The impact of increasing age on anatomic factors affecting carotid angioplasty and stenting

Takeoff orientation of the major aortic arch branches irrespective of arch type: Ramifications for brachiocephalic interventions including carotid stenting

Background:

Our previous work demonstrating great ease and predictability of cannulation of the major aortic arch branches with an upwardly pointing 3DR catheter, irrespective of aortic arch type, led us to hypothesize that centering or “cresting” of these vessels must occur along the superior most aspect of the aortic arch in a curvilinear fashion.

Methods:

We retrospectively analyzed 111 computed tomographic scans of the chest and thoracic aorta with intravenous contrast performed at our hospital between April 2011 and May 2012 utilizing TeraRecon image reconstruction software. Four studies were excluded due to poor image quality and/or surgical changes to native aortic architecture.

Results:

Of the 107 studies included, 104 (97.2%) demonstrated centering of the major aortic arch branches on a curvilinear line “cresting” the superior most aspect of the aortic arch irrespective of arch type. Of the three studies that did not demonstrate this “cresting,” two were found to have aberrant right subclavian arteries associated with a type I aortic arch, and one had an aberrant right common carotid associated with a type II aortic arch.

Conclusion:

Operators engaging major aortic arch branches need to be mindful of the fact that these vessels are indeed centered on a line “cresting” along the superior most aspect of the aortic arch, and any algorithm that, by taking this information into account, reduces catheter manipulation in the aortic arch could potentially result in a reduction in distal atheroembolic events.

The middle-term outcome of carotid endarterectomy and stenting for treatment of ischemic stroke in Chinese patients

This study aims to investigate the complication and middle-term outcome of carotid endarterectomy (CEA) and carotid artery stenting (CAS) in Chinese patients, which was a retrospective case-control study and perioperative complications and 2-year end points were analyzed. Follow-up was done by a certified doctor, and restenosis was detected by ultrasound. Operation success rate were 100% in two groups. CAS showed the higher incidence rate of all stroke/TIA at 30days post-procedure (7.89% VS 1.85%, P = 0.038), odds ratio (OR) with 95% confidence interval, 4.54 (1.09–18.97), but there was no difference in the incidence rate of stroke subgroups, mortality and myocardial infarction between two groups. The higher incidence of hypertension with CEA (14.42% VS 5.26%, P = 0.012), OR: 2.90 (1.26–6.65) and hypotension with CAS (14.91% VS 1.85%, P = 0.001), OR: 0.11 (0.03–0.42). No difference in all stroke, ipsilateral stroke and mortality between two groups at 24 months post-procedures, however, the total incidence rate of stroke/death was higher in CAS (12.84% VS 4.72%, P = 0.036), OR: 2.98 (1.08,8.23). Higher restenosis rate of CAS was examined (13.76% VS 5.66%, P = 0.045), OR: 2.66 (1.02, 6.74). CAS and CEA showed a similar middle-term outcome, but CAS showed a higher incidence rate of stroke and restenosis after operation.

Transcervical access via direct neck exposure for neurointerventional procedures in the hybrid angiosuite

PURPOSE

A complicated course of the femoral route for neurointervention can prevent approaching the target. Thus, we determined whether transcervical access in the hybrid angiosuite is applicable and beneficial in real practice.

METHODS

From January 2014 to March 2017, this approach was used in 17 of 453 (3.75%) cases: 11 cerebral aneurysms (4 ruptured, 7 unruptured), 4 acute occlusions of the large cerebral artery, 1 proximal internal carotid artery (ICA) stenosis, and 1 direct carotid cavernous fistula (CCF).

RESULTS

All patients were elderly (mean age, 78.1 years). The main cause was severe tortuosity of the supra-aortic course or the supra-aortic and infra-aortic courses (eight and five cases, respectively), orifice disturbance (three cases), and femoral occlusion (one case). Through neck dissection, 6-8Fr guiding catheters were placed via subcutaneous tunneling to enhance device stability and support. All cerebral aneurysms were embolized (eight complete and three neck remnants) using the combination of several additional devices. Mechanical stent retrieval with an 8Fr balloon guiding catheter was successfully achieved in a few runs (mean, 2 times; range, 1-3) within the proper time window (mean skin to puncture, 17 ± 4 min; puncture to recanalization, 25 ± 4 min). Each stent was satisfactorily deployed in the proximal ICA and direct CCF without catheter kick-back. All puncture sites were closed through direct suturing without complications.

CONCLUSIONS

In the hybrid angiosuite, transcervical access via direct neck exposure is feasible in terms of device profile and support when the femoral route has an unfavorable anatomy.

Predictors of Perioperative Stroke/Death after Carotid Artery Stenting: A Review Article

Carotid artery stenting (CAS) has been recommended as an alternative treatment to carotid endarterectomy for patients with significant carotid stenosis. Only a few studies have analyzed clinical/anatomical and technical variables that affect perioperative outcomes of CAS. Following a comprehensive Medline search, it was reported that clinical factors, including age of >80 years, chronic renal failure, diabetes mellitus, symptomatic indications, and procedures performed within 2 weeks of transient ischemic attack symptoms, are associated with high perioperative stroke and death rates. They also highlighted that angiographic variables, e.g., ulcerated and calcified plaques, left carotid intervention, >90% stenosis, >10-mm target lesion length, ostial involvement, type III aortic arch, and >60°-angulated internal carotid and common carotid arteries, are predictors of increased stroke rates. Technical factors associated with increased perioperative risk of stroke include percutaneous transluminal angioplasty (PTA) without embolic protection devices, PTA before stent placement, and the use of multiple stents. This review describes the most widely quoted data in defining various predictors of perioperative stroke and death after CAS. (This is a review article based on the invited lecture of the 45th Annual Meeting of Japanese Society for Vascular Surgery.)

