Restenosis and risk of stroke after stenting or endarterectomy for symptomatic carotid stenosis in the International Carotid Stenting Study (ICSS): secondary analysis of a randomised trial

Assessment of Plaque Characteristics by Contrast-Enhanced Ultrasound and Stent Restenosis following Carotid Artery Stenting: A Retrospective Study

Background and objective: carotid artery stenosis contributes significantly to ischemic strokes, with management options including carotid endarterectomy (CEA) and carotid artery stenting (CAS) ischemic stroke risk can be reduced. Controversies persist regarding their efficacy and factors influencing complications, and understanding the relationship between atherosclerotic plaque characteristics and stent restenosis after CAS is crucial. Methods: we conducted a retrospective study involving 221 patients who underwent CAS for symptomatic or asymptomatic carotid artery stenosis. Comprehensive assessments of plaque morphology were performed using contrast-enhanced ultrasound (CEUS) before CAS. Patient demographics, including smoking status and diabetes, were also recorded. Stent restenosis was diagnosed using various imaging modalities, including ultrasound, angiography, and digital subtraction angiography (DSA). Results: plaque analysis using CEUS revealed a significant association between plaque grade and restenosis incidence (p < 0.001), particularly with grade 0 (11.1%) and grade 2 plaques (66.7%). Smoking was notably associated with plaque vascularization and restenosis (p < 0.001), while diabetes did not significantly impact plaque characteristics or restenosis risk (p > 0.05). The mean duration of restenosis was 17.67 months. Stenting was the most frequent treatment modality for restenosis (70.6%). However, no significant relationship was found between restenosis type and plaque morphology (p = 0.268). Furthermore, while no clear relationship was observed between plaque morphology and the type of restenosis, our findings underscored the importance of plaque characterization in predicting post-CAS outcomes. Conclusions: this study highlights the utility of CEUS in predicting stent restenosis following CAS. There was a significant association between stent restenosis within 12-24 months after the carotid stenting procedure and an elevated grade of plaque vascularization. Moreover, one of the main factors possibly determining the grade of plaque vascularization was smoking. Further research is warranted to elucidate the underlying mechanisms and refine risk stratification in this patient population.

Surveillance and risk factors for early restenosis following transcarotid artery revascularization

OBJECTIVE

Restenosis after transcarotid artery revascularization (TCAR) is a known complication. When identified in the early postoperative period, it may be related to technique. We evaluated our TCAR experience to identify potentially modifiable factors impacting restenosis.

METHODS

This is a single-institution, retrospective review of patients undergoing TCAR from November 2017 to July 2022. Restenosis was defined as >50% stenosis on duplex ultrasound (DUS) examination or computed tomographic angiography (CTA). Continuous variables were compared using Kruskal-Wallis's test. Categorical variables were compared using the Fisher's exact test.

RESULTS

Of 61 interventions, 11 (18%) developed restenosis within the median follow-up of 345 days (interquartile range, 103-623 days). Among these patients, 82% (9/11) had >50% stenosis, and 18% (2/11) had >80% stenosis. Both patients with high-grade restenosis were symptomatic and underwent revascularization. Diagnosis of post-TCAR restenosis was via DUS examination in 45% (5/11), CTA in 18% (2/11), or both CTA/DUS examination in 36% (4/11). Restenosis occurred within 1 month in 54% (6/11) and 6 months in 72% (8/11) of patients. However, three of the six patients with restenosis within 1 month had discordant findings on CTA vs DUS imaging. Patient comorbidities, degree of preoperative stenosis, medical management, balloon size, stent size, lesion characteristics, and predilatation angioplasty did not differ. Patients with restenosis were younger (P = .02), had prior ipsilateral endarterectomy (odds ratio [OR], 6.5; P = .02), had history of neck radiation (OR, 18.3; P = .01), and lower rate of postdilatation angioplasty (OR, 0.11; P = .04), without an increased risk of neurological events.

CONCLUSIONS

Although post-TCAR restenosis occurred in 18% of patients, only 3% of patients had critical restenosis and required reintervention. Patient factors associated with restenosis were younger age, prior endarterectomy, and history of neck radiation. Although early restenosis may be mitigated by improved technique, the only technical factor associated with restenosis was less use of postdilatation angioplasty. Balancing neurological risk, this factor may have increased application in appropriate patients. Diagnosis of restenosis was inconsistent between imaging modalities; current surveillance paradigms and diagnostic thresholds may warrant reconsideration.

Drug-Coated Balloon Angioplasty for Carotid Artery In-Stent Restenosis: Case Series

OBJECTIVES

Few case reports have demonstrated promising results of drug-coated balloons (DCBs) as an emerging management for carotid artery in-stent restenosis (CAISR). Herein, we report 6 cases of CAISR which were treated with a DCB with or without new stent deployment.

BACKGROUND

Carotid artery in-stent restenosis is a high-risk condition with an estimated incidence rate that varies widely from 6% to 40%. Several strategies are available now for the management of the CAISR including conventional balloon angioplasty, plaque modification balloon angioplasty, and new stent placement.

METHODS

A retrospective review of consecutive patients with a diagnosis of severe CAISR at Baylor Scott & White The Heart Hospital Plano from 2011 to 2021 was performed. This study was approved by the Baylor Scott & White Research Institute institutional review board.

RESULTS

Six patients underwent DCB angioplasty with or without stent placement under an embolic protection device. Resolution of CAISR was achieved in all cases with 0% to 10% residual stenosis in all cases. Following the procedure, 1 patient had a brief episode of syncope with balloon inflation with immediate recovery on deflation of the balloon. There were otherwise no significant neurological or cardiac events prior to discharge. All patients were asymptomatic at their follow-up visit with no neurological or cardiac events reported at 12, 24, and 36 months following the procedure.

CONCLUSION

While CAISR treatment remains a challenging condition, our study shows that the use of DCB with or without stent placement is a feasible and promising treatment option when compared with other conventional treatment options.

CLINICAL IMPACT

Carotid artery in-stent restenosis treatment remains a challenging condition. Our study shows that the use of drug coated balloon with or without stent placement is a feasible and promising treatment option when compared with current conventional treatment options.

Finite element analysis of braided dense-mesh stents for carotid artery stenosis

When braided dense-mesh stents are used to treat carotid stenosis, the structural mechanics of vascular stents, the contact mechanics with blood vessels, and the fluid mechanics in the blood environment need to be studied in depth to reduce the damage of stents to blood vessels and the incidence of in-stent restenosis. Three types of braided stents with 8, 16, and 24 strands and laser-cut stents with the corresponding size parameters were designed, and the bending behavior of each of these types of stent, deployment, and fluid dynamic analysis of the 24-strand braided stent were simulated. The results show that the bending stress of the 8-, 16-, and 24-strand braided stents is 46.33%, 50.24%, and 31.86% of that of their laser-cut counterparts. In addition, higher strand density of the braided stents was associated with greater bending stress; after the 24-strand braided stent was expanded within the stented carotid artery, the carotid stenosis rate was reduced from 81.52% to 46.33%. After stent implantation, the maximum stress on the vessel wall in a zero-pressure diastolic environment decreased from 0.34 to 0.20 MPa, the maximum pressure on the intravascular wall surface decreased from 4.89 to 3.98 kPa, the area of high-pressure region decreased, the wall shear force of the stenotic segment throat decreased, and blood flow increased in the stenosis segments. The braided stent had less bending stress and better flexibility than the laser-cut stent under the same stent size parameters; after the 24-strand braided stent was implanted into the stented vessel, it could effectively dilate the vessel, and the blood flow status was improved.

Relationship between in-stent restenosis following carotid artery stenting and platelet reactivity to clopidogrel

OBJECTIVE

To analyze the relationship between in-stent restenosis (ISR) following carotid artery stenting (CAS) and platelet clopidogrel reactivity confirmed by the P2Y12 reaction unit (PRU) and inhibition rate (IR).

METHODS

We retrospectively analyzed 171 patients who underwent CAS with extracranial carotid stenosis from January 2016 to December 2019. Dual antiplatelet therapy with 100 mg aspirin and 75 mg clopidogrel was started ≥5 days before CAS. Clopidogrel resistance was measured with the PRU and IR the day before CAS. The ISR degree was classified into R1, R2, and R3 (moderate to severe luminal stenosis of ≥50% or occlusion) by carotid CT angiography after 24-30 months. The degree of quantitative association between platelet reactivity and ISR R3 was determined by the receiver operating characteristic curve method. The optimal cut-off values of PRU and IR were derived using the maximum Youden index.

RESULTS

There were 33 R3 degrees of ISR (19.3%) and nine ipsilateral ischemic strokes (5.3%). The PRU and IR were different between R1+R2 degrees (176.4±50.1, 27.5±18.7%) and R3 degree (247.5±55.0, 10.3±13.4%) (P<0.001). The areas under the curves of PRU and IR were 0.841 and 0.781, and the optimal cut-off values were 220.0 and 14.5%, respectively. Multivariate logistic regression analysis showed that PRU ≥220 and IR ≤14.5% were significant predictive factors for ISR R3 (P<0.001 and P=0.017, respectively). ISR R3 was independently associated with ipsilateral ischemic stroke after CAS (P=0.012).

