Transcervical carotid artery angioplasty and stenting with carotid flow reversal: surgical technique

Impact of the type of anesthesia on adverse events during transcarotid artery revascularization

OBJECTIVE

The use of local or regional anesthesia (LRA) is encouraged during transcarotid artery revascularization (TCAR) because the procedure is performed through a small incision. LRA permits neurologic evaluation during the procedure and may reduce periprocedural cardiac morbidity compared with general anesthesia (GA). There is limited and conflicting information regarding the preferred anesthesia to use during TCAR. We compared periprocedural clinical and technical complications, and intraprocedural performance metrics of TCAR performed under GA vs LRA.

METHODS

Patient, lesion, physician, and procedural information was collected in a worldwide quality assurance program of consecutive TCAR procedures. A composite clinical adverse event rate (death, stroke, transient ischemic attack, myocardial infarction) and a composite technical adverse event rate (aborted procedure, conversion to carotid endarterectomy, bleeding, dissection, cranial-nerve injury, device failure) in the periprocedural period were computed. Four intraprocedural performance measures (flow-reversal time, fluoroscopy time, contrast volume, and skin-to-skin time) were recorded. Deidentified data were analyzed independently at the Center for Vascular Research, University of Maryland. Poisson regressions were used to assess the impact of anesthesia type on adverse event rates. Linear regressions were used to compare performance measures.

RESULTS

A total of 27,043 TCARs were performed by 1456 physicians between 2012 and 2021. A majority of patients (83%) received GA, and this proportion increased over time (R2 = 0.74; P < .0001). Some physicians (33.4%) used LRA in some of their procedures; only 2.7% used LRA in all of their procedures. Clinical risk factors were more common in the LRA group (P < .0001) and anatomic risk factors in the GA group (P < .0001); these differences were adjusted for in subsequent analyses. LRA was more likely to be used by vascular surgeons and by physicians with higher prior transfemoral carotid stenting experience (P < .0001). When comparing GA vs LRA, clinical adverse events (1.49%; 95% confidence interval [CI], 1.3-1.8 vs 1.55%; 95% CI, 1.2-2.0; P = .78), technical adverse events (5.6%; 95% CI, 5.2-6.2 vs 5.3%; 95% CI, 4.5-6.3; P = .47), and intraprocedural performance measures did not differ by type of anesthesia.

CONCLUSIONS

Almost two-thirds of physicians performed TCAR exclusively under GA, and the overall proportion of procedures performed under GA increased over time. A larger fraction of patients with severe medical risk factors received LRA vs GA, whereas a larger fraction of patients with anatomic risk-factors received GA. Periprocedural clinical and technical adverse events did not differ by type of anesthesia. Intraprocedural performance metrics that drive procedural cost were similar between groups; potential differences in procedural cost driven by anesthetic choice require further study.

Next-generation transcarotid artery revascularization: TransCarotid flOw Reversal Cerebral Protection And CGUARD MicroNET-Covered Embolic Prevention Stent System To Reduce Strokes - TOPGUARD Study

BACKGROUND

Stent-assisted carotid artery revascularization employing surgical cutdown for transcervical access and dynamic flow reversal (TCAR) is gaining popularity. TCAR, despite maximized intra-procedural cerebral protection, shows a marked excess of 30-day neurologic complications in symptomatic vs. asymptomatic stenoses. The TCAR conventional single-layer stent (free-cell area 5.89mm2) inability to seal embologenic lesions may be particularly relevant after the flow reversal neuroprotection is terminated.

METHODS

We evaluated peri-procedural and 30-day major adverse cerebral and cardiac events (MACCE) of TCAR (ENROUTE, SilkRoad Medical) paired with MicroNET-covered neuroprotective stent (CGuard, InspireMD) in consecutive patients at elevated risk of complications with transfemoral/transradial filter-protected stenting (increased lesion-related and/or access-related risk). CGuard (MicroNET free cell area ≈0.02-0.03 mm2) has level-1 evidence for reducing intra- and abolishing post-procedural lesion-related cerebral embolism.

RESULTS

One hundred and six increased-risk patients (age 72 [61-76] years, median [Q1-Q3]; 60.4% symptomatic, 49.1% diabetic, 36.8% women, 61.3% left-sided index lesion) were enrolled in three vascular surgery centers. Angiographic stenosis severity was 81 (75-91)%, lesion length 21 (15-26)mm, increased-risk lesional characteristics 87.7%. Study stent use was 100% (no other stent types). 74.5% lesions were predilated; post-dilatation rate was 90.6%. Flow reversal duration was 8 (5-11)min. One stroke (0.9%) occurred in an asymptomatic patient prior to establishing neuroprotection (index lesion disruption with the sheath insertion wire); there were no other peri-procedural MACCE. No further adverse events occurred by 30-days. 30-day stent patency was 100% with normal velocities and absence of any in-stent material by Duplex Doppler.

CONCLUSIONS

Despite a high proportion of increased-risk lesions and clinically symptomatic patients in this study, TCAR employing the MicroNET-covered anti-embolic stent showed 30-day MACCE rate <1%. This suggests a clinical role for combining maximized intra-procedural prevention of cerebral embolism by dynamic flow reversal with anti-embolic stent prevention of peri- and post-procedural cerebral embolism (TOPGUARD NCT04547387).

The Evolution of Current Management for Carotid Artery Bifurcation Disease

Options for treatment of symptomatic carotid bifurcation disease include carotid endarterectomy (CEA) and carotid artery stenting (CAS). While over the years CEA has established itself as the gold standard for carotid artery revascularization, results from recent trials have shown CAS to be safe and effective in selected patients. This review details the evolution of carotid artery bifurcation disease by highlighting key clinical trials.

Prospective evaluation of acute cerebral injury by DW-MRI following transcarotid artery revascularization using a double-layer micromesh stent

BACKGROUND

Transcervical carotid artery revascularization (TCAR) has demonstrated a low overall stroke rate in carotid artery stenting (CAS). Furthermore, the use of a double-layer micromesh stent is expected to reduce embolization and plaque prolapse. The combination of TCAR and the double layer stent may lead to improved results compared to previously reported outcomes. The objective of this study is to present the findings of a prospective study including patients treated with the Roadsaver stent and TCAR.

METHODS

Between January 2017 and May 2022, 85 patients were enrolled. Every patient underwent TCAR with the Roadsaver stent. As per our protocol, a neurological examination and an ultrasound were performed within 24 hours before and after the procedure, and again 30 days after. A diffusion-weighted magnetic resonance imaging (DW-MRI) was conducted 24 hours before the procedure and 48-72 hours after the procedure. The primary endpoint was the detection of new ischemic lesions on postoperative DW-MRI. The secondary endpoint was a composite of all strokes, death, and myocardial infarction within 30 days.

