Contralateral Internal Carotid Artery Research Articles

Assessment of Collateral Flow in Patients with Carotid Stenosis Using Random Vessel-Encoded Arterial Spin-Labeling: Comparison with Digital Subtraction Angiography.

Collateral circulation plays an important role in steno-occlusive internal carotid artery disease (ICAD) to reduce the risk of stroke. We aimed to investigate the utility of planning-free random vessel-encoded arterial spin-labeling (rVE-ASL) in assessing collateral flows in patients with ICAD. Forty patients with ICAD were prospectively recruited. The presence and extent of collateral flow were assessed and compared between rVE-ASL and DSA by using Contingency (C) and Cramer V (V) coefficients. The differences in flow territory alterations stratified by stenosis ratio and symptoms, respectively, were compared between symptomatic (n = 19) and asymptomatic (n = 21) patients by using the Fisher exact test. Good agreement was observed between rVE-ASL and DSA in assessing collateral flow (C = 0.762, V = 0.833, both P < .001). Patients with ICA stenosis of ≥90% were more likely to have flow alterations (P < .001). Symptomatic patients showed a higher prevalence of flow alterations in the territory of the MCA on the same side of ICAD (63.2%), compared with asymptomatic patients (23.8%, P = .012), while the flow alterations in the territory of anterior cerebral artery did not differ (P = .442). The collateral flow to MCA territory was developed primarily from the contralateral internal carotid artery (70.6%) and vertebrobasilar artery to a lesser extent (47.1%). rVE-ASL provides comparable information with DSA on the assessment of collateral flow. The flow alterations in the MCA territory may be attributed to symptomatic ICAD.

Clinical Characteristics of Immediate Contralateral Ischemia Subsequent to Revascularization for Moyamoya Disease

Moyamoya disease is a bilateral steno-occlusive disease involving the cerebral vasculature. While some patients are affected by procedure-related ipsilateral ischemia, ischemic complications contralateral to the revascularization are rarely observed. We retrospectively investigated 135 hemispheres (103 patients) that underwent revascularization in our institution between April 2006 and September 2022. Revascularization surgery comprised single superficial temporal artery-middle cerebral artery anastomosis and encephalo-myo-synangiosis. Certain patients aged under 10years underwent indirect revascularization. Bilateral revascularization was performed with an interval of >3months. Medical records and neuroimages were reviewed, and patients with contralateral ischemic complications were identified. Some cases underwent genetic analysis. The mean age was 34.5 (range: 5-71) years, and 95 cases (70.4%) were in women. Of the 102 cases examined for the RNF213 c.14429G > A (p.Arg4810Lys) variant, 33 (32.4%) and 69 (67.6%) showed the GG and GA genotype, respectively. Three cases (2.2%, all female, age range 44-71years) were complicated with contralateral infarction. The infarcted area distributions of the 2 cases with RNF213 c.14429G > A variant were patchy and peripheral. Theother case showed on magnetic resonance imaging (MRI) angiography total occlusion of the internal carotidartery where patency had been confirmed preoperatively. Contralateral ischemia after revascularization occurred in 2.2% of cases. We classified them into peripheral and central types: peripheral type, an infarction owing to hemodynamic insufficiency or intracranial blood flow redistribution; central type, total occlusion of the contralateral internal carotid artery. Intensive preoperative management can minimize the risk of peripheral types, and neurosurgeons should beware of severe central types.

HEMODYNAMIC PARAMETERS OF EXTRACRANIAL CEREBRAL ARTERIES AND HEART IN PATIENTS WITH OCCLUSION OF THE INTERNAL CAROTID ARTERY DURING VASCULAR SURGERY

