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Abstract The hypothesis of this study was that evaluation of radiodensity assessment beyond a carotid stenosis in arterial and/or venous phase can be used to separate near-occlusion and conventional ≥ 50% stenosis. We prospectively included participants with ≥ 50% carotid stenosis with inclusion preference for cases with extracranial internal carotid artery (ICA) asymmetry. All participants were examined with a research biphasic computed tomography angiography (CTA) protocol (arterial and venous phase). Reference diagnosis was set by interpretation on CTA and radiodensity difference between ipsilateral and contralateral ICA (c-corrected) or vertebral (v-corrected) was compared. We included 93 participants, 62 with near-occlusion and 31 with conventional ≥ 50% stenosis. Just beyond the stenosis, median c-corrected radiodensity was − 20 Hounsfield units (HU) among near-occlusions and − 1 HU among conventional ≥ 50% stenoses (p

Purpose: Compare extracranial internal carotid artery flow rates and intracranial collateral use between conventional ≥ 50% carotid stenosis and carotid near-occlusion, and between symptomatic and asymptomatic carotid near-occlusion. Methods: We included patients with ≥ 50% carotid stenosis. Degree of stenosis was diagnosed on CTA. Mean blood flow rates were assessed with four-dimensional phase-contrast MRI. Results: We included 110 patients of which 83% were symptomatic, and 38% had near-occlusion. Near-occlusions had lower mean internal carotid artery flow (70 ml/min) than conventional ≥ 50% stenoses (203 ml/min, P <.001). Definite use of ≥ 1 collateral was found in 83% (35/42) of near-occlusions and 10% (7/68) of conventional stenoses (P <.001). However, there were no differences in total cerebral blood flow (514 ml/min vs. 519 ml/min, P =.78) or ipsilateral hemispheric blood flow (234 vs. 227 ml/min, P =.52), between near-occlusions and conventional ≥ 50% stenoses, based on phase-contrast MRI flow rates. There were no differences in total cerebral or hemispheric blood flow, or collateral use, between symptomatic and asymptomatic near-occlusions. Conclusion: Near-occlusions have lower internal carotid artery flow rates and more collateral use, but similar total cerebral blood flow and hemispheric blood flow, compared to conventional ≥ 50% carotid stenosis. [ABSTRACT FROM AUTHOR]

Current guidelines recommend best medical treatment (BMT) over revascularization for carotid near-occlusion (CNO); however, it remains unclear whether BMT, carotid artery stenting (CAS), or carotid endarterectomy (CEA) is the optimal treatment strategy. The present meta-analysis aimed to compare outcomes among patients with CNO receiving BMT, CAS, or CEA. PubMed, Web of Science, Scopus, and Embase were searched. English studies with ≥1 month follow-up, that used established CNO diagnostic guidelines, that provided outcomes by treatment, and in which 95% confidence intervals (CIs) were calculable were included. Studies on acute ischemic stroke (AIS) requiring emergent reperfusion therapy, nonatherosclerotic lesions, nonprimary research articles, non-English, and nonhuman studies were excluded. Outcomes were mortality, AIS, transient ischemic attack, myocardial infarction within and beyond 30 days, and restenosis. A generalized linear mixed model, subgroup analysis, and meta-regression were used to compare outcomes. Thirty-eight studies were included. Pooled rates for AIS beyond 30 days were 9.90% (95% CI, 4.31%–21.16%), 0.79% (95% CI, 0.24%–2.53%), and 0.80% (95% CI, 0.15%–4.07%) for BMT, CAS, and CEA, respectively. Subgroup analysis was statistically significant (P < 0.001). Meta-regression showed lower incidence favoring procedural intervention (CAS vs. BMT, P = 0.001; CEA vs. BMT, P = 0.003). Subgroup analysis for mortality beyond 30 days was also significant (P = 0.016) but meta-regression did not favor one treatment over another. Other outcomes were not statistically significant. Revascularization for CNO may decrease long-term stroke rates. Given that current guidelines are based on randomized controlled trials from the 1990s, updated randomized trials are warranted to determine the optimal treatment for CNO. [ABSTRACT FROM AUTHOR]

