Arterial Circulation Research Articles

Association of Peripapillary Arterial Circle of Zinn-Haller with Glaucoma in Highly Myopic Eyes.

The visualization of circle of Zinn-Haller (CZH) on optical coherence tomography angiography (OCTA) or its pattern does not have a clear effect on glaucoma, while the location of CZH is associated with axial length in highly myopic eyes. To investigate the association between the CZH and the presence of glaucoma using swept-source optical coherence tomography angiography (SS-OCTA) images of the optic nerve of patients with high myopia (HM). This retrospective case series included 227 eyes with HM, comprising 134 and 93 eyes with and without glaucoma, respectively. The characteristics of CZH, including visualization, pattern, and location, were assessed using SS-OCTA. Vascular parameters, such as vessel density and microvascular dropout (MvD), were quantified. The factors affecting the presence of glaucoma and the correlations between the CZH distance and axial length (AXL) were identified using logistic regression analysis and Pearson correlation analysis, respectively. CZH was detected more frequently in HM patients with glaucoma (71.6%) than in patients without glaucoma (51.6%) (P<0.002). However, the visualization of CZH was not related to the presence of glaucoma in multivariate regression analysis (odds ratio [OR], 0.688; 95% confidence interval [CI], 0.328-1.444; P=0.322). Moreover, compared to the annular pattern used as a reference, triangular and irregular patterns were not associated with the presence of glaucoma (OR: 1.043, 95% CI: 0.101-10.763, P=0.971; OR: 0.527, 95% CI: 0.255-1.092, P=0.085, respectively). MvD was significantly higher in patients with glaucoma (61.2%) than that in patients without glaucoma (2.2%) (P<0.001) and was identified as a significant factor affecting the presence of glaucoma (OR, 42.120; 95% CI, 9.416-188.413; P<0.001). AXL showed a significant correlation with CZH distance in all patients (R=0.399; P<0.001). CZH was more commonly detected in HM patients with glaucoma. However, no clear associations of glaucoma with the visualization, pattern, or location of CZH were observed in the present study. The correlation between AXL and CZH distance in eyes with HM warrants further investigation. These results may offer insights into the pathogenesis of glaucoma in eyes with HM as OCTA technology advances.

Ultrasonographic and functional evaluation of forearm circulation with occluded radial artery

Abstract Introduction The transradial approach (TRA) has gained popularity in cardiology procedures. This study aims to evaluate forearm and hand arterial circulation in radial artery (RA) occlusion (RAO) patients after coronary angiography (CAG) and percutaneous coronary interventions (PCI). The ulnar (UA) and anterior interosseous artery (AIA) can compensate for RAO. Methods A prospective, observational study was conducted on 40 RAO patients after CAG/PCI. Ultrasonographic and functional evaluation (Barbeau test) of collateral circulation through AIA or UA were performed. Statistical analyses were applied to evaluate various Doppler ultrasound parameters and the anatomical characteristics of the RAO. Results The RAO group mean age was 71.22 ± 9.99 years, and 45% were male. RA, UA, and AIA showed significant differences in peak systolic velocity, end-diastolic velocity, arterial diameter, total flow volume, and stroke volume (p &amp;lt; 0.01). Pulse quality over RA and UA also differed significantly (p &amp;lt; 0.0001). Blood flow direction in the distal RA segment divided patients into an antegrade flow group (50%) from AIA and a retrograde flow group (50%) from UA. The Barbeau test results varied among RAO patients, with type D being the most common. Anatomical locations of RAO included the anatomical snuffbox (10%), wrist (60%), and forearm (30%). The logistic regression model revealed that the Barbeau test results on Finger 2 (p=0.0006, OR=0.1398) and Finger 4 (p=0.004, OR 0.2843) were significant predictors for the occurrence of antegrade or retrograde blood flow in the distal RA when RAO occurred. Furthermore, when the RA was occluded, the study revealed that a palpable pulse over the RA was still possible in 15% of cases. Conclusion Ultrasonographic evaluation and the Barbeau test can assess collateral circulation and predict blood flow patterns in RAO patients. Further research is needed to validate these findings, explore additional factors influencing collateral circulation and access route selection, and investigate the clinical implications of different RAO anatomical locations in cardiology procedures.Radial Artery OcclusionThe pulse quality over RA/UA with RAO

