunction, predominantly in the pontomesencephal brain stem. After transluminal balloon angioplasty with stenting of VA, the improvement of brain stem conductive functions was observed.

Use of Embolic Protection Devices in Peripheral Interventions

The use of embolic protection devices (EPDs) when treating coronary saphenous vein bypass grafts, performing carotid arterial stenting and treating acute coronary syndromes is well accepted. We will review currently available devices and approaches to reduce distal embolisation, first discussing their uses in carotid interventions and then in vertebral and peripheral vascular interventions.

Restenosis after stenting in symptomatic vertebral arterial orifice disease and considerations for better outcome

We have performed stenting in 11 patients with symptomatic vertebral arterial orifice stenosis refractory to medical treatment or impairment in anterior circulation. Three of the 11 patients experienced asymptomatic severe in-stent restenosis or occlusion. Bare metal stents were used in those three patients, two of whom received revascularization therapy. Development of sufficient cervical collateral channels reconstituting the distal vertebral artery was the common feature in patients with asymptomatic in-stent restenosis. In selecting appropriate stents, consideration of mechanical strength and drug-eluting properties of a stent according to characteristics of the target vessel is important to reduce the risk of in-stent restenosis. Any decision to perform revascularization should be based on the presence of abundant cervical collaterals as well as clinical symptoms of vertebrobasilar ischemia.

Dynamic Respiratory Tortuosity of the Vertebral Artery Ostium

PURPOSE

To determine the prevalence of dynamic respiratory tortuosity (DRT) of the vertebral artery ostium (VAO) as well as to evaluate its correlation with in-stent restenosis (ISR) and stent fracture.

METHODS

From March 2012 to June 2015, 178 consecutive patients (mean age 65.2±5.8 years; 124 men) with symptoms of atherosclerotic vertebrobasilar ischemia underwent angiography prior to stent implantation in the vertebral, subclavian, and/or carotid arteries. In this cohort, 54 patients (mean age 67.3±5.3 years; 40 men) had VAO stent implantation. Angiography of the vertebral artery was recorded in 2 phases with breath-hold: deep inspiration (DIP) and deep expiration (DEP). Obvious VAO tortuosity was defined as any VAO angle ≤120° in DIP. Obvious VAO-DRT was defined as any VAO angle increasing ≥60° from DIP to DEP. Computed tomography angiography (CTA) or digital subtraction angiography was used in follow-up to detect ISR and stent fracture.

RESULTS

Of the 178 patients in this study, 21 (11.8%) had obvious VAO tortuosity and 8 (4.5%) had obvious VAO-DRT. Two of the 21 patients with obvious VAO tortuosity also had obvious VAO-DRT. Three of the 54 VAO stent patients had VAO-DRT. There were no correlations between VAO-DRT and age, sex, risk factors, body mass index, chronic obstructive pulmonary disease, asthma, or obvious VAO tortuosity (p>0.05). Over a mean follow-up of 28±10 months, there were 4 (7.4%) asymptomatic VAO ISR cases. Two (3.7%) were occlusions at 6 and 12 months, respectively; both were associated with stent fracture in patients with obvious VAO-DRT before stenting. Both stents fractured at the tortuous VAO region. VAO-DRT was correlated with stent fracture (Spearman ρ=0.81, p<0.01) and ISR (Spearman ρ=0.55, p<0.01).

CONCLUSION

VAO-DRT could be a risk factor for stent fracture and restenosis after VAO stent implantation. Angiography in both inspiration and expiration phases, especially the latter, should be considered before VAO stenting. Using a shorter stent to avoid crossing the tortuosity could reduce the occurrence of fracture.

Radial Artery Bypass for Intractable Vertebrobasilar Insufficiency: Case Series and Review of the Literature

BACKGROUND

Vertebrobasilar insufficiency resulting from embolism, atherosclerosis, or arterial dissection has long been a challenge for successful management and outcomes. The main treatment options include medical therapy, angioplasty and stenting, and surgical revascularization. Unlike cardiac or peripheral vascular revascularization, large randomized trials with cerebrorevascularization have not revealed favorable outcomes. In patients who have failed maximal medical therapy, and having persistent debilitating symptomology, cerebral revascularization may still be a viable option.