Transradial Approach for Deployment of a Flow Diverter for an Intracranial Aneurysm in a Patient with a Type-3 Aortic Arch

BACKGROUND

Flow diversion with the Pipeline embolization device (PED) is an effective treatment for giant and wide-neck intracranial aneurysms, but the standard transfemoral approach may not be feasible in patients with Type-3 aortic arches.

CASE REPORT

An 84-year-old woman presented with a right internal carotid artery (ICA) giant aneurysm and a Type-3 aortic arch, necessitating a transradial approach for access to the right common carotid artery. A triaxial catheter system made for a stable platform for the deployment of two telescoping PEDs to treat the patient's right ICA giant aneurysm. The procedure was technically successful, and there were no immediate complications.

CONCLUSION

The transradial approach allows for carotid access in patients with challenging aortic arches, and this report demonstrates its effectiveness for deployment of flow diverters, especially with a triaxial catheter system. The peripheral access point facilitates hemostasis, which is of great importance in patients on antiplatelet medications to prevent thrombotic complications of flow diverters.

Optimal Guiding Catheter Length for Endovascular Coiling of Intracranial Aneurysms in Anterior Circulation in Era of Flourishing Distal Access System

Purpose

To determine the minimum required guiding catheter length for embolization of various intracranial aneurysms in anterior circulation and to analyze the effect of various patient factors on the required catheter length and potential interaction with its stability.

Materials and Methods

From December 2016 to March 2017, 90 patients with 93 anterior circulation aneurysms were enrolled. Three types of guiding catheters (Envoy, Envoy DA, and Envoy DA XB; Codman Neurovascular, Raynham, MA, USA) were used. We measured the in-the-body length of the catheter and checked the catheter tip location in the carotid artery. We analyzed factors affecting the in-the-body length and stability of the guiding catheter system.

Results

The average (±standard deviation) in-the-body length of the catheter was 84.2±5.9 cm. The length was significantly longer in men (89.1±5.6 vs. 82.1±4.6 cm, P<0.001), patients older than 65 years (87.7±7.8 vs. 82.7±4.2 cm, P<0.001), patients with a more tortuous arch (arch type 2 and 3) (87.5±7.4 vs. 82.7±4.4 cm, P<0.001), and patients with a distal aneurysm location (distal group) (86.2±5.0 vs. 82.7±6.1 cm, P=0.004). A shift in the tip location was noted in 19 patients (20.4%); there was no significant different among the 3 catheters (P=0.942).

Conclusion

The minimum required length of a guiding catheter was 84 cm on average for elective anterior-circulation aneurysm embolization. The length increased in men older than 65 years with a more tortuous arch. We could reach a higher position with distal access catheters with little difference in the stability once we reached the target location.

Carotid artery stenting in clinical practice depending on patient age

BACKGROUND

The age-dependent outcome of carotid artery stenting (CAS) outside of randomized controlled trials is largely unknown. Therefore, we assessed acute and long-term results of CAS in a single-center real-world registry.

METHODS

All symptomatic and asymptomatic patients who consecutively underwent CAS were enrolled into the present analysis. The population was divided into three groups dependent on patients' age (<65, 65-74, and ≥75 years).

RESULTS

Between 1999 and 2015, a total of 878 patients (24%, <65 years; 40%, 65-74 years; and 36%, ≥75 years) underwent CAS. The rate of the primary endpoint (30-day composite of death, stroke, and myocardial infarction [MACCE] plus long-term ipsilateral stroke) was higher in patients aged ≥75 years compared to the middle-age group (hazard ratio [HR] 2.30, confidence interval [CI] 1.22-4.36; P = 0.001). Similarly, the rate of the stroke endpoint (30-day any stroke plus long-term ipsilateral stroke) was higher in patients aged ≥75 years compared to patients aged 65-74 years (HR 2.03, CI 1.01-4.10; P = 0.04). There was no significant age-dependent difference of the primary endpoint and stroke endpoint in the subset of asymptomatic patients. Furthermore, age had no influence on the risk of stroke beyond the periprocedural period.

CONCLUSIONS

Patients aged ≥75 years had poorer outcomes after CAS compared to younger patients. Importantly, age did not influence the outcome in asymptomatic patients and the risk for stroke beyond the periprocedural period.

Vascular Anatomy Predicts the Risk of Cerebral Ischemia in Patients Randomized to Carotid Stenting Versus Endarterectomy

BACKGROUND AND PURPOSE

Complex vascular anatomy might increase the risk of procedural stroke during carotid artery stenting (CAS). Randomized controlled trial evidence that vascular anatomy should inform the choice between CAS and carotid endarterectomy (CEA) has been lacking.

METHODS

One-hundred eighty-four patients with symptomatic internal carotid artery stenosis who were randomly assigned to CAS or CEA in the ICSS (International Carotid Stenting Study) underwent magnetic resonance (n=126) or computed tomographic angiography (n=58) at baseline and brain magnetic resonance imaging before and after treatment. We investigated the association between aortic arch configuration, angles of supra-aortic arteries, degree, length of stenosis, and plaque ulceration with the presence of ≥1 new ischemic brain lesion on diffusion-weighted magnetic resonance imaging (DWI+) after treatment.

RESULTS

Forty-nine of 97 patients in the CAS group (51%) and 14 of 87 in the CEA group (16%) were DWI+ (odds ratio [OR], 6.0; 95% confidence interval [CI], 2.9-12.4; P<0.001). In the CAS group, aortic arch configuration type 2/3 (OR, 2.8; 95% CI, 1.1-7.1; P=0.027) and the degree of the largest internal carotid artery angle (≥60° versus <60°; OR, 4.1; 95% CI, 1.7-10.1; P=0.002) were both associated with DWI+, also after correction for age. No predictors for DWI+ were identified in the CEA group. The DWI+ risk in CAS increased further over CEA if the largest internal carotid artery angle was ≥60° (OR, 11.8; 95% CI, 4.1-34.1) than if it was <60° (OR, 3.4; 95% CI, 1.2-9.8; interaction P=0.035).

