Cervical Carotid Artery Stenosis: Latest Update on Diagnosis and Management

Arterial Stiffness Assessment in Healthy Participants Using Shear Wave Elastography

BACKGROUND

Arterial stiffness is an important biomarker for cardiovascular disease. Shear wave elastography (SWE) provides quantitative estimates of tissue stiffness.

OBJECTIVE

This study aimed to provide reference values for arterial wall, assessing the suitability of SWE to quantify elasticity of the common carotid artery (CCA) and evaluating inter- and intra-observer reproducibility.

METHODS

A Supersonic Aixplorer ultrasound system with L15-4 probe was used to scan longitudinal sections of the CCA. Young's modulus (YM) was measured within 2-mm regions of interest. Reproducibility was assessed within a subgroup of 16 participants by two operators (one novice and one experienced) during two sessions >one week apart.

RESULTS

This study involves seventy-three participants with a mean age of 40±10 years and body mass index of 26 ±6 kg/m2. YM estimates were 59 kPa ±19 in men and 56 kPa ±12 in women. The average YM of the CCA walls was 58 kPa ±15 (57 ±15 kPa for the anterior wall and 58 ±20 kPa for the posterior wall, p=0.75). There was no significant difference in the mean of YM estimates of the CCA between the observers (observer: one 51 ±14 kPa and observer two: 55 ±17 kPa [p=0.46]). inter- and intra-observer reproducibility was fair to good (Intra-class correlations, ranging from 0.46 to 0.71). Inter-frame variability was 28%.

CONCLUSION

In healthy individuals, SWE provided an estimate of YM of the CCA (58 kPa) with fair to good reproducibility. This study demonstrated the potential of using SWE for assessing biomechanical properties of blood vessels.

Relationship Between the Degree of Carotid Stenosis and the Risk of Stroke in Patients Undergoing Cardiac Surgery

BACKGROUND

The impact of carotid stenosis (CS) in patients undergoing cardiac surgery remains controversial. The aim of this study was to evaluate the association between carotid stenosis and stroke and/or transient ischemic attack (TIA) in patients undergoing cardiac surgery on cardiopulmonary bypass.

METHODS

This is a retrospective cohort study including patients undergoing cardiac surgery on cardiopulmonary bypass between January 2006 and March 2018 at the Quebec Heart and Lung Institute. Data of patients' preoperative demographic characteristics, operative and postoperative variables were taken from a computerized database and patients' charts. Univariate and multivariate analyses were performed.

RESULTS

A total of 20,241 patients were included in the study. Among those who had received preoperative carotid ultrasound, 516 (2.6% of the total population) had unilateral or bilateral CS ≥50%. Categorized levels of carotid stenosis severity were identified as independent risk factors for post-operative stroke and/or transient ischemic attack occurrence. There was an almost three-fold increased risk of post-operative neurologic events in 80-99% CS vs. less severe 50-79% CS [OR 2.91; IC95% (1.30-6.54)] suggesting that the degree of severity of CS is potentially a strong independent predictor of post-operative neurologic events.

CONCLUSIONS

CS is an independent risk factor of post-operative stroke and/or TIA. This study suggests for the first time that the risk of stroke increases with the degree of severity of CS, with the greatest risk being for CS between 80-99%. The strength of this relationship and potential causality effect should be further explored in a prospective study focusing on this most at risk population.

Uniaxial Tensile Properties of Atherosclerotic Carotid Artery After Mobilization of Pushing on Qiao-Gong: A Safety Study Using an Animal Model of Carotid Atherosclerosis

OBJECTIVES

This study aimed to preliminarily explore the effects of the soft tissue mobilization of pushing on Qiao-Gong (MPQ) on biomechanical properties of the carotid artery using an animal model of carotid atherosclerosis (CAS).

METHODS

Fifty rabbits were randomly divided into 4 groups: animals with CAS treated with MPQ (CAS-MPQ [n = 15]); animals with CAS treated without MPQ (CAS [n = 15]); normal animals treated with MPQ (normal-MPQ [n = 10]); and a blank control group (n = 10). The MPQ procedure consisted of soft tissue mobilization of the Qiao-Gong acupoint on the front edge of the sternocleidomastoid muscle applied from top to bottom, by flat pushing with the thumb repeatedly for 20 times. Disease in the CAS models was induced by carotid artery balloon injury combined with a high-fat diet for 12 weeks. At the end of modeling, carotid color Doppler ultrasonography examination was performed to confirm which animal models were successfully induced with CAS, excluding model rabbits without typical CAS at the same time. Then, MPQ was applied on rabbits in the CAS-MPQ and the normal-MPQ groups for 3 weeks. By contrast, rabbits in the other 2 groups were fed normally without MPQ. Uniaxial failure tests were later performed on carotid arteries in all 4 groups, and at the end of the study, a 2-way factorial analysis of variance of the results was conducted.