HighlightsWe have analyzed the parameters of cerebral hemodynamics and left ventricular functional capacity in patients with occlusion and stenosis of the contralateral internal carotid artery during vascular surgery. Considering the importance of the left ventricular functional capacity and treatment options to ensure the stability of cerebral circulation in patients with occlusion and hemodynamically significant stenosis of the contralateral carotid artery, its detailed study at all stages of vascular surgery remains necessary. AbstractAim. To study cerebral hemodynamics and left ventricular functional capacity in patients with occlusion and stenosis of the contralateral internal carotid artery (ICA) to optimize treatment at the preoperative phase.Methods. The study compared the hemodynamic parameters of the blood flow of the ICA, vertebral arteries and left ventricular functional capacity in patients with ICA occlusion and contralateral ICA stenosis, which formed the 1 group (12 patients), and patients with unilateral hemodynamically significant stenosis, which formed the 2 group (52 patients). The blood flow in the extracranial portions of the major arteries of the head and heart was assessed using ultrasound, and the arterial vascular system and brain structure was assessed using MRI and MRA.Results. Before surgery, statistically significant differences in velocity parameters in the vertebral arteries on the occlusion side were found; on the contralateral occlusion side, velocity parameters in ICA were significantly different from the corresponding indicators in the group with unilateral stenosis; after surgery, statistically significant differences were found in the common carotid and vertebral arteries on the occlusion side; on the contralateral occlusion side, differences in velocity parameters in the common carotid, internal, and vertebral arteries were revealed in comparison with the group with unilateral stenosis. Of the indicators of the left ventricular functional capacity, only left ventricular ejection fraction differed significantly when comparing the group of patients with occlusion and stenosis of ICA and the group of patients with unilateral stenosis. Moreover, when evaluating pre- and postoperative outcomes in the group of patients with occlusion, significant differences were obtained only regarding the vertebral artery on the side of occlusion – the peak systolic blood flow velocity and the volumetric blood flow velocity significantly decreased. There were no significant differences between the common carotid, internal carotid arteries on the contralateral occlusion side, and middle cerebral arteries.Conclusion. Carrying out a comprehensive ultrasound examination of the main arteries of the head in combination with magnetic resonance imaging of the brain is a reliable and adequate way to assess cerebral hemodynamics, changes in the vascular bed and structure of the brain. Given the extreme importance of the left ventricular functional capacity to ensure the stability of cerebral circulation in patients with occlusion of the internal carotid artery and contralateral hemodynamically significant stenosis, its detailed study before carotid endarterectomy is necessary to adjust therapeutic measures.

The influence of contralateral circulation on computational fluid dynamics of intracranial arteries: simulated versus measured flow velocities

BackgroundThis study aimed to retrospectively evaluate the influence of contralateral anterior circulation on computational fluid dynamics (CFD) of intracranial arteries, by comparing the CFD values of flow velocities in unilateral anterior circulation with the measured values from phase-contrast magnetic resonance angiography (PC-MRA).MethodsWe analyzed 21 unilateral anterior circulation models without proximal stenosis from 15 patients who performed both time-of-flight MRA (TOF-MRA) and PC-MRA. CFD was performed with the inflow boundary condition of a pulsatile flow of the internal carotid artery (ICA) obtained from PC-MRA. The outflow boundary condition was given as atmospheric pressure. Simulated flow velocities of the middle cerebral artery (MCA) and anterior cerebral artery (ACA) from CFD were compared with the measured values from PC-MRA.ResultsThe velocities of MCA were shown to be more accurately simulated on CFD than those of ACA (Spearman correlation coefficient 0.773 and 0.282, respectively). In four models with severe stenosis or occlusion of the contralateral ICA, the CFD values of ACA velocities were significantly lower (< 50%) than those measured with PC-MRA. ACA velocities were relatively accurately simulated in the models including similar diameters of both ACAs.ConclusionIt may be necessary to consider the flow condition of the contralateral anterior circulation in CFD of intracranial arteries, especially in the ACA.Relevance statementIncorporating the flow conditions of the contralateral circulation is of clinical importance for an accurate prediction of a rupture risk in Acom aneurysms as the bidirectional flow and accurate velocity of both ACAs can significantly impact the CFD results.Key points• CFD simulations using unilateral vascular models were relatively accurate for MCA.• Contralateral ICA steno-occlusion resulted in an underestimation of CFD velocity in ACA.• Contralateral flow may need to be considered in CFD simulations of ACA.Graphical

The Positional Relationship between Lacunae and White Matter Hyperintensity in Patients with Cerebral Small Vessel Disease.