Background and objectives: The study sought to examine how symptomatic and asymptomatic carotid near-occlusion appeared on angiography. Methods: A blinded study evaluated 635 patients for consecutive CTAs at NRI Medical College/Hospital from June 2021 to May 2022 for estimation of symptomatic and asymptomatic carotid near occlusion. Results: 380 (60%) of the 635 patients (50% carotid stenosis) were symptomatic. Both symptomatic (112, 30%) and asymptomatic (50, 25%) cases of near-occlusion shared the same prevalence. Between symptomatic and asymptomatic cases with near-occlusion, the angiographic appearance was remarkably similar: the mean stenosis lumen diameter (0.7 mm), distal ICA diameter (2.1 mm), and ECA ratio (0.79) were the same in both groups. The average ICA ratio (0.46 and 0.48) and fraction of full collapse (46% and 40%) were fairly similar. Conclusion: The primary conclusion of this study was that there was no change in the angiographic appearance of near-occlusions between symptomatic patients and asymptomatic individuals. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the angiographic appearance of symptomatic and asymptomatic carotid near-occlusion. We have found no such previous study. The study hypothesis was that among symptomatic patients with ≥ 50% carotid stenosis, near-occlusion is more common and near-occlusions are more severe than among asymptomatic persons with ≥ 50% carotid stenosis. We reassessed consecutive CTAs from 4042 persons, 645 had ≥ 50% carotid stenosis, and 385 (60%) symptomatic. Near-occlusion was similarly common in symptomatic (105, 27%) and asymptomatic (56, 24%) cases. Among near-occlusions, the angiographic appearance was very similar between symptomatic and asymptomatic cases: mean stenosis lumen diameter (0.7 mm), distal ICA diameter (2.1 mm), and ECA ratio (0.79) were the same in both groups. Mean ICA ratio (0.46 and 0.48) and share of full collapse was very similar (45% and 42%). These findings add to the pathophysiological understanding of carotid near-occlusion. [ABSTRACT FROM AUTHOR]

Extracranial internal carotid stenosis (EICS) is a well-established cause of stroke. Carotid near-occlusion (CNO), either distally collapsed or not, is a rare sub-type of EICS with conflicting data regarding the necessity for treatment. The aim of this study is to evaluate the results of carotid artery stenting (CAS) for patients with symptomatic CNOs.Institutional review board (I06-420-23) approval was obtained for this retrospective study. Consecutive data from January 2019 to January 2023 was obtained. Sixty-five patients underwent 66 procedures for symptomatic CNOs. Diagnosis of CNOs were made with DSA images. Treatment decisions were made by a multidisciplinary team. Patient data including age, gender, clinical presentation, affected side, complications (initial/ follow-up), and pre and post mRS scores were recorded and analyzed.There were 22 female and 43 male patients with symptomatic CNOs (mean age: 71.52 ± 9.32 years). The mean time from symptom-to-treatment was 3.91 weeks ± 3.74 weeks (ranging from 0 to 20 weeks). There were eight events recorded in the 30 days period after CAS; five (7.7%) were cerebral hyperperfusion syndrome (one causing haemorrhage) and three (4.5%) ischemic complications. Permanent neurologic deficit rate was 6% and 61 patients (94%) mRS scores were unchanged during last follow-up. Mean follow-up period was 22.94 ± 16.67 months (ranging from 0.5 to 60 months).Our study demonstrated that in the complex population of patients with symptomatic CNOs, CAS is a feasible option with acceptable rate of permanent neurologic deficits. Further studies are needed to assess its safety and long-term efficacy. [ABSTRACT FROM AUTHOR]