CONCLUSIONS

Complex configuration of the aortic arch and internal carotid artery tortuosity increase the risk of cerebral ischemia during CAS, but not during CEA. Vascular anatomy should be taken into account when selecting patients for stenting.

CLINICAL TRIAL REGISTRATION

URL: http://www.isrctn.com/ISRCTN25337470. Unique identifier: ISRCTN25337470.

The Role of Embolic Protection in Carotid Stenting Progress in Cardiovascular Diseases (PCVD)

Embolic protection device (EPD) use has become ubiquitous and is currently mandated by the Centers for Medicare and Medicaid (CMS) for reimbursement in conjunction with carotid artery stenting (CAS). There are two classes of EPD devices: distal filter EPD (f-EPD) and proximal EPD (p-EPD). Measuring the incremental benefit of one strategy over the other remains problematic for several reasons. The first lies in the difficulty of defining an embolic event as transcranial Doppler and diffusion-weighted magnetic resonance imaging abnormalities may not correlate with clinical events. Next, f-EPD is used more frequently than p-EPD making direct comparisons challenging, as analyses to this point have been underpowered. However, there are several promising emerging techniques and technologies that warrant further investigation.

Initial experience with a multiple parallel guidewire support system for complex tortuous aortic arch navigation and great vessel catheterization: technical note

The ability to traverse an anatomically challenging and complex arch is paramount to the success of any neuroendovascular procedure. With age, the aortic arch becomes elongated, calcified, and less compliant. The authors present the initial experience with a multiple parallel guidewire system (ZigiWire Mode 3) for catheterization through a complex tortuous aortic arch to access extracranial vessels. The ZigiWire is an organized guidewire system that uses consecutive delivery of 3 small-diameter (0.014-inch) guidewires that are progressively advanced in parallel to secure support-wire access. The authors have found it useful in situations in which traditional methods for great-vessel access have failed. Moreover, the progressive construction of a large wire from smaller wires prevents "kickback" force from a single larger guidewire, allowing stable distal access. The authors have been able to advance different diagnostic and guide catheters over the ZigiWire. This guidewire has allowed them to successfully complete neuroendovascular procedures in patients who were previously considered unsuitable for the procedure because of tortuous vascular access.

Age-associated changes in human carotid atherosclerotic plaques

Little is known about changes in carotid plaque morphology during aging and the possible impact on cardiovascular events. Only few studies addressed so far age-related modifications within atherosclerotic lesions. Therefore, in this work we endeavored to summarize the current knowledge about changing of plaque composition in elderly. The data from hitherto existing studies confirm that atherosclerotic plaques undergo distinct alternations with advanced age. However, the results are often ambiguous and the changes do not seem to be as disastrous as expected. Interestingly, none of the studies could definitely evidence increased plaque vulnerability with advanced age. Nevertheless, based on the previous work showing decrease in elastin fibers, fibroatheroma, SMCs, overall cellularity and increase in the area of lipid core, hemorrhage, and calcification, the plaque morphology appears to transform toward unstable plaques. Otherwise, even if inflammatory cells often accumulate in plaques of younger patients, their amount is reduced in the older age and so far no clear association has been observed between thin fibrous cap and aging. Thus, the accurate contribution of age-related changes in plaque morphology to cardiovascular events has yet to be elucidated. KEY MESSAGES Composition of carotid atherosclerotic lesions changes during aging. These alternations are however, just moderate and depend upon additional variables, such as life style, accompanying disease, genetics, and other factors that have yet to be determined. Based on the current data, the age-associated plaque morphology seems to transform toward vulnerable plaques. However, the changes do not seem to be as disastrous as expected.

Stenting of a Retropharyngeal Internal Carotid Artery

A retropharyngeal course of the carotid artery is an uncommon variant. Recognition of this anatomic anomaly is important in avoiding severe hemorrhage with endotracheal intubation and oropharyngeal procedures and for planning carotid interventions. We present a rare case of stenting for an asymptomatic, high-grade stenosis in a retropharyngeal internal carotid artery.

Increased airway pressure due to superior mediastinal hematoma during endovascular coiling by transcarotid approach

An elderly woman with subarachanoid hemorrhage presented to our interventional neuroradiology suite for coil embolization of multiple intracranial aneurysms. The patient had difficult vascular access for the passage of microcatheter; hence, the embolization procedure was carried out with direct puncture of the left common carotid artery. During the procedure, the patient developed thromboembolism which was treated by administration of an antiplatelet agent, abciximab. At the end of procedure, she developed airway compromise due to extension of a local neck hematoma into the superior mediastinum. The management issues in such a scenario have been discussed.

Carotid stent-assisted thrombectomy in acute ischemic stroke

Acute carotid occlusion or near-occlusion with concomitant intracranial embolism cause severe acute ischemic strokes in patients. These concomitant occlusions have suggested poor response to intravenous thrombolysis and complicate endovascular treatment. Nevertheless, endovascular stent-assisted thrombectomy may improve outcome in patients but the treatment is not without concerns. Required antiplatelet therapy to prevent stent thrombosis may increase the rate of intracranial hemorrhage, especially after recent thrombolysis. Furthermore, technical difficulties in access of the intracranial vasculature may cause adverse events, even in the hands of experienced interventionalists. These concerns currently defy the treatment in being recommended for general use and only on a compassionate basis. However, recent patient series have suggested reasonable safety and efficacy for carotid stent-assisted thrombectomy.

Mediators of the Age Effect in the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST)

BACKGROUND AND PURPOSE

There is higher combined risk of stroke or death (S+D) at older ages with carotid stenting. We assess whether this can be attributed to patient or arterial characteristics that are in the pathway between older age and higher risk.

METHODS

Mediation analysis of selected patient (hypertension, diabetes mellitus, and dyslipidemia) and arterial characteristics assessed at the clinical sites and the core laboratory (plaque length, eccentric plaque, ulcerated plaque, percent stenosis, peak systolic velocity, and location) was performed in 1123 carotid artery stenting-treated patients in the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST). We assessed the association of age with these characteristics, the association of these characteristics with stroke risk, and the amount of mediation of the association of age on the combined risk of periprocedural S+D with adjustment for these factors.