CONCLUSIONS

High PRU (≥220) and low IR (≤14.5%) are related to ISR R3 following CAS, which may cause ipsilateral ischemic stroke.

Drug-Coated Balloons for Treatment of Internal Carotid Artery Restenosis After Stenting: A Single-Center Mid-Term Outcome Study

PURPOSE

Endovascular and surgical treatments of stenosis of the extracranial internal carotid artery (ICA) are common procedures, yet both introduce a risk of restenosis due to endothelial hyperplasia. Drug-coated balloons (DCBs) are designed to decrease neointimal hyperplasia, however rarely used in the neurovascular setting. This study retrospectively analyzes mid-term results of DCB-treated in-stent restenosis (ISR) of the ICA.

MATERIALS AND METHODS

The medical history, comorbidities, and periprocedural data of patients receiving DCB treatment for > 50% ISR of the ICA after carotid artery stenting were analyzed. Follow-up after DCB treatment was performed with Doppler ultrasound. Suspicious cases were checked with CT- or MR-angiography and-if there was agreement between the modalities-validated with digital subtraction angiography. Potential risk factors for restenosis and differences in outcomes after PTA with three types of DCB balloons were evaluated.

RESULTS

DCB treatment was performed in 109 cases, 0.9% of which involved in-hospital major stroke; no minor strokes occurred. A total of 17 patients (15.6%) had recurrent ISR after DCB treatment, after a mean time of 30.2 months (7-85 months). Tobacco use was significantly associated with a higher incidence of recurrent ISR.

CONCLUSION

DCB angioplasty for ISR is an effective treatment that may delay and decrease restenosis. Treating comorbidities and adopting lifestyle changes may additionally help prevent ISR.

Treatment of In-stent Restenosis of the Internal Carotid Artery Using Drug-eluting Balloons

PURPOSE

In-stent restenosis (ISR) following internal carotid artery (ICA) stenting is relatively common with an estimated incidence of 5%. Treatment options include repeat angioplasty with conventional or drug-eluting balloons (DEB), repeat stent angioplasty and surgical intervention. Application of DEB in ISR of the coronary and peripheral arteries is an established method; however, data on DEB treatment of ICA ISR are sparse. In this work, results from a retrospective cohort of 45 patients harboring 46 ICA ISR lesions treated with DEB angioplasty are presented.

METHODS

Clinical, procedural and imaging data from DEB angioplasty treatment of 46 high-grade ICA ISR lesions in 45 patients, performed between 2013 and 2021 were collected. A single type of DEB (Elutax, Aachen Resonance, Aachen, Germany) was used in all procedures. Imaging follow-up was performed by regular Doppler ultrasound (DUS), verified by computed tomography angiography (CTA) in cases suspicious for a recurrent ISR.

RESULTS

Technical success was 100%. Intraprocedural and postprocedural complications were not encountered. Clinical follow-up was obtained in all patients. Recurrent stroke in the affected territory was not encountered. A recurrent ISR following DEB treatment was confirmed by DUS and CTA in 4/46 (8.7%) of the lesions and were retreated with DEB. A third recurrent ISR occurred in a single case (2%) and following a second DEB retreatment there were no signs of a fourth recurrence after 36 months follow-up.

CONCLUSION

The use of DEB angioplasty is a safe and effective treatment of ICA ISR lesions, yielding significantly better results compared to other modalities. Randomized multicenter studies are warranted.

The Effects of Clopidogrel Duration On Carotid Artery In-stent Restenosis

OBJECTIVE

There is limited data supporting a specific duration for dual antiplatelet therapy in carotid artery stenting (CAS), and most clinical evidence is derived from studies involving coronary interventions. As a result, the appropriate duration of dual antiplatelet therapy after CAS has yet to be determined. We aimed to elucidate whether the duration of dual antiplatelet therapy played a role in the rate of carotid in-stent restenosis.

METHODS

A retrospective analysis of all patients who underwent CAS at our institution over a 20-year period (1996-2016) was performed (n=279). Patients who did not complete their follow-up duplex studies or were not discharged on clopidogrel were excluded from the study. Patients were separated into short-term (<6 weeks, n=159) and long-term (>6 weeks, n=112) clopidogrel users based on duration of therapy. We defined clinically significant in-stent restenosis as >50% restenosis (PSV = 224 cm/s) in symptomatic patients and >80% restenosis (PSV = 325 cm/s) in asymptomatic patients status-post prior CAS based on published velocity criteria. Rates of in-stent restenosis at 1-year, 2-year, and 5-year intervals were analyzed between the two groups using chi-squared analysis.

RESULTS

Demographic information was largely similar between the two groups; however, short-term clopidogrel users were more likely to have a history of atrial fibrillation (9.43% vs. 1.68%, p=0.008) and were less likely to have a history of CABG (16.35% vs. 29.41%, p=0.009), diabetes (33.34% vs. 49.58%, p=0.006) and CAD (50.31% vs. 63.03%, p=0.035). All patients were on long-term aspirin therapy. There was no significant difference between overall rates of in-stent restenosis between the short-term and long-term clopidogrel users (5.03% vs. 9.24%, p=0.168) within 5 years of the index procedure. Similar results were observed when these groups were evaluated at 1-year (5.61 % vs. 3%, p=0.321), 2-year (2.02% vs. 6.59%, p=0.072), and 5-year (2.24% vs. 3.57%, p=0.635) follow-up.

CONCLUSION

No statistically significant difference was observed in the rate of in-stent restenosis after CAS between short-term and long-term clopidogrel therapy. Patients in whom there is no other indication for longer duration clopidogrel therapy may be considered for shorter duration course of dual antiplatelet therapy following CAS.

Assessing the robustness of positive vascular surgery randomized controlled trials using their fragility index

OBJECTIVE

The fragility index (FI) measures the robustness of statistically significant findings in randomized controlled trials (RCTs) by quantifying the minimum number of event conversions required to reverse a dichotomous outcome's statistical significance. In vascular surgery, many clinical guidelines and critical decision-making points are informed by a handful of key RCTs, especially regarding open surgical versus endovascular treatment. The objective of this study is to evaluate the FI of RCTs with statistically significant primary outcomes that compared open vs endovascular surgery in vascular surgery.

METHODS

In this meta-epidemiological study and systematic review, MEDLINE, Embase, and CENTRAL were searched for RCTs comparing open versus endovascular treatments for abdominal aortic aneurysms, carotid artery stenosis, and peripheral arterial disease to December 2022. RCTs with statistically significant primary outcomes were included. Data screening and extraction were conducted in duplicate. The FI was calculated by adding an event to the group with the smaller number of events while subtracting a nonevent to the same group until Fisher's exact test produced a nonstatistically significant result. The primary outcome was the FI and proportion of outcomes where the loss to follow-up was greater than the FI. The secondary outcomes assessed the relationship of the FI to disease state, presence of commercial funding, and study design.

RESULTS

Overall, 5133 articles were captured in the initial search with 21 RCTs reporting 23 different primary outcomes being included in the final analysis. The median FI (first quartile, third quartile) was 3 (3, 20) with 16 outcomes (70%) reporting a loss to follow-up greater than its FI. Mann-Whitney U test revealed that commercially funded RCTs and composite outcomes had greater FIs (median, 20.0 [5.5, 24.5] vs median, 3.0 [2.0, 5.5], P = .035; median, 21 [8, 38] vs median, 3.0 [2.0, 8.5], P = .01, respectively). The FI did not vary between disease states (P = .285) or between index and follow-up trials (P = .147). There were significant correlations between the FI and P values (Pearson r = 0.90; 95% confidence interval, 0.77-0.96), and the number of events (r = 0.82; 95% confidence interval, 0.48-0.97).

CONCLUSIONS

A small number of event conversions (median, 3) are needed to alter the statistical significance of primary outcomes in vascular surgery RCTs evaluating open surgical and endovascular treatments. Most studies had loss to follow-up greater than its FI, which can call into question trial results, and commercially funded studies had a greater FI. The FI and these findings should be considered in future trial design in vascular surgery.

Role of carotid duplex in the assessment of carotid artery restenosis after endarterectomy or stenting

Introduction

Redo carotid endarterectomy (CEA) and carotid stenting (CAS) are often performed when there is evidence of post-procedural restenosis. The incidence of restenosis after carotid reconstruction is not negligible, ranging from 5 to 33%. The diagnosis of significant internal carotid artery (ICA) restenosis is usually based on duplex ultrasound (US) criteria, mostly on peak-systolic flow velocity (PSV). However, there have been no generally accepted duplex US criteria for carotid restenosis after CAS or CEA.