METHODS

We report 3 patients who presented with symptoms of vertebrobasilar ischemia. The diagnosis was verified by computerized tomographic arteriography and digital subtraction angiography.

RESULTS

These patients subsequently underwent revascularization with a radial artery graft. We also present a comprehensive review of the literature of treatment for vertebrobasilar insufficiency.

CONCLUSIONS

Surgical revascularization should be considered in the posterior circulation in the rare subset of patients with VBI, who remain symptomatic despite having a protracted course of maximal medical therapy with large- and medium-sized vessel occlusions and poor collateral circulation.

[Complications after supra-aortic reconstruction]

BACKGROUND

Surgical interventions on the supra-aortic vessels are common procedures to avoid cerebral ischemia or arm pain during exercise. The safety and efficacy has been confirmed by clinical studies. Complications are rare but have serious consequences.

OBJECTIVES

What special indications and recommendations are there for the diagnostics and treatment in the perioperative phase?

METHODS

The current article is a literature-based review that considers international studies, guidelines and personal experiences.

RESULTS

There is a broad range of complications. A simple systematic physical examination is often sufficient to give indications of the problem. Confirming clinical apparative examinations are mostly intraoperative angiography or sonography, whereas postoperative procedures include color-coded duplex sonography (FKDS) and angiography computed tomography (angio-CT). Important basic principles and aspects of operative procedures are presented. Evidence-based differences between the treatment options with resulting complications are mostly unknown; therefore, clinical management mostly relies on expert recommendations.

CONCLUSION

There are several modern treatment options for invasive therapy. Despite a decrease in previous complication rates, typical perioperative complications must be considered. The diagnosis and therapy is carried out according to established strategies.

Comparison of self-expanding stents with distal embolic protection to balloon-expandable stents without a protection device in the treatment of symptomatic vertebral artery origin stenosis: a prospective randomized trial

PURPOSE

To compare the angiographic and clinical outcomes of self-expanding stents (SES) with distal embolic protection devices (EPD) vs balloon-expandable stents (BES) without EPD in the treatment of symptomatic atherosclerotic vertebral artery ostial stenosis (VAOS).

METHODS

Between July 2011 and March 2013, a prospective randomized trial was conducted involving 127 patients (mean age 67.3±10.2 years; 94 men) with symptomatic VAOS randomly assigned to treatment with SES + EPD (Precise RX or RX Acculink stent + Spider FX EPD; n=61) or BES (Palmaz Blue or Resolute RX; n=66) without EPD. In-stent restenosis (ISR) >50% detected by duplex ultrasound was the primary endpoint. Technical success, clinical success, complications within 30 days, and signal intensity abnormalities on diffusion weighted imaging (DWI) after stenting were compared.

RESULTS

The 30-day technical success rate was 95.5% (63/66) for SES+EPD vs 100% (70/70) for BES without EPD (p=0.072). DWI at 24 hours poststenting showed 2 hyperintense lesions in 2 (3.3%) SES + EPD cases and 15 hyperintense lesions in 13 (18.6%) BES patients (p<0.01). At a mean 18-month follow-up, the clinical success rate was 93.9% (62/66) for the SES + EPD group vs 85.7% (60/70) for the BES group (p=0.115). The ISR was seen in 16/70 (22.9%) arteries in the BES group and 2/66 (3.1%) arteries in SES + EPD group (p<0.01). Target vessel revascularization was performed in 7 (10.0%) BES arteries vs none in the SES + EPD group (p<0.01).

CONCLUSION

SES with EPD in the treatment of symptomatic VAOS is technically feasible and safe, with low rates of ISR and significantly reduced thromboembolic events on imaging when compared to BES without EPD.

Lesion location, stability, and pretreatment management: factors affecting outcomes of endovascular treatment for vertebrobasilar atherosclerosis

BACKGROUND AND PURPOSE

The proper role of endovascular treatment of cervicocerebral atherosclerosis is unclear. Posterior circulation disease has not been investigated as extensively as disease in the anterior circulation. In this study, we characterized the rates of technical success, transient ischemic attack, stroke, and death or disability, for both acute and elective endovascular treatment of atherosclerosis in the vertebrobasilar system.