A Case Report on Paradoxical Emboli

Venous Thromboembolism (VTE) is a major public health concern, affecting approximately 900,000 people annually in the United States. In rare cases, a Patent Foramen Ovale (PFO) may allow a venous thrombus to cross into the arterial circulation, causing a paradoxical embolism. This case report presents a 46-year-old male who developed left renal artery stenosis after a paradoxical embolism, likely triggered by a prolonged flight and binge alcohol consumption. The patient was found to have a moderate-sized PFO and renal infarction, confirmed by imaging studies. Despite initial anticoagulation therapy and a planned stenting procedure, intraoperative findings revealed only mild stenosis, leading to cancellation of the stent placement. The patient ultimately underwent PFO closure with an Amplatzer Talisman device. This case underscores the diagnostic challenges in managing paradoxical embolism and the need for individualized treatment, particularly concerning anticoagulation duration, the decision for PFO closure, and post-procedural antithrombotic therapy. Further research is required to establish optimal management strategies for cryptogenic embolic events.

High-Resolution MRA Cerebrovascular Findings in a Tri-Ethnic Population.

Incidental findings on brain MRI and variations of the circle of Willis (CoW) are relatively common among the general population. Ethnic differences have been described before, but few studies have explored the prevalence of incidental intracranial cerebrovascular findings and CoW variants in the setting of a single multiethnic cohort. The purpose of this investigation was to describe both incidental cerebrovascular findings and the morphology of the CoW on high-resolution 3T TOF-MRA in a UK tri-ethnic population-based cohort and to present updated prevalence estimates and morphologic reference values. We studied participants from the UK Southall and Brent REvisited study who underwent 3T brain MRI between 2014 and 2018. TOF-MRA images were assessed for the presence of incidental cerebrovascular findings and used to determine CoW anatomy. Seven hundred fifty participants (mean age, 71.28 [SD, 6.46] years; range, 46-90 years; 337 women), 322 White Europeans, 253 South Asians, and 175 African Caribbeans were included. Incidental cerebrovascular findings were observed in 84 subjects (11.2%, 95% CI, 9.0%-13.7%; 36 women; 42.86%, 95% CI, 32.11%-54.12%), with cerebral aneurysms being the most frequent followed by intracranial arterial stenoses with the highest prevalence among South Asians compared with White European (OR: 2.72; 95% CI, 1.22-6.08; P = .015) and African Caribbean subjects (OR: 2.79; 95% CI, 1.00-7.82; P = .051). Other findings included arteriovenous malformations and infundibula. The CoW was found to be more often complete in women than in men (25.22% compared with 18.41%, P = .024) and in African Caribbean (34.86%) compared with White European (19.19%) and South Asian (14.23%) subjects (P < .001 each). Intracranial arterial stenoses were independently associated with ethnicity after adjusting for vascular risk factors, having the highest prevalence among South Asians. The prevalence of aneurysms was higher than that in previous population-based studies. We observed anatomic differences in the CoW configuration among women, men, and ethnicities.

Reassessment of arterial versus venous perfusion of diabetic retinal neovascularization using ultrawide-field fluorescein angiography.

The purpose of this study was to assess whether diabetic NV is perfused by the arterial or the venous circulation. This is a retrospective, consecutive case series evaluating patients with proliferative diabetic retinopathy (PDR) imaged with ultrawide-field (UWF) fluorescein angiography (FA). Areas of neovascularization elsewhere (NVE) and neovascularization of the disc (NVD) were assessed. Perfusion was defined as arterial, arteriovenous, or venous if the area of diabetic neovascularization (NV) began to hyperfluoresce either prior, during, or after laminar venous flow, respectively. A total of 180 eyes from 176 patients with 928 NV were identified (830 NVE, 98 NVD). Of those, 5.1% of NVE were classified as arterial and 58.2% of NVD were classified as arterial. The remaining NV were classified as arteriovenous except for a small subset (6.1%) which were indeterminate. None of the NV were classified as venous. Noteworthy examples demonstrated NV that nearly fully perfused prior to any detectable fluorescence within nearby veins as well as clear shunting of blood from a feeding artery to a draining vein. UWF FA images suggest that some NV is perfused by retinal arteries. This may be useful in devising strategies for early detection and treatment of NV precursors. What is known • Diabetic retinal neovascularization has long been thought to be perfused by the retinal venous circulation. • Vascular endothelial growth factor has been shown to play key roles in both angiogenesis and arteriogenesis. What is new • Ultrawide-field fluorescein angiography demonstrates that at least some diabetic neovascularization is perfused by the retinal arterial circulation. • This supports the hypothesis that diabetic neovascularization may arise from arterially-perfused intraretinal microvascular abnormalities in the capillary bed.