Methods

In this systematic review, the PubMed/ Medline and Scopus databases were screened to find trials that reported duplex US criteria for significant restenosis after CEA and/or CAS. Only those reports were analyzed in which the restenoses were also assessed by CT/MR or digital subtraction angiography as comparators for duplex US.

Results

Fourteen studies met the predetermined search criteria and were included in this review. In most studies, PSV thresholds for significant in-stent ICA restenosis after CAS were higher than those for significant stenosis in non-procedurally treated (native) ICA. Many fewer studies investigated the US criteria for ICA restenosis after CEA. Despite the heterogeneous data, there is a consensus to use higher flow velocity thresholds for assessment of stenosis in stented ICA than in native ICA; however, there have been insufficient data about the flow velocity criteria for significant restenosis after CEA. Although the flow velocity thresholds for restenosis after CAS and CEA seem to be different, the large studies used the same duplex criteria to define restenosis after the two procedures. Moreover, different studies used different flow velocity thresholds to define ICA restenosis, leading to variable restenosis rates.

Discussion

We conclude that (1) further examinations are warranted to determine appropriate duplex US criteria for restenosis after CAS and CEA, (2) single duplex US parameter cannot be used to reliably determine the degree of ICA restenosis, (3) inappropriate US criteria used in large studies may have led to false restenosis rates, and (4) studies are required to determine if there is a benefit from redo carotid artery procedure, such as redo-CEA or redo-CAS, starting with prospective risk stratification studies using current best practice non-invasive care alone.

Medical and Surgical Management of Symptomatic and Asymptomatic Carotid Artery Stenosis: A Comprehensive Literature Review

Carotid artery stenosis is a condition where the carotid artery is blocked by fatty cholesterol deposits called plaque, increasing the risk of stroke. Elderly individuals with high cardiovascular risk are more susceptible, along with smokers, those with high cholesterol, males, and older individuals. Young females may also be affected by fibromuscular dysplasia. Carotid stenosis significantly raises stroke risk, and the severity is closely linked to stroke incidence and other cardiovascular events. Early detection and treatment are essential to prevent complications. Treatment options include medical and surgical interventions, such as carotid endarterectomy (CEA) and carotid artery stenting (CAS). The choice between surgery and medical management varies depending on patient characteristics and risk factors. This review explores carotid artery stenosis pathophysiology, risk factors, the importance of early detection and treatment, and the surgical approaches of CEA and CAS, addressing their roles and controversies. Healthcare professionals must understand these aspects to provide optimal care to patients with this condition.

Effects of plaque characteristics and artery hemodynamics on the residual stenosis after carotid artery stenting

OBJECTIVE

Carotid artery stenting (CAS) has become an alternative strategy to carotid endarterectomy for carotid artery stenosis. Residual stenosis was an independent risk factor for restenosis, with the latter affecting the long-term outcomes of CAS. This multicenter study aimed to evaluate the echogenicity of plaques and hemodynamic alteration by color duplex ultrasound (CDU) examination and investigate their effects on the residual stenosis after CAS.

METHODS

From June 2018 to June 2020, 454 patients (386 males and 68 females) with a mean age of 67.2 ± 7.9 years, who underwent CAS from 11 advanced stroke centers in China were enrolled. One week before recanalization, CDU was used to evaluate the responsible plaques, including the morphology (regular or irregular), echogenicity of the plaques (iso-, hypo-, or hyperechoic) and calcification characteristics (without calcification, superficial calcification, inner calcification, and basal calcification). One week after CAS, the alteration of diameter and hemodynamic parameters were evaluated by CDU, and the occurrence and degree of residual stenosis were determined. In addition, magnetic resonance imaging was performed before and during the 30-day postprocedural period to identify new ischemic cerebral lesions.

RESULTS

The rate of composite complications, including cerebral hemorrhage, symptomatic new ischemic cerebral lesions, and death after CAS, was 1.54% (7/454 cases). The rate of residual stenosis after CAS was 16.3% (74/454 cases). After CAS, both the diameter and peak systolic velocity (PSV) improved in the preprocedural 50% to 69% and 70% to 99% stenosis groups (P < .05). Compared with the groups without residual stenosis and with <50% residual stenosis, the PSV of all three segments of stent in the 50% to 69% residual stenosis group were the highest, and the difference in the midsegment of stent PSV was the largest (P < .05). Logistic regression analysis showed that preprocedural severe (70% to 99%) stenosis (odds ratio [OR], 9.421; P = .032), hyperechoic plaques (OR, 3.060; P = .006) and plaques with basal calcification (OR, 1.885; P = .049) were independent risk factors for residual stenosis after CAS.

CONCLUSIONS

Patients with hyperechoic and calcified plaques of the carotid stenosis are at a high risk of residual stenosis after CAS. CDU is an optimal, simple and noninvasive imaging method to evaluate plaque echogenicity and hemodynamic alterations during the perioperative period of CAS, which can help surgeons to select the optimal strategies and prevent the occurrence of residual stenosis.

Diagnosis and management of acute conditions of the extracranial carotid artery

Symptomatic carotid stenosis and carotid dissection are acute conditions of extracranial cerebrovascular vessels determining transient ischemic attack or stroke. Medical, surgical, or endovascular management are different options to treat these pathologies. This narrative review focused on the management, from symptoms to treatment, of the acute conditions of extracranial cerebrovascular vessels, including post-carotid revascularization stroke. Symptomatic carotid stenosis (> 50% according to North American Symptomatic Carotid Endarterectomy Trial criteria) with transient ischemic attack or stroke benefits from carotid revascularization-primarily with carotid endarterectomy associated with medical therapy-within 2 weeks from symptom onset to reduce the risk of stroke recurrence. Different from acute extracranial carotid dissection, medical management with antiplatelet or anticoagulant therapy can prevent new neurologic ischemic events, considering stenting only in case of symptom recurrence. Stroke after carotid revascularization can be associated with the following etiologies: carotid manipulation, plaque fragmentation, or clamping ischemia. Medical or surgical management is therefore influenced by the cause and timing of the neurologic events after carotid revascularization. Acute conditions of the extracranial cerebrovascular vessels include a heterogeneous group of pathologies and correct management can reduce symptom recurrence substantially.

Associations between preprocedural carotid artery perivascular fat density and early in-stent restenosis after carotid artery stenting

Objectives

This study investigated the association between perivascular fat density (PFD) via preoperative computed tomographic angiography (CTA) and early in-stent restenosis (ISR) after carotid artery stenting (CAS).

Methods

We retrospectively evaluated 248 consecutive patients who had undergone initial CAS and received a preoperative cervical CTA examination between January 2019 and October 2020. The patients were categorized into two according to whether they sustained ISR during the 2 years postoperative follow-up period. Correlations between PFD and ISR were assessed, and multivariate regression for evaluating predictors of ISR was conducted. Receiver operating characteristic (ROC) curves were used to determine the cutoff value for the PFD.

Results

A total of 181 eligible patients (mean age 61.25 ± 10.35 years, 57 male) were enrolled. The ISR group had a higher proportion of closed-cell stents (48.8% versus 27.5%; p = 0.009) and a greater degree of residual stenosis (28[20,33] % versus 20[14.75,30] %; p < 0.001) than the non-ISR group. The ISR group had a higher mean HU value of PFD than the non-ISR group on the operated side (-42.26 ± 6.81 versus -59.66 ± 10.75; p < 0.001). The degree of residual stenosis (OR 1.146, 95%CI 1.071-1.226, p < 0.001) and PFD on the operated side (OR1.353, 95%CI 1.215-1.506, p < 0.001) were significantly associated with the ISR.

Conclusions

The occurrence of the early ISR after CAS is associated with a higher PFD on the operated side. The results indicate that PFD is a promising marker to predict the ISR after CAS.

Carotid Artery Stenosis: A Look Into the Diagnostic and Management Strategies, and Related Complications

Carotid stenosis (CS) is a buildup of atherosclerotic plaque within the artery leading to a wide range of symptoms, from mild symptoms, including blurred vision and confusion, to much more life-threatening presentations, including paralysis due to stroke. The presentation is insidious, with symptoms exhibiting predominantly at severe stenosis; hence the emphasis is placed on the importance of early diagnosis, treatment, and lifestyle modifications. CS is seen undergoing almost the same pathogenesis of any atherosclerotic plaque formation, from endothelial damage of the artery lumen to the formation of a fibrous cap with a foam cell, lipid-filled core. The findings of our review article were consistent with the recent literature, depicting that comorbid hypertension, diabetes, and chronic kidney disease (CKD), and lifestyle aspects, including smoking and diet, played the most salient role in plaque development. Among several imaging modalities, duplex ultrasound (DUS) imaging is the widely preferred method in clinical practice. Carotid endarterectomy (CEA) and carotid stenting are the primarily advocated procedures for symptomatic severe stenosis, with similar long-term outcomes. Although, earlier clinical trials showed promising results in mitigating the risk of stroke among asymptomatic severe CS with surgical intervention. However, recent advancements have shifted the focus to medical management alone due to comparable results among the asymptomatic population. Both surgical and medical regimens are beneficial in treating patients, but it is still an ongoing debate as to which is predominantly superior. The currently advancing trials and research will help elucidate definitive guidelines. However, the massive impact of lifestyle modifications advocates some degree of individualized multidisciplinary management strategies.