RESULTS

Only plaque length as measured at the sites increased with age, was associated with increased S+D risk and significantly mediated the association of age on S+D risk. However, adjustment for plaque length attenuated the increased risk per 10 years of age from 1.72 (95% confidence interval, 1.26-2.37) to 1.66 (95% confidence interval, 1.20-2.29), accounting for only 8% of the increased risk.

CONCLUSIONS

Plaque length seems to be in the pathway between older age and higher risk of S+D among carotid artery stenting-treated patients, but it mediated only 8% of the age effect excess risk of carotid artery stenting in CREST. Other factors and mechanisms underlying the age effect need to be identified as plaque length will not identify elderly patients for whom stenting is safe relative to endarterectomy.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00004732.

High-Risk Factors in Symptomatic Patients Undergoing Carotid Artery Stenting With Distal Protection

BACKGROUND:

Demographics and vascular anatomy may play an important role in predicting periprocedural complications in symptomatic patients undergoing carotid artery stenting (CAS).

OBJECTIVE:

To predict factors associated with increased risk of complications in symptomatic patients undergoing CAS and to devise a CAS scoring system that predicts such complications in this patient population.

METHODS:

A retrospective study was conducted that included patients who underwent CAS for symptomatic carotid stenosis during a 3-year period. Demographics and anatomic characteristics were subsequently correlated with 30-day outcome measures.

RESULTS:

A total of 221 patients were included in the study. The cumulative rate of periprocedural complications was 7.2%, including stroke (3.2%), myocardial infarction (3.2%), and death (1.4%). Renal disease increased the risk of all complications. National Institutes of Health Stroke Scale score ≥10 at presentation, difficult femoral access, and diseased calcified aortic arch increased the risk of stroke and all complications. Type III aortic arch correlated with increased risk of stroke. Pseudo-occlusion and concentric calcification of the carotid artery increased the risk of myocardial infarction, death, and all complications. Carotid tortuosity and anatomy hostile to the deployment of distal protection devices increased the risk of stroke, myocardial infarction, death, and all complications.

CONCLUSION:

Our results suggest that CAS should be avoided in patients with multiple anatomic risk factors. High presenting National Institutes of Health Stroke Scale score and renal disease also increase the complication risk. The CAS scoring system devised here is simple, reproducible, and clinically valuable in predicting complications risk in symptomatic patients undergoing CAS.

Characteristics that define high risk in carotid endarterectomy from the Vascular Study Group of New England

OBJECTIVE

The Stenting with Angioplasty and Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) trial compared carotid endarterectomy (CEA) to carotid artery stenting (CAS) among high-risk patients using a model of risk that has not been validated by previous publications. The objective of our study was to determine the accuracy of this high-risk model and to determine the true risk factors that result in patients being at high risk for CEA.

METHODS

Prospectively collected data for 3098 CEAs between 2003 and 2011 at 20 Vascular Surgery Group of New England (VSGNE) centers were used. SAPPHIRE general inclusion criteria and primary outcomes were assessed. Factors that were associated with the primary outcome by analysis of variance (P < .10) and not linearly dependent, as determined by a Pearson correlation analysis, were further assessed for an independent association by multivariate logistic regression. A risk index model was developed for these significant predictors to accurately define high-risk CEA.

RESULTS

The average patient age was 69.9 ± 9.5 years, 60% were male, and 45.7% were asymptomatic. The 1-year composite outcome event rate, defined as postoperative myocardial infarction and stroke or death, was 14.2%. Multivariate analysis (P < .05) found the following independently significant risk factors: age in years (95% confidence interval [CI], 1.0-1.1; P < .001), preadmission living in a nursing home (95% CI, 1.2-6.6; P = .020), congestive heart failure (95% CI, 1.4-2.8; P < .001), diabetes mellitus (DM; 95% CI, 1.1-1.3; P < .001), chronic obstructive pulmonary disease (95% CI, 1.2-1.5; P < .001), any previous cerebrovascular disease (95% CI, 1.1-1.9; P = .003), and contralateral internal carotid artery stenosis (95% CI, 1.0-1.2; P = .001). Three of the SAPPHIRE high-risk criteria-abnormal stress test, recurrent stenosis after CEA, and previous radiotherapy to the neck-were not independently associated with an adverse outcome. Independently significant risk factors not included in the SAPPHIRE criteria are inclusion of ages <80 years, preadmission living in a nursing home, DM, contralateral carotid stenosis, and any previous cerebrovascular accident. The risk index predictors are age in years (40-49: 0 points; 50-59: 2 points; 60-69: 4 points; 70-79: 6 points; 80-89: 8 points), living in a nursing home (4 points), any cardiovascular disease (2 points), congestive heart failure (5 points), chronic obstructive pulmonary disease (3 points), DM (2 points), degree of contralateral stenosis (<50%: 0 points; 50%-69%: 1 point; 70%-near occlusion: 2 points; occlusion: 3 points). High-risk CEA is defined as >13 points, representing adverse outcome rate of 22.5%.

CONCLUSIONS

SAPPHIRE and other previously reported high-risk CAS inclusion criteria do not include all of the factors found to be independently associated with outcomes. Further studies are required to determine whether CAS is inferior to CEA in high-risk patients using a validated model of risk. In addition, this preoperative assessment includes novel criteria that can be used to stratify risks.

A Protocol-Based Decision for Choosing a Proper Surgical Treatment Option for Carotid Artery Stenosis

OBJECTIVE

There are two established surgical treatment options for carotid artery stenosis. Carotid endarterectomy (CEA) has been accepted as a gold standard for surgical treatment while carotid artery stenting (CAS) has recently become an alternative option. Each treatment option has advantages and disadvantages for the treatment outcomes. We propose a protocol for selection of a proper surgical treatment option for carotid artery stenosis.