RESULTS

Sixty-four patients (75.29%) were symptomatic, out of which 25 were treated within 14 days of the onset of the symptoms. Pre and postprocedural DW-MRI were performed in 83 patients. Postprocedural lesions were found in nine patients (10.84%). There were no strokes or death within 30 days, but two patients experienced a myocardial infarction.

CONCLUSIONS

Our study suggests that the use of TCAR and the Roadsaver stent could be a safe alternative to carotid endarterectomy because it entails a low incidence of cerebral embolization, even in recently symptomatic and elderly patients.

Predicting Transcarotid Artery Revascularization adverse outcomes by Imaging Characteristics

OBJECTIVES

Approximately 20-30% of ischemic strokes are caused by internal carotid artery stenosis. Stroke is the leading cause of disability and the second leading cause of death in the United States. Second generation Trans Carotid Arterial Revascularization (TCAR) stenting, using the ENROUTE flow reversal technology to prevent embolic stroke during the stenting process, has demonstrated stroke and death outcomes equivalent to CEA with reduced cranial nerve injury. However, at present, it is not known whether imaging characteristics obtained pre-operatively can predict outcomes of TCAR procedures.

METHODS

This retrospective cohort study included patients who underwent TCAR with flow reversal at 3 hospitals within a single hospital network who had CT angiography, MRI angiography or pre-operative diagnostic angiogram to determine whether carotid and lesion characteristics could predict patients who experienced Major Adverse Critical Events (MACE) versus those who did not. MACE was defined as myocardial infarction at 30 days, restenosis/persistent stenosis (peak systolic velocity within the stent >230cm/sec by post-operative ultrasound), stroke within any time of follow up or death within 1 year of TCAR. Student's t-tests and chi-squared tests were used to compare imaging characteristics, such as presence of pinpoint stenosis, calcification within the common carotid artery (CCA) at the take-off from the aorta, and plaque length in millimeters. Binomial logistic regression was used to examine the likelihood that imaging characteristics were associated with MACE.

RESULTS

Of 220 patients who underwent TCAR in our network, 7 were excluded because flow reversal was not used or appropriate imaging had not been performed prior to TCAR. Of the 213 patients that were included in analysis, the median length of follow up was 10.8 months (IQR: 3.4-33.1 months). Twelve percent (26/213) experienced a MACE, and a model based on imaging characteristics was statistically significant in predicting MACE with 68% accuracy (P=0.005). The presence of pinpoint stenosis was highly predictive of MACE (HR: 3.34, CI: 1.2 to 9.3, P=0.021). A shorter clavicle to carotid bifurcation distance was associated with an increased likelihood of experiencing a MACE (P=0.009), but it was weakly predictive (HR 1.03, CI: 1.01 to 1.05).

CONCLUSIONS

Pre-operative imaging characteristics, such as pinpoint stenosis and clavicle to carotid bifurcation distance, can be used to predict adverse outcomes in TCAR placement.

Learning curve and proficiency metrics for transcarotid artery revascularization

BACKGROUND

When introduced to a new procedure, physicians improve their performance and reduce their procedural adverse event rates rapidly during the initial cases and then improvement slows, signaling that proficiency has been achieved. Determining when they have acquired proficiency has important implications for procedural innovation, education, credentialing, and patient safety. We analyzed the worldwide experience with transcarotid artery revascularization (TCAR), a hybrid approach to carotid revascularization, to identify the (1) procedural performance measures associated with clinical and technical adverse events; (2) target levels of performance measures that minimize adverse event rates; and (3) number of TCAR cases needed to achieve the target levels for the performance measures.

METHODS

The patient, lesion, and physician characteristics were collected for each TCAR procedure performed by each physician worldwide in an international quality assurance database. Four procedural performance measures were recorded for each procedure: flow-reversal time, fluoroscopy time, contrast volume, and total skin-to-skin time. Composite clinical adverse events (ie, transient ischemic attack, stroke, myocardial infarction, death) and composite technical adverse events (ie, aborted procedure, conversion to surgery, bleeding, dissection, cranial nerve injury, device failure), occurring within 24 hours were also recorded. Correlations between each performance measure and the clinical and technical adverse event rates were computed. The inflection points in the performance measures were identified at which no further improvements occurred in the adverse event rates. Finally, the minimum number of TCAR cases required to achieve the target performance measure levels was computed.

RESULTS

A total of 18,240 procedures performed by 1273 physicians were analyzed. Of the 18,240 patients, 34.9% were women and 62.5% were asymptomatic. The flow-reversal time correlated with clinical adverse events adjusted for age, sex, and symptomatic status (R2 = 0.91; P < .0001) and adjusted technical adverse events (R2 = 0.86; P < .0001). The skin-to-skin time correlated with adjusted technical adverse events (R2 = 0.92; P < .0001). A reduction in flow-reversal times to <13.1 minutes and the skin-to-skin time to <81 minutes did not translate into further improvements in the adverse event rates. A minimum of 26 TCAR cases was required to achieve the target flow-reversal time, and a minimum of 15 cases was required to achieve the target skin-to-skin time.

CONCLUSIONS

The flow-reversal time and skin-to-skin time are appropriate performance measures for establishing the level of expertise of physicians as they acquire skills to perform TCAR. A target time of ≤13.1 minutes for flow-reversal and 81 minutes for skin-to-skin time minimized the adverse event rates. Familiarity with the steps involved in performing TCAR was achieved after ≥15 cases, and minimizing clinical adverse events occurred after ≥26 cases.

Transcarotid revascularization outcomes do not differ by patient age or sex

BACKGROUND

Transcarotid artery revascularization (TCAR) is a hybrid approach to carotid revascularization. Limited information is available on the differences in periprocedural complications and performance measures of TCAR for men compared with women and for older vs younger adults.

METHODS

The patient, lesion, and physician characteristics were collected for all TCAR procedures performed by each physician worldwide in an international quality assurance database between March 3, 2009 and May 7, 2020. Clinical composite (ie, death, stroke, transient ischemic attack, myocardial infarction) and technical composite (ie, aborted procedure, conversion to surgery, bleeding, dissection, cranial nerve injury, device failure) adverse events within 24 hours of the procedure were recorded. Four performance measures were recorded: flow-reversal time, fluoroscopy time, contrast volume, and skin-to-skin time. Poisson regressions were used to assess the effects of age and sex on the incidence of clinical and technical composite adverse events. Linear regressions were used to compare the four performance measures.