Association of red cell distribution width (RDW) and the RDW to platelet count ratio with cardiovascular disease among US adults: a cross-sectional study based on the National Health and Nutrition Examination Survey 1999-2020

OBJECTIVE

To investigate the association between red cell distribution width (RDW) and the RDW to platelet count ratio (RPR) and cardiovascular diseases (CVDs) and to further investigate whether the association involves population differences and dose-response relationships.

DESIGN

Cross-sectional population-based study.

SETTING

The National Health and Nutrition Examination Survey (1999-2020).

PARTICIPANTS

A total of 48 283 participants aged 20 years or older (CVD, n=4593; non-CVD, n=43 690) were included in this study.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the presence of CVD, while the secondary outcome was the presence of specific CVDs. Multivariable logistic regression analysis was performed to determine the relationship between RDW or the RPR and CVD. Subgroup analyses were performed to test the interactions between demographics variables and their associations with disease prevalence.

RESULTS

A logistic regression model was fully adjusted for potential confounders; the ORs with 95% CIs for CVD across the second to fourth quartiles were 1.03 (0.91 to 1.18), 1.19 (1.04 to 1.37) and 1.49 (1.29 to 1.72) for RDW (p for trend <0.0001) compared with the lowest quartile. The ORs with 95% CIs for CVD across the second to fourth quartiles were 1.04 (0.92 to 1.17), 1.22 (1.05 to 1.42) and 1.64 (1.43 to 1.87) for the RPR compared with the lowest quartile (p for trend <0.0001). The association of RDW with CVD prevalence was more pronounced in females and smokers (all p for interaction <0.05). The association of the RPR with CVD prevalence was more pronounced in the group younger than 60 years (p for interaction=0.022). The restricted cubic spline also suggested a linear association between RDW and CVD and a non-linear association between the RPR and CVD (p for non-linear <0.05).

CONCLUSION

There are statistical heterogeneities in the association between RWD, RPR distributions and the CVD prevalence, across sex, smoking status and age groups.

Commentary on a case report and literature review of acute carotid stent thrombosis

In this commentary on the article entitled “Acute carotid stent thrombosis: A case report and literature review”, the key points of the article are discussed. Acute carotid stent thrombosis (ACST) in the setting of carotid artery stenting (CAS) represents a rare but potentially catastrophic event. There is a wide range of treatment options available, including carotid endarterectomy, which is generally recommended for cases of refractory ACST. While there is no standard treatment regimen, dual antiplatelet therapy is typically recommended both before and after CAS to reduce risk of ACST.

Nanozyme-Enabled Treatment of Cardio- and Cerebrovascular Diseases

Cardio- and cerebrovascular diseases are two major vascular-related diseases that lead to death worldwide. Reactive oxygen species (ROS) play a vital role in the occurrence and exacerbation of diseases. Excessive ROS induce cellular context damage and lead to tissue dysfunction. Nanozymes, as emerging enzyme mimics, offer a unique perspective for therapy through multifunctional activities, achieving essential results in the treatment of ROS-related cardio- and cerebrovascular diseases by directly scavenging excess ROS or regulating pathologically related molecules. This review first introduces nanozyme-enabled therapeutic mechanisms at the cellular level. Then, the therapies for several typical cardio- and cerebrovascular diseases with nanozymes are discussed, mainly including cardiovascular diseases, ischemia reperfusion injury, and neurological disorders. Finally, the challenges and outlooks for the application of nanozymes are also presented. This review will provide some instructive perspectives on nanozymes and promote the development of enzyme-mimicking strategies in cardio- and cerebrovascular disease therapy.

In-stent restenosis and stented-territory infarction after carotid and vertebrobasilar artery stenting

BACKGROUND

Prognosis after vertebrobasilar stenting (VBS) may differ from that after carotid artery stenting (CAS). Here, we directly compared the incidence and predictors of in-stent restenosis and stented-territory infarction after VBS and compared them with those of CAS.

METHODS

We enrolled patients who underwent VBS or CAS. Clinical variables and procedure-related factors were obtained. During the 3 years of follow-up, in-stent restenosis and infarction were investigated in each group. In-stent restenosis was defined as reduction in the lumen diameter > 50% compared with that after stenting. Factors associated with the occurrence of in-stent restenosis and stented-territory infarction in VBS and CAS were compared.

RESULTS

Among 417 stent insertions (93 VBS and 324 CAS), there was no statistical difference in in-stent restenosis between VBS and CAS (12.9% vs. 6.8%, P = 0.092). However, stented-territory infarction was more frequently observed in VBS than in CAS (22.6% vs. 10.8%; P = 0.006), especially a month after stent insertion. HbA1c level, clopidogrel resistance, and multiple stents in VBS and young age in CAS increased the risk of in-stent restenosis. Diabetes (3.82 [1.24-11.7]) and multiple stents (22.4 [2.4-206.4]) were associated with stented-territory infarction in VBS. However, in-stent restenosis (odds ratio: 15.1, 95% confidence interval: 3.17-72.2) was associated with stented-territory infarction in CAS.

CONCLUSIONS

Stented-territory infarction occurred more frequently in VBS, especially after the periprocedural period. In-stent restenosis was associated with stented-territory infarction after CAS, but not in VBS. The mechanism of stented-territory infarction after VBS may be different from that after CAS.

Carotid artery bypass versus endarterectomy as an alternative treatment of carotid artery stenosis: A propensity score matching analysis

OBJECTIVES

The main focus of this study is to evaluate the reliability and durability of saphenous vein bypass grafting from common carotid artery to internal carotid artery (CBG) asan alternative treatment of patients with carotid artery stenosis.

METHODS

459 patients with carotid artery stenosis underwent initial carotid endarterectomy (CEA) or CBG between 2009 and 2019. Propensity score matching was performed, and outcomes of two different surgical procedures were analyzed.

RESULTS

Outcomes of the 142 pairs of matched patients were investigated. There were no significant differences in the preoperative characteristics of these matched groups. Overall mean time of follow-up was 91.364 ± 3.265 months. Mortality rate during the follow-up period was 18.309% (26 patients) in the CEA group, and 11.971% (17 patients) in the CBG group. Stroke was encountered in 8 patients in the CEA group (5.63%), and 3 patients in the CBG group (2.11%) during follow-up. Restenosis was detected in 11 patients in the CEA group (7.75%), and 3 patients in the CBG group (3.52%) during follow-up. There were no significant differences in the survival, stroke - free survival, and restenosis - free survival distributions of both groups.

CONCLUSIONS

In carotid artery stenosis, it is reasonable to consider CBG as an alternative surgical option when adequate disease-free inflow (common carotid artery) and outflow (distal internal carotid artery) segments are present.

Carotid Endarterectomy Versus Stenting for the Treatment of Patients With Carotid Artery Stenosis: An Updated Systematic Review and Meta-Analysis

Carotid endarterectomy (CEA) is a surgical procedure that treats the narrowed carotid arteries, which may be narrowed by atherosclerosis. Stenting is the insertion of a wire mesh scaffold into the narrowed portion of the carotid artery to keep it open by preventing blood from clotting. Using the study done over 10 years back as a point of reference, this study will seek an update on an assessment comparing CEA and stenting in studies carried out between 2015 and to date. The PICOS (population, intervention, control, outcome, and study designs) criteria were used to construct a set of inclusion and exclusion guidelines. This meta-analysis and systematic review used two forms of investigative analysis; both quantitative and qualitative assessments. From the studies, stroke (95% CI: 0.51-0.71, P < 0.001), myocardial infarction (95% CI: 1.49-3.42, P = 0.001), and stroke or death analysis (95% CI: 0.53-0.77, P < 0.001) were noted to be significant. From the analysis, CEA was observed as having better treatment results in terms of stroke events and stroke or death incidences when compared to stenting. Carotid stenting was observed as having lower cases of myocardial infarctions when compared to endarterectomy.

Fully implantable batteryless soft platforms with printed nanomaterial-based arterial stiffness sensors for wireless continuous monitoring of restenosis in real time

Atherosclerosis is a common cause of coronary artery disease and a significant factor in broader cardiovascular diseases, the leading cause of death. While implantation of a stent is a prevalent treatment of coronary artery disease, a frequent complication is restenosis, where the stented artery narrows and stiffens. Although early detection of restenosis can be achieved by continuous monitoring, no available device offers such capability without surgeries. Here, we report a fully implantable soft electronic system without batteries and circuits, which still enables continuous wireless monitoring of restenosis in real-time with a set of nanomembrane strain sensors in an electronic stent. The low-profile system requires minimal invasive implantation to deploy the sensors into a blood vessel through catheterization. The entirely printed, nanomaterial-based set of soft membrane strain sensors utilizes a sliding mechanism to offer enhanced sensitivity and detection of low strain while unobtrusively integrating with an inductive stent for passive wireless sensing. The performance of the soft sensor platform is demonstrated by wireless monitoring of restenosis in an artery model and an ex-vivo study in a coronary artery of ovine hearts. The capacitive sensor-based artery implantation system offers unique advantages in wireless, real-time monitoring of stent treatments and arterial health for cardiovascular disease.

