Distal Internal Carotid Artery Research Articles

Inverted stent deployment technique for stent assisted coiling of wide-necked posterior communicating artery aneurysm: Technical report.

Wide-necked aneurysms of the posterior communicating artery associated with a fetal posterior cerebral artery that arises from the neck or dome of the aneurysm is a clinical scenario that poses a challenge to endovascular methods. A patient presented with spontaneous subarachnoid hemorrhage and was found to have a 4 × 3 × 3 mm posterior communicating artery aneurysm. Of note the aneurysm projected superiorly and a fetal posterior communicating artery aneurysm arose from the neck of the aneurysm. After multidisciplinary discussion a treatment strategy of endovascular stent-assisted coiling was chosen. Given the unique morphology of the aneurysm a novel stent-inversion maneuver was used, in which the stent was deployed from the posterior communicating artery into the distal supra-clinoid internal carotid artery. The patient tolerated the procedure well and complete aneurysm occlusion was achieved. This case demonstrates a novel stent inversion technique that can be used for stent-assisted coiling of certain challenging aneurysms.

CT angiography for diagnosis of carotid near-occlusion: a digital subtraction angiography validation study.

Carotid near-occlusion (CNO) is a variant of severe stenosis where there is a distal luminal collapse of the internal carotid artery (ICA) beyond a tight stenosis. This study aimed to validate new visual extracranial diagnostic CT angiography (CTA) criteria, for the diagnosis of CNO. The new criteria include distal ICA diameter smaller than contralateral ICA and distal ICA diameter less than or equal to the ipsilateral external carotid artery (ECA). We also assessed the previously described CTA criteria: stenosis ≤ 1.3mm, ipsilateral distal ICA ≤ 3.5mm, ipsilateral distal ICA/contralateral distal ICA ratio ≤ 0.87, ipsilateral distal ICA/ipsilateral ECA ≤ 1.27. Fifty-eight patients with ICA stenosis (including the near-occlusion variant) or occlusion on digital subtraction angiography (DSA) were included. These patients had DSA and CTA studies completed within 30days of each other. DSA was considered the reference test. Two neuroradiologists blinded to the DSA results assessed the CTA images and evaluated the new and previously published CNO diagnostic criteria. Twenty-eight CNO were identified with DSA. The "distal ICA diameter less than or equal to the ipsilateral ECA" criterion had 79% sensitivity and 83% specificity with excellent interobserver agreement (kappa = 0.80), while three or more of the previously published criteria reached 82% sensitivity and 90% specificity, with a good interobserver agreement (kappa = 0.64). CT angiography may be useful for CNO diagnosis. The new visual diagnostic criteria provide acceptable results of sensitivity and specificity with an excellent interobserver agreement. However, false-negative and positive results persist.

Evaluation of Stent Apposition in the LVIS Blue Stent-Assisted Coiling of Distal Internal Carotid Artery Aneurysms : Correlation with Clinical and Angiographic Outcomes.