RESULTS

A total of 18,240 TCARs were performed by 1273 physicians; 34.9% of the patients were women and 37.5% were symptomatic. The overall incidence of clinical and technical composite adverse events was low. The adjusted clinical (1.62% [95% confidence interval (CI), 1.17%-2.23%] vs 1.35% [95% CI, 1.01%-1.79%]; P = .22) and technical (7.84% [95% CI, 6.85%-8.97%] vs 7.80% [95% CI, 6.94%-8.77%]; P = .93) composite adverse event rates did not vary for women vs men. The adjusted clinical (P = .65) and technical (P = .55) composite adverse event rates also did not vary by age. The adjusted skin-to-skin time was shorter for the women (76.6 minutes; 95% CI, 74.6-78.6) than for the men (77.7 minutes; 95% CI, 75.7-79.6; P = .002). Significant differences were found by age group for fluoroscopy time, flow-reversal time, and skin-to-skin time, although the magnitude of these differences was small (<1 minute for each).

CONCLUSIONS

The clinical and technical outcomes of TCAR are not affected by age or sex. We found clinically minor differences in the procedural performance measures when stratified by age and sex. In addition to being safe for younger individuals, TCAR could also be the preferred method for performing carotid stenting in women and older patients, in particular, older women.

Evaluating the optimal training paradigm for transcarotid artery revascularization based on worldwide experience

BACKGROUND

Transcarotid artery revascularization (TCAR) is a new hybrid approach to carotid artery revascularization. Proctored training on live cases is an effort-, time-, and resource-intensive approach to learning new procedures. We analyzed the worldwide experience with TCAR to develop objective performance metrics for the procedure and compared the effectiveness of training physicians using cadavers or synthetic models to that of traditional in-person training on live cases.

METHODS

Physicians underwent one of three mandatory training programs: (1) in-person proctoring on live TCAR procedures, (2) supervised training on human cadavers, and (3) supervised training on synthetic models. The training details and information from all subsequent independently performed TCAR procedures were recorded. The composite clinical adverse events (ie, transient ischemic attack, stroke, myocardial infarction, death) and composite technical adverse events (ie, aborted procedure, conversion to surgery, bleeding, dissection, cranial nerve injury, or device failure, occurring within 24 hours were recorded). Four procedural proficiency measures were recorded: procedure time, flow-reversal time, fluoroscopy time, and contrast volume. We compared the adverse event rates between the procedures performed by physicians after undergoing the three training modes and tested whether the proficiency measures achieved during TCAR after training on cadavers and synthetic models were noninferior to proctored training.

RESULTS

From March 3, 2009 to May 7, 2020, 1160 physicians had undergone proctored (19.1%), cadaver-based (27.4%), and synthetic model-based (53.5%) TCAR training and had subsequently performed 17,283 TCAR procedures. The proctored physicians had treated younger patients and more patients with asymptomatic carotid stenosis and had had more prior experience with transfemoral carotid stenting. The overall 24-hour composite clinical and technical adverse event rates, adjusted for age, sex, and symptomatic status, were 1.0% (95% confidence interval, 0.8%-1.3%) and 6.0% (95% confidence interval, 5.4%-6.6%), respectively, and did not differ significantly by training mode. The proficiency measures of cadaver-trained and synthetic model-trained physicians were not inferior to those for the proctored physicians.

CONCLUSIONS

We have presented key objective proficiency metrics for performing TCAR and an analytic framework to assess adequate training for the procedure. Training on cadavers or synthetic models achieved clinical outcomes, technical outcomes, and proficiency measures for subsequently performed TCAR procedures similar to those achieved with training using traditional proctoring on live cases.

Transcervical Versus Transfemoral Approach in Carotid Stenting Real World Experience in a Community Hospital

INTRODUCTION

Peri-procedural embolic events are the Achilles' heel of carotid stenting. To overcome this complication, transcervical access to the carotid artery was introduced. In this study we describe our "our life" experience with the transcervical approach in a community hospital.

MATERIAL AND METHODS

All carotid stent procedures between January 2010 and December 2020 were included in this retrospective analysis. The transcervical approach was compared to the transfemoral approach. In both procedures open-cell, closed-cell design and hybrid stents were used. In-hospital stroke was the primary outcome measure.

RESULTS

A total of 340 procedures were performed, in 184 patients the transfemoral approach was used and in 156 patients the transcervical approach was used. In 12 patients (3.5%) an in-hospital stroke was diagnosed, 4 in the transfemoral group (2.2%) and 8 in the transcervical group (5.1%) (P = 0.14). In the multivariate analyses a symptomatic lesion was associated with in-hospital stroke. Neither type of access nor cell design was associated with increased risk of in-hospital stroke.

CONCLUSIONS

In contrast to previous studies, we could not confirm the advantages of the transcervical approach. However, conclusions should be carefully drawn, since this study is retrospective and was performed with multiple surgeon and different kind of stents.

Transcervical approach for carotid artery stenting with transitory reversal flow: Case report

Introduction

Carotid artery stenting (CAS) has been indicated as an alternative to carotid endarterectomy in high risk patients. Sometimes, an aortic arch can be anatomically unfavourable for CAS. Herein we report our experience in a case of CAS with transcervical approach.

Presentation of case

A 77-year-old male was referred to our hospital for severe subtotal occlusion of the left internal carotid artery. He had a past medical history of radiation to the head and neck for laryngeal cancer. Previous CT-angiography had shown a type III aortic with bovine arch. CAS via transcervical approach was performed with transitory reversal flow during the placement of RX Spider Filter 6 Fr (Medtronic, Minneapolis, MN). After release of 7 × 30 mm RX Xact carotid stent (Abbott Vascular, Chicago, IL) and ballooning with a 5.5 × 30 mm Rx Submarine balloon catheter (Medtronic Minneapolis, MN), angiography check showed a good result.

Discussion

The transcervical approach is an innovative technique where usually a shunt is created, either between the common carotid artery and the internal jugular vein or between the common carotid artery and the common femoral vein. This flow reversal reduces the risk of periprocedural embolic events. In our experience a short proximal clamping with transitory reversal flow, reduces the invasiveness of procedure with good outcomes.

Conclusion

Transcervical carotid access with transitory reversal flow is a valid alternative in complicated patient with anatomy unfit for CAS.

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Carotid stenting can be an alternative to endarterectomy in high risk patients.

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Aortic arch can be anatomically unfavourable for Carotid artery stenting.

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Transcervical approach is a technique suited to patients unfit for stenting.

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Transcervical access with transitory reversal flow is useful in complicated patient.

Critical Appraisal on the Quality of Reporting on Safety and Efficacy of Transcarotid Artery Stenting With Flow Reversal

Transcarotid revascularization is an alternative to transfemoral carotid artery stenting, designed to avoid aortic arch manipulation and concomitant periprocedural stroke. This article aims to perform a detailed analysis on the quality of the currently available evidence on safety and efficacy of transcarotid artery revascularization. Although current evidence is promising, independent randomized controlled studies comparing transcarotid artery revascularization with carotid endarterectomy in recently symptomatic patients are lacking and will be necessary to establish the true value of transcarotid artery revascularization in carotid artery revascularization.