Ultrasound diagnosis of carotid artery stenosis and occlusion

Carotid artery ultrasonography is capable of diagnosing or inferring the presence or absence of stenosis or occlusion of the internal carotid artery (ICA) and vertebral artery (VA), as well as the not directly observable distal ICA, middle cerebral artery (MCA), and basilar artery (BA). Stenosis at the origin of the ICA is mainly evaluated using the parameter peak systolic velocity (PSV), with values of ≥ 200-230 cm/s indicating severe stenosis. Recently, the acceleration time ratio has been reported for diagnosis of ICA origin stenosis. An indicator called the end-diastolic (ED) ratio can be used for diagnosing occlusion of the distal ICA or the M1 segment of the MCA. The PSV of stenosis can be used to diagnose stenosis at the beginning of the VA or V1, and mean flow velocity, mean ratio, and diameter ratio can be used to diagnose distal VA occlusion. Furthermore, the usefulness of the VA pulsatility index and resistance index has been suggested for diagnosing stenosis or occlusion of the BA. This review outlines diagnostic sonography criteria for stenosis and occlusion of extracranial and intracranial arteries.

Short- and Mid-Term Outcomes of Stenting in Patients with Isolated Distal Internal Carotid Artery Stenosis or Post-Surgical Restenosis

The aim was to evaluate the outcome of stenting in patients with isolated distal internal carotid artery (ICA) stenosis or post-surgical restenosis, as no data are currently available in the literature. Sixty-six patients (men, N = 53; median age: 66 [IQR, 61–73] years) with ≥50% distal ICA (re)stenosis were included in this single-center retrospective study. The narrowest part of the (re)stenosis was at least 20 mm from the bifurcation in all patients. Patients were divided into two etiological groups, atherosclerotic (AS, N = 40) and post-surgical restenotic (RES, N = 26). Postprocedural neurological events were observed in two patients (5%) in the AS group and in two patients (7.7%) in the RES group. The median follow-up time was 40 (IQR, 18–86) months. Three patients (7.5%) in the AS group had an in-stent restenosis (ISR) ≥ 50%, but none in the RES group. Three patients (7.5%) in the AS group and seven patients (26.9%) in the RES group died. None of the deaths in the RES group were directly related to stenting itself. The early neurological complication rate of stenting due to distal ICA (re)stenoses is acceptable. However, the mid-term mortality rate of stenting for distal ICA post-surgical restenoses is high, indicating the vulnerability of this subgroup.

Prediction of risk factors for intraoperative hypotension during general anesthesia undergoing carotid endarterectomy

Objective

Carotid endarterectomy (CEA) has been considered as “gold standard” treatment for patients with significant carotid stenosis Intra-operative hypotension was a risk factor for post-operative complications in patients undergoing CEA. This study aimed to investigate the predictors for intra-operative hypotension during CEA.

Methods

This retrospective study included consecutive patients underwent CEA from June 1, 2020 to May 31, 2021 in the neurosurgery department of Xuanwu Hospital, Capital Medical University. The intraoperative hypotension was defined as blood pressure (BP) of 20% below standard value for longer than 5 min. Univariable and multivariable analyses were performed to identify the prediction of risk factors for intraoperative hypotension.

Results

Overall, 367 patients were included, and 143 (39.0%) patients had hypotension during CEA procedure. Univariate analysis indicated Grade 3 hypertension (P = 0.002), peripheral artery disease (P = 0.006) and shunting (P = 0.049) were associated with occurrence of intraoperative hypotension during CEA procedure. On multivariable analysis, Grade 3 hypertension (P = 0.005), peripheral artery disease (P = 0.009), and shunting (P = 0.034) were all found to be independent predicting factors of hypotension during the CEA process.

Conclusion

Intraoperative hypotension is a dynamic phenomenon may be affected by patients with grade 3 hypertension, peripheral artery disease and intra-operative shunting. It is necessary to pay special attention to these patients, both intraoperatively and postoperatively, to improve the final clinical outcome.

Selection criteria for patch angioplasty material in carotid endarterectomy

Background:

Carotid endarterectomy (CEA) with patch angioplasty has been favored due to its lower reoccurrence of restenosis compared to primary CEA. There are multiple types of patch angioplasty material available. However, selection of patch material is based on uncertain criteria. The aim of this study is to determine the ideal criteria for selecting the best patch material for CEA.

Methods:

We conducted a comprehensive literature search for studies that describe the ideal criteria for selecting patch material for CEA. We compiled all of the criteria mentioned into one table and selecting the criteria which were most frequently mentioned with a simple scoring system.

Results:

A total of 65 studies out of 784 studies were assessed for its full-text eligibility. Thus, we found 23 studies that were eligible for analysis. There are 22 ideal criteria that were mentioned in the analyzed studies. We grouped these criteria into physical characteristics, safety, contribution to hemodynamic, contribution in tissue healing, economic aspect, and ability to prevent postsurgical complication. We proposed 10 ideal criteria for guiding vascular surgeon in selecting the best patch angioplasty material.

Conclusion:

To this day, no material has been discovered which meets all ten criteria. This study’s proposed ideal criteria serve as the foundation for the creation of the best patch angioplasty material.

Clinical Outcomes of Second- versus First-Generation Carotid Stents: A Systematic Review and Meta-Analysis

Background: Single-cohort studies suggest that second-generation stents (SGS; “mesh stents”) may improve carotid artery stenting (CAS) outcomes by limiting peri- and postprocedural cerebral embolism. SGS differ in the stent frame construction, mesh material, and design, as well as in mesh-to-frame position (inside/outside). Objectives: To compare clinical outcomes of SGS in relation to first-generation stents (FGSs; single-layer) in CAS. Methods: We performed a systematic review and meta-analysis of clinical studies with FGSs and SGS (PRISMA methodology, 3302 records). Endpoints were 30-day death, stroke, myocardial infarction (DSM), and 12-month ipsilateral stroke (IS) and restenosis (ISR). A random-effect model was applied. Results: Data of 68,422 patients from 112 eligible studies (68.2% men, 44.9% symptomatic) were meta-analyzed. Thirty-day DSM was 1.30% vs. 4.11% (p < 0.01, data for SGS vs. FGS). Among SGS, both Casper/Roadsaver and CGuard reduced 30-day DSM (by 2.78 and 3.03 absolute percent, p = 0.02 and p < 0.001), whereas the Gore stent was neutral. SGSs significantly improved outcomes compared with closed-cell FGS (30-day stroke 0.6% vs. 2.32%, p = 0.014; DSM 1.3% vs. 3.15%, p < 0.01). At 12 months, in relation to FGS, Casper/Roadsaver reduced IS (−3.25%, p < 0.05) but increased ISR (+3.19%, p = 0.04), CGuard showed a reduction in both IS and ISR (−3.13%, −3.63%; p = 0.01, p < 0.01), whereas the Gore stent was neutral. Conclusions: Pooled SGS use was associated with improved short- and long-term clinical results of CAS. Individual SGS types, however, differed significantly in their outcomes, indicating a lack of a “mesh stent” class effect. Findings from this meta-analysis may provide clinically relevant information in anticipation of large-scale randomized trials.

Guideline on carotid surgery for stroke prevention: updates from the Italian Society of Vascular and Endovascular Surgery. A trend towards personalized medicine

BACKGROUND

This guideline (GL) on carotid surgery as updating of "Stroke: Italian guidelines for Prevention and Treatment" of the ISO-SPREAD Italian Stroke Organization-Group, has recently been published in the National Guideline System and shared with the Italian Society of Vascular and Endovascular Surgery (SICVE) and other Scientific Societies and Patient's Association.

METHODS

GRADE-SIGN version, AGREE quality of reporting checklist. Clinical questions formulated according to the PICO model. Recommendations developed based on clinical questions by a multidisciplinary experts' panel and patients' representatives. Systematic reviews performed for each PICO question. Considered judgements filled by assessing the evidence level, direction, and strength of the recommendations.

RESULTS

The panel provided indications and recommendations for appropriate, comprehensive, and individualized management of patients with carotid stenosis. Diagnostic and therapeutic processes of the best medical therapy, carotid endarterectomy (CEA), carotid stenting (CAS) according to the evidences and the judged opinions were included. Symptomatic carotid stenosis in elective and emergency, asymptomatic carotid stenosis, association with ischemic heart disease, preoperative diagnostics, types of anesthesia, monitoring in case of CEA, CEA techniques, comparison between CEA and CAS, post-surgical carotid restenosis, and medical therapy are the main topics, even with analysis of uncertainty areas for risk-benefit assessments in the individual patient (personalized medicine [PM]).

