Search Results (103)

Background: Carotid artery stenting (CAS) is a common revascularization approach for carotid artery stenosis. While its impact on the internal carotid artery (ICA) has been extensively studied, the effects on the external carotid artery (ECA)—a key collateral pathway for cerebral perfusion—remain insufficiently explored. This study aimed to assess structural changes in the ECA following CAS and their clinical significance. Methods: A retrospective observational cohort study of 963 patients treated with CAS between 2018 and 2024 was conducted. Demographic data, comorbidities, and procedural characteristics were collected. Pre- and postprocedural ICA and ECA diameters were measured via angiography. Spearman’s correlation, regression modeling, and receiver operating curver (ROC) analysis were used to identify predictors of ECA narrowing and occlusion and their relationship with neurological outcomes. Results: The median ECA diameter decreased post-CAS (from 4.7 mm to 3.8 mm, p < 0.001). ECA overstenting occurred in 96.4% of cases, with 71.7% exhibiting diameter reduction. De novo ECA occlusion occurred in 2.5% of patients and was associated with a higher incidence of stroke, transient ischemic attack, and in-stent restenosis (ISR). Multivariate analysis identified preoperative ECA diameter (p < 0.001), ICA diameter (p = 0.001), and second-generation stents (p = 0.02) as independent predictors of ECA narrowing. ROC analysis confirmed that a preoperative ECA diameter ≤ 3.05 mm strongly predicted occlusion (Area under the curve (AUC) = 0.93, p < 0.001). Conclusions: CAS frequently leads to ECA remodeling, including occlusion, compromising collateral perfusion and contributing to adverse ischemic incidences and ISR. Preprocedural ECA assessment may aid in optimizing patient selection and procedural planning. Full article

Introduction: Isolated true subclavian artery aneurysm (SAA) is a rare form of peripheral arterial aneurysm that poses significant anatomical challenges to endovascular repair, especially in cases requiring planned vertebral artery (VA) sacrifice. The Balloon Occlusion Test (BOT) is a critical preoperative tool for evaluating collateral circulation before VA embolization. Case Report: A 74-year-old male was admitted with a pulsatile mass in the left supraclavicular fossa, and a 65 mm aneurysm of the intrathoracic segment of the left subclavian artery (LSA) involving critical arterial branches was diagnosed by computed tomography angiography. Due to his comorbidities, the patient was judged unfit for an open surgical repair of the aneurysm, and a two-stage endovascular subclavian aneurysm repair (EVSAR) was planned. The first step included embolization of the internal mammary artery and thyrocervical trunk, followed by BOT of the left VA, which confirmed an adequate perfusion of the posterior cerebral and cerebellar circulation that allowed safe VA embolization. The second step included zone 2 thoracic endograft placement (TEVAR) with LSA coverage and vascular plug occlusion of the proximal segment of the LSA and the axillary artery. Postoperative monitoring revealed no neurological deficit, and the patient was discharged home without complications. Follow-up imaging up to 24 months confirmed complete aneurysm exclusion and significant sac shrinkage. Conclusions: EVSAR with thoracic endograft and VA sacrifice, preceded by BOT, may be a safe and effective minimally invasive approach for the treatment of intrathoracic SAA. Full article