Transcarotid Artery Revascularization Results in Low Rates of Periprocedural Neurologic Events, Myocardial Infarction, and Death

PURPOSE OF REVIEW

Transcarotid artery revascularization (TCAR) is a novel hybrid procedure that reverses carotid flow and places a stent using surgical access of the carotid artery in the neck under local anesthesia. We discuss the indications for carotid revascularization, the clinical rationale for TCAR, and evidence for its potential role in the management of carotid stenosis.

RECENT FINDINGS

Results from pre-clinical studies, prospective single-arm studies, and comparative analyses of registry data indicate that TCAR results in low amounts of periprocedural microembolization, cerebral lesions detectable on magnetic resonance imaging, and neurologic events, myocardial infarctions (MIs), and death. Non-randomized comparisons suggest that TCAR may offer a novel solution to reducing periprocedural stroke, death, and MI in patients with carotid stenosis. A state of equipoise appears to have been reached with TCAR versus the traditional carotid revascularization procedures and a well-controlled randomized trial with careful oversight should be prioritized to obtain level 1 evidence.

Direct Transcervical Access vs the Transfemoral Approach for Carotid Artery Stenting: A Systematic Review and Meta-Analysis

PURPOSE

To examine the safety profile of transcervical access (TCA) in comparison with the transfemoral approach (TFA) in carotid artery stenting.

MATERIALS AND METHODS

A systematic review and meta-analysis was performed according to current guidelines. Eleven eligible studies including 11,592 patients (10,736 in the TFA group and 856 in the TCA group) were identified through a search of the PubMed, Scopus, and Cochrane databases up to October 2018. A random effects model meta-analysis was conducted, and the I2 statistic was used to assess heterogeneity. Publication bias was assessed using funnel plots and quantified using the Egger method.

RESULTS

The TFA group had a statistically significantly higher risk of periprocedural (30-day) stroke compared with the TCA group (OR 1.98, 95% CI 1.08 to 3.63, p=0.027; I2=0%). Also, patients in the TFA group had a significantly higher risk of developing new ischemic lesions (OR 2.97, 95% CI 1.48 to 5.96, p=0.002; I2=0%) on diffusion-weighted magnetic resonance imaging (DW-MRI). No differences in terms of transient ischemic attack (OR 1.50, 95% CI 0.73 to 3.10, p=0.268; I2=5.9%), myocardial infarction (OR 0.64, 95% CI 0.30 to 1.35; p=0.242; I2=0%), local hematoma (OR 0.53, 95% CI 0.12 to 2.25, p=0.389; I2=0%), or mortality (OR 1.35, 95% CI 0.62 to 2.92, p=0.449; I2=0%) were identified between the groups.

CONCLUSION

TCA is associated with a significantly lower risk for periprocedural stroke and DW-MRI ischemic lesions compared with TFA. Other periprocedural outcomes were similar between the groups.

Transcervical Carotid Artery Stenting Without Flow Reversal: A Report of Two Cases

Case series

Patients: Male, 78 • Male, 69

Final Diagnosis: Severe carotid artery stenosis

Symptoms: Asymptomatic

Medication: —

Clinical Procedure: Carotid artery stenting

Specialty: Cardiology

Analysis of the ROADSTER pivotal and extended-access cohorts shows excellent 1-year durability of transcarotid stenting with dynamic flow reversal

OBJECTIVE

We report the 1-year outcomes of the Safety and Efficacy Study for Reverse Flow Used During Carotid Artery Stenting Procedure (ROADSTER) multicenter trial. This trial introduced a novel transcarotid neuroprotection system (NPS), the ENROUTE transcarotid NPS (Silk Road Medical Inc, Sunnyvale, Calif). Postoperative results demonstrated that the use of the ENROUTE transcarotid NPS is safe and effective. The aim of this study was to evaluate the safety of transcarotid artery revascularization (TCAR) and to present the 1-year outcomes.

METHODS

This study is a prospective, single-arm clinical trial. Current enrollment occurs in 14 centers. Primary end points were incidence rates of ipsilateral stroke at 1 year after TCAR. Occurrence of stroke was ascertained by an independent Clinical Events Committee. Patients with anatomic or medical high-risk factors for carotid endarterectomy (CEA) were eligible to be enrolled in the ROADSTER trial.

RESULTS

Overall, 165 patients were included in the long-term follow-up (112 of 141 patients from the pivotal phase and 53 of 78 patients from the extended access). Mean age was 73.9 years (range, 42.1-91.3 years). Patients aged 75 years and older were 43.3% of the cohort. The majority of patients were white (92.7%) and male (75.2%). Most patients were asymptomatic (79.9%). Anatomic risk factors were distributed as follows: contralateral carotid artery occlusion (11.0%), tandem stenosis of >70% (1.8%), high cervical carotid artery stenosis (25.0%), restenosis after CEA (25.6%), bilateral stenosis requiring treatment (4.3%), and hostile neck (14.6%). Medical high-risk criteria included two-vessel coronary artery disease (14.0%) and severe left ventricular dysfunction with ejection fraction <30% (1.8%). In general, 43.3% of patients had at least one anatomic high-risk factor, whereas 29.9% of patients had medical high-risk factors. Both subsets of factors were present simultaneously in 26.8% of the cohort. At 1-year follow-up, ipsilateral stroke incidence rate was 0.6%, and seven patients (4.2%) died. None of the deaths were neurologic in origin.

CONCLUSIONS

TCAR with dynamic flow reversal had previously shown favorable 30-day perioperative outcomes. This excellent performance seems to extend to 1 year after TCAR as illustrated in this analysis. The promising results from the ROADSTER trial likely stem from the novel cerebral protection provided through the ENROUTE transcarotid NPS in comparison to distal embolic protection devices as well as the transcarotid approach's circumventing diseased aortic arch manipulation and minimizing embolization. TCAR offers a safe and durable revascularization option for patients who are deemed to be at high risk for CEA.

Transcervical access, reversal of flow and mesh-covered stents: New options in the armamentarium of carotid artery stenting

In the last 25 years, the very existence of carotid artery stenting (CAS) has been threatened on a number of occasions. The initial disappointing results that even lead to the discontinuation of an early randomized controlled trial have improved considerably with time. Novel devices, advanced stent and equipment technology, alternative types of access and several types of filters/emboli protecting devices have been reported to reduce stroke/death rates during/after CAS and improve CAS outcomes. The present review will provide a description of the various technology advances in the field that aim to reduce stroke and death rates associated with CAS. Transcervical access, reversal of flow and mesh-covered stents are currently the most promising tools in the armamentarium of CAS.

