Feeding Arteries Research Articles

691 Correlation of Cerebral Arteriovenous Malformation Flow Measured by Quantitative Magnetic Resonance Angiography and MR-detected Arteriovenous Malformation Microhemorrhage

INTRODUCTION: Intracranial hemorrhage (ICH) significantly contributes to morbidity and mortality in cerebral arteriovenous malformations (AVM) patients, with a history of prior hemorrhage being the most significant predictor of a future hemorrhage. Recently, silent microhemorrhage as detected on magnetic resonance imaging (MRI) has been proposed as a potential risk factor for future hemorrhage in AVM patients. Recent data suggests that silent microhemorrhage is associated with higher nidal velocity measured through color-coded DSA, raising the question of correlation between flow and microhemorrhage. METHODS: All unruptured AVM patients with a baseline QMRA with noninvasive optimal vessel analysis (NOVA) and gradient echo or susceptibility-weighted MRI were retrospectively reviewed (2004-2022). AVM flow was calculated from the aggregate flow within primary arterial feeders relative to their contralateral counterparts. A review of the MRI determined the presence of microhemorrhages. Descriptive statistics, the X2 test, and a binomial logistic regression were performed to test the association of demographics, clinical, and AVM features with microhemorrhage. RESULTS: The study consisted of ninety patients, with fifty microhemorrhage-positive and forty microhemorrhage-negative patients. The presence of venous anomaly (varix, ectasia, aneurysm) is independently predictive of microhemorrhage (OR = 2.444, p = 0.050), and a compact AVM nidus trended towards independent negative predictability of microhemorrhage (OR =.462, p = 0.081). Calculated AVM flow trends higher in the microhemorrhage-positive group with the median flow 407 mL/min vs. 238 mL/min, and a trend towards predicting presence of microhemorrhage (OR = 1.375, p = 0.106). CONCLUSIONS: Patients with AVM-associated venous anomalies have an increased likelihood of AVM microhemorrhage. Higher AVM flow and a diffuse AVM nidus trend towards a higher likelihood of AVM microhemorrhage. These findings demonstrate the possible relationship between higher AVM flow and risk of future bleeding.

Comparative Study for Identification of Feeding Arteries of Hepatocellular Carcinoma by 3D Reformatted CT Angiography and Digital Subtraction Angiography during Transcatheter Arterial Chemoembolization (TACE)

Comparative Study for Identification of Feeding Arteries of Hepatocellular Carcinoma by 3D Reformatted CT Angiography and Digital Subtraction Angiography during Transcatheter Arterial Chemoembolization (TACE)

Current and Future Applications of Arterial Spin Labeling MRI in Cerebral Arteriovenous Malformations.

Arterial spin labeling (ASL) has emerged as a promising noninvasive tool for the evaluation of both pediatric and adult arteriovenous malformations (AVMs). This paper reviews the advantages and challenges associated with the use of ASL in AVM assessment. An assessment of the diagnostic workup of AVMs and their variants in both adult and pediatric populations is proposed. Evaluation after treatments, whether endovascular or microsurgical, was similarly examined. ASL, with its endogenous tracer and favorable safety profile, offers functional assessment and arterial feeder identification. ASL has demonstrated strong performance in identifying feeder arteries and detecting arteriovenous shunting, although some studies report inferior performance compared with digital subtraction angiography (DSA) in delineating venous drainage. Challenges include uncertainties in sensitivity for specific AVM features. Detecting AVMs in challenging locations, such as the apical cranial convexity, is further complicated, demanding careful consideration due to the risk of underestimating total blood flow. Navigating these challenges, ASL provides a noninvasive avenue with undeniable merits, but a balanced approach considering its limitations is crucial. Larger-scale prospective studies are needed to comprehensively evaluate the diagnostic performance of ASL in AVM assessment.

Immunological alterations in intracranial aneurysm: a prospective study on selected biomarker profiles in blood collected during endovascular neurointervention.