Lacunae and white matter hyperintensity (WMH) are two crucial imaging biomarkers of cerebral small vessel disease (CSVD). Multiple studies have revealed a close relationship between WMH and lacunae and found that a double penumbra existed at the edge of WMH that affects lacunae formation. The study aimed to explore the spatial distribution characteristics and possible influencing factors of lacuna in relation to white matter hyperintensity in patients with CSVD. A total of 480 CSVD patients with WMH and with or without lacunae were included. Data about blood biochemical indicators, cerebrovascular CT angiography, 24-hour ambulatory blood pressure and ambulatory electrocardiogram, brain magnetic resonance imaging, and transcranial Doppler ultrasound were gathered from all subjects. They were categorised into four groups based on the spatial interaction between lacunae and WMH. Univariate analyses and multiple logistic regression analyses were used to compare the differences in traditional vascular risk factors, heart rate and blood pressure indicators, arterial pulsatility index (PI) values, and arterial stenosis among different groups. The average age of 480 patients was (58.63 ± 11.91) years, with 347 males (72.3%). Univariate analysis indicated that age, fasting blood glucose, triglycerides, total cholesterol, highdensity lipoprotein, 24-hour and daytime and night systolic and diastolic blood pressure, nocturnal heart rate, heart rate variability, PI values of ipsilateral and contralateral MCA (middle cerebral artery) and ICA (Internal carotid artery) of the lacunae, Fazekas score of PWMH (periventricular white matter hyperintensities), the proportion of MCA or ICA with stenosis rate over 50% on the ipsilateral side of the lacunae were significantly different between different groups (p < 0.05). High fasting blood glucose (OR=1.632, 95% CI= (1.128, 2.361), p =0.009), (OR=1.789, 95%CI= (1.270, 2.520), p = 0.001), (OR=1.806, 95% CI= (1.292, 2.524), p =0.001) was identified as a risk factor for lacunae formation by logistic regression analysis. High fasting blood glucose can be considered a risk factor for lacunae formation in patients with WMH. The more severe the PWMH and the higher the nocturnal heart rate, the more likely the lacunae, as well as PWMH, overlap completely. Ipsilateral arteriosclerosis and stenosis are independent risk factors for no contact between lacunae and PWMH.

Interventional reperfusion for acute embolism of the middle cerebral artery trunk with contralateral internal carotid artery congenital absence.

Internal carotid artery congenital absence with acute embolism of the middle cerebral artery trunk is very rare. A 65-year-old female with a history of hypertension and atrial fibrillation was admitted to the neurology department of our hospital. Computed tomography of the head and neck showed no carotid canal of the petrous portion of the temporal bone; digital subtraction angiography (DSA) showed no left internal carotid artery and the right middle cerebral artery trunk occlusion. These results suggested acute embolism of the middle cerebral artery trunk with contralateral internal carotid artery congenital absence. Mechanical thrombectomy was performed, which had a good outcome. This case showed the vascular anatomy features of ICA congenital absence with contralateral large vessel acute occlusion, and it is essential to promptly identify the vascular variation during the interventional procedure.

Society for Vascular Surgery duplex ultrasound surveillance guidelines are safe and cost effective for transcarotid artery revascularization

BackgroundCarotid duplex ultrasound (CDUS) examination is used in the long-term surveillance after transcarotid artery revascularization (TCAR). The objective of this study was to evaluate the usefulness and cost effectiveness of post-TCAR CDUS surveillance regimens in monitoring for in-stent restenosis (ISR) and associated stroke risk at a single-center community institution. MethodsCDUS data were collected retrospectively from patients who had undergone TCAR between January 2017 and January 2023. ISR >50% was defined as a peak systolic velocity (PSV) of >220 cm/s and an internal carotid artery (ICA) to common carotid velocity ratio of >2.7. ISR >80% was defined as a PSV of >340 cm/s and an ICA/common carotid artery ratio of >4.15. Study outcomes included incidences of ISR, reintervention, transient ischemic attacks (TIAs), strokes, and mortality. A Kaplan-Meier survival analysis was done to calculate the rates of freedom from ISR. ResultsDuring the study period, 108 TCAR stents were deployed in 104 patients. Eight patients were excluded in analysis or lost to follow-up. Preoperatively, 62% of patients had >80% stenosis, and 39% were symptomatic. No intraprocedural complications were noted. One patient suffered an immediate postoperative dissection. Eight stents (8%) experienced ISR progression from <50% to >50%. Three of the eight had further ISR progression to >80%. One patient had high-grade ISR and a contralateral ICA occlusion that warranted reintervention. There were no occurrences of postoperative TIAs, strokes, or TCAR-related deaths. Rates of freedom from ISR progression from <50% to >50% were 97.4%, 95.9%, 90.9%, 88.2%, and 88.2% at 6, 12, 24, 36, and 42 months, respectively. Rates of freedom from ISR >80% were 100%, 100%, 98.5%, 95.5%, and 95.5% at the same time points. Patients with >50% ISR tended to be females with hyperlipidemia. In addition, they had higher average lesion lengths and lower rates of postdilation balloon angioplasty. The 5-year estimated surveillance cost in this cohort using the Society for Vascular Surgery 2022, and 2018 guidelines, as well as our current protocol would be $113,853, $221,382, and $193,207, respectively. ConclusionsThis study revealed a low incidence of ISR progression, as well as no TIA, stroke, or TCAR-related deaths, highlighting the safety and efficacy of TCAR. Post-TCAR CDUS examination using the updated Society for Vascular Surgery guidelines are safe and cost effective. Patients with contralateral occlusion or stenosis, or who have significant risk factors, should have more frequent surveillance regimens.