To evaluate the stent apposition of a low-profile visualized intraluminal support (LVIS) device in distal internal carotid artery (ICA) aneurysms, examine its correlation with clinical and angiographic outcomes, and determine the predictive factors of ischemic adverse events (IAEs) related to stent-assisted coiling. We retrospectively analyzed a prospectively maintained database of 183 patients between January 2017 and February 2020. The carotid siphon from the cavernous ICA to the ICA terminus was divided into posterior, anterior, and superior bends. The anterior bends were categorized into angled (V) and non-angled (C, U, and S) types depending on the morphology and measured angles. Complete stent apposition (CSA) and incomplete stent apposition (ISA) were evaluated using unsubtracted angiography and flat-panel detector computed tomography. Dual antiplatelet therapy with aspirin 200 mg and clopidogrel 75 mg was administered. Clopidogrel resistance was defined as fewer responders (≥10%, <40%) and non-responders (<10%) based on the percent inhibition (%INH) of the VerifyNow system. These were counteracted by a dose escalation to 150 mg for fewer responders or substitution with cilostazol 200 mg for non-responders. IAEs included intraoperative in-stent thrombosis, transient ischemic attack, cerebral infarction, and delayed in-stent stenosis. A multivariate logistic regression analysis was used to determine the predictive factors for ISA and IAEs. There were 33 ISAs (18.0%) and 27 IAEs (14.8%). The anterior bend angle was narrower in ISA (-4.16°±25.18°) than in CSA (23.52°±23.13°) (p<0.001). The V- and S-types were independently correlated with the ISA (p<0.001). However, treatment outcomes, including IAEs (15.3% vs. 12.1%), aneurysmal complete occlusion (91.3% vs. 88.6%), and recanalization (none of them), did not differ between CSA and ISA (p>0.05). The %INH of 27 IAEs (13.78%±14.78%) was significantly lower than that of 156 non-IAEs (26.82%±20.23%) (p<0.001). Non-responders to clopidogrel were the only significant predictive factor for IAEs (p=0.001). The angled and tortuous anatomical peculiarity of the carotid siphon caused ISA of the LVIS device; however, it did not affect clinical and angiographic outcomes, while the non-responders to clopidogrel affected the IAEs related to stent-assisted coiling.

Eversion endarterectomy of a segmental occlusion of internal carotid artery patent due to an aberrant ascending pharyngeal artery: A case report

Type II segmental internal carotid artery (ICA) occlusion has been described by Kniemeyer et al1 as total occlusion of the ICA at the carotid bifurcation with delayed orthograde filling through atypical collateral vessels of the proximal ICA. We present a rare case of segmental ICA occlusion with an aberrant ascending pharyngeal artery (APA) that maintains the patency of the distal ICA.

Extracranial-to-Intracranial Bypass for Distal Internal Carotid Artery and/or Proximal Middle Cerebral Artery Steno-Occlusive Disease: A Case Series of Clinical Outcomes at a Single, High-Volume Cerebrovascular Center.

Extracranial-to-intracranial (EC-IC) bypass was first described by Yasargil in the 1960s for treatment of symptomatic distal internal carotid artery (ICA) and/or proximal middle cerebral artery (MCA) steno-occlusive disease through direct anastomosis. Subsequent bypass trials failed to demonstrate benefit for overall outcomes and stroke rates compared with best medical therapy. However, the procedure remained in the neurosurgeon's armament, with studies showing benefits in select patient populations. With advancements in technology, patient selection has become more comprehensive. To provide a contemporary evaluation of EC-IC bypass from our high-volume cerebrovascular center, focusing on associated clinical outcomes. Consecutive patients who underwent direct EC-IC bypass surgeries for symptomatic distal ICA and/or proximal MCA steno-occlusive disease between April 2015 and September 2019 were identified retrospectively. Medical records were reviewed to collect demographics, clinical presentation, computed tomography perfusion imaging findings, transcranial Doppler results, procedure indication, donor vessel types, anastomosis site, bypass patency, periprocedural complications, postprocedural complications, symptom recrudescence, repeat or new interventions, subjective improvements, and modified Rankin Scale scores. We identified 27 patients who underwent 32 EC-IC bypass procedures. The rate of ipsilateral stroke was 9.4%, with a median follow-up of 8 months (IQR, 4-13 months). Patients experienced a 22.3% improvement in modified Rankin Scale scores, and 70.3% of patients reported subjective improvement and satisfaction at follow-up. Direct EC-IC bypass remains a viable option for revascularization in symptomatic patients with distal ICA and/or proximal MCA steno-occlusive disease.

The predictive value of internal carotid artery wall thickness in computed tomography angiography to avoid complications of plaque removal failure in modified eversion carotid endarterectomy.