Previous studies showed that the concentrations of selected chemokines are locally elevated in samples collected from the lumen of intracranial aneurysms (IA). Our objective was to determine whether the observed differences in analyte concentrations were influenced by the origin of the blood samples (i.e. cerebral versus peripheral), thus providing insight into the localised nature of these alterations and their significance in IA pathogenesis. This prospective study included 24 patients with IA who underwent endovascular embolisation. Concentrations of selected analytes were analysed in blood samples from the IA lumen, feeding artery, and aorta. The analytes included MPO, Lipocalin-2/NGAL, sICAM-1, sVCAM-1, and serum amyloid A. Higher median plasma concentrations of MPO, lipocalin-2/NGAL, sVCAM-1, and SAA were found in samples obtained from the IA lumen and the feeding artery compared to the aorta. The concentration of sICAM-1 was significantly higher in the IA compared to the aorta, but did not differ between the proximal artery and the aorta. No significant differences in any analyte concentration were observed between the IA and the proximal artery. These findings suggest that the IA and the proximal vessel share similarities in the local immunological environment, which is different from that observed in the aorta. Further studies are needed to fully understand and elucidate these observations.

Microsurgical excision of intracranial arteriovenous malformation

Objectives: Brain Arteriovenous malformations are high-flow cerebrovascular lesions with dysplastic vascular nidus, fed by arteries and drained by veins without intervening capillaries. Prevalence is 0.2% and is an important cause of intracerebral haemorrhage in about 38% of young adults. The objective of this study is to analyze surgically managed Intracranial AV malformations with respect to their demographic features, varied clinical presentations, imaging features Spetzler Martin grading and outcome. Methods: A study of 48 patients with Intracranial Arteriovenous malformations who underwent microsurgical excision at the Institute of Neurosurgery, Madras Medical College and Rajiv Gandhi Government General Hospital, Chennai over a period of 5 years from July 2018 to June 2022 and extracted their data including demographic characteristics, clinical presentations, Spetzler-Martin (SM) grades, complications and outcome were assessed. Results: Of the 48 patients treated with microsurgery, the most common 51% belongs to the age group between 21 to 40years, left-sided is slightly more common with headache major symptom, involving Parietooccipital lobe 33% commonly, 28 (62.2%) patients initially presented with haemorrhage. Anterior circulation artery feeders was common 68.8% and mostly drainage involving superficial venous drainage system. Based on the Spetzler-Martin (SM) grading system, the patients were graded as follows: 6(13 %) Grade I, 10(21%) Grade II, 25(52%) Grade III, 3 (6%) Grade IV and 4(8%) Grade V. Overall, 35(73%) patients had a favorable outcome, most commonly seen in Grade I, II and Grade III. Almost complete obliteration of the AVMs were achieved in all favorable outcome cases. Conclusion: Microsurgical excision is the gold standard treatment of choice for low grade AVMs and certain high-grade AVMs with increased risk of rupture. The Spetzler-Martin grading system is a simple and effective method to estimate the risk of surgery and to evaluate the prognosis. Proper patient selection combined with appropriate preoperative evaluation, meticulous surgical technique and postoperative care all lead to reduced mortality and morbidity.

Overloaded transnidal pressure gradient as the hemodynamic mechanism leading to arteriovenous malformation rupture: a quantitative analysis using intravascular pressure monitoring and color-coded digital subtraction angiography

BackgroundThe hemodynamics of brain arteriovenous malformations (AVMs) may have implications for hemorrhage. This study aimed to explore the hemodynamics of ruptured AVMs by direct microcatheter intravascular pressure monitoring (MIPM) and...

Does central venous stenosis affects the brachial artery flow volume and peripheral vascular resistive index in patients on maintenance hemodialysis? A retrospective study.

A well-functioning vascular access (VA) is crucial for the patients on maintenance hemodialysis (HD). Central venous stenosis (CVS) is a common, yet, overlooked complication of VA as its diagnosis is challenging. Moreover, its effect on the flow volume (FV) and the peripheral resistive index (RI) was not well discussed before. Despite the availability of doppler ultrasound (DUS) in most centers, direct visualization of central veins using DUS is quite difficult. This is a retrospective single-center self-controlled cohort study that was conducted in a specialized vascular access management tertiary center in Japan and included all patients with CVS who underwent percutaneous transluminal angiography (PTA) with or without vascular stenting in the period from January 2014 to September 2022. The patients were divided according to their VA type into arteriovenous fistula (AVF), and arteriovenous graft (AVG) groups, then subdivided, according to the type of stenosis, into two subgroups: CVS, and mixed central and peripheral venous stenosis (MVS) groups. The FV and RI of the feeding artery were compared in the same procedure before and after PTA to assess the impact of the procedure itself. Data of 485 percutaneous transluminal angiography procedures (PTA), performed in 95 patients during the period from January 2014 to September 2022, were collected. FV and RI were significantly affected in the patients with MVS than patients with CVS. After PTA, both FV and RI were significantly improved. The improvement rate of FV and RI after PTA were significantly higher in patients with MVS than patients with CVS. However, it was difficult to determine the cut-off value to diagnose or to assess the improvement of CVS. Our findings suggest that FV and RI measurement by DUS are good tools, along with the clinical findings for assessment of CVS in certain situations.