Background/Objectives: We report on the association of clinical, demographic, and peri- and intraoperative factors with patient outcomes in large- and, separately, medium-vessel acute ischemic stroke (AIS) occlusions treated with mechanical thrombectomy or medical thrombolysis. Increasingly, neuroimaging, particularly novel markers of collateral status, has become useful in predicting response to endovascular treatment (EVT) among AIS patients. However, the relationship between these neuroimaging markers, documented predictors of stroke outcomes, and post-EVT functional status in anterior circulation large-vessel occlusions (LVOs) as compared to medium-vessel occlusions (MeVOs) remains unclear. We evaluated whether shared predictors of 90-day post-EVT functional outcomes in LVO compared to MeVO AIS patients within our institution exist. Methods: We retrospectively evaluated AIS patients treated at our institution between 9 January 2017 and 10 January 2023. The following were the inclusion criteria were applied: (i) CTA confirmed anterior circulation large or medium vessel occlusion; (ii) diagnostic CT perfusion was performed; (iii) mechanical thrombectomy was performed. A low modified Rankin score (mRS) indicating good functional outcomes (i.e., functional independence) was defined as less than or equal to 2, in accordance with prior studies. Univariate and multivariate logistic regression analyses were conducted to determine associations between demographic, clinical, and radiologic factors and mRS ≤ 2. Results: A total of 249 LVO (mean age 65.3 ± 16.2, 53.8% female) and 91 MeVO (mean age 68.9 ± 13.3, 46.2% female) patients met the inclusion criteria. Upon multivariate regression adjusted for race, age, hypertension, diabetes mellitus, radiologic features, IV alteplase, admission NIHSS, and reperfusion status, young age (p = 0.004), low admission NIHSS (p = 0.0001), and good reperfusion status (p = 0.007) were associated with good functional outcomes in LVO stroke. By contrast, no factors were significantly associated with good functional outcomes in MeVO stroke. Conclusions: Known factors, including young age, low admission stroke severity, and successful reperfusion predict EVT outcomes in LVO stroke but not necessarily in MeVO stroke. Further studies regarding predictors of MeVO outcomes in nonsurgical cases, including collateral status, may guide optimal medical management for this population. Full article

Background: The anterior cerebral artery (ACA), a critical component of the cerebral arterial circle, exhibits substantial morphological variability. While previous studies have explored ACA morphology using cadaveric and imaging methods, a comprehensive meta-analysis incorporating the latest evidence is lacking. Methods: Following current guidelines, a systematic review and meta-analysis were performed across four major databases, supplemented by the gray literature and targeted journal searches. Ninety-nine studies, encompassing 85,316 patients, met the inclusion criteria. Statistical analyses were conducted using R, applying random effects models to estimate pooled prevalence and morphometric parameters. Results: The pooled prevalence of typical ACA morphology was 93.75%, whereas variants were noted in 6.25% of cases. The predominant variation identified was the accessory ACA (aACA) (1.99%), followed by unilateral absence of the A1 segment (1.78%), with the latter being more frequently recognized in imaging studies (p < 0.0001). Rare variants encompassed azygos ACA (azACA) (0.22%), fenestrated ACA (fACA) (0.02%), and bihemispheric ACA (bACA) (0.02%). The mean diameter and length of the A1 segment were measured at 2.10 mm and 14.24 mm, respectively. Hypoplasia of the A1 segment (<1 mm diameter) was recorded in 3.15% of cases. The influences of imaging modality, laterality, and population distribution on prevalence estimates were minimal. No significant publication bias was detected. Conclusions: Although infrequent, variants of the ACA possess significant clinical importance attributable to their correlation with aneurysm formation and the impairment of collateral circulation. The aACA and the absence of the A1 segment emerged as the most common variations. This meta-analysis presents an updated and high-quality synthesis of ACA morphology, serving as a valuable reference for clinicians and anatomists. Full article

Background: Intercellular communication, facilitated by exosomes (Exos) derived from endothelial cells (ECs), significantly influences the regulation of angiogenesis. Leech extract significantly reduces ischemia–reperfusion injury, promotes angiogenesis, and improves neurological function in mice with stroke. However, further investigation is required to determine whether leech promotes angiogenesis through EC-Exo. Objective: This study aims to further explore whether leech regulates Exos to promote the establishment of collateral circulation in mice with ischemic stroke (IS) and the specific mechanisms involved. Methods: Here, we utilized an in vitro co-culture system comprising ECs and pericytes to investigate the impact of Leech-EC-Exo on enhancing the proliferation and migration of mouse brain microvascular pericytes (MBVPs). We further established an in vivo mouse model of middle cerebral artery occlusion/reperfusion (MCAO/R) to investigate the effects and underlying mechanisms of leech on collateral circulation establishment. Results: The findings demonstrated that leech significantly enhanced the in vitro cell migration number and migration number of pericytes. Therefore, it can also enhance the effect of EC-Exo on improving the infarct area and gait of mice, as well as modulating the HIFα-VEGF-DLL4-Notch1 signaling pathway to promote cerebral angiogenesis and facilitating the stable maturation of neovascularization in vivo. Conclusions: These results suggest that leech has the potential to enhance collateral circulation establishment, and its mechanism may involve the modulation of miRNA content in Exos and the promotion of signaling pathways associated with angiogenesis and vascular maturation. Full article