Protected Carotid Artery Stenting and Angioplasty via Transfemoral versus Transcervical Approaches

This prospective cohort study was taken to determine whether transcervical carotid artery stenting (CAS) with internal carotid artery (ICA) flow reversal is associated with a lower incidence of embolization and femoral access complication when compared with protected, transfemoral CAS in selected, high-risk patients. From 2002 to October 2004, the authors performed 55 carotid stentings and angioplasties. Among the 24 cases via transfemoral approach, 1 developed transient ischemic attack (TIA), 1 stroke, 1 asystolic cardiac arrest, 2 groin hematoma, 2 technical failure, and 1 restenosis. Among the 31 cases via transcervical approach, 2 patients developed TIAs, 4 bradycardia, 2 cervical hematoma, and 3 technical failures leading to open conversion and carotid endarterectomy. Transcervical CAS with ICA flow reversal eliminates the risk of aortic arch emboli, provides cerebral protection during predeployment manipulation across the carotid lesion, negates preprocedure mapping of the aortic arch configuration, and surpasses difficult aortic arch or transfemoral access.

Outcomes of 1000 Carotid Wallstent Implantations

Purpose: To evaluate the outcomes of carotid artery stenting (CAS) with Wallstents in a single-center experience. Methods: From January 2003 to December 2013, 1000 carotid artery lesions were treated with Carotid Wallstents under cerebral protection in 877 patients (mean age 71.7±8 years; 621 men). Indications for treatment were de novo lesions (>70% asymptomatic and >60% symptomatic); stenoses following carotid endarterectomy, radiation, or neck surgery; contralateral laryngeal nerve palsy; and high surgical risk. All the patients underwent duplex ultrasound and clinical evaluation during follow-up; radiography was performed when fracture or stent migration was suggested by ultrasound. Results: Procedure success was achieved in 99.3% of patients. Major and minor 30-day adverse events occurred in 2.1% of patients, including stroke (1.8%: 1.3% minor, 0.5% major), myocardial infarction (0.1%), and death (0.2%). Plaque morphology, nature of stenosis, and symptomatic status were significantly associated with the risk of postoperative neurologic events. Restenosis occurred in 3.2% at a mean 45.5-month follow-up and was significantly associated with diabetes, smoking, symptomatic stenosis, de novo stenosis, and calcification (plaque III/IV). No fracture or migration was registered during follow-up. Conclusion: CAS is a valid method for treating carotid artery disease, with very low rates of major adverse events and neurologic complications. The Carotid Wallstent seems to have excellent results, even with complex plaque morphology, and a low incidence of restenosis at follow-up.

Incidence and timing of hypotension after transcervical carotid artery stenting: correlation with postoperative complications

OBJECTIVES

To assess the incidence and timing of hypotension after carotid artery stenting (CAS) and its correlation with postoperative complications.

BACKGROUND

CAS-associated postoperative hypotension has been linked to surgical morbidity and mortality, especially to stroke and cardiac complications.

METHODS

Ninety-seven consecutive patients undergoing transcervical CAS were monitored for at least 12 hr after operation. Hypotension was defined as systolic blood pressure < 90 mm Hg. Patients were divided into three groups: normal blood pressure and early (≤6 hr) and late (>6 hr) hypotension. Complications were recorded.

RESULTS

Hypotension occurred in 34% of the patients (early hypotension in 63% of them). Hypotension was recorded in 21.6% of patients during surgery and in 21.6%, 15.5%, and 1.0% at 6, 12, and 24 hr postoperatively. Bradycardia occurred in 26.8% during operation and in 25.8%, 13.4%, and 10.3% at 6, 12, and 24 hr after surgery. Intraoperative bradycardia (P = 0.01) and hypotension (P = 0.02) were predictors of postoperative hypotension. The overall rate of complications was 5% without differences between the study groups. The mean length of stay was 3, 3.6, and 2.8 days in the normotensive, early hypotension, and late hypotension groups, respectively.

CONCLUSIONS

Most postoperative hypotension episodes occurred within the first 6 hr, and more than one-third between the 6 and 12 hr post-procedure. All patients with late hypotension were asymptomatic. There was no difference in complications between the study groups. In patients undergoing ambulatory CAS, hemodynamic monitoring in the postoperative period is particularly important during the first 12 hr.

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.

A diffusion-weighted magnetic resonance imaging-based study of transcervical carotid stenting with flow reversal versus transfemoral filter protection

BACKGROUND

Transfemoral carotid artery stenting (CAS) has been associated with a high incidence of embolic phenomena and silent brain infarction. The goal of this study was to compare the incidence of new ischemic cerebral lesions on diffusion-perfusion magnetic resonance imaging (MRI) sequences after transcervical CAS performed with carotid flow reversal vs stenting via transfemoral approach with distal filter protection.

METHODS

During a 26-month period, 64 consecutive patients diagnosed with significant carotid stenosis by ultrasound imaging were assigned to transcervical CAS with carotid flow reversal or a transfemoral approach with a distal filter. The Rankin stroke scale was administered by an independent neurologist, and diffusion-weighted MRI (DW-MRI) studies were performed ≤24 hours before and ≤24 to 48 hours after the procedure. DW-MRI studies were compared by two neuroradiologists not involved in the study and blinded for time, clinical status, and treatment option. Hyperintense DW-MRI signals found after the procedure were interpreted as postoperative ischemic infarcts. All patients were assessed at 1, 6, and 12 months after the intervention.

RESULTS

The distribution of demographic and pathologic variables was similar in both groups. All procedures were technically successful, with a mean carotid flow reversal time of 22 minutes. Twenty-one (70%) and 23 patients (69.69%) were symptomatic in the transcervical and transfemoral groups, respectively (P=.869). After intervention, new postprocedural DW-MRI ischemic infarcts were found in four transcervical (12.9%) and in 11 transfemoral (33.3%) patients (P=.03), without new neurologic symptoms. No major adverse events occurred at 30 days after the intervention. All patients remained neurologically intact, without an increase in stroke scale scoring. All stents remained patent, and all patients remained stroke-free during follow-up. In multivariate analysis, age (relative risk [RR], 1.022; P<.001), symptomatic status (RR, 4.109; P<.001), and open-cell vs closed-cell stent design (RR, 2.01; P<.001) were associated with a higher risk of embolization in the transfemoral group but not in the transcervical group.

CONCLUSIONS

These data suggest that transcervical carotid stenting with carotid flow reversal carries a significantly lower incidence of new ischemic brain infarcts than that resulting from transfemoral CAS with a distal filter. The transcervical approach with carotid flow reversal may improve the safety of CAS and has the potential to improve results in especially vulnerable patients such as the elderly and symptomatic.

