The role of transfemoral carotid artery stenting with proximal balloon occlusion embolic protection in the contemporary endovascular management of carotid artery stenosis

Predictors of Occlusion after Carotid Stenting

BACKGROUND

Carotid artery stent (CAS) occlusion is a rare complication not well studied. We used a national dataset to assess real world CAS experience to determine the rate of stent occlusion. The purpose of this study was to 1) Identify risk factors associated with CAS occlusion on long-term follow-up (LTFU) and 2) Determine the adjusted odds of death/transient ischemic attack (TIA)/stroke (cerebrovascular accident (CVA)) in patients with occlusion.

METHODS

The national Vascular Quality Initiative CAS dataset (2016-2021) comprised the sample. The primary endpoint was occlusion on LTFU (9-21 months postoperatively as defined by the Vascular Quality Initiative LTFU dataset) with secondary endpoint examining a composite of death/TIA/CVA. Descriptive analyses used chi-square and Wilcoxon tests for categorical and continuous variables respectively. Adjustment variables were selected a priori based on clinical expertise and univariate analyses. Multivariable logistic regression was used to model the odds of occlusion and the odds of death/TIA/CVA. Generalized estimating equations accounted for center level variation.

RESULTS

During the study period, 109 occlusions occurred in 12,143 cases (0.9%). On univariate analyses, symptomatic indication, prior stroke, prior neck radiation, lesion calcification (>50%), stenosis (>80%), distal embolic protection device (compared to flow reversal), balloon size, >1 stent and current smoking at time of LTFU were predictive for occlusion. Age ≥ 65, coronary artery disease (CAD), elective status, preoperative statin, preoperative and discharge P2Y12 inhibitor, use of any protection device intraoperatively and protamine were protective. On multivariable analyses, age ≥ 65, CAD, elective status and P2Y12 inhibitor on discharge were protective for occlusion, while patients with prior radiation and those taking P2Y12 inhibitor on LTFU were at increased odds. The adjusted odds of death/TIA/CVA in patients with occlusion on LTFU were 6.05; 95% confidence interval: 3.61-10.11, P < 0.0001.

CONCLUSIONS

This study provides an in-depth analysis of predictors for CAS occlusion on LTFU. On univariate analyses, variables related to disease severity (urgency, degree of stenosis, nature of lesion) and intraoperative details (balloon diameter, >1 stent) were predictive for occlusion. These variables were not statistically significant after risk adjustment. On multivariable analyses, prior neck radiation was strongly predictive of occlusion. Elective status, patient age ≥ 65, CAD, and P2Y12 inhibitor upon discharge (but not on LTFU) were protective for occlusion. Additionally, patients who developed occlusion had high odds for death/TIA/CVA. These findings provide important data to guide clinical decision-making for carotid disease management, particularly identifying high-risk features for CAS occlusion. Closer postoperative follow-up and aggressive risk factor modification in these patients may be merited.

Bailout Distal Internal Carotid Artery Stenting after Carotid Endarterectomy: Indications, Technique, and Outcomes

BACKGROUND

Distal internal carotid artery (ICA) stenting may be employed as a bailout maneuver when an inadequate end point or clamp injury is encountered at the time of carotid endarterectomy (CEA) in a surgically inaccessible region of the distal ICA. We sought to characterize the indications, technique, and outcomes for this infrequently encountered clinical scenario.

METHODS

We performed a retrospective review of all patients who underwent distal ICA stenting at the time of CEA at our institution between September 2008 and July 2022. Procedural details and postoperative follow-up were reviewed for each patient.

RESULTS

Six patients were identified during the study period. All were male with an age range of 63 to 82 years. Five underwent carotid revascularization for asymptomatic carotid artery stenosis, and one patient was treated for amaurosis fugax. Three patients were on dual antiplatelet therapy preoperatively, whereas 2 were on aspirin monotherapy, and one was on aspirin and low-dose rivaroxaban. Five patients underwent CEA with patch angioplasty, and one underwent eversion CEA. The indication for stenting was distal ICA dissection due to clamp or shunt injury in 2 patients and an inadequate distal ICA end point in 4 patients. In all cases, access for stenting was obtained under direct visualization within the common carotid artery, and a standard carotid stent was deployed with its proximal aspect landing within the endarterectomized site. Embolic protection was typically achieved via proximal common carotid artery and external carotid artery clamping for flow arrest with aspiration of debris before restoration of antegrade flow. There was 100% technical success. Postoperatively, 2 patients were found to have a cranial nerve injury, likely occurring due to the need for high ICA exposure. Median length of stay was 2 days (range 1-7 days) with no instances of perioperative stroke or myocardial infarction. All patients were discharged on dual antiplatelet therapy with no further occurrence of stroke, carotid restenosis, or reintervention through a median follow-up of 17 months.