RESULTS

(1) At the end of modeling, 10 rabbits in the CAS-MPQ group and 9 in the CAS group were included with typical carotid atherosclerotic characteristics. (2) Young's elastic modulus of the rabbit carotid artery increased more significantly in the CAS-MPQ group than the CAS group. (3) Compared with normal rabbit carotid arteries, atherosclerotic carotid arteries had lower levels of ultimate stress and ultimate strain but higher levels of ultimate load.

CONCLUSIONS

The uniaxial tensile mechanical properties of the rabbit atherosclerotic carotid artery were impaired after MPQ.

Evaluation of the relationship between plaque formation leading to symptomatic carotid artery stenosis and cytomegalovirus by investigating the virus DNA

Introduction

The most common etiologic factor of coronary artery disease (CAD), carotid artery disease, and peripheral artery disease is atherosclerosis. In our study, we aimed to show the effect of cytomegalovirus (CMV), which can occur almost everywhere in the human body, on triggering the chronic inflammatory process in the pathophysiology of atherosclerosis, and its presence and impact in the plaques leading to carotid artery stenosis.

Material and methods

Thirty-six patients, who underwent carotid endarterectomy at the Department of Cardiovascular Surgery, Istanbul University Istanbul Medical Faculty between April 2017 and April 2018, were included in this study upon their consent. Patients with additional immunosuppressive conditions were not included in the study. Unilateral atheromatous plaque was preferred for patients undergoing bilateral carotid endarterectomy and all risk factors (DM, HT, hyperlipidemia, etc.) were evaluated together for all patients.

Results

When the relationship between CMV (DNA) presence in samples taken from patients' plaques and sex, age and comorbidities was examined, CMV (DNA) positivity (45.8%) was significantly higher in DM patients than non-DM patients (8.3%) (p = 0.024). Likewise, CMV(DNA) positivity (40%) was significantly higher in HT patients than in non-HT patients (25%) (p = 0.008). CMV(DNA) positivity (63%) was significantly higher in patients with bilateral carotid artery stenosis than patients without bilateral carotid artery stenosis (0%) (p < 0.001).

Conclusions

It has not yet been clarified whether CMV is a primary trigger for atherosclerosis on the vascular wall, or whether it presents incidentally due to its affinity. When CMV (DNA) positivity was examined according to the presence of bilateral carotid artery stenosis in our study, CMV (DNA) positivity was found to be significantly higher in patients with bilateral carotid artery stenosis (63.16%).

Do standard carotid artery endarterectomy and primary closure technique cause early restenosis in diabetic patients?

Introduction

We aimed to investigate carotid restenosis in 2-year follow-up in diabetic and nondiabetic patients who underwent standard carotid endarterectomy with primary carotid closure and determine whether diabetes mellitus is a risk factor for early stenosis for this surgical procedure.

Material and methods

We retrospectively assessed the data of patients who underwent standard carotid endarterectomy with primary carotid closure from the hospital registry and outpatient clinic follow-up between January 2006 and January 2012. The study included 25 diabetics and 25 nondiabetics, in total 50 patients. The control carotid Doppler ultrasonographies and/or computed tomography angiographies of the patients at postoperative 1, 6, 12, and 24 months were examined and a stenosis rate between 70% and 99% was regarded as significant carotid restenosis.

Results

When the diabetic and nondiabetic group patients were compared for early carotid restenosis at 2 years, there were 3 (12%) patients in the diabetic group and 4 (16%) patients in the nondiabetic group with restenosis. A statistically significant difference in early carotid restenosis was not observed between the two groups (p > 0.05).

Conclusions

Standard carotid endarterectomy and primary closure of the artery is a successfully performed surgical procedure in diabetic patients. We concluded that diabetes mellitus is not a risk factor for early restenosis in the diabetic patient population according to the results of our research.