Background: Acute ischemic stroke (AIS) remains a leading cause of mortality and disability worldwide. Accurate evaluation of collateral circulation is essential for predicting outcomes following endovascular thrombectomy (EVT). However, conventional visual collateral scoring (vCS) based on multiphase CT angiography (mCTA) is limited by subjectivity and inter-observer variability. This preliminary study introduces the multiphase quantitative collateral score (mqCS), a novel imaging biomarker designed to provide an objective and reproducible assessment of both the morphological extent and temporal dynamics of collateral flow. Methods: In this exploratory study, 54 AIS patients treated with EVT were retrospectively analyzed. Collateral status was evaluated using both vCS (graded by two blinded neuroradiologists) and mqCS, derived from mCTA-based fractal dimension (FD) and delay indicator (DI) metrics. Logistic regression and receiver operating characteristic (ROC) analyses were performed to assess the predictive value of each scoring system for favorable 90-day functional outcomes (modified Rankin scale, mRS ≤ 2). Results: The mqCS was significantly associated with favorable outcomes. Patients with mqCS ≥ 0.8674 had significantly higher odds of achieving favorable outcomes (adjusted OR = 5.98, 95% CI: 1.38–25.93, p = 0.017; AUC = 0.80). In comparison, the visual collateral score (vCS) showed a lower adjusted predictive value (adjusted OR = 2.84, 95% CI: 1.17–6.89, p = 0.02; AUC = 0.79). Patients in the highest mqCS quartiles (Q3–Q4) exhibited significantly better recovery rates (69%, p < 0.01). Conclusions: This proof-of-concept study suggests that mqCS provides a potentially more objective and robust alternative to visual scoring for collateral assessment in AIS. By integrating structural and temporal characteristics, mqCS enhances outcome prediction and may inform EVT decision-making, particularly in borderline cases. These preliminary findings warrant validation in larger, prospective cohorts and support its potential integration into automated imaging platforms. Full article

CRISPR-Cas proteins from bacteria are powerful tools for gene editing and molecular diagnostics. Expanding capacity of CRISPR to low cost, multiplexed assays of biomarkers is a key to future disease diagnostics, since multiple biomarker detection is essential for reliable diagnostics. Herein we describe a multiplexed assay in a 3D-printed 96-well plate with CRISPR-Cas13a immobilized in each well to target three circulating blood biomarker microRNAs (miRNAs 34c-5p, 200c-3p, and 30e-5p) for Alzheimer’s disease (ALZ). Immobilized Cas13a is equipped with different crRNAs complementary to each miRNA target. MiRNA binding to crRNA complements activates the collateral RNase activity of Cas13a, cleaving a quenched fluorescent reporter (RNaseAlert) with fluorophore and quencher connected by an RNA oligonucleotide to enable fluorescence measurements. We achieved ultralow limits of detection (LOD) of 0.74 fg/mL for miRNA 34c-5p, 0.70 fg/mL for miRNA 30e-5p, and 7.4 fg/mL for miRNA 200c-3p, with dynamic ranges from LODs up to about 1800 pg/mL. The accuracy of the assay was validated by spike-recovery studies and good correlation of levels of patient plasma samples vs. a referee method. This new approach provides selective, sensitive multiplex miRNA biosensing, and simultaneously accommodates analysis of standards and controls. Full article