CONCLUSIONS

Distal ICA stenting is a useful adjunct in the setting of CEA complicated by inadequate end point or vessel dissection in a surgically inaccessible region of the ICA and can minimize the need for high-risk extensive distal dissection of the ICA in this situation.

Debris generated by laser and/or balloon cause cerebral infarction with different severity

The purpose of this study is to determine the effects that debris generated by laser and/or balloon on the brain. Debris generated by laser, balloon, and laser combined with balloon were collected and then injected into rats' left common carotid artery. Rats were divided into five groups: sham, saline, laser (L), balloon (B), and laser combined with balloon (LB). The cognition ability of rats was evaluated by Morris water maze. Cerebral blood flow (CBF) was examined by laser speckle. TTC staining and MRI scan were conducted to detect cerebral ischemic infarction. Intracranial arteries in rats were visualized by MRI angiography via contrast medium injected via tail vein. Immunohistologic staining for NeuN and Iba1 and hematoxylin-eosin staining were performed to assess brain infarction. White matter demyelination was assessed by Luxol fast blue staining. Long-term memory and CBF of rats in different groups exhibited no significant difference. No obstruction sign in intracranial artery tree was noticed in each group. Debris generated by different treatments all caused brain infarction. Infarction lesion caused by debris produced by balloon was much more severe than the one caused by debris generated by laser. While the LB group lay in between. The thickness of white matter decreased in the B group, but not in the L and LB groups. Rat brain has a tolerance for debris as cognition ability and cerebral blood flow are not significantly declined. The severity of cerebral infarction varies by debris generated by different treatments.

Distal embolic protection use during transfemoral carotid artery stenting is associated with improved in-hospital outcomes

OBJECTIVE

Despite current guidelines recommending the use of distal embolic protection during transfemoral carotid artery stenting (tfCAS) to prevent periprocedural stroke, there remains significant variation in the routine use of distal filters. We sought to assess in-hospital outcomes in patients undergoing tfCAS with and without embolic protection using a distal filter.

METHODS

We identified all patients undergoing tfCAS in the Vascular Quality Initiative from March 2005 to December 2021 and excluded those who received proximal embolic balloon protection. We created propensity score-matched cohorts of patients who underwent tfCAS with and without attempted placement of a distal filter. Subgroup analyses of patients with failed vs successful filter placement and failed vs no attempt at filter placement were performed. In-hospital outcomes were assessed using log binomial regression, adjusted for protamine use. Outcomes of interest were composite stroke/death, stroke, death, myocardial infarction (MI), transient ischemic attack (TIA), and hyperperfusion syndrome.

RESULTS

Among 29,853 patients who underwent tfCAS, 28,213 (95%) had a filter attempted for distal embolic protection and 1640 (5%) did not. After matching, 6859 patients were identified. No attempted filter was associated with significantly higher risk of in-hospital stroke/death (6.4% vs 3.8%; adjusted relative risk [aRR], 1.72; 95% confidence interval [CI], 1.32-2.23; P < .001), stroke (3.7% vs 2.5%; aRR, 1.49; 95% CI, 1.06-2.08; P = .022), and mortality (3.5% vs 1.7%; aRR, 2.07; 95% CI, 1.42-3.020; P < .001). In a secondary analysis of patients who had failed attempt at filter placement vs successful filter placement, failed filter placement was associated with worse outcomes (stroke/death: 5.8% vs 2.7%; aRR, 2.10; 95% CI, 1.38-3.21; P = .001 and stroke: 5.3% vs 1.8%; aRR, 2.87; 95% CI, 1.78-4.61; P < .001). However, there were no differences in outcomes in patients with failed vs no attempted filter placement (stroke/death: 5.4% vs 6.2%; aRR, 0.99; 95% CI, 0.61-1.63; P = .99; stroke: 4.7% vs 3.7%; aRR, 1.40; 95% CI, 0.79-2.48; P = .20; death: 0.9% vs 3.4%; aRR, 0.35; 95% CI, 0.12-1.01; P = .052).