Assessing the impact of fetal-type posterior cerebral artery variations on cerebral hemodynamics

The circle of Willis (CoW) is a critical, arterial structure that ensures balanced, cerebral-blood supply. The fetal-type posterior cerebral artery (f-PCA) is a CoW variant that can significantly affect hemodynamics and elevate the risk of cerebrovascular diseases. This study used computational fluid dynamics simulations and a patient-specific, three-dimensional model to evaluate the hemodynamic effects of the f-PCA variants on cerebral-blood flow and key hemodynamic indices—such as time-averaged wall-shear stress (TAWSS), oscillatory shear index (OSI), pulsatility index, and resistive index. The fetal ratio (FR) is defined as the ratio of the diameter of the posterior communicating artery (PCoA) to that of the first segment (P1) of the PCA. Our findings indicate that as the FR increases, the contribution of the basilar artery to the second segment (P2) of PCA decreases significantly. Specifically, the flow rate through ipsilateral P1 decreased by 40.0% for FR = 1 and 70.9% for FR = 2, with the internal carotid artery (ICA) compensating for this reduction. Moreover, variations in f-PCA led to significant increases in TAWSS and OSI in key arterial segments (including the ipsilateral P1, PCoA, and the anterior communicating artery), which are associated with a higher risk of aneurysm initiation and growth. Under conditions of unilateral stenosis in the ipsilateral ICA, f-PCA models exhibit a more complex and pronounced impact on blood flow than models without f-PCA, emphasizing the need for detailed hemodynamic assessments in clinical evaluations and preoperative planning to mitigate the risks associated with CoW anatomical variations.

Collateral is brain: Low perfusion triggers spreading depolarization and futile reperfusion after acute ischemic stroke

Futile reperfusion is a phenomenon of inadequate perfusion despite successful recanalization after acute ischemic stroke (AIS). It is associated with poor patient outcomes and has received increasing interest due to its clinical diagnosis becoming more common. However, the underlying mechanisms remain elusive, and experimental studies are focused on the pathological background of futile reperfusion. Our recent study has confirmed that poor primary collateralization plays a crucial role in the insufficiency of reperfusion after AIS in mice. Specifically, the absence of primary collaterals in the circle of Willis (CoW) promoted the development of spreading depolarizations (SDs) during AIS. In our experimental stroke model, the occurrence of SDs during ischemia always predicted futile reperfusion. Conversely, in mice with a complete CoW, no SDs were observed, and reperfusion was complete. Importantly, the human CoW displays variation in the primary collaterals in approximately 50% of the population. Therefore, futile reperfusion may result from SD evolution in AIS patients. Our purpose here is to emphasize the crucial role of SD in the development of futile reperfusion. We propose that adequate collateral recruitment can prevent SD occurrence, leading to improved reperfusion and AIS outcomes.

Transcatheter vacuum-assisted aspiration of large intracardiac and intravascular masses.

Intravascular and intracardiac masses are usually represented by thrombi, tumours, and vegetations. They can affect both the right and left chambers of the heart and the venous and arterial circulation. Traditionally, their treatment is surgical or, in some circumstances, based on systemic anticoagulation/fibrinolysis. However, the complexity and frailty of patients who sometimes present with these conditions have pushed surgeons to find alternative minimally invasive effective treatments. While small masses can be removed with multiple devices, large masses are a more challenging problem. Vacuum-assisted aspiration systems such as the AngioVac System were developed to treat intravenous and right-sided heart thrombi. The application of the AngioVac System was widened to right-sided endocarditis and, later, to left-sided thrombi and vegetations. This review summarises the clinical results of different uses of the vacuum-assisted aspiration system to treat intravenous and intracardiac masses.