Background: The literature reports few instances of spontaneous bowel eviscerations through umbilical hernia sites. Spontaneous rupture of the hernia sac is a less common complication, primarily associated with persistent ascites or congenital wall defects. Materials and methods: A systematic review was conducted using the PubMed database—the United States National Library of Medicine, with the search terms “spontaneous bowel evisceration” and “umbilical hernia evisceration”. However, several results were deemed unsuitable for this manuscript. From a total of 185 cases, this review was narrowed down to 9 usable reports. Non-English language cases, duplicates, and cases unrelated to the pathology, including pediatrics, malformations, herniation through other organs, and animal cases, were excluded. Conclusions: Spontaneous evisceration in a hernia is an uncommon yet serious condition. A major risk factor appears to be underlying liver disease with its complications, such as ascites, chronic malnutrition with hypoalbuminemia, and collateral circulation formation. These factors contribute to the susceptibility of the sac and the hernia wall to rupture. However, the limited number of reported cases precludes the establishment of a preferred treatment approach. In the acute phase, the use of prosthetics may be less advisable, but in an elective setting, the cirrhotic patient could be offered repair. Full article

Background. Statins appear to be useful in patients with acute ischemic stroke. Our aim was to evaluate the association between premorbid statin treatment and CT perfusion characteristics of acute ischemic stroke. Methods. A retrospective analysis of patients with acute stroke secondary to occlusion of large vessels in the anterior circulation was performed to assess collateral flow, ischemic core volume, and ischemic penumbra using CT angiography and CT perfusion maps. Fisher’s exact test was used to compare baseline characteristics of patients in the two groups. The Wilcoxon rank-sum test for independent groups was used to compare all variables obtained for the two different groups with and without statin use. Results. We identified 61 patients, including 29 treated with statins and 32 not treated with statins before stroke onset matched by age, gender, and vascular risk factors except for hypercholesterolemia. The statin group showed lower National Institutes of health Stroke Scale scores at onset (14 ± 6.1 vs. 16 ± 4.5; p = 0.04) and lower volumes of brain tissue characterized by impaired cerebral blood flow (CBF), cerebral blood volume (CBV), and ${\mathrm{T}}_{\mathrm{m}\mathrm{a}\mathrm{x}}^{9.5-25\mathrm{s}}$; otherwise, no statistically significant difference was found in the volume of the ${\mathrm{T}}_{\mathrm{m}\mathrm{a}\mathrm{x}}^{16-25\mathrm{s}}$ between the two groups. Conclusions. Premorbid statin treatment is associated with a favorable imaging condition of acute ischemic stroke in terms of ischemic core and ischemic penumbra volume. Full article

Anomalous origin of the right coronary artery from the pulmonary artery (ARCAPA) is a rare congenital coronary anomaly, with an uncertain prevalence and often diagnosed incidentally. This case report presents a 62-year-old male with ARCAPA diagnosed during an evaluation for chest surgery. The patient had a history of colon cancer and active tuberculosis, complicating the clinical management. He reported chest pain, shortness of breath, and palpitations, with atrial fibrillation observed on a 24 h Holter ECG. Coronary angiography revealed robust collateral circulation and a suspected anomalous origin of the right coronary artery, confirmed by CT imaging. The patient’s stress MRI showed mildly reduced left and right ventricular ejection fractions and perfusion deficits in the apical segments (2/17) of the septal and inferior walls. Given the patient’s comorbidities, including active tuberculosis, the Heart team decided on a non-operative management approach, focusing on careful monitoring and pharmacological management rather than immediate surgery. This case emphasizes the complexity of managing ARCAPA in the context of significant comorbidities, highlighting the importance of individualized, multidisciplinary treatment strategies. Early diagnosis using advanced imaging techniques is crucial, and a non-operative approach can be considered in patients with preserved left ventricular function and no significant ischemia, as demonstrated in this case. Full article