The benefits of computed tomography carotid angiography (CTA) in terms of evaluating the anatomical structure of the carotid arteries, surgical planning, and evaluating possible risks were reported in previous studies. This study aimed to calculate the predictive value of internal carotid wall thickness in CTA that can predict whether a modified carotid eversion endarterectomy (MCEE) will result in a successful or not. This study was designed in a retrospective cross-sectional format. Consecutive 83 symptomatic carotid surgery patients who were operated in our hospital and had CTA were included in this study. The wall thickness of the internal carotid artery (ICA) 20mm distal from the carotid bifurcation was calculated in axial sections using a three-dimensional imaging technique. In addition, all patients' characteristics and laboratory findings were recorded. Patients who failed MCEE and required classical carotid endarterectomy were compared with patients who had successful MCEE. MCEE technique was applied to 62 patients. In 21 patients, the MCEE technique failed and the classical endarterectomy technique was required. Preoperative clinical and laboratory characteristics were similar in both groups. The mean ICA wall thickness was 0.65mm 20mm distal to from the carotid bifurcation and it was lower in the group with successful MCEE (1.03 ± 0.21mm vs. 0.56 ± 0.08mm) (p < 0.001). The critical ICA wall thickness was calculated as 0.76mm in the group that MCEE failed and classical carotid endarterectomy was required. Cut-off analysis of ICA wall thickness was calculated as 0.755mm in ROC analysis (p < 0.001), (95% confidence interval, curve area; 0.985). Successful carotid endarterectomy with the MCEE method is associated with distal ICA wall thickness and distal extension of the atheroma plate. The use of ICA wall thickness 20mm distal to from the bifurcation as a predictive value for the success of the MCEE technique is beneficial to avoid serious complications.

Endovascular treatment of distal internal carotid artery aneurysms and vertebral artery dissecting aneurysms with the Willis covered stent: A single-center, retrospective study.

More data is needed on the short- and medium-term efficacy and safety of the Willis covered stent in treating distal internal carotid artery (DICA) aneurysms and vertebral artery dissecting aneurysms (VADAs). Records of all 42 patients with DICA aneurysms or VADAs treated with the Willis covered stents at our institute between July 2014 and January 2019 were retrospectively examined. The patients' demographic information, symptoms, diagnosis, treatment procedure, immediate and follow-up clinical and angiographic outcomes were extracted. 46 Willis covered stents were successfully implanted in all of the 42 patients (total 43 aneurysms). Immediate complete aneurysm occlusion was achieved in 37 patients (38 aneurysms) (88.4%), and endoleak occurred to 5 patients (5 aneurysms) (11.6%). 2 patients died post-operatively from procedure-related complications, another one died from reasons unrelated to the procedure. Among the remaining 39 patients, non-lethal complications occurred in 4 patients including ptosis and diplopia of the right eye, intra-operative hemorrhage and carotid cavernous fistulas (CCF). Angiographic and clinical follow-ups (means ± standard deviation: 8.8 ± 5.3 months) were done for 32 patients (33 aneurysms). Complete occlusion was maintained in all of the 33 aneurysms. 2 of the 32 patients had significant though asymptomatic parent artery (PA) occlusion. No ischemic or hemorrhagic event occurred during the follow-up period. The modified Rankin Scale (mRS) score was 0 in 31 patients and 1 in the remaining 1 patient. The Willis covered stent could be a safe and effective treatment for complex DICA aneurysms with excellent durability. In addition, the Willis covered stent treated all of the 3 cases of VADAs in the study with complete success without any complications, however, as the number of the VADA cases was small, more cases are needed to further confirm the efficacy and safety of the Willis covered stent in treating VADAs.

Poststenotic Distal Caliber Reduction Predicts Very High-Grade Proximal Internal Carotid Artery Stenosis.