METHODS

We identified patients with atherosclerosis of the vertebrobasilar circulation who underwent endovascular intervention at our hospital through retrospective medical record review, and evaluated the association between lesion and treatment features and subsequent stroke, death, or disability at 30 days and 1 year.

RESULTS

We identified 136 lesions in 122 patients, including 13 interventions for acute strokes. Technical success was achieved in 123 of 136 cases (90.4%). Elective procedures had higher rates of technical success (6.5% vs 15.4%, p=0.21) and better clinical outcomes. In multivariate analysis, intracranial lesions were associated with more disability (modified Rankin Scale score >2) at 30 days (OR 7.1, p=0.01) and 1 year (OR 10, p=0.03). Patients with non-hypoperfusion related symptoms had fewer strokes at follow-up at 1 year when treated after an asymptomatic interval of >10 days compared with those treated within 10 days of the presenting symptoms (OR 0.2, p=0.03). Statin treatment prior to intervention was associated with favorable outcomes across several examined endpoints. Preoperative antiplatelet treatment was associated with lower rates of disability at 30 days and 1 year (OR 0.1, p<0.01 and OR 0.07, p=0.01, respectively), and preoperative anticoagulation treatment was associated with higher rates of death at 30 days, particularly when prescribed for reasons other than atrial fibrillation (OR 6.4, p=0.01).

CONCLUSIONS

Endovascular treatment of symptomatic vertebrobasilar atherosclerosis can be performed safely and with good outcomes. Technical results were better for those with extracranial disease while clinical outcomes were more favorable in those patients with non-progressive symptoms in the subacute period and those receiving statin therapy.

Transradial approach for vertebral artery stenting

INTRODUCTUION

Symptomatic severe vertebral artery (VA) stenosis may be treated safely with stent supported angioplasty via femoral access. There is limited clinical data on transradial approach for VA angioplasty in case of peripheral artery disease.

AIM

To evaluate the safety and efficacy of transradial angioplasty of symptomatic VA stenosis.

MATERIAL AND METHODS

Fifteen patients (age 66 ±7.4 years, 73% men, with VA > 80% stenosis, 11 right-side, all symptomatic from posterior circulation (history of stroke, TIA, or chronic ischaemia symptoms)) with peripheral artery disease (PAD) or unsuccessful attempt via femoral approach were scheduled for VA angioplasty by radial access. Clinical and duplex ultrasound (DUS) follow-up were performed before discharge and 1, 12, and 24 months after VA angioplasty.

RESULTS

The technical success rate was 100%. In all cases VA angioplasty was performed with the use of single balloon-mounted stent (9 bare metal stents, 6 drug-eluting stents). The mean NASCET VA stenosis was reduced from 85.3% to 5.3% (p < 0.001). No periprocedural death, stroke, myocardial infarction, or transient ischaemic attack occurred. During 24-months follow-up, in 12 of 15 patients chronic ischaemia symptoms release was observed, and no new acute ischaemic neurological symptoms were diagnosed in all patients. One patient died 20 months after intervention from unknown causes. There was one symptomatic borderline VA in-stent stenosis 12 months after angioplasty.

CONCLUSIONS

Transradial VA stenting may be a very effective and safe procedure, and it may constitute an alternative to the femoral approach in patients with symptomatic VA stenosis.

Percutaneous Treatment of Vertebral Artery Stenosis

Endovascular treatment of the ostial and proximal portions of the vertebral artery is a safe and effective technique for alleviating symptoms and improving cerebral blood flow to the posterior circulation. Vertebral artery angioplasty can be performed with high technical and clinical success rates, low complication rates, and durable long-term results. Although restenosis rates range from 0% to 48%, the durability of vertebral artery angioplasty is evidenced by low restenosis rates in multiple large series reported in the literature using multiple treatment options, including balloon angioplasty alone, bare metal stents, and drug-coated stents.