Spatial Transcriptomic Profiling of Human Saphenous Vein Exposed to Ex Vivo Arterial Haemodynamics-Implications for Coronary Artery Bypass Graft Patency and Vein Graft Disease.

Vein graft disease is the process by which saphenous vein grafts, utilised for revascularisation during coronary artery bypass graft surgery, undergo an inflammation-driven intimal hyperplasia and accelerated atherosclerosis process in subsequent years after implantation. The role of the arterial circulation, particularly the haemodynamic properties' impact on graft patency, have been investigated but have not to date been explored in depth at the transcriptomic level. We have undertaken the first-in-man spatial transcriptomic analysis of the long saphenous vein in response to ex vivo acute arterial haemodynamic stimulation, utilising a combination of a custom 3D-printed perfusion bioreactor and the 10X Genomics Visium Spatial Gene Expression technology. We identify a total of 413 significant genes (372 upregulated and 41 downregulated) differentially expressed in response to arterial haemodynamic conditions. These genes were associated with pathways including NFkB, TNF, MAPK, and PI3K/Akt, among others. These are established pathways involved in the initiation of an early pro-inflammatory response, leukocyte activation and adhesion signalling, tissue remodelling, and cellular differentiation. Utilising unsupervised clustering analysis, we have been able to classify subsets of the expression based on cell type and with spatial resolution. These findings allow for further characterisation of the early saphenous vein graft transcriptional landscape during the earliest stage of implantation that contributes to vein graft disease, in particular validation of pathways and druggable targets that could contribute towards the therapeutic inhibition of processes underpinning vein graft disease.

Insights into multilevel tissue-level collateral status using ColorViz maps from dual data sources in acute ischemic cerebrovascular diseases: A STARD-compliant retrospective study.

This study aims to explore the utility of ColorViz mapping from dual data sources for assessing arterial collateral circulation and predicting cerebral tissue-level collateral (TLC) in patients with acute ischemic cerebrovascular diseases. A retrospective study was conducted at a single center on a cohort of 79 patients diagnosed with acute ischemic cerebrovascular diseases between November 2021 and April 2022, who had undergone both multi-phase CT angiography (mCTA) and computed tomography perfusion (CTP). The quality of images and arterial collateral status depicted on ColorViz maps from dual data-sets (mCTA and CTP) were assessed using a "5-point scale" and a "10-point scale," respectively. The status of TLC was evaluated by analyzing multilevel hypoperfusion volume and the hypoperfusion intensity ratio (HIR). The Spearman correlation coefficient was employed to examine the association between arterial collateral status derived from dual data sources and TLC. Receiver operating characteristic curve analysis was used to determine the diagnostic efficacy in detecting large vessel occlusive acute ischemic stroke (LVO-AIS). The ColorViz maps derived from dual data sources facilitated comparable image quality, with over 95% of cases meeting diagnostic criteria, for the evaluation of arterial level collateral circulation. Patients with robust arterial collateral circulation, as determined by dual data sources, were more likely to exhibit favorable TLC status, as evidenced by reductions in hypoperfusion volume (Tmax > 4 seconds, Tmax > 6 seconds, Tmax > 8 seconds, and Tmax > 10 seconds, P < .05) and HIR (Tmax > 6 seconds/4 seconds, Tmax > 8 seconds/4 seconds, Tmax > 10 seconds/4 seconds, and Tmax > 8 seconds/6 seconds, P < .05). The sensitivity and specificity in detecting LVO-AIS was 60.00% and 97.73% for mCTA source maps, while 74.29% and 72.73% for CTP source maps (P > .05 based on De-Long test). In conclusion, this study indicates that ColorViz maps derived from both data sources are equally important in evaluating arterial collateral circulation and enhancing diagnostic efficiency in patients with LVO-AIS, as well as offering insights into the TLC status based on hypoperfusion volume and HIR.