Background and Objectives: The neutrophil-percentage-to-albumin ratio (NPAR) has been recognized as an independent risk factor for cardiovascular diseases. In our study, we investigated whether the NPAR is associated with the formation of coronary collateral circulation (CCC) in patients with chronic coronary syndrome (CCS). Materials and Methods: A total of 681 patients with CCS were included in this study. Of these patients, 571 had chronic total occlusion in at least one major vessel and developed collateral vessels. In total, 110 patients were in the control group, who had CCS but did not have complete occlusion in a major vessel and did not develop collateral vessels. Patients with collateral vessels on coronary angiography were divided into two groups according to the Rentrop score: poor CCC (Rentrop 0–1) and good CCC (Rentrop 2–3). Blood samples were taken for the NPAR and other biochemical parameters in all patients during hospitalization. The NPAR was calculated as the neutrophil-percentage-to-albumin ratio. Results: The group of patients with poor CCC had a higher white blood count (WBC), neutrophil, C-reactive protein (CRP), neutrophil–lymphocyte ratio (NLR), CRP/albumin ratio (CAR), and NPAR values than patients with good CCC (p < 0.001, for all). Multivariate logistic regression analysis showed that high NPAR levels were an independent predictor of poor CCC (OR: 2.79, 95% CI:1.7–4.6, p < 0.001), accompanied by neutrophil, CRP, CAR, and NLR levels. In the receiver operator characteristic curve (ROC analysis), the cut-off value for the NPAR to indicate poor CCC was 1.78 with a sensitivity of 76.6% and specificity of 81.4% (area under ROC curve = 0.804 95% CI (0.753–0.854), p < 0.001). Conclusions: We demonstrated that the NPAR may be an independent predictor of poor CCC development in clinical practice. Full article

Background and Objectives: Carotid artery stenosis is a significant risk factor for ischemic stroke due to impaired cerebral blood flow (CBF). Even asymptomatic unilateral stenosis can induce subclinical cerebrovascular changes, potentially affecting both hemispheres through collateral circulation. This study aimed to systematically assess cerebral perfusion in asymptomatic individuals with unilateral carotid artery stenosis by comparing ipsilateral and contralateral hemispheres with healthy controls, challenging the assumption that the contralateral hemisphere remains unaffected. Materials and Methods: This cross-sectional study included 114 participants, comprising 54 asymptomatic individuals (mean age 65.5) with significant unilateral carotid stenosis and 60 age-matched controls (mean age 64.8). Cerebral perfusion was assessed using 1.5T Magnetic Resonance Imaging (MRI) with pseudo-continuous arterial spin labeling (pCASL). CBF was measured bilaterally in four predefined middle cerebral artery (MCA) regions: precentral gyrus, lentiform nucleus, insular cortex, and temporal cortex. Statistical analyses included multivariate analysis of variance (MANOVA), analysis of variance (ANOVA), paired t-tests, and discriminant analysis (DA). Results: Significant bilateral reductions in CBF were observed in individuals with carotid stenosis compared to controls (MANOVA and ANOVA, p < 0.001). The greatest perfusion deficit was in the ipsilateral insular cortex (49.88 ± 10.83 mL/100 g/min), followed by intermediate contralateral perfusion (51.49 ± 8.86 mL/100 g/min) and higher control values (58.78 ± 10.44 mL/100 g/min). DA indicated the insular cortex as the region with the highest discriminative contribution (64.7%). Conclusions: Unilateral carotid artery stenosis in asymptomatic individuals is associated with significant bilateral cerebral hypoperfusion, suggesting widespread hemodynamic effects. Pronounced perfusion deficits in the insular cortex underline its vulnerability. The observed contralateral perfusion reductions challenge the traditional use of the contralateral hemisphere as a reference standard, underscoring the need for comprehensive perfusion assessment in carotid artery disease. Full article