Change in Peak Systolic Velocity Estimation in Internal Carotid Artery Following Contralateral Near Occlusive Carotid Endarterectomy

Carotid artery stenosis (CAS) is one of the main causes of stroke, as the internal carotid artery (ICA) is a major source of cerebral blood supply. A common surgical intervention for CAS is carotid endarterectomy (CEA), which carries a high risk of stroke and mortality. CEA is indicated for 50% to 99% stenosis in symptomatic patients and 60% to 99% stenosis in asymptomatic patients. Carotid duplex ultrasound is frequently used to estimate peak systolic velocity (PSV), end diastolic velocity (EDV), and ICA/common carotid artery (CCA) ratio to determine the extent of stenosis. This does not account for other factors that can artificially change PSV and EDV, such as a contralateral carotid artery near occlusion with >90% stenosis. Although >70% contralateral stenosis has been previously studied, limited research exists on the impact of ICA near occlusions. We hypothesize that the degree of stenosis in an ipsilateral patent vessel can be more accurately estimated by examining the change in PSV pre- vs post-CEA of the contralateral ICA near occlusion. A retrospective study was conducted on 239 patients, at least 18 years of age, who underwent standard, routine carotid duplex ultrasound at a single institution. Patients who qualified for the study had bilateral carotid stenosis with ICA near occlusive disease on at least one side and underwent CEA. Near occlusion was determined by either a carotid duplex ultrasound >70% with one of the following criteria: PSV >400, EDV >140, or ratio of ICA/CCA >6, or a carotid computed tomography angiography showing near occlusion interpreted by a physician. Preoperative duplex velocities contralateral to the CEA were recorded and compared postoperatively. Interestingly, in the presence of contralateral >50% ICA stenosis, the PSV, EDV, and ICA/CCA ratio in the unoperated artery increased significantly following contralateral CEA (P < .001). In greater than 70% contralateral ICA occlusion, PSV, EDV, and ICA/CCA ratio increased to a greater extent compared with >50% contralateral ICA stenosis (P < .001). In detecting ≥70% stenosis of the patent vessel pre-CEA, PSV ≥250 cm/s had 87.2% sensitivity. In predicting ≥70% stenosis of the patent vessel pre-CEA, PSV >300 cm/s had 96.0% sensitivity. The present study deviates from the current theoretical model and shows that ultrasound PSV, EDV, ICA/CCA ratios can be significantly elevated in the patent vessel pre-CEA and post-CEA of the contralateral ICA near occlusion. This study provides novel insight into customized duplex ultrasound criteria for estimation of stenosis and to avoid unnecessary high-risk surgery.

Concomitant occurrence of Cerebral Hyperperfusion Syndrome (CHS) and Reversible Cerebral Vasoconstriction Syndrome (RCVS) after right Carotid Endarterectomy (CEA) (P2-5.018)