Transcervical carotid stenting with flow reversal is a safe technique for high-risk patients older than 70 years

BACKGROUND

Recent evidence regarding carotid revascularization advises against carotid angioplasty and stenting (CAS) in patients aged >70 years with conventional risk for carotid endarterectomy (CEA). The poor outcome of transfemoral CAS in this age group may be explained by the anatomic characteristics of the aortic trunk and supra-aortic vessels in elderly patients, as well as by a high prevalence of aortic arch atheromatosis. Transcervical CAS with flow reversal for cerebral protection avoids these unfavorable characteristics. This study analyzed the short-term and middle-term results of transcervical CAS with flow reversal in patients aged >70 years at high risk for CEA.

METHODS

Between January 2006 and January 2011, 219 cases of >70% carotid artery stenosis in high-risk patients aged >70 years (55.7% asymptomatic and 44.3% symptomatic) were treated by transcervical CAS. All patients underwent complete neurologic examination by a stroke neurologist before and after the procedure. Primary end points were stroke, death, or myocardial infarction (MI), technical success, and complications at 30 days. During follow-up, we analyzed the rate of restenosis ≥50% and ipsilateral stroke. Data were collected prospectively and outcome was analyzed in all cases, including technical failures.

RESULTS

The 30-day combined stroke/death/MI rate was 2.2% (stroke, 1.8%; stroke/death, 2.2%; and MI, 0.45%). In symptomatic patients, stroke/death/MI was 5.1% (stroke, 4.1%; stroke/death, 5.1%). None of the asymptomatic patients suffered stroke, MI, or death postoperatively. Technical success was 96.3% (four inability to cross lesion, two major common carotid dissections, one failed preangioplasty, one stent thrombosis). One cervical hematoma required surgical drainage. At follow-up (18.8 ± 16.9 months), cumulative (standard error) incidence of >70% restenosis was 3% (1%) at 1 year and 8% (3%) at 2 and 3 years. Only one patient experienced ipsilateral stroke during follow-up. Overall survival (standard error) was 94% (2%) at 1 year and 90% (3%) at 2 and 3 years.

CONCLUSIONS

In our experience, transcervical CAS with flow reversal is a safe technique for treating carotid stenosis in patients aged >70 years. We believe that avoiding the aortic arch and tortuous supra-aortic vessels is responsible for the favorable results in this study.

Percutaneous superficial temporal artery access for carotid artery stenting in patients with a hostile aortic arch

PURPOSE

To describe an entirely percutaneous treatment for carotid artery stenting in a type IIa aortic arch via the superficial temporal artery (STA) for through-and-through guidewire access.

TECHNIQUE

The technique is demonstrated in an 83-year-old man status post left carotid endarterectomy 3 months prior who presented with 2.5 hours of confusion and dysphasia following diagnostic carotid arteriography. The patient was known to have a type IIa bovine aortic arch and a severe 70% stenosis of the left internal carotid artery. The patient was referred for carotid artery stenting by his vascular surgeon. Due to the bovine arch, a percutaneous ultrasound-guided approach via the STA for through-and-through wire access facilitated carotid artery stenting from the right common femoral artery. The procedure was successful, and follow-up duplex ultrasound confirmed patency of the STA the next day.

CONCLUSION

A percutaneous ultrasound-guided STA access can help facilitate transfemoral carotid artery stenting in an otherwise difficult type IIa aortic arch setting.

Safety and feasibility of a novel transcervical access neuroprotection system for carotid artery stenting in the PROOF Study

BACKGROUND

Randomized controlled trials have shown that periprocedural rates of stroke and death are higher with carotid artery stenting (CAS) than with carotid endarterectomy (CEA) in the treatment of carotid artery stenosis. Diffusion-weighted magnetic resonance imaging (DW-MRI) has shown higher rates of clinically silent new ischemic brain lesions when CAS is performed as compared with CEA. The Silk Road Medical Embolic PROtectiOn System: First-In-Man (PROOF) Study is a single-arm first-in-man study using the MICHI Neuroprotection System (Silk Road Medical Inc, Sunnyvale, Calif), a novel transcervical access and cerebral embolic protection system. This system enables stent implantation under controlled blood flow reversal of the carotid artery, also known as Flow Altered Short Transcervical Carotid Artery Stenting (FAST-CAS).

METHODS

Between March 2009 and February 2010, a total of 44 subjects were enrolled into the study. The primary composite endpoint was major stroke, myocardial infarction, or death within 30 days. Forty-three patients (97.7%) completed the study through the 30-day endpoint. One patient was lost to follow-up. In a subgroup of consecutive subjects, DW-MRI examinations were performed preprocedure and within 24 to 48 hours after the stent implantation. Blinded independent neuroradiologists reviewed all DW-MRI studies and confirmed the absence or presence of new ischemic brain lesions.

RESULTS

All enrolled patients were successfully treated, and no major adverse events were seen through the follow-up period. Thirty-one subjects had DW-MRI examinations. Of these, five patients (16%) had evidence of new ischemic brain lesions but no clinical sequelae. Transient intolerance to reverse flow was reported in 9% of cases, but in all cases, a stent was successfully placed, and the intolerance was managed by minimizing the duration of reverse flow during the procedure.

CONCLUSION

In this first-in-man experience, FAST-CAS using the MICHI Neuroprotection System was shown to be a safe and feasible method for carotid revascularization. DW-MRI findings suggest controlled reverse flow provides cerebral embolic protection similar to that seen with CEA.

Angioplastia carotídea com reversão do fluxo em octogenários: relato de caso

Pacientes octogenários submetidos à angioplastia carotídea apresentam maior incidência de eventos neurológicos quando comparados a grupos de pacientes mais jovens e a grupos da mesma faixa etária submetidos à endarterectomia carotídea. A maior taxa de complicações pode ser explicada por fatores anatômicos e anatomopatológicos que aumentam a dificuldade técnica e o risco de ateroembolismo do procedimento endovascular. O procedimento foi realizado no centro cirúrgico, com o paciente em decúbito dorsal e sob anestesia geral. Realizamos acesso cirúrgico transverso limitado, na base do pescoço à direita, com dissecção, identificação e reparo da artéria carótida comum e veia jugular interna. Foram administradas 10.000 U de heparina e puncionada a carótida comum pela técnica de Seldinger com introdução de bainha 8F em sentido cranial. Na sequência, foi puncionada a veia jugular interna com instalação de bainha 8F em sentido caudal. Em seguida, ambas as bainhas foram conectadas, utilizando-se um segmento de equipo de soro. A carótida comum foi fechada por cadarço duplo de silicone e o fluxo retrógrado pela carótida interna foi estabelecido. Subsequentemente, foi introduzido fio guia 0.014 x 190 cm com cruzamento da lesão, realizando-se angioplastia com balão 5 x 20 mm e em seguida stent (Wallstent® 7 x 50 - Boston Scientific) foi introduzido, posicionado e liberado. A angioplastia carotídea com reversão de fluxo, por via transcervical, constitui estratégia de proteção cerebral custo-eficiente e com menor potencial emboligênico em pacientes octogenários com anatomia desfavorável.