Angiography relates the residual lumen to the poststenotic distal lumen (NASCET criterion) and expresses the result in percent lumen reduction. This method is not applicable when there is a collapse of the distal lumen, as seen in severe stenosis. The purpose of this study was to evaluate whether the reduced poststenotic caliber could be an additional sonographic criterion for estimation of the degree of stenosis. We measured the caliber of the distal lumen of the extracranial internal carotid artery (ICA) in 57 patients with low-grade stenosis <50% (NASCET criterion), and in 57 patients with unilateral stenosis of ≥ 50 %. All were classified following international recommendations. The criteria used included the poststenotic velocity to discriminate moderate to high-grade stenosis (50-70%) from very high-grade (≥ 80 %) stenosis. In addition, we measured the interrater reliability of the ultrasonic measurement of the lumen in the distal ICA. In the group of patients with 50% to 70% stenosis, the distal lumen was 4.3 ± 0.6 mm. In the group with very high-grade stenosis ≥ 80%, the distal lumen was 2.6±0.5mm (p<0.0001). A distal lumen of 3.2 mm or less predicted a very high-grade stenosis with a sensitivity of 0.92 and a specificity of 0.96 (AUC 0.986; 95% CI 0.97-1.00; p=0.0001). The distal poststenotic lumen is an additional ultrasonic criterion to discriminate a very high-grade ICA stenosis from a lesser degree of ICA stenosis. It can help avoid misinterpretation due to the high variability of intrastenotic peak systolic velocities (PSV) in very high-grade ICA stenoses.

Acute Ischemic Stroke Caused by Internal Carotid Artery Occlusion: Impact of Occlusion Type on the Prognosis

We aimed to compare clinical outcomes of acute ischemic stroke (AIS) due to internal carotid artery (ICA) occlusion following mechanical thrombectomy (MT), focusing on occlusion types. We retrospectively reviewed 67 AIS patients who had an ICA occlusion on computed tomography angiography and underwent MT in a single tertiary center. ICA occlusion types were categorized as (1) true cervical ICA (cICA) occlusion (true occlusion), (2) pseudo-occlusion of the cICA (pseudo-occlusion), and (3) distal ICA (dICA) occlusion. We compared the clinical characteristics and their outcomes according to the ICA occlusion type. Fourteen patients were diagnosed with true occlusion, 32 with pseudo-occlusion, and 21 with dICA occlusion. The main etiologies were atherothrombotic in true occlusion (64.3%) and cardioembolic in pseudo-occlusion (81.3%) and dICA occlusion (71.4%) (P < 0.001). Pseudo-occlusion showed lower rates of successful reperfusion (37.5%, P= 0.009, 78.6% in true occlusion and 71.4% in dICA occlusion) and poor functional outcome at 3 months (18.8%, P= 0.037, 50% in true occlusion and 47.6% in dICA occlusion) with statistical significance. The infarction volume (169.4 ± 154.4 mL, P= 0.004, 29.2 ± 52.7 mL in true occlusion and 105.8 ± 13.4 mL in dICA occlusion) was significantly higher in pseudo-occlusion. On multivariate logistic analysis, pseudo-occlusion (odds ratio [OR]: 4.84, 95% confidence interval [CI] 1.02-22.87, P= 0.023) was an independent risk factor for poor reperfusion, which was significantly associated with a poor functional prognosis (OR: 22.04, 95% CI 1.99-243.83, P= 0.012). Patients with pseudo-occlusion showed poorer clinical outcomes compared with other ICA occlusion types, possibly due to a poor reperfusion rate after MT.

Abstract 144: Nuclear Smooth Muscle α-actin Is Critical For Smooth Muscle Cell Differentiation And To Prevent Cerebrovascular Disease

Missense pathogenic variants in ACTA2, encoding α-smooth muscle actin (SMA), predispose to thoracic aortic aneurysms. A subset of these ACTA2 pathogenic variants also predispose to childhood onset cerebrovascular disease characterized by occlusion of the distal internal carotid arteries and small vessel disease. In our studies to identify how specific ACTA2 pathogenic variants predispose to cerebrovascular disease, we confirmed that SMA is localized to the nucleus in wildtype (WT) smooth muscle cells (SMCs), is enriched in the nucleus over β-actin with differentiation of SMCs, associates with the INO80 chromatin remodeling complex, and selectively binds to the promoters of SMC contractile genes. Pluripotent stem cell-derived SMCs from patients with ACTA2 -associated cerebrovascular disease ( ACTA2 R179C) as well as SMCs explanted from a knockin mouse model ( Acta2 SMC-R179C/+ ) confirm that R179 variants disrupt SMA nuclear localization. Both mouse and human cells harboring the R179C pathogenic variant proliferate and migrate more than WT SMCs, are less differentiated than WT SMCs, and have increased expression of pluripotency-associated genes. Although the variant is heterozygous, these cells show a dominant negative impact on nuclear SMA function through dramatically reduced levels of SMA in the nucleus, in the INO80 chromatin remodeling complex, and on the promoters of SMC-specific genes. Finally, single cell RNA sequencing analysis of aortic tissue from an ACTA2 R179H patient confirms dedifferentiation of SMCs as a key phenotype associated with this mutation. Taken together, we have identified a novel role for α-SMA in driving differentiation of SMCs, and our data supports that defects in this nuclear role drive cellular phenotypes consistent with the cerebrovascular disease seen in patients with ACTA2 R179 pathogenic variants.