<h3>Objective:</h3> To describe an interesting case of CHS and RCVS occurring concomitantly following CEA <h3>Background:</h3> Both CHS and RCVS are known complications of CEA. On rare occasions both complications can occur concomitantly after CEA. <h3>Design/Methods:</h3> Case report <h3>Results:</h3> A 58-year-old female with long-standing history of smoking and hyperlipidemia presented to outside hospital (OSH) with pressure-like headache on top of her head and feeling of facial swelling. CT angiogram of head and neck (CTA) showed right internal carotid artery (ICA) stenosis of 85% and left ICA stenosis of 80%. Three months after the initial presentation she underwent right CEA. Immediately following procedure, she had severe throbbing headache on right side which responded to Toradol. Neurologic examination was otherwise unremarkable, and she was discharged home on dual anti-platelet therapy. After discharge, she continued to have headache. Ten days after the procedure, she developed left sided weakness and presented to an outside hospital where she had a seizure and was started on levetiracetam. MRI of the brain showed edematous changes on the right consistent with CHS without evidence of acute stroke. Right ICA was patent and there was segmental vasoconstriction and dilation of cerebral vasculature consistent with RCVS. Due to increased risk of hemorrhagic strokes with CHS and RCVS, left CEA was not recommended and maximal medical therapy was recommended. There was resolution of edematous changes in right cerebral hemisphere on MRI two months later. CTA at two months follow up showed resolution of segmental vasoconstriction and vasodilation, patent right ICA and unchanged left ICA stenosis. <h3>Conclusions:</h3> CHS and RCVS can occur concomitantly after CEA and can lead to devastating hemorrhagic strokes. In patients who develop CHS and RCVS concomitantly maximal medical therapy should be recommended for contralateral ICA stenosis. <b>Disclosure:</b> Dr. Anjum has nothing to disclose. Dr. Burton has nothing to disclose. Dr. Javalkar has nothing to disclose. Dr. Chernyshev has nothing to disclose.

Bilateral Internal Carotid Artery Agenesis : Very Rare Cause of Bilateral Pulsatile Tinnitus

Bilateral internal carotid artery agenesis is a very rare congenital anomaly. Intracranial blood circulation in the affected internal carotid artery side is provided by collateral vasculature, contralateral internal carotid artery through the anterior communicating artery, and from the vertebrobasilar system through the posterior communicating artery. People with this abnormality may be asymptomatic for many years. However, patients may also be present with ischemic stroke orsubarachnoid hemorrhage, headache, and blurred vision. Diagnosis is usually incidental by the performance of carotid artery doppler ultrasonography or cervical/cranial magnetic resonance imaging owing to other symptoms. We report a case of bilateral internal carotid artery agenesis with pulsatile tinnitus lasting five years in the light of clinical presentation and imaging findings.

Cerebral autoregulation and blood flow distribution in the precerebral arteries for determining indications of extra-intracranial bypass in patients with carotid artery occlusion

Background. Prevention of ischemic stroke in patients with carotid artery occlusion is conventionally associated with performing cerebral revascularization. However, determining the indications for it is still an actual problem. The informative value of noninvasive assessment of cerebral autoregulation and blood flow distribution in the precerebral arteries in patients with carotid artery stenosis is shown. At the same time, in patients with carotid artery occlusion, these indicators have been studied to a lesser extent.Aim. To evaluate the informative value of cerebral autoregulation and blood flow distribution in the precerebral arte ries for determination the indications of extra‑intracranial bypass in patients with carotid occlusion.Materials and methods. 54 patients (aged from 41 to 83 y. o.) with carotid artery occlusion were studied. Blood flow velocity in intracranial arteries was determined with transcranial Doppler (system Multi‑Dop X), whereas flow velocity index in precerebral arteries – with duplex scanning (system Vivid Е). Cerebral autoregulation was assessed based on phase shift between spontaneous oscillations of blood flow velocity in basal cerebral arteries and systemic blood pressure within the range of Mayer’s waves (80–120 mHz).Results. The state of cerebral autoregulation was imparied on both sides in 90 % patients with the symptomatic carotid occlusion (0.3 ± 0.3 rad ipsilateral, 0.7 ± 0.6 rad contralateral). The state of cerebral autoregulation was not impaired in 79 % patients with asymptomatic carotid occlusion (1.0 ± 0.3 rad ipsilateral, 1.1 ± 0.4 rad contralateral). The flow velocity index in the contralateral internal carotid artery (306 ± 109 ml / min) and the ipsilateral vertebral (139 ± 69 ml / min) and external carotid (175 ± 72 ml / min) arteries was increased.Conclusions. Noninvasive preoperative assessment of cerebral autoregulation and blood flow distribution in the precerebral arteries makes to evaluate the state of the cerebrovascular reserve to quantify and can be used to determining indications for cerebral revascularization in patients with carotid occlusion.