Strategies for conditional two-locus nonparametric linkage analysis

In this article we deal with two-locus nonparametric linkage (NPL) analysis, mainly in the context of conditional analysis. This means that one incorporates single-locus analysis information through conditioning when performing a two-locus analysis. Here we describe different strategies for using this approach. Cox et al. [Nat Genet 1999;21:213-215] implemented this as follows: (i) Calculate the one-locus NPL process over the included genome region(s). (ii) Weight the individual pedigree NPL scores using a weighting function depending on the NPL scores for the corresponding pedigrees at speci fi c conditioning loci. We generalize this by conditioning with respect to the inheritance vector rather than the NPL score and by separating between the case of known (prede fi ned) and unknown (estimated) conditioning loci. In the latter case we choose conditioning locus, or loci, according to prede fi ned criteria. The most general approach results in a random number of selected loci, depending on the results from the previous one-locus analysis. Major topics in this article include discussions on optimal score functions with respect to the noncentrality parameter (NCP), and how to calculate adequate p values and perform power calculations. We also discuss issues related to multiple tests which arise from the two-step procedure with several conditioning loci as well as from the genome-wide tests.

Transcervical carotid stenting with flow reversal protection: Experience in high-risk patients

BACKGROUND

Carotid angioplasty and stenting (CAS) with cerebral embolic protection is a safe alternative to carotid endarterectomy in high-risk patients. Among the various systems proposed for cerebral protection, transcervical CAS avoids crossing the lesion without protection and eliminates the complications associated with transfemoral access. This study analyzes our experience and the results obtained with a transcervical stenting technique for carotid revascularization.

METHODS

From January 2005 to June 2006, 62 CAS were performed in our center in high-risk patients with >70% stenosis (38.7% had a previous neurologic event and 61.3% were asymptomatic). The indications for CAS were severe heart disease (45.1%), severe pulmonary disease (6.4%), paralysis of the contralateral laryngeal nerve (6.4%), recurrent stenosis (3.2%), and high carotid lesion (1.6%). Twenty-one patients were >80 years old. A complete neurologic examination was performed by a stroke neurologist in all patients before and after stenting. The protection system used was carotid flow reversal by transcervical access. Transcranial Doppler monitoring was done during the procedure in 35 patients. We analyzed technical success, the presence of high-intensity transient signals during the procedure, neurologic morbidity and mortality at 30 days and 6 months, and stent patency at 6 months (range, 1 to 18 months). Technical success was 96.8%. Perioperative high-intensity transient signals were observed in two patients (5.7%). In the immediate postoperative period, one patient had a transient ischemic attack of the anterior cerebral artery and another had a stroke, with contralateral hemiplegia. At 48 hours after discharge, a third patient returned to the hospital with a severe cerebral hemorrhage that required surgical drainage; hence, neurologic morbidity was 4.9%. There were no deaths at 6 months. Among the total, 98.4% of the stents remained patent, two showed restenosis of 50% to 70%, and one restenosis of >70%. No patients presented a neurologic event during the follow-up.

CONCLUSIONS

Transcervical carotid artery stenting with flow reversal cerebral protection is a relatively simple, safe technique that avoids instrumentation of the aortic arch and crossing the target lesion without protection. It is less expensive than techniques requiring a filter device and provides excellent outcome with an acceptable incidence of complications.

Transcervical carotid stenting with flow reversal for neuroprotection: technique, results, advantages, and limitations

Carotid angioplasty and stenting are progressively earning a role as a less invasive alternative in the treatment of carotid occlusive disease. The most common approach for carotid artery stenting involves transfemoral access and use of a filter or balloon device for neuroprotection. This approach has limitations related to both the site of access and the method of neuroprotection. Specifically, an aortoiliac segment with advanced occlusive or aneurysmal disease or an anatomically unfavorable or atheromatous arch and arch branches can significantly limit the safety of the retrograde transfemoral pathway to the carotid bifurcation. Additionally, data provided by the use of transcranial Doppler monitoring and diffusion-weighted magnetic resonance imaging in patients undergoing filter- or balloon-protected carotid artery stenting demonstrate that currently available devices are associated with a considerable incidence of cerebral embolization. To address these limitations, we, along with others, have employed a direct transcervical approach for carotid artery stenting that incorporates the principle of flow reversal for neuroprotection. The technique bypasses all of the anatomic limitations of transfemoral access and simplifies the application of flow reversal, which is one of the safest neuroprotection techniques. The purpose of this review is to describe our method of transcervical carotid artery stenting, review the accumulating outcomes data, and discuss the clinical advantages of and indications for this increasingly popular technique.

Transcranial Doppler Monitoring of Transcervical Carotid Stenting With Flow Reversal Protection

Background and Purpose— Transfemoral carotid stenting, despite becoming very frequent, has some limitations such as difficult groin access in few patients, lack of distal protection during filter placement, or embolization despite protection. Transcervical stenting (TCS) is a novel technique during which a common carotid to jugular vein shunt is placed creating a protective reversal flow in the internal carotid artery after proximal common carotid artery (CCA) clamping. We aim to study, with transcranial Doppler (TCD), cerebral flow changes and microemboli detection during transcervical stenting.

Methods— From September 2005 to March 2006, of 65 consecutive patients eligible for carotid revascularization, 23 were considered high risk (sapphire criteria) and underwent TCS. Neurologic examination was performed before and after the procedure by a neurologist and a preprocedure vascular reactivity TCD examination was done in all patients.

Results— After CCA clamping, flow inversion was observed in the anterior cerebral artery, supplying blood to the middle cerebral artery (MCA) and internal carotid artery (reversal). TCD did not detect any air/solid emboli during stent deployment and angioplasty confirming the reversal flow protection hypothesis. Mean reversal flow time was 15.4 minutes; in all cases, substantial MCA flow was present during CCA clamping (initial mean velocity 30 cm/s), and a slow gradual increase was observed traducing collateral flow recruitment (mean velocity after 5 minutes 36 cm/s, P <0.001). Flow increase was observed in all patients except in those with preprocedural exhausted ipsilateral vascular reactivity (16% versus 2%, P =0.036). The only in-procedure complication was one transient ischemic attack. After CCA unclamping, normal antegrade flow was restored in anterior cerebral artery and mean final MCA velocity increased 16% according to preprocedure flow.

Conclusions— TCS with protective internal carotid artery flow reversal can eliminate showers of micoremboli during stent deployment making it a promising carotid revascularization technique in high-risk patients with carotid stenosis.