Quantitative evaluation of the effect of Circle of Willis structures on cerebral hyperperfusion: A multi-scale model analysis

Cerebral hyperperfusion occurs in some patients after superficial temporal artery–middle cerebral artery bypass surgery. However, there is uncertainty about cerebral hyperperfusion after bypass for patients with different Circle of Willis (CoW) structures.This study established a lumped–parameter model coupled with one–dimensional model (0–1D), whilst a deep learning model for predicting pressure drop (DLM–PD) caused by stenosis and a cerebral autoregulation model (CAM) were introduced into the model. Based on this model, 9 CoW structural models before and after bypass were constructed, to investigate the effects of different CoW structures on cerebral hyperperfusion after bypass. The model and the results were further validated by clinical data.The MSE of mean flow rates from 0–1D model calculation and from clinical measurement was 1.4%. The patients exhibited hyperperfusion in three CoW structures after bypass: missing right anterior segment of the anterior cerebral artery (mRACA1) (13.96% hyperperfusion); mRACA1 and foetal–type right anterior segment of posterior cerebral artery (12.81%), and missing anterior communicating artery and missing left posterior communicating artery (112.41%). The error between the average flow ratio from the model calculations and from clinical measurements was less than 5%.This study demonstrated that the CoW structure had a significant impact on hyperperfusion after bypass. The general 0–1D model coupled with DLM–PD and CAM proposed in this study, could accurately simulate the hemodynamic environment of different CoW structures before and after bypass, which might help physicians identify high–risk patients with hyperperfusion before surgery, and promote the development of non–invasive diagnosis and treatment of cerebrovascular diseases.

Amylase intrapancreatic infusion delays insulin release during an intravenous glucose tolerance test, proof of acini-islet-acinar interactions.

The possible existence of an acini-islet-acinar (AIA) reflex, involving mutual amylase and insulin interactions, was investigated in the current acute experiment on pigs. To confirm the existence of an AIA reflex and justify the placement of the exocrine and endocrine pancreatic components within the same organ. The study was performed on six pigs under general anesthesia. An intravenous glucose tolerance test was performed, with a bolus infusion of 50% glucose to the jugular vein, while amylase (5000 U/kg) or vehicle intrapancreatic infusions were administered via the pancreaticoduodenalis cranialis artery during 30 min with a 1 mL/min flow rate. The amylase infusion to pancreatic arterial circulation inhibited and delayed the insulin release peak which is usually associated with the highest value of blood glucose and is typically observed at 15 min after glucose infusion, for > 1 h. The intrapancreatic infusion of the vehicle (saline) did not have any effect on the time frame of insulin release. Infusion of 1% bovine serum albumin changed the insulin release curve dramatically and prolonged the high range of insulin secretion, far beyond the glucose peak. Intrapancreatic arterial infusion of amylase interrupted the integrated glucose-insulin interactions. This confirms an AIA reflex and justifies placement of the exocrine and endocrine pancreatic components within the same organ.

Intracranial bypass for giant aneurysms treatment assessed by computational fluid dynamics (CFD) analysis

Unruptured giant intracranial aneurysms (GIA) are those with diameters of 25 mm or greater. As aneurysm size is correlated with rupture risk, GIA natural history is poor. Parent artery occlusion or trapping plus bypass revascularization should be considered to encourage intra-aneurysmal thrombosis when other treatment options are contraindicated. The mechanistic background of these methods is poorly studied. Thus, we assessed the potential of computational fluid dynamics (CFD) and fluid–structure interaction (FSI) analyses for clinical use in the preoperative stage. A CFD investigation in three patient-specific flexible models of whole arterial brain circulation was performed. A C6 ICA segment GIA model was created based on CT angiography. Two models were then constructed that simulated a virtual bypass in combination with proximal GIA occlusion, but with differing middle cerebral artery (MCA) recipient vessels for the anastomosis. FSI and CFD investigations were performed in three models to assess changes in flow pattern and haemodynamic parameters alternations (wall shear stress (WSS), oscillatory shear index (OSI), maximal time averaged WSS (TAWSS), and pressure). General flow splitting across the entire domain was affected by virtual bypass procedures, and any deficiency was partially compensated by a specific configuration of the circle of Willis. Following the implementation of bypass procedures, a reduction in haemodynamic parameters was observed within the aneurysm in both cases under analysis. In the case of the temporal MCA branch bypass, the decreases in the studied parameters were slightly greater than in the frontal MCA branch bypass. The reduction in the magnitude of the chosen area-averaged parameters (averaged over the aneurysm wall surface) was as follows: WSS 35.7%, OSI 19.0%, TAWSS 94.7%, and pressure 24.2%. FSI CFD investigation based on patient-specific anatomy models with subsequent stimulation of virtual proximal aneurysm occlusion in conjunction with bypass showed that this method creates a pro-thrombotic favourable environment whilst reducing intra-aneurysmal pressure leading to shrinking. MCA branch recipient selection for optimum haemodynamic conditions should be evaluated individually in the preoperative stage.