MATERIALS AND METHODS

A total of 192 published articles on management of carotid artery stenosis were reviewed. Preoperatively considerable factors which had been repeatedly noted in those articles for the risk/benefits of CEA or CAS were selected. According to those factors, a protocol with four categories was established.

RESULTS

CEA or CAS is indicated when the patient has a symptomatic stenosis ≥ 50%, or when the patient has an asymptomatic stenosis ≥ 80%. Each treatment option has absolute indications and favorable indications. Each absolute indication is scored with three points, and each favorable indication, one point. Based on the highest scores, a proper treatment option (CEA or CAS) is selected.

CONCLUSION

We have been treating patients according to this protocol and evaluating the outcomes of our protocol-based decision because this protocol might be helpful in assessment of risk/benefit for selection of a proper surgical treatment option in patients with carotid artery stenosis.

Management of extracranial carotid artery disease

Stroke is the third leading cause of death in developed nations. Up to 88% of strokes are ischemic in nature. Extracranial carotid artery atherosclerotic disease is the third leading cause of ischemic stroke in the general population and the second most common nontraumatic cause among adults younger than 45 years. This article provides comprehensive, evidence-based recommendations for the management of extracranial atherosclerotic disease, including imaging for screening and diagnosis, medical management, and interventional management.

Anatomical risk factors for ischemic lesions associated with carotid artery stenting

The purpose of this study was to investigate the anatomical risk factors for ischemic lesions detected by diffusion-weighted imaging (DWI) associated with carotid artery stenting (CAS). DWI was performed within four days after CAS in 50 stenotic lesions between January 2008 and September 2013. We retrospectively analyzed the correlation between the anatomical factors and ischemic lesions associated with CAS. Post-procedural DWI revealed new ischemic lesions after 24 (48%) of the 50 CAS procedures. All three patients with common carotid artery tortuosity, defined as the presence of severe angulation (less than 90 degrees) in the common carotid artery, developed new ischemic lesions. However, there were no significant differences between the patients with and without tortuosity, likely due to the small number of cases. Meanwhile, seven of eight patients with internal carotid artery tortuosity, defined as the presence of severe angulation (less than 90 degrees) in the cervical segment of the internal carotid artery, developed new ischemic lesions. A multivariate analysis showed internal carotid artery tortuosity (odds ratio: 11.84, 95% confidence interval: 1.193-117.4, P= 0.035) to be an independent risk factor for the development of ischemic lesions associated with CAS. Anatomical factors, particularly severe angulation of the internal carotid artery, have an impact on the risk of CAS. The indications for CAS should be carefully evaluated in patients with these factors.

Safety and efficacy assessment of carotid artery stenting in a high-risk population in a single-centre registry

Introduction

Ischaemic stroke is the primary cause of long-term disability and the third most common cause of death. Internal carotid artery stenosis is an important risk factor for stroke and transient ischaemic attack (TIA). European Society of Cardiology (ESC) and American Heart Association (AHA) guidelines allow carotid artery stenting (CAS) as an alternative to endarterectomy in centres with low rates of death or stroke.

Aim

To assess the safety and efficacy of CAS in a single-centre observation.

Material and methods

We performed a retrospective analysis of all patients treated with CAS between March 2008 and July 2012. Clinical data and outcomes in both asymptomatic and symptomatic patients were analysed.

Results

A total of 214 consecutive patients were included in the registry. Symptomatic patients accounted for 57% of the study group and were more likely to have a history of stroke and/or TIA that occurred more than 6 months before the procedure (50% vs. 8%, p < 0.001). Asymptomatic patients were more likely to have a history of coronary artery disease (88% vs. 61%, p < 0.001), and the rates of previous acute coronary syndrome and revascularisation were also higher in this group (58% vs. 41% and 71% vs. 52%, respectively, both p < 0.05). The symptomatic group had higher incidence of stroke in periprocedural and 30-day observation (4% vs. 0%, p < 0.05). There was no difference in incidence of adverse events in long-term observation.

Conclusions

Carotid artery stenting is a safe and efficacious procedure. Every centre performing CAS should monitor the rate of periprocedural complications.

Carotid artery stenting: current and emerging options

Carotid artery stenting technologies are rapidly evolving. Options for endovascular surgeons and interventionists who treat occlusive carotid disease continue to expand. We here present an update and overview of carotid stenting devices. Evidence supporting carotid stenting includes randomized controlled trials that compare endovascular stenting to open surgical endarterectomy. Carotid technologies addressed include the carotid stents themselves as well as adjunct neuroprotective devices. Aspects of stent technology include bare-metal versus covered stents, stent tapering, and free-cell area. Drug-eluting and cutting balloon indications are described. Embolization protection options and new direct carotid access strategies are reviewed. Adjunct technologies, such as intravascular ultrasound imaging and risk stratification algorithms, are discussed. Bare-metal and covered stents provide unique advantages and disadvantages. Stent tapering may allow for a more fitted contour to the caliber decrement between the common carotid and internal carotid arteries but also introduces new technical challenges. Studies regarding free-cell area are conflicting with respect to benefits and associated risk; clinical relevance of associated adverse effects associated with either type is unclear. Embolization protection strategies include distal filter protection and flow reversal. Though flow reversal was initially met with some skepticism, it has gained wider acceptance and may provide the advantage of not crossing the carotid lesion before protection is established. New direct carotid access techniques address difficult anatomy and incorporate sophisticated flow-reversal embolization protection techniques. Carotid stenting is a new and exciting field with rapidly advancing technologies. Embolization protection, low-risk deployment, and lesion assessment and stratification are active areas of research. Ample room remains for further innovations and developments.