CONCLUSIONS

This GL updates on the main recommendations for the most appropriate diagnostic and medical-surgical management of patients with atherosclerotic carotid artery stenosis to prevent ischemic stroke. This GL also provides useful elements for the application of PM in good clinical practice.

Comparison of Restenosis Risk in Single-Layer versus Dual-Layer Carotid Stents: A Duplex Ultrasound Evaluation

PURPOSE

The aim of this study was to report intermediate-term results of duplex ultrasound follow-up of carotid artery stenting performed with the dual-layer stent as compared to concurrent patients treated with other commercially available single-layer carotid stents.

MATERIALS AND METHODS

A single centre, retrospective, nonrandomized study including 162 non-consecutive patients with 199 implanted carotid stents treated over a 7-year period was conducted. Patients with at least one ultrasound examination after treatment were included. Procedural and follow-up data for patients treated with the dual-layer stent implantation (83 stents) vs first-generation carotid stents implantations (116 stents) were compared.

RESULTS

The median follow-up time was 24.0 months (IQR 10-32 months) for dual-layer stents and 27.5 months (IQR 10.3-59 months) for single-layer stents. The rate of severe restenosis was significantly higher in the dual-layer stent group than in the single-layer group (13.3% [11/83] vs 3.4% [4/116], p = 0.01). Seven reinterventions were performed in 5 patients with dual-layer stents. The rate of reintervention was significantly higher compared to no reinterventions in single-layer stents (6% [5/83] vs 0% [0/116], p = 0.012). Patients with restenosis had significantly higher presence of dyslipidaemia (100% [12/12] vs 63.3% [95/150], p = 0.009).

CONCLUSIONS

In this real-world cohort of patients undergoing carotid artery stenting, the patients treated with low-profile dual-layer micromesh stent showed higher rates of restenosis and reinterventions compared to first-generation single-layer stents.

Prediction of Long-Term Restenosis After Carotid Endarterectomy Using Quantitative Magnetic Resonance Angiography

Background

To detect restenosis after carotid endarterectomy (CEA), long-term monitoring is required. However, non-selective follow-up is controversial and can be limited by costs and logistical considerations.

Objective

To examine the value of immediate perioperative vessel flow measurements after CEA using quantitative magnetic resonance angiography (QMRA) to detect patients at risk of long-term restenosis.

Methods

A prospective cohort study with long-term sonographic follow-up after CEA for symptomatic internal carotid artery stenosis (ICAs) > 50%. In all patients, vessel flow has been assessed both pre- and postoperatively using QMRA within ±3 days of surgery. Data on QMRA assessment were analyzed to identify patients at risk of restenosis for up to 10 years.

Results

Restenosis was recorded in 4 of 24 patients (17%) at a median follow-up of 6.8 ± 2.6 years. None of them experienced an ischemic event. Perioperative flow differences were significantly greater in patients without long-term restenosis, both for the ipsilateral ICA (p < 0.001) and MCA (p = 0.03), compared to those with restenosis (p = 0.22 and p = 0.3, respectively). The ICA mean flow ratio (p = 0.05) tended to be more effective than the MCA ratio in predicting restenosis over the long term (p = 0.35).

Conclusion

Our preliminary findings suggest that QMRA-based mean flow increases after CEA may be predictive of restenosis over the long term. Perioperative QMRA assessment could become an operator-independent screening tool to identify a subgroup of patients at risk for restenosis, in whom long-term monitoring is advised.

Synthesis of Prussian Blue Nanoparticles and Their Antibacterial, Antiinflammation and Antitumor Applications

In recent years, Prussian blue nanoparticles (PBNPs), also named Prussian blue nano-enzymes, have been shown to demonstrate excellent multi-enzyme simulation activity and anti-inflammatory properties, and can be used as reactive oxygen scavengers. Their good biocompatibility and biodegradability mean that they are ideal candidates for in vivo use. PBNPs are highly efficient electron transporters with oxidation and reduction activities. PBNPs also show considerable promise as nano-drug carriers and biological detection sensors owing to their huge specific surface area, good chemical characteristics, and changeable qualities, which might considerably increase the therapeutic impact. More crucially, PBNPs, as therapeutic and diagnostic agents, have made significant advances in biological nanomedicine. This review begins with a brief description of the synthesis methods of PBNPs, then focuses on the applications of PBNPs in tissue regeneration and inflammation according to the different properties of PBNPs. This article will provide a timely reference for further study of PBNPs as therapeutic agents.

Carotid endarterectomy with stent removal for recurring in-stent restenosis: A case report and literature review

Background:

Percutaneous transcatheter angioplasty (PTA) and carotid artery stenting (CAS) are often performed repeatedly for in-stent restenosis (ISR) after CAS. Only a few reports describe the treatment for repeated ISR. Furthermore, only a few reports describe carotid endarterectomy (CEA) after CAS; thus, the evidence for this procedure is insufficient.

Case Description:

Herein, we describe a case in which CEA with stent removal was performed in a patient with repeated ISR after CAS. A 78-year-old man presented with dysarthria and slight left limb weakness. CAS was performed for the right internal carotid artery stenosis. ISR occurred again and PTA and stenting were performed. After the second CAS, ISR occurred again. CEA with stent removal was performed. After the CEA with stent removal, the patient experienced no restenosis or other complications.

Conclusion:

CEA with stent removal can be a good option for treating repeated ISR after CAS.

Carotid Restenosis Rate After Stenting for Primary Lesions Versus Restenosis After Endarterectomy With Creation of Risk Index

PURPOSE

Carotid artery stenting (CAS) is an option for carotid restenosis (CR) treatment with favorable outcomes. However, CAS has also emerged as an alternative to carotid endarterectomy (CEA) for the management of patients with primary carotid stenosis. This study aimed to report CR rates after CAS was performed in patients with primary lesions versus restenosis after CEA, to identify predictors of CR, and to report both neurological and overall outcomes.

MATERIALS AND METHODS

From January 2000 to September 2018, a total of 782 patients were divided into 2 groups: The CAS (prim) group consisted of 440 patients in whom CAS was performed for primary lesions, and the CAS (res) group consisted of 342 patients with CAS due to restenosis after CEA. Indications for CAS were symptomatic stenosis/restenosis >70% and asymptomatic stenosis/restenosis >85%. A color duplex scan (CDS) of carotid arteries was performed 6 months after CAS, after 1 year, and annually afterward. Follow-up ranged from 12 to 88 months, with a mean follow-up of 34.6±18.0 months.

RESULTS

There were no differences in terms of CR rate between the patients in the CAS (prim) and CAS (res) groups (8.7% vs 7.2%, χ²=0.691, p=0.406). The overall CR rate was 7.9%, whereas significant CR (>70%) rate needing re-intervention was 5.6%, but there was no difference between patients in the CAS (prim) and CAS (res) groups (6.4% vs 4.7%, p=0.351). Six independent predictors for CR were smoking, associated previous myocardial infarction and angina pectoris, plaque morphology, spasm after CAS, the use of FilterWire or Spider Fx cerebral protection devices, and time after stenting. A carotid restenosis risk index (CRRI) was created based on these predictors and ranged from -7 (minimal risk) to +10 (maximum risk); patients with a score >-4 were at increased risk for CR. There were no differences in terms of neurological and overall morbidity and mortality between the 2 groups.

CONCLUSIONS

There was no difference in CR rate after CAS between the patients with primary stenosis and restenosis after CEA. A CRRI score >-4 is a criterion for identifying high-risk patients for post-CAS CR that should be tested in future randomized trials.

Characterization of Restenosis following Carotid Endarterectomy Using Contrast-Enhanced Vessel Wall MR Imaging

BACKGROUND AND PURPOSE

Restenosis is an important determinant of the long-term efficacy of carotid endarterectomy. Our aim was to assess the role of high-resolution vessel wall MR imaging for characterizing restenosis after carotid endarterectomy.

MATERIALS AND METHODS

Patients who underwent vessel wall MR imaging after carotid endarterectomy were included in this study. Restenotic lesions were classified as myointimal hyperplasia or recurrent atherosclerotic plaques based on MR imaging features of lesion compositions. Imaging characteristics of myointimal hyperplasia were compared with those of normal post-carotid endarterectomy and recurrent plaque groups. Recurrent plaques were matched with primary plaques by categories of stenosis, and differences in plaque features were compared between the 2 groups.

RESULTS

Twenty-two recurrent lesions from 18 patients (14 unilateral and 4 bilateral) were classified as myointimal hyperplasia or recurrent plaque. Myointimal hyperplasia showed no difference in enhancement compared with normal post-carotid endarterectomy vessels (5 unilateral) but showed stronger enhancement than recurrent plaques (80.10% [SD, 42.42%] versus 56.74% [SD, 46.54%], P = .042). A multivariate logistic regression model of plaque-feature detection in recurrent plaques compared with primary plaques adjusted for maximum wall thickness revealed that recurrent plaques were longer (OR, 4.27; 95% CI, 1.32-13.85; P = .015) and more likely to involve a flow divider and side walls (OR, 6.96; 95% CI, 1.37-35.28; P = .019). Recurrent plaques had a higher prevalence of intraplaque hemorrhage (61.5% versus 30.8%, P = .048) by a χ² test, but compositional differences were not significant in the multivariate model.