Endovascular Treatment of Unruptured Pancreatic Arcade Aneurysms.

This study aimed to assess the safety and efficacy of endovascular treatment of unruptured pancreatic arcade aneurysms in a single-center series. The electronic medical records of patients who underwent endovascular treatment for unruptured pancreatic arcade aneurysms between 2011 and 2022 at our tertiary center were retrospectively reviewed. The presence of celiac artery stenosis/occlusion; aneurysm number, location, and size; endovascular technique; procedure-related complication incidence; and clinical outcomes were assessed. Twenty-three patients (12 men and 11 women; mean [range] age, 63.8 [45-84] years) with 33 unruptured pancreatic arcade aneurysms were identified. Celiac artery stenosis/occlusion coexisted in 17 (74%) patients. Five (21%) patients had multiple aneurysms. The median aneurysm size was 9.3mm (range, 4-18mm). Seven, 6, 6, 5, 4, 3, and 2 aneurysms were located in the gastroduodenal, dorsal pancreatic, anterior superior pancreaticoduodenal, inferior pancreaticoduodenal, posterior inferior pancreaticoduodenal, posterior superior pancreaticoduodenal, and anterior inferior pancreaticoduodenal arteries, respectively. Four (15%) and 22 (85%) aneurysms were treated with endosaccular packing alone and coil embolization with endosaccular packing and parent artery occlusion, respectively, with resulting exclusion from arterial circulation. The remaining 7 aneurysms coexisting with larger aneurysms in other peripancreatic arteries were observed without embolization because they were small and for preserving collateral blood flow to the celiac artery. The treated aneurysms did not rupture or recur during the follow-up period (median, 40months). Endovascular treatment is a safe and effective treatment for unruptured pancreatic arcade aneurysms. 3, non-controlled retrospective cohort study.

Computational fluid dynamics; a new diagnostic tool in giant intracerebral aneurysm treatment

Giant intracerebral aneurysms (GIA) comprise up to 5 % of all intracranial aneurysms. The indirect surgical strategy, which leaves the GIA untouched but reverses the blood flow by performing a bypass in combination with proximal parent artery occlusion is a useful method to achieve spontaneous aneurysm occlusion. The goal of this study was to assess the utility of computational fluid dynamics (CFD) in preoperative GIA treatment planning. We hypothesise that CFD simulations will predict treatment results.A fluid-structure interaction (FSI) CFD investigation was performed for the entire arterial brain circulation. The analyses were performed in three patient-specific CT angiogram models. The first served as the reference geometry with a C6 internal carotid artery (ICA) GIA, the second a proximal parent artery occlusion (PAO) and virtual bypass to the frontal M2 branch of the middle cerebral artery (MCA), and the third a proximal PAO in combination with a temporal M2 branch bypass. The volume of “old blood”, flow residence time (FRT), dynamic viscosity and haemodynamic changes were also analysed.The “old blood” within the aneurysm in the bypass models reached 41 % after 20 cardiac cycles while in the reference model it was fully washed out. In Bypass 2 “old blood” was also observed in the main trunk of the MCA after 20 cardiac cycles. Extrapolation of the results yielded a duration of 4 years required to replace the “old blood” inside the aneurysm after bypass revascularization. In both bypass models a 7-fold increase in mean blood viscosity in the aneurysm region was noted.Bypass revascularization combined with proximal PAO favours thrombosis. Areas prone to thrombus formation, and subsequently the treatment outcomes, were accurately identified in the preoperative model. Virtual surgical operations can give a remarkable insight into haemodynamics that could support operative decision-making.

Anatomical study of variations in the configurations of the circle of Willis in relation to age, sex, and diameters of the components.