CONCLUSIONS

tfCAS performed without attempted distal embolic protection was associated with a significantly higher risk of in-hospital stroke and death. Patients undergoing tfCAS after failed attempt at filter placement have equivalent stroke/death to patients in whom no filter was attempted, but more than a two-fold higher risk of stroke/death compared with those with successfully placed filters. These findings support current Society for Vascular Surgery guidelines recommending routine use of distal embolic protection during tfCAS. If a filter cannot be placed safely, an alternative approach to carotid revascularization should be considered.

Impact of Flow Reversal Duration on Neurological Outcomes of Transcarotid Artery Revascularization (TCAR)

BACKGROUNDS

Flow reversal is a key component of transcarotid artery revascularization (TCAR). However, the impact of flow reversal duration on neurological outcomes and the duration of flow reversal which optimizes TCAR's outcomes is not known. We evaluated the association of flow reversal time with the intraoperative and postoperative neurological outcomes of TCAR.

METHODS

We studied all patients undergoing TCAR from September 2016 to October 2021. The exposure of interest was the duration of flow reversal. Multivariable logistic and fractional polynomial models were used to study the impact of flow reversal duration on in-hospital stroke, intraoperative neurological change/intolerance and stroke/death following TCAR and to identify the flow reversal time above which significant perioperative neurological events occur.

RESULTS

The study included 19,462 patients with mean age of 73.4 years who were mostly Caucasian (91%) and male (63%). The mean flow reversal time was 10.7 minutes, and the overall stroke rate was 1.4%. The odds of intraoperative neurological change increased by 3.6% per minute increase in flow reversal time (odds ratio (OR), 1.04; 95%, 1.01-1.06; P < 0.002). Flow reversal duration >10 minutes was associated with 78% increased odds of neurological changes compared to flow reversal duration <10 minutes. There was no significant association between flow reversal duration and stroke, and stroke/death in the first 5 minutes after initiation of flow reversal. The odds of stroke increased by 2.7% per minute increase in flow reversal time >5 minutes (OR, 1.03; 95%, 1.01-1.04; P < 0.001), with flow reversal duration >10 minutes associated with 38% increased odds of stroke compared to flow reversal duration ≤10 minutes (OR, 1.37, 95% confidence interval (CI), 1.09-1.73, P = 0.006). The odds of stroke/death increased by 2.5% per minute increase in flow reversal time >5 minutes (OR, 1.03; 95%, 1.01-1.04; P < 0.001). Flow reversal duration >10 minutes was associated with 25% increased odds of stroke/death compared to flow reversal duration <10 minutes (OR, 1.25, 95% CI, 1.01-1.53, P = 0.038). Symptomatic status did not modify outcomes.

CONCLUSIONS

Our findings suggest that outcomes following TCAR are optimal if the duration of flow reversal is minimized. A clinical cutoff time of 10 minutes is suggested by this study and recommended as a guide. Further studies targeted at the flow reversal component of TCAR are needed to solidify the evidence regarding the clinical effects of temporarily induced retrograde cerebral blood flow during TCAR.

Not a trifecta: complementary use of carotid artery revascularization techniques in the era of hybrid neurosurgery

OBJECTIVE

Carotid stenosis is currently treated by carotid endarterectomy (CEA), carotid artery stenting (CAS), or transcarotid artery revascularization (TCAR). This study sought to add to the literature by providing real-world data comparing the safety and effectiveness associated with the performance of these carotid revascularization techniques by dual-trained neurosurgeons.

METHODS

The authors performed a retrospective review of carotid stenosis databases at two US centers. Patients treated by CEA, transfemoral CAS, or TCAR for atherosclerotic carotid artery disease were included. Clinical outcomes were compared at 30 days after the procedure.

RESULTS

Seven hundred eighty patients were included (583 with CAS, 165 with CEA, and 32 with TCAR). Overall, 486 patients (62.3%) were men, and 393 (50.4%) had left-sided carotid stenosis. Most patients (n = 617, 79.1%) had symptomatic disease. Among the three treatment groups, there were no statistically significant differences with respect to 30-day ischemic events (CAS 3.8%, CEA 1.8%, TCAR 6.3%; p = 0.267) or 30-day mortality rates (CAS 3.6%, CEA 2.4%, TCAR 3.1%; p = 0.857). Male sex had significantly lower odds of 30-day transient ischemic attack (TIA) or stroke in both univariable (p = 0.024) and multivariable (p = 0.023) regression models. Increasing age had significantly higher odds of 30-day mortality on univariable (p = 0.006) and multivariable (p = 0.003) regression. Patients with the occurrence of 30-day TIA or stroke also had significantly higher odds of 30-day mortality on univariable (p < 0.001) and multivariable (p < 0.001) regression.