Discovery of a Moya-Moya Vascular Disease during an Inaugural Epileptic Seizure Leading to the Discovery of Ischemic Sequel: A Case Report and Review of the Literature

Moya-Moya disease is a vascular disease. In its typical form, it is characterized by a narrowing of the distal internal carotid artery that extends to the proximal segments of the middle and anterior cerebral arteries, resulting in the formation of collateral vessels. We report on a 49-year-old female patient who initially presented with epileptic seizures and was diagnosed with this condition.

Asymptomatic Carotid Bruit/Carotid Artery Stenosis

Stroke used to be the third leading cause of death in the United States, behind coronary artery disease and cancer. However, a 2011 report states that stroke has now dropped to the fourth leading cause of death. Nearly 80% of strokes are ischemic, but only 15% of stroke patients have warning transient ischemic attacks. The management of patients with asymptomatic carotid stenosis is controversial; in this review, a stepwise approach to the management of asymptomatic carotid bruit/extracranial carotid artery stenosis is provided. Specifically, this review covers clinical evaluation, carotid bruits, vascular risk evaluation, imaging modalities, natural history of asymptomatic carotid artery disease, carotid plaque progression, natural history of asymptomatic carotid stenosis with evidence of clinically silent cerebral emboli, recommendations for carotid intervention/medical therapy, level 1 evidence supporting carotid endarterectomy in asymptomatic patients, and decision making for medical therapy alone versus intervention. Figures show color Doppler image with Doppler sampling from the right common carotid artery (CCA) and internal carotid artery (ICA), color duplex image with Doppler sampling of the distal left CCA and proximal ICA, color duplex ultrasound image of a plaque at the carotid bifurcation, magnetic resonance angiography showing severe stenosis of the right ICA and occluded left ICA, computed tomographic angiography showing severe stenosis of the left ICA with calcification, diagram for management of patients with both carotid stenosis and coronary artery disease, and protocol of management of asymptomatic bruit/carotid artery stenosis. Tables list the annual risk of stroke, prevalence of carotid stenosis in patients with bruits and in healthy volunteers, duplex velocity criteria for carotid stenosis, consensus criteria, validation of consensus criteria: duplex ultrasonography versus angiographic stenosis, risk factors for stroke, ranking of modifiable stroke risk factors, asymptomatic randomized trials comparing medical with medical and surgical treatment (stenosis &gt; 60%), and a summary of specialty/societal guidelines. This review contains 7 highly rendered figures, 9 tables, and 91 references