Abstract Number ‐ 66: Symptomatic Chronic Internal Carotid Artery Occlusion Managed With Bilateral Common Carotid Angioplasty: A Case Report

Introduction Several guidelines have addressed symptomatic or asymptomatic carotid artery stenosis treatment with intensive medical management and surgical management based on the severity of stenosis [1]. In acute occlusions, endovascular treatment (EVT) and carotid endarterectomy (CEA) with or without prior thrombolytics provide the best recanalization and functional outcomes when compared to intravenous or intra‐arterial thrombolysis alone. There is, however, less robust evidence on management of symptomatic chronic internal carotid artery (ICA) occlusion occurring in tandem with significant contralateral ICA stenosis [2]. In chronic ICA occlusion (ICAO), EVT and carotid endarterectomy (CEA) are technically unfeasible, but indirect procedures have been arising as safe and effective alternatives, notably CEA or stenting of contralateral stenotic ICA [3] and CEA or stenting of ipsilateral external carotid artery (ECA) [4]. We hereby report a case of symptomatic chronic ICAO that was managed with staggered angioplasty and stenting of bilateral common carotid artery (CCA) bifurcations. Methods We hereby present a case report. Results A 62‐year‐old male with atrial fibrillation and hypertension woke up with sudden dysarthria and right upper extremity and facial weakness. NIHSS at presentation was 4. Last seen normal 9 hours prior. Non‐contrast head computerized tomography (CT) did not show acute intracranial abnormality, CT angiogram of head and neck showed severe right ICA stenosis and complete occlusion of the left ICA at cervical, petrous and cavernous segments, with distal reconstitution at the supraclinoid segment with left proximal middle cerebral artery (MCA) thrombus. CT perfusion showed a core infarct volume of 8cc in left MCA territory, mismatch volume of 78cc and ratio of 10.8. Risks of acute neuro‐intervention were deemed to outweigh benefits. Given favorable perfusion imaging, and in concordance with the EXTEND trial [5], tPA was administered. The patient remained stable without hemorrhagic complications with residual deficits of mild right upper extremity weakness and mild expressive aphasia. MRI confirmed left ICA territory ischemic infarcts. Patient underwent stenting of the asymptomatic right ICA at the CCA bifurcation first, followed by left CCA stent after one month with impressive improvement in subsequent perfusion imaging. Conclusions Our case encourages consideration of well‐timed angioplasty and stenting in cases of chronic bilateral carotid artery disease especially when the asymptomatic side is also significantly stenotic

Results of carotid endarterectomy with the use of temporary shunts with reduced retrograde pressure in the internal carotid artery - analysis of the multicenter Russian register.

The aim of the study was to assess the role of a temporary carotid shunt in patients undergoing carotid endarterectomy. This was a retrospective, multicentric (n = 159) study carried out between January 2005 and October 2020. The study included 3114 patients undergoing carotid endarterectomy who had a reduced retrograde internal carotid artery pressure (<60% of systolic blood pressure). A temporary carotid shunt was used in 1328 patients and 1786 patients underwent carotid endarterectomy without a shunt. The in-hospital outcomes were comparable in terms of the incidence of deaths, myocardial infarctions, and stroke between the two groups. However, asymptomatic strokes (confirmed on computed tomography) occurred more frequently in the group where the temporary shunt was used (34 (2.5%) vs. 10 (0.55%), p < 0.0001). The composite endpoints of adverse events were also higher in the group where a temporary shunt was used (44 (3.3%) vs. 28 (1.5%), p = 0.002). The risk of symptomatic stroke (both fatal and non-fatal) was higher in the group where a temporary shunt was not used, though this was statistically not significant. Logistic regression analysis identified diabetes mellitus and stenosis (81-90%) of the contralateral internal carotid artery to be important predictors for stroke. Temporary carotid shunts during carotid endarterectomy were associated with increased rates of asymptomatic stroke. There were no statistically significant differences in the incidence of non-fatal or fatal stroke, myocardial infarction, and mortality.

Unilateral developmental absence of internal carotid artery with contralateral middle cerebral artery occlusion.