CONCLUSIONS

This real-world experience reflects the current practice of hybrid neurosurgery at two high-volume tertiary care centers and suggests that all three treatment modalities have comparable safety and effectiveness if patients are properly selected.

Transcarotid Artery Revascularization: Is It Better than Carotid Endarterectomy?

Transcarotid artery revascularization (TCAR) is a novel carotid stenting method that avoids the manipulation of the aortic arch and uses a flow-reversal neuroprotection system that effectively reduces the risk of embolic events during carotid intervention. Studies have shown a lower risk of stroke or death compared with the transfemoral carotid stenting approach, and an equivalent risk of stroke or death compared with traditional carotid endarterectomy. TCAR has added benefits of lower risk of myocardial infarction, cranial nerve injuries, and shorter operative times compared with endarterectomy. TCAR has become widely adopted by vascular surgeons in the United States for the treatment of patients with high-risk medical comorbidities and those with challenging surgical anatomy.

Outcomes of transcarotid artery revascularization: A systematic review

BACKGROUND

Ischemic stroke and disability caused by carotid artery stenosis have always been worldwide problems. At present, carotid endarterectomy (CEA) and transfemoral carotid artery stenting (TFCAS) have been commonly used to treat carotid artery stenosis. Recently, transcarotid artery revascularization (TCAR) seems to be another option.

METHODS

We searched PubMed and Embase to find literatures comparing TCAR with TFCAS and CEA. The primary outcomes were stroke, myocardial infarction (MI), transient ischemic attack (TIA), death, cranial nerve injure (CNI), and operative time. Secondary outcomes were stroke, death, MI in the elderly; cost; radiation; and entry site complication.

RESULTS

Initial search of the literature included 165 articles, of which 12 studies were chosen in the end. These studies demonstrated high technical success rate of TCAR. Patients who received TCAR had lower risks of death, stroke/death and less radiation exposure compared to TFCAS. In meta analysis, the risk of stroke was significantly lower in TCAR group than TFCAS (OR 0.63; 95%CI 0.47-0.85). And there was no significant difference in TIA and MI. TCAR was associated with shorter operative time, lower risk of CNI and less blood loss compared to CEA. In older patients, the effect of TCAR was significantly better than that of TFCAS.

CONCLUSION

TCAR is associated with a lower risk of perioperative stroke compared to TFCAS. TCAR is also associated with shorter operative time, lower risk of CNI and less blood loss compared to CEA. TCAR may be a promising treatment option besides TFCAS and CEA.

The Efficacy of Transcarotid Artery Revascularization With Flow Reversal System Compared to Carotid Endarterectomy: A Systematic Review and Meta-Analysis

Background: Carotid artery stenosis has long been a critical cause of stroke and death, and it can seriously affect the life quality. Transcarotid artery revascularization (TCAR) and carotid endarterectomy (CEA) are both feasible therapies for this disease. This systematic review and meta-analysis aim to evaluate if the efficacy of the two approaches is comparable.

Methods: Clinical studies up to March 2021 were searched through PubMed, Embase, and Scopus from a computer. The screening process was designed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Newcastle-Ottawa Scale (NOS) was used for methodological quality assessment of works of literature meeting the inclusion criteria, and Review Manager 5.4 was used for data synthesis. The I² statistic was performed to measure the heterogeneity, and M-H/I-V fixed or random model was utilized depending on the I² value. The evidence evaluation was accomplished based on grades of recommendation, assessment, development, and evaluation (GRADE) online tool.

Results: A total of 14,200 subjects (six comparative studies) were finally included in this pooled study. There is no statistical discrepancy between the two treatments on reducing stroke/death/myocardial infarction (odds ratio [OR] 0.85, 95% CI 0.67–1.07), stroke (OR 1.03, 95% CI 0.77–1.37), or death (OR 1.14, 95% CI 0.67–1.94). Besides, TCAR is associated with a lower incidence of myocardial infarction (P = 0.004), cranial nerve injury (P < 0.00001), and shorter procedure time (P < 0.00001) than CEA among the overall cohort.

Conclusions: TCAR is a rapidly developing treatment that reaches a comparable prognosis to CEA and significantly reduces the risk of myocardial infarction under the well-matched condition, which is a dependable choice for patients with carotid stenosis.

Contemporary Results of Carotid Artery Stenting Using Low-Profile Dual-Metal Layer Nitinol Micromesh Stents in Relation to Single-Layer Carotid Stents

PURPOSE

To evaluate patients characteristics, procedural details, perioperative outcomes, and midterm results of carotid artery stenting (CAS) performed with the Roadsaver/Casper stent (Terumo Corp, Tokyo, Japan) as compared to concurrent patients treated with other commercially available carotid stents.