Angioplasty and stenting of symptomatic vertebral artery stenosis. Clinical and angiographic follow-up of 206 cases from Northwest Iran

Percutaneous transluminal angioplasty (PTA) has recently become a noteworthy treatment option for significant stenosis involving the vertebral artery (VA) in selected patients. We conducted a prospective study to evaluate the efficacy, safety and mid-term follow up results of 206 cases received PTA with or without stent implant to treat their symptomatic atherosclerotic VA stenosis in all segments (V1-V4). In a prospective mono-arm trial from October 2008 to July 2012 in a single center, 239 lesions affecting the intra or extracranial VA (171 in V1, 17 in V2, 14 in V3, 21 in V4 and 16 in combined segments) were treated by PTA with or without stent implant. Non-disabling stroke patients who had failed conservative medical treatment and had angiographic evidence of >50% stenosis in the dominant VA with clinical signs and symptoms of VB stenosis were included in this study. They were mean followed for 13.15±5.24 months after treatment. Overall, 206 patients underwent the procedure. A stent was implemented in 199 patients (96.6%). The periprocedural complication rate was 7.2%. The procedural (technical) success rate was 97.6%. Of the total 239 lesions, 223 were treated with stent implant. Clinical success was achieved in all 206 symptomatic patients after the procedure. Restenosis occurred in 15.9% after a mean 10.8 (6-24) months. Of those, 63.1% and 34.2% had mild and moderate stenosis that was treated medically, whereas one case (2.6%) with severe restenosis underwent balloon angioplasty. No deaths occurred during the follow-up period. The follow-up complication rate was 6.3%. TIA occurred in 4.4%, a minor stroke in 1.4% and a major stroke in one patient. The overall patient event-free survival was 92.4%. These results demonstrate the safety and feasibility of PTA with or without stent implant, with a high technical success rate, a low complication rate, a low restenosis rate and durable clinical success in patients with symptomatic VA stenosis. This approach seems to improve patients' immediate and mid-term clinical results. Randomized controlled trials are necessary to further validate this treatment option.

HEMODYNAMIC ANALYSIS OF STENT EXPANSION RATIO FOR VERTEBRAL ARTERY OSTIAL STENOSIS INTERVENTION

Stents have been used successfully for treating stenosis in the vertebral artery ostium. The size of stent is found to be an important link in stent design, implantation strategy, and clinical outcome. However, there is no direct evidence of a relationship between stent expansion ratio and the stented artery. This study investigated the influence of stent expansion ratio on local hemodynamics (such as pressure distribution and pressure gradient) of vertebral artery ostial stenosis to determine a possible biomechanical mechanism. Computer-aided design of models with stents with different expansion ratios (i.e., 1.00, 1.125, and 1.25) and internal flow fields were created. All the models were meshed and simulated using computational fluid dynamics (CFD) tools. The comparisons of pressure distribution and pressure gradient are specifically presented. The results showed that the pressures increase and the pressure gradient decreases after stent implantation. The mean pressure at the stented region rises significantly with the increase of stent oversize. The heterogeneity of the pressure gradient was reduced at the stented region in the case with the expansion ratio of 1.125, whereas this effect was not obvious in other expansion ratio cases. Additionally, the combination of higher pressure and a lower pressure gradient in the case with the expansion ratio of 1.125 was significantly observed. This study demonstrated that the proper size of stent, especially with regards to the expansion ratio, is an important factor influencing the treatment of vertebral artery ostial stenosis. It is the recognition of the necessity to consider the relationship between expansion ratio and stenosis in vertebral artery ostium. These findings could help to address the optimization of hemodynamic performance for stent implantation.

Crossover balloon technique for vertebral artery thrombus: a novel method

A 54-year-old man presented with recurrent episodes of transient ischemic attacks and acute stroke secondary to a floating thrombus in the right vertebral artery (VA) with narrowing of the right VA. He was initially treated medically with anticoagulation, antiplatelets and statins but developed multiple fresh infarcts. He was then referred for endovascular treatment, which was performed in a novel way.