Transcervical Approach With Protective Flow Reversal for Carotid Angioplasty and Stenting

PURPOSE

To report our initial experience using a transcervical approach for carotid angioplasty/stenting (CAS) that employs internal carotid artery (ICA) flow reversal for neuroprotection.

METHODS

Seventeen patients (15 men; mean age 65 years, range 49-77) with significant carotid stenosis (mean 88%, 8 symptomatic) were treated with protected transcervical CAS. Eleven patients were considered at high risk for carotid endarterectomy; 8 were also considered high risk for transfemoral access (unfavorable aortic arch anatomy or advanced aortoiliac occlusive disease). Anesthesia was based on patient and anesthesiologist preferences. The approach consisted of a 2-cm cutdown over the common carotid artery and placement of a 9-F sheath. ICA flow was reversed and shunted into the jugular vein during the carotid intervention.

RESULTS

Access and carotid stenting were successful in all cases. Thirteen procedures were performed under general and 4 under local anesthesia. Mean flow reversal time was 34+/-4 minutes (25 minutes in the last 7 cases). The patients tolerated the procedure well and had no neurological events. Four (23%) patients had significant oozing from the operative site; 2 developed small neck hematomas that were treated conservatively. All patients were discharged on the first postoperative day. There were no deaths, changes in neurological status, or restenosis over a mean follow-up of 12 months (range 1-24).

CONCLUSIONS

Our initial experience demonstrates that a transcervical approach is a viable alternative for CAS. The procedure can be performed safely, with good initial clinical outcomes. The approach allows carotid flow reversal and emboli protection without introducing neuroprotection devices. The method appears best suited for patients at high risk for endarterectomy and transfemoral access.

Transcervical carotid stenting with internal carotid artery flow reversal: Feasibility and preliminary results

OBJECTIVE

Transfemoral carotid artery stenting (CAS), with or without distal protection, is associated with risk for cerebral and peripheral embolism and access site complications. To establish cerebral protection before crossing the carotid lesion and to avert transfemoral access complications, the present study was undertaken to evaluate a transcervical approach for CAS with carotid flow reversal for cerebral protection.

METHODS

Fifty patients underwent CAS through a transcervical approach. All patients with symptoms had greater than 60% internal carotid artery (ICA) stenosis, and all patients without symptoms had greater than 80% ICA stenosis. Twenty-one patients (42%) had symptomatic disease or ipsilateral stroke, and 8 patients (16%) had contralateral stroke. Four patients (8%) had recurrent stenosis, 7 patients (14%) had contralateral ICA occlusion, and 1 patient (2%) had undergone previous neck radiation. Twenty-seven procedures (54%) were performed with local anesthesia, and 23 (46%) with general anesthesia. Using a cervical cutdown, flow was reversed in the ICA by occluding the common carotid artery and establishing a carotid-jugular vein fistula. Pre-dilation was selective, and 8-mm to 10-mm self-expanding stents were deployed and post-dilated with 5-mm to 6-mm balloons in all cases.

RESULTS

The procedure was technically successful in all patients, without significant residual stenoses. No strokes or deaths occurred. There was 1 wound complication (2%). All patients were discharged within 2 days of surgery. Mean flow reversal time was 21.4 minutes (range, 9-50 minutes). Carotid flow reversal was not tolerated in 2 patients (4%). Early in the experience, carotid flow reversal was not possible in 1 patient, and there were 1 major and 3 minor common carotid artery dissections, which resolved after stent placement. One intraoperative transient ischemic attack (2%) occurred in 1 patient in whom carotid flow was not reversed, and 1 patient with a contralateral ICA occlusion had a contralateral transient ischemic attack. At 1 to 12 months of follow-up, all patients remained asymptomatic, and all but 1 stent remained patent.

CONCLUSION

Transcervical CAS with carotid flow reversal is feasible and safe. It can be done with the patient under local anesthesia, averts the complications of the transfemoral approach, and eliminates the increased complexity and cost of cerebral protection devices. Transcervical CAS is feasible when the transfemoral route is impossible or contraindicated, and may be the procedure of choice in a subset of patients in whom carotid stenting is indicated.

Carotid angioplasty with internal carotid artery flow reversal is well tolerated in the awake patient

OBJECTIVE

The purpose of this study was to evaluate the neurologic tolerance and changes in ipsilateral hemispheric oxygen saturation during transcervical carotid artery stenting with internal carotid artery (ICA) flow reversal for embolic protection.

PATIENTS AND METHODS

This was a prospective study of 10 patients (mean age 68 years) undergoing transcervical carotid angioplasty and stenting. All ICA stenoses were greater that 70%. Seven patients had an ipsilateral hemispheric stroke (3) or transient ischemic attack (4), two patients had a contralateral stroke, and one patient was asymptomatic. Nine procedures were done under local anesthesia. Cerebral protection was established through a cervical common carotid (CCA) cutdown to create an external fistula between the ICA and the internal jugular vein with temporally CCA occlusion. Venous oxygen saturation (SVO(2)) was continuously monitored through a catheter placed in the distal internal jugular vein. Mental status and motor-sensory changes were categorized and assessed throughout and after the procedure.

RESULTS

All procedures were technically successful without significant residual stenosis. Mean ICA flow reversal time was 22 minutes (range, 15 to 32). Common carotid artery (CCA) occlusion produced a slight (SVO(2) = 72.6%+/-9.4) but significant decrease (P =.012) in SVO(2), compared with baseline (SVO(2) = 77% +/-10.5). During ICA flow reversal (SVO(2) = 72.4% +/-10.1) cerebral oxygen saturation did not change compared with CCA occlusion alone (P =.85). Transient balloon occlusion during angioplasty of the ICA (SVO(2) = 64.6%+/-12.9) produced a significant decrease in cerebral SVO(2) compared with CCA occlusion (P =.015) and compared with CCA occlusion with ICA flow reversal (P =.018). No mental status changes or ipsilateral hemispheric focal symptoms occurred during CCA occlusion with ICA flow reversal. One patient with contralateral ICA occlusion sustained brief upper extremity weakness related to the contralateral hemisphere. Five patients sustained a vasovagal response during balloon dilatation, four did not require treatment, and one had asystole requiring atropine injection. Mean SVO(2) saturation was not different in these five patients compared with the five who did not sustain a vasovagal response. No deaths or neurologic deficits occurred within 30 days after the procedure.

CONCLUSIONS

Our data suggest that transcervical carotid angioplasty and stenting with ICA flow reversal is well tolerated in the awake patient, even in the presence of symptomatic carotid artery disease. Cerebral oxygenation during ICA flow reversal is comparable to that during CCA occlusion. ICA angioplasty balloon inflation produces a decrease in cerebral SVO(2) significantly greater than that occurring during ICA flow reversal.