Outcomes after carotid endarterectomy: is there a high-risk population? A National Surgical Quality Improvement Program report

OBJECTIVE

Carotid endarterectomy (CEA) is the standard treatment of carotid stenosis for symptomatic and asymptomatic patients. Carotid angioplasty and stenting (CAS), however, has been proposed as alternative therapy for patients deemed at high-risk for CEA. This study examined 30-day adjudicated outcomes in a contemporary series of CEAs and assessed the validity of criteria used to define a potential high-risk patient population for CEA.

METHODS

Patients undergoing isolated CEA in private sector hospitals between Jan 1, 2005, and Dec 31, 2006, were identified using the prospectively gathered National Surgical Quality Improvement Program database. The primary study end points were 30-day stroke and death rates. Demographic, preoperative, and intraoperative variables were examined using multivariate models to identify variables associated with the study end points. Variables used to define systemic "high-risk" patients in the Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) study (active cardiac disease, severe chronic obstructive pulmonary disease, and octogenarian status) were examined individually and in composite fashion for association with study endpoints.

RESULTS

Of the 3949 CEAs performed, 59% were in men, 30% were "high-risk" (19% age >80), and 43% had a previous neurologic event. The 30-day stroke rate was 1.6%, the death rate was 0.7%, and combined stroke/death rate was 2.2%. Multivariate analysis showed that intraoperative transfusion (odds ratio [OR], 5.95; 95% confidence interval [CI], 1.71-20.66; P = .005), prior major stroke (OR, 5.34; 95% CI, 2.96-9.64; P < .0001), shorter height (surrogate for small artery size; OR, 1.09; 95% CI, 1.02-1.16; P = .010), and increased anesthesia time (OR, 1.02; 95% CI, 1.00-1.03; P = .008) were predictive of stroke. Critical limb ischemia (OR, 12.72; 95% CI, 3.49-46.40; P < .0001) and poor functional status (OR, 7.05; 95% CI, 2.95-16.82; P < .0001) were independent correlates of death. Systemic high-risk variables, either combined or individually, did not increase risk of stroke or death on multivariate analysis.

CONCLUSION

CEA is associated with favorable 30-day outcomes across a spectrum of patient comorbidity features including octogenarian status. Anatomic and technical features are the important predictors of perioperative stroke, whereas critical limb ischemia and poor functional status are important predictors of death for patients undergoing CEA. These data refute the concept that CAS is preferred for patients deemed high-risk by virtue of systemic comorbidities.

Transradial access or Simmons shaped 8F guide enables delivery of flow diverters in patients with large intracranial aneurysms and type III aortic arch: technical case report

BACKGROUND AND IMPORTANCE

Flow diversion with the pipeline embolization device (PED) is an emerging endovascular technology allowing curative embolization of very large and giant intracranial aneurysms. Many patients with these complex aneurysms are older. The presence of a tortuous type III aortic arch reduces the chances of successful PED delivery and increases the risk of complications. We report 2 technical nuances regarding the delivery of the PED in older patients with a complex aortic arch.

CLINICAL PRESENTATION

In case 1, an 87-year-old woman presented with acute-onset left third nerve palsy. Workup demonstrated an 18-mm left posterior carotid wall aneurysm with a large daughter aneurysm on its dome. Endovascular access was complicated by a type III aortic arch with a hyperacute angle at the origin of the left common carotid artery. An 8F Simmons II shaped guide formed a stable platform, allowing successful PED delivery. In case 2, a 76-year-old woman experienced a transient ischemic attack. She harbored a right-sided 20-mm cavernous internal carotid artery aneurysm. She was treated with 2 PEDs deployed via a transradial approach.

CONCLUSION

Transradial access or guide support with the 8F Simmons II catheter grants stable access for curative embolization with the PED in elderly patients with a large intracranial aneurysm and a complex aortic arch.

Impact of aortorenal morphology on renal artery stent procedures: significance of aortic tortuosity and renal artery derivation

PURPOSE

To clarify the impact of aortorenal morphology on renal artery stenting procedures.

METHODS

A retrospective study evaluated 142 consecutive renal artery stenting procedures performed for de novo atherosclerotic renal artery stenosis in 119 patients (62 men; mean age 72±9 years, range 41-93). All procedures were done via a transfemoral approach without distal protection. Aortorenal morphology was classified into 3 types based on the relationship between abdominal aortic tortuosity and renal artery derivation. Using a straight reference line centered on the most angulated point of the inner curve of the infrarenal abdominal aorta, type 1 referred to a renal artery ostium that was more than half of the aortic diameter distance from the reference line in the greater curvature and less than half in the lesser curvature. Type 2 referred to a renal artery ostium that was less than half of the aortic diameter distant from the reference line in the greater curvature and more than half in the lesser curvature. Type 3 referred to a renal artery ostium that was beyond the reference line in the greater curvature or more than one aortic diameter from the reference line in the lesser curvature. The technical success rate, procedure time, final engagement technique, shape of the guide catheter used, and any adverse events were analyzed.

RESULTS

Type 1 aortorenal morphology was observed in 91 cases, type 2 in 30, and type 3 in 21. All cases were successfully treated; there were no technical complications, in-hospital cardiovascular events, or deaths. Procedure time differed significantly (p<0.001) among the 3 types (type 1: 19.6±5.6 minutes, type 2: 23.3±6.8 minutes, and type 3: 32.3±9.6 minutes; p<0.05 for type 1 vs. 2, p<0.001 for type 2 vs. 3, and p<0.001 for type 1 vs. 3). There were also significant differences among types in terms of engagement technique and guide catheter shape.

CONCLUSION

Aortorenal morphology was significantly associated with procedure time and the selection of engagement technique and guide catheter shape.

Prospective evaluation of the correlation between torso height and aortic anatomy in respect of a fluoroscopy free aortic balloon occlusion system

BACKGROUND

To report the lengths of key torso vascular and to develop regression models that will predict these lengths, based on an external measure of torso height (EMTH, sternum to pubis) in the development of a fluoroscopy-free balloon occlusion system for hemorrhage control.