The hypothesis of this study was that evaluation of radiodensity assessment beyond a carotid stenosis in arterial and/or venous phase can be used to separate near-occlusion and conventional ≥ 50% stenosis. We prospectively included participants with ≥ 50% carotid stenosis with inclusion preference for cases with extracranial internal carotid artery (ICA) asymmetry. All participants were examined with a research biphasic computed tomography angiography (CTA) protocol (arterial and venous phase). Reference diagnosis was set by interpretation on CTA and radiodensity difference between ipsilateral and contralateral ICA (c-corrected) or vertebral (v-corrected) was compared. We included 93 participants, 62 with near-occlusion and 31 with conventional ≥ 50% stenosis. Just beyond the stenosis, median c-corrected radiodensity was - 20 Hounsfield units (HU) among near-occlusions and - 1 HU among conventional ≥ 50% stenoses (p < 0.001) in the arterial phase. For the venous phase, these findings were + 17 HU and + 3 HU (p = 0.007). Similar group differences were seen for v-correction. No parameter had good diagnostic performance, area under the curve ≤ 0.82. With specificity set at ≥ 95%, detected near-occlusions were foremost those with large side-to-side differences in distal ICA-diameter. Carotid near-occlusions can have reduced radiodensity beyond the stenosis in arterial phases and increased radiodensity in venous phases compared to a reference artery-which was not clearly seen for conventional stenoses. However, these radiodensity findings are best seen in near-occlusion cases that are not diagnostically challenging, while they work poorly as additional diagnostic aids., (© 2024. The Author(s).)

Purpose: Create a new definition of near-occlusion with full collapse to predicting recurrent stroke. Methods: Pooled analysis of two studies. Patients with symptomatic ≥ 50% carotid stenoses were included. Outcome was preoperative recurrent ipsilateral ischemic stroke or retinal artery occlusion within 28 days of presenting event. We analyzed several artery diameters on computed tomography angiography and stenosis velocity on ultrasound. Results: A total of 430 patients with symptomatic ≥ 50% carotid stenosis were included, 27% had near-occlusion. By traditional definition, 27% with full collapse and 11% without full collapse reached the outcome (p = 0.047). Distal internal carotid artery (ICA) diameter, ICA ratio, and ICA-to-external carotid artery ratio were associated with the outcome. Best new definition of full collapse was distal ICA diameter ≤ 2.0 mm and/or ICA ratio ≤ 0.42. With this new definition, 36% with full collapse and 4% without full collapse reached the outcome (p < 0.001). Conclusions: Defining near-occlusion with full collapse as distal ICA diameter ≤ 2.0 mm and/or ICA ratio ≤ 0.42 seems to yield better prognostic discrimination than the traditional appearance-based definition. This novel definition can be used in prognostic and treatment studies of near-occlusion with full collapse. [ABSTRACT FROM AUTHOR]

Purpose: To assess the sensitivity and specificity of common carotid ultrasound method for carotid near-occlusion diagnosis. Methods: Five hundred forty-eight patients examined with both ultrasound and CTA within 30 days of each other were analyzed. CTA graded by near-occlusion experts was used as reference standard. Low flow velocity, unusual findings, and commonly used flow velocity parameters were analyzed. Results: One hundred three near-occlusions, 272 conventional ≥50% stenosis, 162 <50% stenosis, and 11 occlusions were included. Carotid ultrasound was 22% (95%CI 14–30%; 23/103) sensitive and 99% (95%CI 99–100%; 442/445) specific for near-occlusion diagnosis. Near-occlusions overlooked on ultrasound were found misdiagnosed as occlusions (n = 13, 13%), conventional ≥50% stenosis (n = 65, 63%) and < 50% stenosis (n = 2, 2%). No velocity parameter or combination of parameters could identify the 65 near-occlusions mistaken for conventional ≥50% stenoses with >75% sensitivity and specificity. Conclusion: Near-occlusion is difficult to diagnose with commonly used carotid ultrasound methods. Improved carotid ultrasound methods are needed if ultrasound is to retain its position as sole preoperative modality. [ABSTRACT FROM AUTHOR]