Background and Clinical Significance: Hypoplasia of the internal carotid artery (ICA) is a rare vascular anomaly, with an estimated incidence of less than 0.01%. This condition can result in reduced blood flow to the anterior circulation, often compensated by collateral circulation. Radiological imaging, particularly computed tomography angiography (CTA), digital subtraction angiography (DSA), magnetic resonance angiography (MRA), and ultrasound, plays a crucial role in diagnosing this condition, revealing structural abnormalities in the arterial system. Case Presentation: This case is about a 75-year-old woman who lived her entire life unaware of ICAH until a basilar artery aneurysm ruptured, leading to a large, centrally localized SAH. Further diagnostic workup, including CTA and DSA, confirmed left ICA hypoplasia, with the artery terminating as the ophthalmic artery, along with a developmental anomaly of the left middle cerebral artery from posterior circulation territory. Due to the high risk associated with surgical and endovascular intervention, conservative management was pursued, and the patient’s condition stabilized, though she continued to have significant neurological deficits. Conclusions: This case report supports the hypothesis that ICAH may be associated with aneurysm formation. This case demonstrates that if ICAH is not diagnosed early, it can lead to severe complications with permanent neurological deficits. Additionally, it highlights the critical importance of advanced imaging techniques, such as CTA and DSA, in diagnosing complex vascular conditions. Full article

Early neurological deterioration is associated with poor functional outcomes in stroke patients, but the underlying mechanisms remain unclear. This study aims to understand the progression of stroke-related brain damage using a rhesus monkey model with ischemic occlusion. Multiparameter MRI was used to monitor the progressive evolution of the brain lesion following stroke. Resting-state functional MRI, dynamic susceptibility contrast perfusion MRI, diffusion tensor imaging, and T1- and T2-weighted scans were acquired prior to surgery and at 4–6 h, 48 h, and 96 h following the stroke. The results revealed a sudden increase in infarction volume after the hyper-acute phase but before 48 h on diffusion-weighted imaging (DWI), with a slight extension by 96 h. Lower relative cerebral blood flow (CBF) and time to maximum (Tmax) prior to the stroke, along with a progressive decrease post-stroke, were observed when compared to other stroke monkeys in the same cohort. Functional connectivity (FC) in the ipsilesional secondary somatosensory cortex (S2) and primary motor cortex (M1) exhibited an immediate decline on Day 0 compared to baseline and followed by a slight increase on Day 2 and a further decrease on Day 4. These findings provide valuable insights into infarction progression, emphasizing the critical role of collateral circulation and its impact on early neurological deterioration during acute stroke. Full article

Background: Systemic-to-pulmonary collaterals (SPCs) are common in congenital heart disease (CHD). Particularly in single ventricle anatomy and Fontan circulation, SPC can both complicate the postoperative course and lead to clinical deterioration in the long term. The treatment of SPC is controversial. The aim of our study was (1) to retrospectively analyse patients who underwent SPC embolization using Concerto™ Helix nylon-fibred microcoils (CHMs) and (2) to describe the interventional technique. Methods: In this single-centre retrospective observational cohort study, we analysed clinical and imaging data of all patients who underwent transcatheter embolization of SPCs using CHMs from January 2016 to December 2023. Results: In 38 consecutive patients (65.8% male, median age 41 months, range 2–490), a total number of 141 CHMs had been implanted into 64 SPCs in 49 procedures. The majority were arterial SPCs (n = 59/64) originating from the thoracic aorta or its branches; 5/64 were veno-venous SPCs. Primary closure succeeded in all procedures. The CHM diameters ranged from 3 to 8 mm, with 5 mm being the most commonly used diameter. The mean coil/SPC ratio was 2.6 (range 1.3–5.3). CHM implantation was performed via four French sheaths. Both detachment and stable positioning were simple and safe. Neither non-target embolization nor coil migration occurred. One complication was a vascular injury with resulting extravasation of contrast medium. In 18/49 procedures (36.7%), coils other than CHMs or vascular plugs were additionally inserted into separate SPCs. Conclusions: CHMs are appropriate for SPC embolization in all age groups, including infants, with a low complication rate. The coils are particularly suitable for the closure of collaterals with a small diameter or tortuous course. They can be used in combination with other embolization devices to achieve comprehensive collateral closure. Full article