Crossover balloon technique for vertebral artery thrombus: a novel method

A 54-year-old man presented with recurrent episodes of transient ischemic attacks and acute stroke secondary to a floating thrombus in the right vertebral artery (VA) with narrowing of the right VA. He was initially treated medically with anticoagulation, antiplatelets and statins but developed multiple fresh infarcts. He was then referred for endovascular treatment, which was performed in a novel way.

Endovascular treatment of extracranial vertebral artery stenosis

Percutaneous angioplasty and stenting for the treatment of extracranial vertebral artery (VA) stenosis seems a safe, effective and useful technique for resolving symptoms and improving blood flow to the posterior circulation, with a low complication rate and good long-term results. In patients with severe tortuosity of the vessel, stent placement is a real challenge. The new coronary balloon-expandable stents may be preferred. A large variability of restenosis rates has been reported. Drug-eluting stents may be the solution. After a comprehensive review of the literature, it can be concluded that percutaneous angioplasty and stenting of extracranial VA stenosis is technically feasible, but there is insufficient evidence from randomized trials to demonstrate that endovascular management is superior to best medical management.

Treatment of vertebral disease: appropriate use of open and endovascular techniques

Vertebral artery disease is an often underdiagnosed and undertreated cause of posterior circulation ischemia. Revascularization of the vertebral circulation should be considered in patients refractory to medical therapy. Surgical and endovascular techniques are discussed and reviewed in the context of the location and type of vertebral artery disease.

Doppler criteria for identifying proximal vertebral artery stenosis of 50% or more

OBJECTIVES

The proximal segment of the vertebral artery is a frequent site of obstructive atherosclerosis. The purpose of this study was to determine Doppler criteria for identifying proximal vertebral artery stenosis of 50% or more by comparison with digital subtraction angiography.

METHODS

Forty-eight patients with vertebral artery stenosis were examined prospectively with color Doppler sonography and digital subtraction angiography. The peak systolic velocity (PSV), end-diastolic velocity (EDV), peak systolic velocity ratio (PSVr), and end-diastolic velocity ratio (EDVr) were evaluated by receiver operating characteristic curve analysis for their ability to detect vertebral artery stenosis of 50% or more. The optimal criteria for identifying proximal vertebral artery stenosis of 50% or more were determined.

RESULTS

For identifying vertebral artery stenosis, the parameter with the highest accuracy was the PSVr (area under the receiver operating characteristic curve, 0.967 [95% confidence interval, 0.899-0.994]). A PSVr of greater than 2.2 was found to be the optimal criterion for identifying proximal vertebral artery stenosis of 50% or more, with sensitivity and specificity of 96% and 89%, respectively. The optimal thresholds for the other Doppler parameters in identifying proximal vertebral artery stenosis of 50% or more were as follows: PSV, greater than 108 cm/s; EDV, greater than 36 cm/s; and EDVr, greater than 1.7.

CONCLUSIONS

Color Doppler sonography is an accurate method for identifying proximal vertebral artery stenosis. The PSVr is superior to other Doppler parameters for detecting vertebral artery stenosis.

Unilateral right occipital condyle to C2 level spinal cord infarction associated with ipsilateral vertebral artery stenosis and contralateral vertebral artery dissection: a case report

OBJECTIVES

To illustrate the clinical presentation, diagnosis, management, and outcome of unilateral right occipital condyle to C2 level spinal cord infarction.

SETTING

A teaching hospital in Taiwan.

FINDINGS

A 37-year-old man presented with acute-onset severe right neck pain before weakness developed in both right limbs. Early diagnosis was delayed due to mild intervertebral herniation of the C4-C5 disk. Magnetic resonance imaging revealed unilateral right occipital condyle to C2 level infarction. Angiography showed stenosis of the right vertebral artery (foraminal and intradural segments), and dissection of the left vertebral artery at the C1-C2 level. At discharge, he walked with assistance; 2 weeks later, he walked independently.

CONCLUSIONS

An early diagnosis is difficult but important, as it facilitates appropriate treatment for better functional and survival outcomes. Accurate early diagnosis can be made with adequate knowledge of spinal cord infarction and high index of suspicion for this condition.