Purpose: The ultrasonographic and hemodynamic features of patients with carotid near-occlusion (CNO) are still not well known. Our aim was to describe the ultrasonographic and hemodynamic characteristics of a cohort of patients with CNO. Methods: A prospective, observational, nationwide, and multicenter study was conducted from January/2010 to May/2016. Patients with digital subtraction angiography (DSA)–confirmed CNO were included. We collected information on clinical and demographic characteristics, carotid and transcranial ultrasonography and DSA findings, presence of full-collapse, collateral circulation, and cerebrovascular reactivity (CVR). Results: One hundred thirty-five patients were analyzed. Ultrasonographic and DSA diagnosis of CNO were concordant in only 44%. This disagreement was related to the presence/absence of full-collapse: 45% of patients with CNO with full-collapse were classified as a complete carotid occlusion, and 40% with a CNO without full-collapse were interpreted as severe stenosis (p < 0.001). Mean velocities (mV) and pulsatility indexes (PIs) were significantly lower in the ipsilateral middle cerebral artery compared with the contralateral (43 cm/s vs 58 cm/s, p < 0.001; 0.80 vs 1.00, p < 0.001). Collateral circulation was identified in 92% of patients, with the anterior communicating artery (73%) being the most frequent. CVR was decreased or exhausted in 66% of cases and was more frequent in patients with a poor or absent collateral network compared with patients with ≥ 2 collateral arteries (82% vs 56%, p = 0.051). Conclusion: The accuracy of carotid ultrasonography in the diagnosis of CNO seems to be limited, with significant discrepancies with DSA. Decreased ipsilateral mV, PI, and CVR suggest a hemodynamic compromise in patients with CNO. [ABSTRACT FROM AUTHOR]

Background and purpose: The risk of recurrent stroke amongst patients with symptomatic carotid near‐occlusion (SCNO) has not been clearly established, and its management remains controversial. The aim was to define the 24‐month risk of recurrent stroke and to analyse the effect of the different treatment modalities (medical treatment and revascularization) in a population of patients with SCNO. Methods: A multicentre, nationwide, prospective study from January 2010 to May 2016 was performed. Patients with angiography‐confirmed SCNO were included. The primary end‐point was ipsilateral ischaemic stroke including periprocedural events within 24 months following the presenting event. Revascularization results and periprocedural complications, ipsilateral transient ischaemic attack, disabling or fatal stroke, and mortality were also noted. Results: The study population comprised 141 patients from 17 Spanish centres. Seventy patients (49.6%) were treated by revascularization (carotid stenting in 47, endarterectomy in 23). Complete revascularization was achieved in 58 patients (83%). Periprocedural stroke or death occurred in 5.7%. The 24‐month cumulative incidence of the primary end‐point was 11.1% (95% confidence interval 5.8–16.4; n = 15), 12% in the medical treatment group and 10.2% in the revascularization group, log‐rank P = 0.817. The cumulative rates of ipsilateral ischaemic stroke or transient ischaemic attack, disabling or fatal stroke, and mortality, were 17%, 4.5% and 7.5%, respectively. Conclusions: The rate of ipsilateral ischaemic stroke in patients with SCNO seems to be lower than the known rate associated with severe carotid stenosis without near‐occlusion. The potential benefit of revascularization in the prevention of stroke in patients with SCNO may be influenced by the effectiveness and safety of the procedure. [ABSTRACT FROM AUTHOR]

Background: The risk of recurrent stroke among patients with symptomatic carotid near-occlusion is not well established, and management of the condition remains controversial. Symptomatic carotid near-occlusion with full collapse has been identified as a strong predictor of early recurrence. We aimed to analyze the 90-day risk of recurrent ipsilateral ischemic stroke in medically treated patients with symptomatic carotid near-occlusion. Methods: We performed a multicenter, nationwide, prospective study from January 2010 to May 2016. Patients with angiography-confirmed symptomatic carotid near-occlusion were included. The primary endpoint was ipsilateral ischemic stroke or transient ischemic attack (TIA) within 90 days after the presenting event. For this analysis, patients who underwent revascularization within 90 days after stroke were excluded. Results: The study population comprised 141 patients from 17 Spanish centers; 83 patients were treated medically. Primary endpoint occurred in eight patients, resulting in a cumulative rate of 10.6% (95% CI, 3.7-17.5). Previous history of stroke or transient ischemic attack was identified as an independent predictor for recurrence in the multivariate Cox regression analysis (HR, 4.37 [95% CI, 1.05-18.18]; p=0.043), while the presence of full collapse was not associated with an increased risk (HR, 0.81 [95% CI, 0.17-3.92]; p=0.793). The risk of recurrence was also not affected by the presence of significant stenosis or occlusion of the contralateral carotid artery, or by the collateral circulation. Conclusions: Patients with symptomatic carotid near-occlusion seem to have an increased risk of early ipsilateral recurrent stroke. Our results contrast with the low risk of symptomatic carotid near-occlusion reported to date. Full collapse did not increase the risk of recurrent stroke in our study. [ABSTRACT FROM AUTHOR]