CONCLUSIONS

Vessel wall MR imaging can distinguish recurrent plaques from myointimal hyperplasia and reveal features that may differ between primary and recurrent plaques, highlighting its value for evaluating patients with carotid restenosis.

Diabetes Mellitus and Clinical Outcomes in Carotid Artery Revascularization Using Second-Generation, MicroNet-Covered Stents: Analysis from the PARADIGM Study

INTRODUCTION

Carotid artery stenting (CAS) using conventional (single-layer) stents is associated with worse clinical outcomes in diabetes mellitus (DM) vs. non-DM patients: an effect driven largely by lesion-related adverse events. CAS outcomes with MicroNet-covered stents (MCS) in diabetic patients have not been evaluated.

AIM

To compare short- and long-term clinical outcomes and restenosis rate in DM vs. non-DM patients with carotid stenosis treated using MCS.

MATERIALS AND METHODS

In a prospective study in all-comer symptomatic and increased-stroke-risk asymptomatic carotid stenosis, 101 consecutive patients (age 51-86 years, 41% diabetics) underwent 106 MCS-CAS. Clinical outcomes and duplex ultrasound velocities were assessed periprocedurally and at 30 days/12 months.

RESULTS

Baseline characteristics of DM vs. non-DM patients were similar except for a higher prevalence of recent cerebral symptoms in DM. Type 1 and type 1+2 plaques were more prevalent in DM patients (26.7% vs. 9.8%, p = 0.02; 62.2% vs. 37.7%, p = 0.01). Proximal embolic protection was more prevalent in DM (60% vs. 36%; p = 0.015). 30-day clinical complications were limited to a single periprocedural minor stroke in DM (2.4% vs. 0%, p = 0.22). 12-month in-stent velocities and clinical outcomes were not different (death rate 4.8% vs. 3.3%; p = 0.69; no new strokes). Restenosis rate was not different (0% vs. 1.7%, p = 0.22).

CONCLUSIONS

MCS may offset the adverse impact of DM on periprocedural, 30-day, and 12-month clinical complications of CAS and minimize the risk of in-stent restenosis. In this increased-stroke-risk cohort, adverse event rate was low both in DM and non-DM. Further larger-scale clinical datasets including extended follow-ups are warranted.

Symptomatic atherosclerotic plaque progression in a first-generation carotid stent: management and 5-year clinical and imaging outcome-a case report

Background

Restenosis in first-generation (single-layer) carotid stents (FGS) is believed to represent an exaggerated healing response of (neo)intimal hyperplasia (NIH) formation. Rather than NIH, we describe symptomatic in-FGS unstable plaque (neo)atherosclerosis mandating re-revascularization. To halt continued plaque evolution, we propose a novel treatment strategy involving a microNet-covered stent (MCS, second-generation carotid stent) to sequestrate the plaque from the vessel lumen. A durable long-term result is documented using multi-modal imaging.

Case summary

With a seemingly optimal result of FGS (Precise) symptomatic carotid lesion revascularization followed by optimal medical therapy, a late (≥3 years) progressive in-stent restenosis (ISR) arose. At Year 11, crescendo ipsilateral transient ischaemic attacks occurred. Angiography showed an ulcerated tight lesion throughout stent length. Intravascular ultrasound (IVUS) virtual histology imaging revealed thin-cap fibroatheroma. Reintervention was performed under distal protection. Undersized balloon predilatation to insert a stent caused symptomatic no-flow, and aspiration catheter was used to reduce the filter load. A MCS (CGuard) was implanted and post-dilated to ensure full lumen gain; IVUS confirmed complete plaque sequestration. The optimal anatomic result remained unchanged throughout 5 years (ultrasound and computed tomography verification); this was accompanied by clinical cure.

Discussion

This is the first demonstration of in-FGS (neo)atherosclerosis resolution using an MCS to sequestrate and insulate the atherosclerotic plaque. We show that ISR may be underlined by atherosclerotic plaque progression via the FGS single-layer stent struts that may show vulnerable plaque phenotype and may be associated with cerebral ischaemia. The anatomically and clinically effective exclusion of the atherosclerotic plaque by an MCS enabled lasting, optimal endovascular reconstruction and clinical cure.

ANALYSIS OF SPIN IN VASCULAR SURGERY RANDOMIZED CONTROLLED TRIALS WITH NONSIGNIFICANT OUTCOMES

OBJECTIVES

Spin is the manipulation of language that distorts the interpretation of objective findings. The purpose of this study is to describe the characteristics of spin found in statistically nonsignificant randomized controlled trials (RCT) comparing carotid endarterectomy (CEA) to carotid artery stenting (CAS) for carotid stenosis (CS), and endovascular repair (EVAR) to open repair (OR) for abdominal aortic aneurysms (AAA).

METHODS

A search of MEDLINE, EMBASE, and the Cochrane Controlled Register of Trials was performed in June 2020 for studies published describing AAA or CS. All phase three RCTs with nonsignificant primary outcomes comparing OR to EVAR or CEA to CAS were included. Studies were appraised for the characteristics and severity of spin using a validated tool. Binary logistic regression was performed to assess the association of spin grade to (1) funding source (commercial vs non-commercial) and (2) the publishing journal's impact factor.

RESULTS

Thirty-one of 355 articles captured were included for analysis. Spin was identified in nine abstracts (9/18) and 13 main texts (13/18) of AAA articles and seven abstracts (7/13) and ten main texts (10/13) of CS articles. For both AAA and CS articles, spin was most commonly found in the manuscript discussion section, with the most commonly employed strategy being the interpretation of statistically nonsignificant primary results to show treatment equivalence or rule out adverse treatment effects. Increasing journal impact factor was associated with a statistically significant lower likelihood of spin in the study title or abstract conclusion (βOR = 0.96, 95% CI: 0.94 - 0.98, p < 0.01) while no significant association could be found with funding source (βOR = 1.33, 95% CI: 0.30-5.92, p = 0.71).

CONCLUSIONS

A large proportion of statistically nonsignificant RCTs contain interpretations that are inconsistent with their results. These findings should prompt authors and readers to appraise study findings independently and to limit the use of spin in study interpretations.

Ultrasound Assessment of Plaque Characteristics to Predict Re-occlusion after Surgical Treatment of Internal Carotid Artery Occlusion

The purpose of this study was to explore the relationship between plaque characteristics and re-occlusion after surgical treatment of internal carotid artery occlusion (ICAO). From January 2015 to January 2021, 177 patients with ICAO underwent surgery. Eighty-five cases were included in the study, and in 13 of them, re-occlusion occurred within 6 mo after surgery treatment (13/85, 15.85%). The calcification at the base of the plaque was longer in the re-occlusion group than in the non-occlusion group (10.70 ± 4.22 mm vs. 7.15 ± 1.41 mm, p = 0.001). Multivariate regression analysis revealed that the length of calcification at the base of the plaque was an independent risk factor for postoperative re-occlusion (odds ratio [OR]: 1.414, 95% confidence interval [CI]: 1.078-1.855, p = 0.012). The cutoff value for the length of calcification at the base of the plaque predicting re-occlusion after ICAO was 8.5 mm (95% CI: 0.700-0.962, p = 0.001). The area under the receiver operating characteristic curve was 0.831. Sensitivity and specificity were 70% and 80.9%, respectively. These results indicate that pre-operative ultrasound examination of the length of calcification at the base of the plaque could predict re-occlusion after surgical treatment of ICAO.

Carotid Artery Stenting: Applications and Technical Considerations

PURPOSE OF THE REVIEW

To examine current understanding of diverse etiologies of extracranial carotid disease, including clinical and imaging manifestations as well as treatment approaches.

RECENT FINDINGS

Increasing availability of advanced cerebrovascular imaging modalities continues to elucidate atherosclerotic and nonatherosclerotic carotid steno-occlusive disease as a common culprit of cerebral ischemia. Individualized treatment strategies targeting each etiologic subset would optimize preventive measures and minimize recurrence of cerebral ischemia.

SUMMARY

Ischemic stroke is a prominent cause of mortality and long-term disability worldwide. The magnified effect of carotid disease warrants constant and close inspection.

MEAN PLATELET VOLUME PREDICTS RESTENOSIS AFTER CAROTID ENDARTERECTOMY

BACKGROUND

Carotid restenosis following carotid endarterectomy (CEA) has a cumulative risk at 5-years up to 32%, which may impact the well-being of patients following CEA. Haematological parameters in the standard complete blood cell count (CBC) are emerging as potential biomarkers, but their application in CEA is scarce. The primary aim of this study was to investigate haematological markers for restenosis following CEA. The secondary aim was to characterize clinical risk factors for restenosis.