Asymptomatic Carotid Bruit/Carotid Artery Stenosis

Stroke used to be the third leading cause of death in the United States, behind coronary artery disease and cancer. However, a 2011 report states that stroke has now dropped to the fourth leading cause of death. Nearly 80% of strokes are ischemic, but only 15% of stroke patients have warning transient ischemic attacks. The management of patients with asymptomatic carotid stenosis is controversial; in this review, a stepwise approach to the management of asymptomatic carotid bruit/extracranial carotid artery stenosis is provided. Specifically, this review covers clinical evaluation, carotid bruits, vascular risk evaluation, imaging modalities, natural history of asymptomatic carotid artery disease, carotid plaque progression, natural history of asymptomatic carotid stenosis with evidence of clinically silent cerebral emboli, recommendations for carotid intervention/medical therapy, level 1 evidence supporting carotid endarterectomy in asymptomatic patients, and decision making for medical therapy alone versus intervention. Figures show color Doppler image with Doppler sampling from the right common carotid artery (CCA) and internal carotid artery (ICA), color duplex image with Doppler sampling of the distal left CCA and proximal ICA, color duplex ultrasound image of a plaque at the carotid bifurcation, magnetic resonance angiography showing severe stenosis of the right ICA and occluded left ICA, computed tomographic angiography showing severe stenosis of the left ICA with calcification, diagram for management of patients with both carotid stenosis and coronary artery disease, and protocol of management of asymptomatic bruit/carotid artery stenosis. Tables list the annual risk of stroke, prevalence of carotid stenosis in patients with bruits and in healthy volunteers, duplex velocity criteria for carotid stenosis, consensus criteria, validation of consensus criteria: duplex ultrasonography versus angiographic stenosis, risk factors for stroke, ranking of modifiable stroke risk factors, asymptomatic randomized trials comparing medical with medical and surgical treatment (stenosis &gt; 60%), and a summary of specialty/societal guidelines. This review contains 7 highly rendered figures, 9 tables, and 91 references

Extradural anterior clinoidectomy versus endoscopic transplanum-transcavernous approach to the paraclinoid region: quantitative anatomical exposure analysis.

Transcranial anterior clinoidectomy is a conventional microsurgical approach for treatment of paraclinoid aneurysms. The endoscopic endonasal approach (EEA) is an alternative method for clipping intracranial aneurysms. No analysis has been conducted to anatomically compare approaches with respect to treating paraclinoid aneurysms. The surgical anatomical exposures of the paraclinoid region during transcranial extradural anterior clinoidectomy (EAC) and the endoscopic endonasal transplanum-cavernous approach (EETC) are described and quantitatively assessed. Seven cadaveric heads underwent EAC and EETC. Measurements included the area of exposure, volume of surgical freedom, angle of attack, ophthalmic artery (OphA) origin, and coronal exposure angle of the internal carotid artery (ICA). The EETC provided a larger area of exposure than the EAC (100.1±24.9 vs 76.1±12.9 mm2, p = 0.04). The EAC provided a higher volume of surgical freedom and greater angle of attack than the EETC in all neurovascular parameters, including the OphA, superior hypophyseal artery (SHA), distal ICA, and distal dural ring (all p < 0.001). The OphA origin was intradural in 85.7% and extradural in 14.3% of specimens. With regard to the coronal angle of exposure, the EAC exposed the OphA and SHA in the upper lateral quadrant (67.9±7.8° and 80.6±4.5°, respectively) and the distal ICA in the upper medial and upper lateral quadrants (92±7.5°). The EEA exposed the OphA, SHA, and distal ICA in the upper medial and lower medial quadrants (130.4±10.7°, 68.4±10.8°, and 58±11.4°, respectively). The EAC and EETC each offer specific advantages for paraclinoid region exposure. The EAC is appropriate for paraclinoid aneurysms that occur at the dorsolateral surface of the paraclinoid ICA. The EETC is an alternative approach for aneurysms that occur along medial surface of the paraclinoid ICA (e.g., carotid cave and SHA aneurysms). The EETC provides greater surgical exposure to the medial aspect of the paraclinoid ICA.

Treatment of ruptured aneurysms of the choroidal collateral system in moyamoya disease: a systematic review and data analysis.