Background The risk of early stroke recurrence amongst patients with symptomatic carotid near-occlusion with and without full collapse is unknown. Therefore, the aim of this study was to analyse the 90-day risk of recurrent ipsilateral ischaemic stroke in patients with symptomatic carotid near-occlusion both with and without full collapse. Methods This study was a secondary analysis of the Additional Neurological SYmptoms before Surgery of the Carotid Arteries: a Prospective study ( ANSYSCAP). We prospectively analysed 230 consecutive patients with symptomatic 50-99% carotid stenosis or near-occlusion. Based on the combination of several imaging modalities, 205 (89%) patients were classified as having 50-99% carotid stenosis, and 10 (4%) and 15 (7%) as having near-occlusion with and without full collapse, respectively. The 90-day risk of recurrent ipsilateral ischaemic stroke was compared between these three groups. Only events that occurred before carotid endarterectomy were analysed. Results The 90-day risk of recurrent stroke was 18% [95% confidence interval ( CI) 12-25%; n = 29] for patients with 50-99% carotid stenosis, 0% for patients with near-occlusion without full collapse and 43% (95% CI 25-89%; n = 4) for patients with near-occlusion with full collapse ( P = 0.035, log-rank test). The increased risk of recurrent ipsilateral ischaemic stroke for patients with symptomatic near-occlusion with full collapse remained significant after multivariable adjustment for age, sex and type of presenting event. Conclusions Patients with symptomatic carotid near-occlusion with full collapse might have a very high risk of stroke recurrence. Carotid endarterectomy could be considered for these patients. [ABSTRACT FROM AUTHOR]

In the present case, we directly visualized the pendulum movement of the contrast agent downstream of a carotid near-occlusion during digital subtraction angiography, suggesting the existence of "to-and-fro" stagnant flow created by the significant flow reduction and high back pressure from visible ophthalmic collaterals with blood stagnation distal to the stenosis. The pendular movement phenomenon represents a stagnation of blood that could be associated with an increased risk of thrombus formation and subsequent embolization to more distal arterial territories. This case may partially explain not only the embolic mechanism for stroke in carotid near-occlusion but the recent observation that collateral circulation through the ipsilateral ophthalmic artery is associated independently with an increased risk of the progression of carotid near-occlusion to complete occlusion. [ABSTRACT FROM AUTHOR]

Background: Symptomatic carotid near-occlusion is often described as rare. Recent studies have shown that near-occlusions are overlooked, especially near-occlusion without full collapse (with a small but normal-appearing distal internal carotid artery)., Objective: To assess the prevalence of near-occlusion among symptomatic ≥50% carotid stenosis, incidence of symptomatic near-occlusion, and review the literature., Methods: Prospective controlled single-center cross-sectional study. Consecutive cases with symptomatic ≥50% carotid stenosis were examined with computed tomography angiography (CTA). The CTAs were assessed for near-occlusion by two observers. A systematic literature review was performed with emphasis on how study design affects prevalence estimate., Results: Totally, 186 patients with symptomatic ≥50% carotid stenosis were included, 34% (n = 63, 95% CI 27, 41) had near-occlusion. The incidence of symptomatic near-occlusion was 3.4 (95% CI 2.5, 4.2) per 100,000 person-years. Inter-rater κ was 0.71. The average prevalence of near-occlusion among symptomatic ≥50% carotid stenosis was higher in studies with good design (30%, range 27%-34%) than studies without good design (9%, range 2%-10%)., Conclusions: Near-occlusion is common variant of symptomatic ≥50% carotid stenosis, both in the current study and in all previous studies of good design. Studies that suggest that near-occlusion is rare have had methodological issues.