Diagnosis of a Dural Arteriovenous Fistula Involving the Superior Sagittal Sinus: The MMA Sign on Routine 3D-TOF MR Angiography

The main feeding artery of a dural arteriovenous fistula (DAVF) involving the superior sagittal sinus (SSS) is the middle meningeal artery (MMA). MMA extends continuously from the proximal part to SSS in DAVF involving SSS. It is possible to diagnose DAVF involving SSS by evaluating the proximal part of MMA on routine three-dimensional time-of-flight MR angiography (MRA). We termed the finding in an anteroposterior maximum intensity projection (MIP) image of routine MRA in which MMA was continuously visualized at the top of the imaging slab (the upper corpus callosum level) without tapering as the MMA sign. The purpose of the present study was to examine the frequency of the MMA sign on routine MRA in patients with DAVF involving SSS and control patients. Subjects comprised 18 patients with DAVF involving SSS confirmed by angiography and 871 control subjects who underwent routine MRA. The presence of the MMA sign was retrospectively evaluated using an anteroposterior MIP image of routine MRA in patients with DAVF involving SSS and control patients. The MMA sign was observed in 17 of the 18 (94%) patients with DAVF involving SSS. In one patient with DAVF involving the posterior part of SSS without the MMA sign, the main feeding artery was the occipital artery, not MMA. The MMA sign was observed in 13 of the 871 (1.5%) control patients. The MMA sign on routine MRA is useful, suggesting DAVF involving SSS.

Combination of intrahepatic TARE and extrahepatic TACE to treat HCC patients with extrahepatic artery supply: A case series

PurposeThe aim of this study was to report the safety and tumor response rate of combined transarterial radioembolization (TARE) through the intrahepatic arteries and transarterial chemoembolization (TACE) through the extrahepatic feeding arteries (EHFA) in patients with hepatocellular carcinoma (HCC). MethodsPatients with HCC, who had both intrahepatic and extrahepatic arterial supply visible on preinterventional multiphase CT and were treated between 2016 and 2021 with a combination of TACE and TARE on the same nodule, were retrospectively included. Epidemiological, clinical, biological, and radiological characteristics were recorded. Safety and tumor response were assessed at 6 months. ResultsNine patients (8 men, median age 62 years [IQR: 54–72 years]) were included. Seven patients had previous treatments on the target nodule (TARE: 5; TACE: 2). The median longest axis (LA) of the lesion was 70 mm (IQR: 60–79 mm). Three patients had portal vein invasion (VP3). The EHFA originated from the right diaphragmatic artery (n = 6), the right adrenal artery (n = 2), and the left gastric artery (n = 1). The LA of the tumor portion treated with TACE was 47 mm (range: 35–64 mm). The ratio between the LA of the entire lesion and the LA treated with TACE was 1.44 (range: 1.27–1.7). One major complication occurred: acute on chronic liver failure. Median follow-up was 23 months (range: 16–29 months). Seven patients underwent further treatment: on the same lesion (n = 2), on newly appeared nodules (n = 2), and systemic treatment (n = 3). At 6-month follow-up, seven patients showed a local objective response. Time-to-progression was 13 (3.5–19) months. ConclusionThe combination of TARE and extrahepatic TACE for HCC with both intrahepatic and extrahepatic arterial supplies seems feasible and safe. Further studies are needed to validate the effectiveness of these preliminary results.