METHODS

We conducted a prospective, observational study at a Combat Support Hospital in Southern Afghanistan using adult male patients undergoing computed tomography (CT). EMTH was recorded using a tape measure and intra-arterial distance was derived from CT imaging. Regression models to predict distance from the common femoral artery (CFA) into the middle of aortic zone I (left subclavian artery to celiac trunk) and zone III (infrarenal aorta) were developed from a random 20% of the cohort and validated by the remaining 80%.

RESULTS

Overall, 177 male patients were included with a median (interquartile range [IQR]) age of 23 (8) years. The median (IQR) lengths of aortic zone I and III were 222 (24), 31 (9), and 92 (15) mm. The mid-zone distance from the left and right CFA to zone I were 423 (27) and 418 (29) and for zone III 232 (21) and 228 (22). Linear regression models demonstrated an accuracy between 99.3% to 100% at predicting the insertion distance required to place a catheter within the middle of each aortic zone.

CONCLUSION

This study demonstrates the use of morphometric analysis in the development of a fluoroscopy-free balloon occlusion system for torso hemorrhage control. Further study in a larger population of mixed gender is required to further validate insertion models.

Perioperative stroke

It is increasingly recognized that one can identify a higher risk patient for perioperative stroke. The risk of stroke around the time of operative procedures is fairly substantial and it is recognized that patients initially at risk for vascular events are those most likely to have this risk heightened by invasive procedures. Higher risk patients include those of advanced age and there is a cumulative risk, over time, of coexistent hypertension, atherosclerosis, diabetes mellitus, cardiac disease and clotting disorders. There are a number of possible mechanisms associated with the procedure (e.g., preoperative hypercoagulability, holding of antithrombic therapy at the time of the procedure and cardiac arrhythmia) that can promote a thrombo-embolic event. Examples of these include: direct mechanical trauma to extracranial vessels related to operations on the head and neck; and vascular injury as a consequence of vascular and innovative endovascular procedures affecting the cerebral circulation (e.g., carotid endarterectomy, extracranial or intracranial angioplasty with stenting, and use of the MERCI clot retrieval device), as well as various endovascular methods that have been developed to obliterate cerebral aneurysms and arteriovenous malformations as an alternative to surgical clipping and surgical resection, respectively.

Patient, Anatomic, and Procedural Characteristics That Increase the Risk of Carotid Interventions

Subjective characteristics for increased risk of carotid artery stenting (CAS) have included thrombus-containing lesions, heavily calcified lesions, very tortuous vessels, and near occlusions. More objective high-risk features include contraindications to dual antiplatelet therapy, a history of bleeding complications, and lack of femoral artery vascular access. Variables that increase the risk of CAS complications are attributed to patient characteristics, anatomic features, or procedural factors. Operator and hospital volume affect the risk of complications occurring with CAS. As the complexity and difficulty of CAS patients increases, the need for more highly skilled operators and teams becomes even more necessary to minimize complications.

A Clinical Rule (Sex, Contralateral Occlusion, Age, and Restenosis) to Select Patients for Stenting Versus Carotid Endarterectomy

Background and Purpose—

Compared with carotid endarterectomy (CEA), carotid angioplasty and stenting (CAS) is associated with a higher risk of procedural stroke or death especially in patients with symptomatic stenosis. However, after the perioperative period, risk is similar with both treatments, suggesting that CAS could be an acceptable option in selected patients.

Methods—

We performed systematic reviews of observational studies of procedural risks of CEA or CAS and extracted data on 9 predefined risk factors (age, contralateral carotid occlusion, coronary artery disease, diabetes mellitus, sex, hypertension, peripheral artery disease, and type and side of stenosis). We calculated pooled relative risks of procedural stroke or death. Factors with differential effects on risk of CAS versus CEA were identified by interaction tests and used to derive a rule. The rule was tested using individual patient data from randomized trials of CAS versus CEA from the Carotid Stenting Trialists’ Collaboration (CSTC).

Results—

We identified 170 studies. The effects of sex, contralateral occlusion, age, and restenosis (SCAR) on the procedural risk of stroke or death differed. Patients with contralateral occlusion or restenosis and women <75 years were at relatively low risk for CAS (SCAR negative), with all others being high risk (SCAR positive). Among the 3049 patients in the CSTC validation, 694 (23%) patients were SCAR negative. The pooled RR of procedural stroke and death with CAS versus CEA was 0.93 (0.49–1.77; P =0.83) in SCAR-negative and 2.41 (1.68–3.45; P <0.0001) in SCAR-positive patients ( P [interaction]=0.05).

Conclusions—

The SCAR rule is potentially useful to identify patients in whom CAS has a similar risk of perioperative stroke or death to CEA.

Results of carotid artery stenting with transcervical access

OBJECTIVE

Carotid artery stenting (CAS) is usually performed with femoral access; however, this access may be impeded by anatomic limitations. Moreover, many embolic events happen during aortic arch catheterization. To overcome these problems, transcervical access to the carotid artery can be used as an alternative approach for CAS.

METHODS

An electronic search of the literature using PubMed was performed. All studies reporting the results of CAS using the transcervical approach were retrieved and analyzed.

RESULTS

The analysis included 12 studies reporting the results of 739 CAS procedures performed in 722 patients (mean age, 75.5 years). Of 533 lesions reported, 235 (44%) were symptomatic, with no data regarding symptomatic status available for 206 lesions. Two techniques were used: direct CAS with transcervical access (filter protected or unprotected) in 250 patients and CAS with transcervical access under reversed flow (with arteriovenous shunt in most cases) in 489 patients. Local anesthesia was used in 464 of 739 procedures (63%), and the remaining were performed under general anesthesia or cervical block. Technical success was 96.3% for 579 procedures with available data (558 successful procedures and 21 failures: inability to cross the lesion, 10; dissection, 5; failure of predilatation, 1; stent thrombosis, 1; patient agitation, 1; and no data, 3). The incidence of conversion to open repair was 3.0% (20 of 579 procedures: 18 carotid endarterectomies and two common carotid-internal carotid bypass grafts). Stroke occurred in eight patients (two fatal) and a fatal myocardial infarction in one patient. The incidence of stroke, myocardial infarction, and death was 1.1%, 0.14%, and 0.41%, respectively. The incidence of stroke was 1.2% (3 of 250) in direct CAS with transcervical access and 1.02% (5 of 489) in CAS under reversed flow (P > .05). Transient ischemic attack occurred in 20 patients (2.7%). Local complications were encountered in 17 of 579 CAS (2.9%), comprising 15 hematomas and two patients with transient laryngeal palsy.