Shear Wave Elastography Quantifies Stiffness in Ex Vivo Porcine Artery with Stiffened Arterial Region

Five small porcine aortas were used as a human carotid artery model, and their stiffness was estimated using shear wave elastography (SWE) in the arterial wall and a stiffened artery region mimicking a stiff plaque. To optimize the SWE settings, shear wave bandwidth was measured with respect to acoustic radiation force push length and number of compounded angles used for motion detection with plane wave imaging. The mean arterial wall and simulated plaque shear moduli varied from 41 ± 5 to 97 ± 10 kPa and from 86 ± 13 to 174 ± 35 kPa, respectively, over the pressure range 20-120 mmHg. The results revealed that a minimum bandwidth of approximately 1500 Hz is necessary for consistent shear modulus estimates, and a high pulse repetition frequency using no image compounding is more important than a lower pulse repetition frequency with better image quality when estimating arterial wall and plaque stiffness using SWE.

Vessel Wall Imaging of the Intracranial and Cervical Carotid Arteries

Vessel wall imaging can depict the morphologies of atherosclerotic plaques, arterial walls, and surrounding structures in the intracranial and cervical carotid arteries beyond the simple luminal changes that can be observed with traditional luminal evaluation. Differentiating vulnerable from stable plaques and characterizing atherosclerotic plaques are vital parts of the early diagnosis, prevention, and treatment of stroke and the neurological adverse effects of atherosclerosis. Various techniques for vessel wall imaging have been developed and introduced to differentiate and analyze atherosclerotic plaques in the cervical carotid artery. High-resolution magnetic resonance imaging (HR-MRI) is the most important and popular vessel wall imaging technique for directly evaluating the vascular wall and intracranial artery disease. Intracranial artery atherosclerosis, dissection, moyamoya disease, vasculitis, and reversible cerebral vasoconstriction syndrome can also be diagnosed and differentiated by using HR-MRI. Here, we review the radiologic features of intracranial artery disease and cervical carotid artery atherosclerosis on HR-MRI and various other vessel wall imaging techniques (e.g., ultrasound, computed tomography, magnetic resonance, and positron emission tomography-computed tomography).

Perioperative Complications After Carotid Artery Stenting

BACKGROUND:

Technological advances have resulted in diminishing perioperative complications reported during carotid artery stenting (CAS) trials. Because trial experience lags behind technological advances, an understanding of the incidence of perioperative complications after CAS remains in flux.

OBJECTIVE:

In this single-arm, observational study, a contemporary experience of CAS at a high-volume academic training center for neuroendovascular surgeons was reviewed to assess perioperative morbidity.

METHODS:

A prospectively maintained database of all neuroendovascular procedures was queried for all CAS procedures performed for stenotic atherosclerotic disease between 2009 and 2011. Each case was assessed for major perioperative (30 day) adverse events, including new acute ischemic stroke, postoperative symptomatic intracranial hemorrhage, myocardial infarction (MI), and mortality.

RESULTS:

A total of 474 patients were identified. Perioperative adverse events were noted in 13 patients (2.7%). These included 4 ischemic strokes, 4 intracranial hemorrhages, 3 MIs, and 5 deaths. Most perioperative events occurred in symptomatic patients (10 of 239 symptomatic patients with events, 4.2% event incidence), whereas these events occurred rarely in asymptomatic patients (3 of 235 asymptomatic patients with events, 1.3% event incidence).

CONCLUSION:

In this retrospective analysis of consecutive patients treated with CAS, the perioperative incidence of stroke (0.9%), MI (0.6%), and death (1.1%) was favorable.

Off-label use of drugs and devices in the neuroendovascular suite

SUMMARY

The off-label use of drugs and devices in neuroendovascular procedures is common. Neurointerventionalists should be well aware of the level of evidence available in support of the off-label use of drugs and devices in their practice and some of the potential adverse events associated with them. These uses are categorized as I or II if they have been evaluated as primary or ancillary interventions in prospective trials/registries of neuroendovascular procedures and III if they were evaluated in case series. Category IV use is based on evaluation as primary or ancillary interventions in prospective trials/registries of non-neuroendovascular procedures. Physicians are allowed to use off-label drugs and procedures if there is strong evidence that they are beneficial for the patient. The neurointerventional professional societies agree that off-label use of drugs and devices is an important part of the specialty, but practicing providers should base their decisions on sound evidence when using such drugs and devices.