Developmental absence of the internal carotid artery (ICA) is a rare congenital anomaly that results from an insult to the third aortic arch or dorsal aorta during early embryogenesis. Patients are often asymptomatic and are diagnosed incidentally during imaging to investigate neurological complaints. We report a rare finding of an absent ICA during a workup of stroke in a middle-aged patient. CT brain perfusion (CTP) and CT angiography (CTA) revealed the right middle cerebral artery (MCA) thrombotic stroke with the demonstration of contralateral left ICA absence. The patient showed spontaneous recovery, and no thrombolysis or neurointervention was considered. This article highlights the importance of screening the head CT on bone window settings in case of the non-visualization of ICA to differentiate congenital absence from a steno-occlusive disease. It also illustrates the role of Magnetic resonance imaging (MRI) and MR Angiography (MRA) in demonstrating further possible vascular anomalies, structural brain malformations, and collateral circulation.

Preclinical model of anterior circulation intracranial stenting

BackgroundPreclinical testing of intracranial stents is currently performed in the peripheral circulation, and rarely in the basilar artery of the dog.ObjectiveTo test the feasibility of intracranial stenting in the middle...

СРАВНИТЕЛЬНАЯ ОЦЕНКА РЕЗУЛЬТАТОВ СТЕНТИРОВАНИЯ СОННЫХ АРТЕРИЙ И КАРОТИДНОЙ ЭНДАРТЕРЭКТОМИИ У ПАЦИЕНТОВ С ВЫСОКИМ ХИРУРГИЧЕСКИМ РИСКОМ

ents with high surgical risk. Methods: 84 patients with combined lesions of carotid bifurcations and coronary arteries were examined. There were 55 men (65.6%), and 29 women (34.4%) aged 42-84 years (median age 64 years). Various comorbidities were identified in 52 (61.9%) patients. Patients were divided into two groups: those who underwent CAS (35) and CEA (49). The follow-up period after surgery was up to 30 days (early), and up to 8 years (long-term). A comparative assessment of perioperative complications and long-term results after CAS and CEA were carried out. Results: The identified cerebrovascular risk factors for the development of perioperative complications were identical in both groups: recent stroke, occlusion of the contralateral internal carotid artery (ICA), intracranial lesions, and anomalies of the circle of Willis. Other risks included psychoemotional stress (85%), risk of nerve damage, bleeding, angina III, and IV functional classes (53.5%). Although not statistically significant, noticeable differences were found in perioperative complications after CAS and CEA (14.3% vs. 28.6%, respectively, p&gt;0.05). In the long term, there were no statistically significant differences between the CAS and CEA groups in terms of overall survival (97.2% versus 100%, respectively, p&gt;0.05), transient ischemic attacks (2.8% versus 4.1%, respectively, p&gt;0.05), development of non-fatal myocardial infarction (MI) (11.4% versus 12.2%, respectively, p&gt;0.05), fatal MI (2.8% versus 0%, respectively). Conclusion: Analysis of the immediate results of CAS and CEA showed, although statistically insignificant, noticeable advantages of the first method in the overall frequency of perioperative complications (14.3% vs. 28.6%, p&gt;0.05) in patients from the category of high surgical risk. According to the main criteria of long-term results of the two methods, there was also no statistically significant difference, which allowed us to consider the endovascular method of treatment as an alternative to the traditional surgical technique. Keywords: Carotid artery stenting, carotid endarterectomy, high surgical risk, complications.

CTA Study of Ruptured Aneurysms of the Posterior Communicating Artery.

Background Only a few reported studies have used computed tomography angiography (CTA) to image ruptured aneurysms at the junction of the internal carotid artery (ICA) and posterior communicating artery (PcomA) in the context of the adjacent arteries. Therefore, we performed such a study using a GE Workstation. Methods The parameters of each aneurysm and its adjacent arteries were measured. Then, statistical assessments were performed to compare the parameters of the aneurysm side and the lesion-free (control) side. Results Sixty-three patients were included in this study. The average age was 62.1 ± 11.0 years, and the ratio of males to females was 0.8 : 1. The measurement results showed that the mean aneurysmal height was 5.2 ± 2.3 mm, the mean width was 4.7 ± 2.2 mm, and the mean neck width was 4.5 ± 1.9 mm. On the aneurysm side, the intradural ICA diameter was 4.34 ± 0.90 mm, and the diameter of the ICA at its termination was 3.55 ± 0.72 mm. A fetal-type PcomA was found in 52.4% of aneurysms. The other measured parameters were also provided. Statistical results showed that the height of the aneurysm was larger than the width (P < 0.05). The intradural ICA diameter, the ICA diameter at termination, the intradural ICA length, and the angle between the ICA and PcomA were larger in the aneurysm group than in the control group (P < 0.05). Conclusions This CTA study showed that the ruptured PcomA aneurysm was often wide-necked, nonspherical, and approximately 5 mm in size. In the presence of a ruptured PcomA aneurysm, the affected intradural ICA became thicker and longer than the contralateral control ICA, and the aneurysm significantly reduced the angle between the ICA and the PcomA.