The circle of Willis (COW) refers to the anastomotic arterial network found on the brain base, tasked with provision of collateral circulation aimed at prevention of ischemia. The COW is of immense clinical importance especially with regard to the assessment of neurovascular diseases. Individuals portray significant variations in the COW's anatomical configuration. The present study seeks to evaluate the existing anatomical variations of the COW and within the anterior and posterior segments of the COW. Thus, the study seeks to evaluate the different anatomical variations of the COW and its segments and components within the study population. To attain the set objectives, the present study has utilized the angiographic images for studying the COW variants in patients who underwent cerebral angiography during assessment of different types of cerebral anomalies and conditions. Therefore, this study used conventional angiography as an important tool in the evaluation of the different variations in the COW, and is most appropriate for evaluation of smaller anatomical variations owing to its perfect spatial resolution and portrayal of COW anatomy. The study findings indicated the existence between age and sex, and anatomical variations of the COW, particularly with regard to diameters of COW components like basilar artery (BA), P1, and internal carotid arterys (ICAs). Males had bigger BA, P1 and ICA diameters than females, while individuals aged below 40 years had bigger BA, A1, posterior communicating artery, and ICA diameters than those aged above 40 years.

Microembolizations in the arterial cerebral circulation during atrial fibrillation ablation: cryoballoon technique advantages and neurocognitive safety-results of a prospective observational study.

The significance of micro-embolic signals (MESs) during atrial fibrillation (AF) ablation is unclear. Previous studies had limitations, and cryoballoon (CB) ablation patients were under-represented. Minimizing MESs is recommended due to their uncertain neurocognitive impact. This prospective observational study included AF patients from a German centre between February 2021 and August 2022. Patients were equally divided into paroxysmal (Group A) and persistent (Group B) AF. Group A received cryoballoon-pulmonary vein isolation only, while Group B also had left atrial roof ablation. MESs were detected using transcranial Doppler ultrasonography during ablation. Neurocognitive status was assessed pre- and post-procedure and at 3 months using the CERAD Plus battery. The study analyzed 100 patients with a median age of 65.5 years. A total of 19 698 MESs were observed, with 80% being gaseous and 20% solid in origin, primarily occurring during pulmonary vein angiography and the balloon freeze and thawing phase. The median MES per patient was 130 (IQR: 92-256) in total, 298 (IQR: 177-413) in bilateral (36%), and 110 (IQR: 71-130) in unilateral (64%) recordings. No significant difference in total MES counts was found between the groups. None of the 11 neuropsychological tests showed cognitive decline post-procedure or at 3 months. Our observations confirm that neurocognitive abilities are not affected either 24 h or 3 months after AF ablation using the CB technique. However, despite the low MES burden associated with the CB, more work is needed to reduce small embolic events during AF ablation.

Correlation between Circle of Willis configuration and intracranial arterial dolichoectasia, and genetic contributions

ObjectivesIntracranial arterial dolichoectasia (IADE) is characterized by the dilation, elongation, and tortuosity of intracranial arteries. We aimed to investigate the association between variations of the Circle of Willis (COW) and IADE in the general population, as well as estimate the genetic correlation between COW variations and IADE. MethodsA total of 981 individuals from a population-based cohort were included. Brain magnetic resonance angiography was performed to assess COW variants and measure the diameters of intracranial arteries. IADE was defined as a total intracranial volume-adjusted diameter ≥ 2 standard deviations. Logistic regression models were used to analyze the association between COW variations and IADE. The heritability and genetic correlation were estimated using genome-wide complex trait analysis (GCTA) based on single nucleotide polymorphism (SNP) array data. ResultsThe prevalence of IADE was 6.2 %. Hypoplastic/absent A1 segments were associated with an increase in contralateral ICA diameter (β ± SE, 0.279 ± 0.049; p = 0.001) and a decrease in ipsilateral ICA diameter (β ± SE, -0.300 ± 0.050; p = 0.001). Fetal-type posterior cerebral artery (FTP) was associated with a larger ICA diameter (β ± SE, 0.326 ± 0.048; p = 0.001) and a smaller BA diameter (β ± SE, -0.662 ± 0.043; p = 0.001). FTP revealed a positive genetic correlation with ICA dilation (rG = 0.259 ± 0.175; p = 0.0009) and a negative genetic correlation with BA dilation (rG = -0.192 ± 0.153, p = 0.015). ConclusionsThere was an association between COW variations and larger intracranial arterial diameters in the general population. Genetic factors may play a role in the development of intracranial arterial dilation and the formation of COW variants.