Moyamoya disease (MMD) is a chronic, progressive steno-occlusive condition of the distal internal carotid arteries of unknown etiology. Collateral arterial networks typically develop in MMD, bypassing the steno-occlusion. Aneurysms arising on the collateral networks are a known source of hemorrhage. The choroidal collateral system is the most common location for collateral pathway aneurysms in MMD and associated hemorrhage. The authors performed data collection and analysis to further elucidate the best treatment approaches for ruptured aneurysms of the choroidal collateral system in MMD, which as yet remain unclear. A comprehensive data collection and analysis of case reports and case series with ruptured choroidal collateral artery aneurysms (CCAAs) was performed. PRISMA guidelines for systematic reviews were followed and the Medline, Embase, and Scopus databases were searched for relevant studies. A database was created including patients with ruptured CCAA in MMD. Original data from case series were included whenever possible. A previously unreported case of a ruptured choroidal artery aneurysm in MMD treated by the authors was also included. The database comprised 72 patients with ruptured CCAA in MMD. The most common clinical symptoms were headache, nausea, and vomiting (39%). Initially, a conservative treatment approach was chosen in 29% of cases but led to rehemorrhage in 40% of cases; 63% of these rehemorrhages occurred during the first 35 days. Endovascular treatment seemed a safe option for aneurysm exclusion, mainly through parent vessel sacrifice, but had a treatment failure rate of 21%, due to inadequate access. Aneurysm treatment with revascularization as the initial treatment strategy led to aneurysm regression in 82% with no reported rehemorrhage. Aneurysm exclusion through open surgery was effective but was associated with a relatively high complication rate (25%). Outcome after rupture of CCAA was poor, with 41% of patients deceased or permanently disabled. Overall, patient outcomes were better in the endovascular and revascularization treatment group than in the conservative treatment group. Rupture of CCAA in MMD is associated with high morbidity and rerupture rate requiring urgent treatment.

Thrombosis or vasospasm: The utility of intraoperative neuromonitoring during TCAR.

Transcarotid artery revascularization (TCAR) has become more prevalent as a treatment modality for carotid stenosis. Many centers perform TCAR without any adjunctive neuromonitoring, for example, somatosensory-evoked potential (SSEP) and electroencephalogram (EEG). We present a case of transcarotid artery revascularization (TCAR) performed with concomitant somatosensory-evoked potential (SSEP) and electroencephalogram (EEG) neuromonitoring in the setting of concerning intraoperative angiographic images. TCAR was undertaken for a 58year-old man presenting with symptomatic left carotid stenosis and right ICA occlusion. Based on his comorbidities, pre-existing conditions, and the need for dual antiplatelet therapy, TCAR was offered as an alternative to standard carotid endarterectomy. Intraoperatively, following stent delivery, no flow was appreciated through the carotid stent or distal ICA. Neuromonitoring remained stable and was reassuring for distal ICA spasm with no-reflow phenomenon. The patient tolerated the procedure well and has had no stent-related complications through 10months of follow-up. This case highlights the utility of neuromonitoring with TCAR as an adjunct to intraoperative decision-making in the setting of suspected internal carotid artery (ICA) vasospasm versus thrombosis after stent delivery.

Functional Aplasia of the Contralateral A1 Segment Influences Clinical Outcome in Patients with Occlusion of the Distal Internal Carotid Artery.

Background: The importance of an A1 aplasia remains unclear in stroke patients. In this work, we analyze the impact of an A1 aplasia contralateral to an acute occlusion of the distal internal carotid artery (ICA) on clinical outcomes. Methods: We conducted a retrospective study of consecutive stroke patients treated with mechanical thrombectomy at 12 tertiary care centers between January 2015 and February 2021 due to an occlusion of the distal ICA. Functional A1 aplasia was defined as the absence of A1 or hypoplastic A1 (>50% reduction to the contralateral site). Functional independence was measured by the modified Rankin Scale (mRS ≤ 2). Results: In total, 81 out of 1068 (8%) patients had functional A1 aplasia contralateral to distal ICA occlusion. Patients with functional contralateral A1 aplasia were more severely affected on admission (median NIHSS 18, IQR 15–23 vs. 17, IQR 13–21; aOR: 0.672, 95% CI: 0.448–1.007, p = 0.054) and post-interventional ischemic damage was larger (median ASPECTS 5, IQR 1–7, vs. 6, IQR 3–8; aOR: 1.817, 95% CI: 1.184–2.789, p = 0.006). Infarction occurred more often within the ipsilateral ACA territory (20/76, 26% vs. 110/961, 11%; aOR: 2.482, 95% CI: 1.389–4.437, p = 0.002) and both ACA territories (8/76, 11% vs. 5/961, 1%; aOR: 17.968, 95% CI: 4.979–64.847, p ≤ 0.001). Functional contralateral A1 aplasia was associated with a lower rate of functional independence at discharge (6/81, 8% vs. 194/965, 20%; aOR: 2.579, 95% CI: 1.086–6.122, p = 0.032) and after 90 days (5/55, 9% vs. 170/723, 24%; aOR: 2.664, 95% CI: 1.031–6.883, p = 0.043). Conclusions: A functional A1 aplasia contralateral to a distal ICA occlusion is associated with a poorer clinical outcome.