Developed Circuminfundibular Anastomosis Associated with Vascular Abnormalities

We report a 74-year-old male patient who presented with left hemiplegia and disturbance of consciousness. Computed tomography revealed diffuse subarachnoid hemorrhage, which was prominent in the right Sylvian and basal cisterns. Digital subtraction angiography revealed absence of the C2 segment of the right internal carotid artery (ICA) and a significantly developed circuminfundibular anastomosis. Occlusion of the bilateral vertebral arteries (VAs) was also seen. The upper basilar artery was supplied by the circuminfundibular anastomosis and collaterals from the VAs. Since the source of bleeding was unclear, the patient was treated conservatively. Circuminfundibular anastomosis is a potential anastomosis around the pituitary stalk. It is formed by the superior hypophyseal arteries, prechiasmal arteries, and infundibular arteries bilaterally. Agenesis of the contralateral ICA often leads to development of ICA-ICA anastomoses. In this case, the anastomosis developed due to agenesis of the C2 segment of the right ICA and occlusion of the bilateral VAs.

Effects of Manual Versus Instrumental Spinal Manipulation on Blood Flow of the Vertebral and Internal Carotid Arteries in Participants With Chronic Nonspecific Neck Pain: A Single-Blind, Randomized Study

ObjectiveThe aim of this study was to compare the hemodynamic effects of manual spinal manipulation (MSM) and instrumental spinal manipulation (ISM) on the vertebral artery (VA) and internal carotid artery (ICA) in participants with chronic nonspecific neck pain (NNP). MethodsThirty volunteers aged 20 to 40 years old with NNP over 3 months duration were included. Participants were randomly divided into the following 2 groups: (1) MSM group (n = 15) and (2) ISM group (n = 15). Ipsilateral (intervention side) and contralateral (opposite side of intervention) VAs and ICAs were evaluated using spectral color Doppler ultrasound before and immediately after manipulation. Measurements were recorded by visualizing the ICA carotid sinus (C4 level) and the VA at the V3 segment (C1-C2 level). The blood flow parameters of peak systolic velocity (PSV), end-diastolic velocity, resistive index, and volume flow (only for VA) were evaluated. The spinal segment, in which biomechanical aberrant movement was detected by palpation in the upper cervical spine, was manually manipulated in the MSM group. The same methodology was performed for the ISM group using an Activator V instrument (Activator Methods). ResultsIntragroup analysis exhibited no statistically significant difference between the MSM and ISM groups in terms of PSV, end-diastolic velocity, resistive index of ipsilateral and contralateral ICA and VA, in addition to volume flow of both VAs preintervention and postintervention (P > .05). Within the intergroup analysis, there was a significant difference in ipsilateral ICA PSV (P = .031) (preintervention vs postintervention difference was –7.9 ± 17.2 cm/s [95% confidence interval, –17.4 to 1.6] in the ISM group and 8.7 ± 22.5 cm/s [95% confidence interval, –3.6 to 21.2]) in the MSM group (P < .05). Other parameters did not show any significant difference (P > .05). ConclusionManual and instrumental spinal manipulations applied to the upper cervical spine in participants with chronic NNP did not appear to alter blood flow parameters of the VAs and ICAs.

Hybrid revascularization: stenting of left internal carotid artery after restenosis, combined with left anterior descending artery stenting and right carotid endarterectomy

We present a description of internal carotid artery restenosis five years after eversion carotid endarterectomy, progression of contralateral internal carotid artery stenosis and coronary atherosclerosis with imaging of haemodynamically significant stenosis of the anterior descending artery. The efficacy of hybrid revascularization is demonstrated: carotid angioplasty with stenting of the left internal carotid artery stenosis + percutaneous coronary intervention for the anterior descending artery + left carotid endarterectomy. We explain the choice of these types of reconstruction and staging of the intervention. We make a conclusion regarding the effectiveness and safety of the implemented treatment strategy.