A Study on Ejection Fraction in Patients with Mitral and Aortic Regurgitation Based on Cardiovascular Models

Background: Whether it is healthy or patients with mitral and aortic regurgitation, clinicians cannot measure the regurgitation of the valve when using two-dimensional echocardiography to measure ejection fraction. Whether the mitral valve and aortic valve are in a healthy state or in a reflux state, there is a reflux volume. The actual stroke output will be less than the stroke output measured by echocardiography, making the calculated ejection fraction higher. Methods: This article proposes for the first time the concept of net ejection fraction (NEF) as the percentage of net stroke output to left ventricular end diastolic volume. The net stroke output is the integral of aortic valve flow during one cardiac cycle at the same time. Using a systemic arterial circulation model, investigate the relationship between ejection fraction and net ejection fraction through numerical simulation methods. Results: The final results showed a strong linear correlation between mitral regurgitation volume (VRmi), aortic regurgitation volume (VRao), and the difference between ejection fraction and net ejection fraction (DEF). The net ejection fraction of the moderate mitral regurgitation group decreased by an average of 26.3% ± 9.95% compared to the ejection fraction measured by echocardiography. The severe mitral regurgitation group showed a decrease of 31.9% ± 9.3%. Moderate descent of aortic valve by 25.8% ± 11.1%. Severe aortic valve descent of 30.9% ± 10.3%. Conclusions: Clinical doctors can evaluate the left ventricular systolic function of patients based on the ejection fraction measured by echocardiography combined with valve regurgitation. The net ejection fraction avoids overestimation of left ventricular systolic function and has high reliability. It can accurately reflect the left ventricular systolic function of patients with mitral and aortic regurgitation, and has certain guiding significance for clinical doctors to grasp the patient's condition.

Phoenixin-14 maintains the contractile type of vascular smooth muscle cells in cerebral aneurysms rats.

The rupture of intracranial aneurysm (IA) is the primary reason contributing to the occurrence of life-threatening subarachnoid hemorrhages. The oxidative stress-induced phenotypic transformation from the contractile phenotype to the synthetic phenotype of vascular smooth muscle cells (VSMCs) plays a pivotal role in IA formation and rupture. Our study aimed to figure out the role of phoenixin-14 in VSMC phenotypic switching during the pathogenesis of IA by using both cellular and animal models. Primary rat VSMCs were isolated from the Willis circle of male Sprague-Dawley rats. VSMCs were stimulated by hydrogen peroxide (H2O2) to establish a cell oxidative damage model. After pretreatment with phoenixin-14 and exposure to H2O2, VSMC viability, migration, and invasion were examined through cell counting kit-8 (CCK-8), wound healing, and Transwell assays. Intracellular reactive oxygen species (ROS) production in VSMCs was evaluated by using 2',7'-Dichlorofluorescin diacetate (DCFH-DA) fluorescence probes and flow cytometry. Rat IA models were established by ligation of the left common carotid arteries and posterior branches of both renal arteries. The histopathological changes of rat intracranial blood vessels were observed through hematoxylin and eosin staining. The levels of contractile phenotype markers (alpha-smooth muscle actin [α-SMA] and smooth muscle 22 alpha [SM22α]) in VSMCs and rat arterial rings were determined through real-time quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. Our results showed that H2O2 stimulated the production of intracellular ROS and induced oxidative stress in VSMCs, while phoenixin-14 pretreatment attenuated intracellular ROS levels in H2O2-exposed VSMCs. H2O2 exposure promoted VSMC migration and invasion, which, however, was reversed by phoenixin-14 pretreatment. Besides, phoenixin-14 administration inhibited IA formation and rupture in rat models. The decrease in α-SMA and SM22α levels in H2O2-exposed VSMCs and IA rat models was antagonized by phoenixin-14. Collectively, phoenixin-14 ameliorates the progression of IA through preventing the loss of the contractile phenotype of VSMCs.