CONCLUSIONS

CAS with the transcervical approach is a safe procedure with low incidence of stroke and complications. It can be used as an alternative to femoral access in patients with unfavorable aortoiliac or aortic arch anatomy.

Incidence and risk factors for medical complications and 30-day end points after carotid artery stenting

With the extensive use of carotid artery stenting (CAS) surgeries, scholars are paying more attention to the safety and efficiency of CAS. Our study aims to analyze the clinical efficiency, safety, and technical feasibility of CAS surgery in the treatment of carotid artery stenosis. A total of 379 cases of CAS were collected and retrospectively analyzed. The outcomes were summarized according to decrease in stenosis extent, incidence of early complications after procedure, 30-day end point events, and the follow-up data. Logistic regression was employed to analyze the correlations between risk factors and complications within 30 days and 30-day end points of stroke, myocardial infarctions (MIs), and mortality. The average extent of stenosis reduced from preoperative (81% ± 17%) to postoperative (26% ± 17%). In all, 53 patients had 72 medical complications, including 6 (1.58%) cerebral hemorrhage, 7 (1.85%) cerebral infarction, 5 (1.32%) transient ischemic attack (TIA), 5 (1.32%) heart failure, 10 (2.63%) symptomatic hypertension, 21 (5.54%) symptomatic hypotension, 10 (2.63%) symptomatic bradycardia, and 8 other complications; 15 patients had at least 2 complications. Advanced age, diabetes, and heart failure were associated with the high incidence of early complications (P < .05). Asymptomatic stenosis (odds ratio [OR] = 0.39, 95% confidence interval [CI]: 0.131-1.131, P = .0426) and diabetes (OR = 3.38, 95% CI: 1.340-8.574, P = .0099) were correlated with the incidence of 30-day end point events. Diabetes and symptomatic stenosis are independent risk factors for 30-day end point events of CAS. Advanced age, hypertension, and vascular unstable plaque will increase the risk of postoperative complications.

Carotid artery stenting: patient, lesion, and procedural characteristics that increase procedural complications

From the earliest experiences with carotid artery stenting (CAS) presumptive high risk features have included thrombus-containing lesions, heavily calcified lesions, very tortuous vessels, and near occlusions. In addition patients have been routinely excluded from CAS trials if they have contra-indications to dual antiplatelet therapy (aspirin and thienopyridines), a history of bleeding complications and severe peripheral arterial disease (PAD) making femoral artery vascular access difficult. Variables that increase the risk of CAS complications can be attributed to patient characteristics, anatomic or lesion features, and procedural factors. Clinical features such as older age (≥80 years), decreased cerebral reserve (dementia, multiple prior strokes, or intracranial microangiopathy) and angiographic characteristics such as excessive tortuosity (more than two 90° bends within 5 cm of the target lesion) and heavy calcification (concentric calcification ≥ 3 mm in width) have been associated with increased CAS complications. Other high risk CAS features include those that prolong catheter or guide wire manipulation in the aortic arch, make crossing a carotid stenosis more difficult, decrease the likelihood of successful deployment or retrieval of an embolic protection device (EPD), or make stent delivery or placement more difficult. Procedure volume for the operator and the catheterization laboratory team are critical elements in reducing the risk of the procedure. In this article, we help CAS operators better understand procedure risk to allow more intelligent case selection, further improving the outcomes of this emerging procedure.

Results of carotid angioplasty and stenting are equivalent for critical versus high-grade lesions in patients deemed high risk for carotid endarterectomy

BACKGROUND

To examine outcomes of carotid angioplasty and stenting (CAS) in patients with critical carotid stenosis who are deemed high risk for carotid endarterectomy.

METHODS

Medical records were retrospectively analyzed for patients undergoing CAS between September 2002 and March 2011 at a single institution. Patients were classified as having either critical (≥ 90%) or high-grade (70%-89%) carotid stenosis based on angiography. The primary composite end point was stroke, myocardial infarction, or death from any cause during the periprocedural period or any ipsilateral stroke during the follow-up period.

RESULTS

A total of 245 patients underwent 257 CAS procedures during the study period. Fifty-one percentage (n = 130) of cases involved critical stenosis (66.2% male; mean age, 71 ± 10 y), with the remaining group (n = 127) involving high-grade stenosis (67.7% male; mean age, 71 ± 9 y). Symptomatic carotid disease was present in 25% of the critical stenosis and 31% of the high-grade stenosis groups (P = 0.33). Chronic obstructive pulmonary disease was more commonly found in the high-grade stenosis group (20% versus 8%, P = 0.01). No difference was observed between the groups relative to other baseline demographic characteristics, presence of contralateral carotid occlusion, stent diameter or length, maximum balloon diameter or length, use of embolic protection device, or procedural duration. Technical success was achieved in all cases. There was no difference in the need to predilate before the introduction of the filter or stent based on the degree of stenosis. We found no difference in the primary composite end point between the high-grade or critical stenosis groups (7.1% versus 7.7%, P = 0.74), or there were no differences between the individual components of the composite end point. Mid-term survival was similar between the two groups at a mean follow-up period of 2.4 y.

CONCLUSIONS

Despite concerns regarding the potential for increased neurologic complications, our data demonstrate that patients with high-grade and critical stenosis are able to safely undergo CAS and achieve similar periprocedural outcomes and mid-term prognosis.