METHODS

From January 2012 to January 2019, 151 patients who underwent CEA under regional anaesthesia due to carotid stenosis were selected from a prospectively maintained cohort database. Patients were included if a preoperative CBC was available in the two weeks preceding CEA. Multivariable analysis was performed alongside propensity score matching (PSM) analysis, using the preoperative CEA parameters, to reduce confounding factors between categories.

RESULTS

The study group comprised 28 patients who developed carotid restenosis. The remaining 123 patients without restenosis composed the control group. Mean age of the patients did not differ significantly between groups (70.25±8.05 vs. 70.32 ± 9.61 YO, p=0.973), neither did gender (male gender 89.3% vs. 78.9%, p=0.206). Regarding haematological parameters, only MPV remained statistically significant within multivariable analysis (1.855, aOR [1.174-2.931], p=0.008), a result supported by PSM analysis (2.072, aOR [1.036-4.147], p=0.042).

CONCLUSION

MPV was able to predict restenosis two years after CEA. Thus, MPV can be incorporated into score calculations to identify patients at greater risk of restenosis, who could benefit from specific monitoring during follow-up. While results are promising, more research is necessary to corroborate them.

CaRotid Artery Filtering Technique (CRAFT): A Technique for Carotid Artery Stenting with Intrinsic Embolic Protection

Purpose

Carotid artery stenting (CAS) is an established treatment for symptomatic carotid artery stenosis as an alternative to carotid endarterectomy. A variety of techniques and devices have been devised to minimise periprocedural stroke risk using either proximal or distal embolic protection. This study presents a method of embolic protection during CAS–the CaRotid Artery Filtering Technique (CRAFT).

Materials and Methods

The CRAFT technique employs aspects of both proximal and distal embolic protection. The CASPER RX stent (MicroVention, Tustin, CA, USA), which is a double-layered, closed-cell, micromesh nitinol stent, is deployed across the carotid artery stenosis with the assistance of a FlowGate balloon guide catheter (Stryker Neurovascular, Fremont, CA, USA). The partially deployed stent acts as a distal filter while the balloon guide is deflated midway during stent deployment to prevent distal plaque embolisation, followed by completion of stent deployment and angioplasty.

Results

A total of 94 patients underwent CAS using the CRAFT technique between June 2016 and March 2021. Successful stent deployment was achieved in all patients. Preliminary results demonstrated acute stent occlusion in 6 patients (6.4%) and distal embolic stroke in 5 patients (5.3%). The median procedural fluoroscopy time was 34 minutes with an interquartile range of 22 to 55 minutes.

Conclusion

The CRAFT technique of CAS presented by this study can be applied in the treatment of symptomatic carotid artery stenosis in both emergency and elective procedure settings with a high technical success and low distal embolic stroke risk.

4D Reconstruction and Identification of Carotid Artery Stenosis Utilizing a Novel Pulsatile Ultrasound Phantom

As a major application focus of vascular ultrasonography, the carotid artery has long been the subject of phantom design and procedure focus. It is therefore important to devise procedures that are minimally invasive and informative, initially using a physiologically accurate anthropomorphic phantom to validate the methodology. In this article, a novel phantom design protocol is presented that enables the efficient production of a pulsatile ultrasound phantom consisting of soft and vascular tissue mimics, as well as a blood surrogate fluid. These components when combined give the phantom high acoustic compatibility and lifelike mechanical properties. The phantom was developed using "at-home" purchasable components and 3D printing technology. The phantom was subsequently used to develop a 4D reconstruction algorithm of the pulsing vessel in MATLAB. In pattern with recent developments in medical imaging, the 4D reconstruction enables clinicians to view vessel wall motion in a 3D space without the need for manual intervention. The reconstruction algorithm also produces measured inner luminal areas and vessel wall thickness, providing further information relating to structural properties and stenosis, as well as elastic properties such as arterial stiffness, which could provide helpful markers for disease diagnosis. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Constructing a pulsatile ultrasound phantom model Support Protocol: Creating a vascular mimic mold Basic Protocol 2: Creating a 4D reconstruction from ultrasound frames.

Treatment of the Carotid In-stent Restenosis: A Systematic Review

Background and Purpose: In-stent restenosis (ISR) after carotid artery stent (CAS) is not uncommon. We aimed to evaluate therapeutic options for ISR after CAS. Methods: We searched PubMed and EMBASE until November 2, 2020 for studies including the treatment for ISR after CAS. Results: In total, 35 studies, covering 1,374 procedures in 1,359 patients, were included in this review. Most cases (66.3%) were treated with repeat CAS (rCAS), followed by percutaneous transluminal angioplasty (PTA) (17.5%), carotid endarterectomy (CEA) (14.3%), carotid artery bypass (1.5%), and external beam radiotherapy (0.4%). The rates of stroke & TIA within the postoperative period were similar in three groups (PTA 1.1%, rCAS 1.1%, CEA 1.5%). CEA (2.5%) was associated with a slightly higher rate of postoperative death than rCAS (0.7%, P = 0.046). Furthermore, the rate of long-term stroke & TIA in PTA was 5.7%, significantly higher than rCAS (1.8%, P = 0.036). PTA (27.8%) was also associated with a significantly higher recurrent restenosis rate than rCAS (8.2%, P = 0.002) and CEA (1.6%, P < 0.001). The long-term stroke & TIA and recurrent restenosis rates showed no significant difference between rCAS and CEA. Conclusions: rCAS is the most common treatment for ISR, with low postoperative risk and low long-term risk. CEA is an important alternative for rCAS. PTA may be less recommended due to the relatively high long-term risks of stroke & TIA and recurrent restenosis.

Long Term Restenosis Rate After Carotid Endarterectomy: Comparison of Three Surgical Techniques and Intra-Operative Shunt Use

OBJECTIVE

Closure of the artery during carotid endarterectomy (CEA) can be done with or without a patch, or performed with the eversion technique, while the use of intra-operative shunts is optional. The influence of these techniques on subsequent restenosis is uncertain. Long term carotid restenosis rates and risk of future ipsilateral stroke with these techniques were compared.

METHODS

Patients who underwent CEA in the International Carotid Stenting Study were divided into patch angioplasty, primary closure, or eversion endarterectomy. Intra-operative shunt use was reported. Carotid duplex ultrasound was performed at each follow up. Primary outcomes were restenosis of ≥ 50% and ≥ 70%, and ipsilateral stroke after the procedure to the end of follow up.

RESULTS

In total, 790 CEA patients had restenosis data at one and five years. Altogether, 511 (64.7%) had patch angioplasty, 232 (29.4%) primary closure, and 47 (5.9%) eversion endarterectomy. The cumulative incidence of ≥ 50% restenosis at one year was 18.9%, 26.1%, and 17.7%, respectively, and at five years it was 25.9%, 37.2%, and 30.0%, respectively. There was no difference in risk between the eversion and patch angioplasty group (hazard ratio [HR] 0.90, 95% confidence interval [CI] 0.45 - 1.81; p = .77). Primary closure had a higher risk of restenosis than patch angioplasty (HR 1.45, 95% CI 1.06 - 1.98; p = .019). The cumulative incidence of ≥ 70% restenosis did not differ between primary closure and patch angioplasty (12.1% vs. 7.1%, HR 1.59, 95% CI 0.88 - 2.89; p = .12) or between patch angioplasty and eversion endarterectomy (4.7%, HR 0.45, 95% CI 0.06 - 3.35; p = .44). There was no effect of shunt use on the cumulative incidence of restenosis. Post-procedural ipsilateral stroke was not more common in either of the surgical techniques or shunt use.

CONCLUSION

Restenosis was more common after primary closure than conventionally with a patch closure. Shunt use had no effect on restenosis. Patch closure is the treatment of choice to avoid restenosis.

Influence of Anatomic Conditions on Efficacy and Safety of Combined Intermediate Cervical Plexus Block and Perivascular Infiltration of Internal Carotid Artery in Carotid Endarterectomy: A Prospective Observational Trial

Ultrasound-guided intermediate cervical plexus blockade with perivascular infiltration of the carotid artery bifurcation perivacular block (PVB) is a reliable technique for regional anesthesia in carotid endarterectomy (CEA). We investigated the effect of the carotid bifurcation level (CBL) on PVB efficacy and safety in patients undergoing CEA. This prospective observational cohort study included 447 consecutive CEA patients who received PVB over a 6-y period. Vascular and neurologic puncture-related complications were recorded. The CBL was localized at the low level (C4 and C5 vertebra, low-level [LL] group) in 381 (85.2%) patients and at the high level (C2 and C3 vertebra, high-level [HL] group) in 66 (14.8%) patients. Local anesthetic supplementation by surgeons was necessary in 64 (14.3%) patients in the LL group and 38 (59.4%) patients in the HL group (p < 0.001) and was associated with a higher rate of central neurologic complications in the HL group (p = 0.031). Therefore, the efficacy of the PVB may be influenced by the CBL.