MATERIALS AND METHODS

This is a single-center, retrospective, nonrandomized study including 200 consecutive patients who underwent a total of 205 elective CAS procedures due to severe internal carotid artery stenosis between April 2015 and December 2018. Procedural data and outcomes for patients treated with the Roadsaver/Casper stent implantation (100 procedures, in 97 patients) vs first-generation carotid stents implantations (90 procedures, in 88 patients) were compared. Fifteen patients were treated with CGuard carotid stent (InspireMD, Tel Aviv, Israel), and outcomes were reported separately. Primary endpoints were the occurrence of major adverse cerebrovascular events (MACE), including death, ipsilateral stroke, and transitory ischemic attack (TIA). Secondary endpoints were the rate of intrastent stenosis, the need for reintervention, and the occurrence of adverse cardiovascular events, including myocardial infarction, arrhythmias, and need for inotropic support.

RESULTS

No difference in demographics and preoperative risk factors were observed between patients treated with and without the Roadsaver/Casper stent. The mean procedure time was shorter in the Roadsaver/Casper group (40.7±16.9 vs 49.4±27.3 minutes; p=0.008), while radial percutaneous access was more frequent (24% vs 5%; p<0.001). The rate of stroke/TIA/death at 30 days was 3% in the Roadsaver group vs 1% in the first-generation stent group (p=0.623). The primary patencyrate was 100% and 93.4% at 1- and 3-year of follow-up in the Roadsaver/Casper groupand 99% and 94.3% in the other stent group, respectively (p=0.95).

CONCLUSIONS

In this real-world cohort of patients undergoing CAS, the Roadsaver/Casper stent was used to treat more symptomatic and vulnerable carotid plaques as compared to other carotid stents. Nevertheless, patients treated with this low-profile dual-layer micromesh stent showed low events rates at both 30 days and follow-up, similar to that observed for other stents.

Transcarotid Artery Revascularization Versus Carotid Endarterectomy and Transfemoral Stenting in Octogenarians

OBJECTIVE

Transfemoral carotid artery stenting (TFCAS) has higher combined stroke and death rates in elderly patients with carotid artery stenosis compared with carotid endarterectomy (CEA). However, transcarotid artery revascularization (TCAR) may have similar outcomes to CEA. This study compared outcomes after TCARs relative to those after CEAs and TFCAS, focusing on elderly patients.

METHODS

We included all patients with carotid artery stenosis, and no prior endarterectomy or stenting, who underwent either a CEA, TFCAS, or TCAR in the Vascular Quality Initiative from September 2016 (TCAR commercially available) to December 2019. We categorized patients into age decades: 60-69 years, 70-79 years, and 80-90 years. Outcomes included 30-day and one-year composite rates of stroke or death. Cox-proportional hazards models evaluated both outcomes after adjusting for patient demographics, clinical factors, symptomatology, hospital CEA volume, and clustering.

RESULTS

We identified 33,115 patients who underwent either a CEA, TFCAS, or TCAR for carotid artery stenosis (35% in their 60s, 44% in their 70s, and 21% in their 80s), where half (50%) were symptomatic. The majority of patients had CEAs (80%), followed by TFCAS (11%) and then TCARs (9.1%). The overall rate of 30-day stroke/death was 1.5% and of one-year stroke/death was 4.4%. Octogenarians had the highest 30-day and one-year stroke/death rates relative to their peers (2.3% and 6.3%, respectively). Among all patients, the adjusted hazards of TCARs relative to CEAs was similar for 30-day stroke/death (HR 1.10 [95%-CI 0.75-1.62]) and slightly higher for one-year stroke/death (HR 1.34 [1.02-1.76]). Among octogenarians, however, the adjusted hazards of TCARs relative to CEAs was similar for both 30-day stroke/death (HR 1.12 [0.59-2.13]) and one-year stroke/death (HR 1.28 [0.85-1.94]). TFCAS relative to CEAs had higher hazards of both 30-day stroke/death (HR 1.78 [1.10-2.89]) and one-year stroke/death (HR 1.85 [1.35-2.54]) in octogenarians.

CONCLUSIONS

TCARs had similar outcomes relative to CEAs among octogenarians with respect to 30-day and one-year rates of stroke/death. TCAR may serve as a promising less-invasive treatment for carotid disease in older patients who are deemed high anatomic, surgical, or clinical risk for CEAs.