Factors Distinguishing Proximal and Distal Internal Carotid Artery Occlusions in Patients with Acute Ischemic Stroke.

Acute internal carotid artery (ICA) occlusions cause extensive brain ischemia. Accurate determination of the occlusion site facilitates rapid revascularization interventions and improves prognosis. However, proximal ICA occlusions, as determined with computed tomography (CT) angiography, often are located more distally. Therefore, we assessed clinical and imaging factors associated with the accurate determination of occlusion sites. In this observational study, we evaluated 102 patients who presented acute ischemic stroke symptoms and had a CT angiography within 6 h, showing proximal ICA occlusion. The participants were divided into two groups, depending on whether there was correspondence between digital subtraction angiography and CT angiography regarding the occlusion location. Proximal occlusions were, accordingly, categorized as “true” (correspondence) or “false” (no correspondence; distal). Demographic, clinical, and imaging features were analyzed. Multivariate regression analysis was performed to identify factors predicting the correspondence between actual ICA occlusion sites and those detected by CT angiography. The shape (Odds ratios, OR = 646.584; Confidence interval, CI = 21.703–19263.187; p < 0.001) and the length (OR = 0.696; CI = 0.535–0.904; p = 0.007) of the ICA occlusion and atrial fibrillation (OR = 0.024; CI = 0.002–0.340; p = 0.006) were significant factors. The cut-off length of ICA stump at 6.2 mm, the sensitivity was 71%, and the specificity was 70% (area under the ROC curve = 0.767).

Acute and Delayed Cerebrovascular Injury From Gunshot to the Head in a 12-Year-Old Child During the COVID-19 Pandemic

Acute and Delayed Cerebrovascular Injury From Gunshot to the Head in a 12-Year-Old Child During the COVID-19 Pandemic

Artificial intelligence software for diagnosing intracranial arterial occlusion in patients with acute ischemic stroke.

To evaluate the diagnostic performance of AI software in diagnosing intracranial arterial occlusions in the proximal anterior circulation at CT angiography (CTA) and to compare it to manual reading performed in clinical practice. Patients with acute ischemic stroke underwent CTA to detect arterial occlusion in the proximal anterior circulation. Retrospective review of CTA scans by two neuroradiologists served as reference standard. Sensitivity and specificity of AI software (StrokeViewer) were compared to those of manual reading using the McNemar test. The proportions of correctly detected occlusions in the distal internal carotid artery and/or M1 segment of the middle cerebral artery (large vessel occlusion [LVO]) and in the M2 segment of the middle cerebral artery (medium vessel occlusion [MeVO]) were calculated. Of the 474 patients, 75 (15.8%) had an arterial occlusion in the proximal anterior circulation according to the reference standard. Sensitivity of StrokeViewer software was not significantly different compared to that of manual reading (77.3% vs. 78.7%, P = 1.000). Specificity of StrokeViewer software was significantly lower than that of manual reading (88.5% vs. 100%, P < 0.001). StrokeViewer software correctly identified 40 of 42 LVOs (95.2%) and 18 of 33 MeVOs (54.5%). StrokeViewer software detected 8 of 16 (50%) intracranial arterial occlusions which were missed by manual reading. The current AI software detected intracranial arterial occlusion with moderate sensitivity and fairly high specificity. The AI software may detect additional occlusions which are missed by manual reading. As such, the use of AI software may be of value in clinical stroke care.