Endovascular occlusion of segmental arteries feeding the anterior spinal artery to stage endovascular thoracoabdominal aortic repair

ObjectiveMinimally invasive segmental artery coil embolization was introduced to prevent spinal cord ischemia after endovascular repair of thoracoabdominal aortic aneurysms. There is no consensus on whether the endovascular occlusion of segmental arteries feeding directly the anterior radiculomedullary artery and anterior spinal artery can be safely performed without causing spinal cord ischemia. Our aim was to investigate the feasibility and clinical impact of endovascular occlusion of segmental arteries supplying the anterior spinal artery during minimally invasive segmental artery coil embolization in patients with thoracoabdominal aortic aneurysms. MethodsBetween January 2018 and July 2020, 54 patients (36 male; mean age, 71.1 ± 9.3 years) underwent direct embolization of segmental arteries feeding the anterior radiculomedullary artery before endovascular repair of thoracoabdominal aortic aneurysms. End points included technical success of minimally invasive segmental artery coil embolization of segmental arteries, anterior radiculomedullary artery, neurological complications, and in-hospital mortality after minimally invasive segmental artery coil embolization and endovascular repair of thoracoabdominal aortic aneurysms. ResultsThe thoracoabdominal aortic aneurysm classification was type I (n = 8), type II (n = 24), type III (n = 11), and type IV (n = 11). During minimally invasive segmental artery coil embolization, 388 segmental arteries were occluded, each patient having 7.2 ± 3.1 coiled segmental arteries occluding 64.5% (25-100%) of open segmental arteries within the treated aortic segment. Altogether, 66 anterior radiculomedullary arteries were seen originating between Th8 and L3 levels from 85 (21.9%) segmental arteries. In 10 patients (18.5%), 2 large anterior radiculomedullary arteries were identified, and 1 patient (1.9%) showed 3 anterior radiculomedullary arteries on the spinal arteriography. No spinal cord ischemia or procedure-related complications occurred after minimally invasive segmental artery coil embolization. After 47.9 ± 39.4 days, all patients received endovascular repair of their thoracoabdominal aortic aneurysms. There was no in-hospital mortality. One male patient developed incomplete temporary spinal cord ischemia after endovascular repair. ConclusionsMinimally invasive segmental artery coil embolization of segmental arteries feeding the anterior spinal artery in patients with thoracoabdominal aortic aneurysms to prevent spinal cord ischemia after endovascular repair is feasible and clinically safe.

Cerebral Arteriovenous Malformation in a Pediatric Patient with Severe Systemic Hypertension

AbstractArteriovenous malformations (AVMs) are a tangle of blood vessels that connects arteries and veins in which the feeding arteries are directly connected to the venous channels. Cerebral AVM needs special consideration due to high risk of bleeding and neurological deficit associated with morbidity and mortality. In pediatric population, prevalence rate of cerebral AVM is 0.02%. The systemic hemodynamic changes are seen more frequently with peripheral AVM, whereas its association with cerebral AVM is rare. We report a rare case of cerebral AVM in a 12-year-old child with severe systemic hypertension and electrocardiogram changes of biventricular hypertrophy planned for surgical resection of AVM in view of intracerebral bleed. This case illustrates the importance of detailed cardiac, renal, and endocrine evaluation in children with cerebral AVM with systemic hypertension and left ventricular hypertrophy to rule out other causes of systemic hypertension prior to surgery.

Arterial-Portal Venous Shunt after Drug-Eluting Bead Transarterial Chemoembolization for Hepatocellular Carcinoma Patients: Risk factors and Impact on Patient Survival

Introduction: The effectiveness of transarterial chemoembolization (TACE) in treating hepatocellular carcinoma (HCC) has been well established. The differential impacts of drug-eluting bead TACE (DEB-TACE) as opposed to conventional TACE (cTACE) on vascular changes, such as arterial-portal venous shunts (APSs), have been recognized. However, their subsequent effects on treatment outcomes have not been fully explored. This study aims to identify risk factors associated with the occurrence of APS in HCC patients treated with DEB-TACE and to evaluate its impact on patient survival. Methods: A retrospective analysis was conducted from January 2012 to December 2018 including 74 HCC patients receiving DEB-TACE as initial treatment and a 1:1 cTACE. Kaplan-Meier analysis estimated overall survival (OS) and progression-free survival (PFS). Logistic regression identified significant risk factors for APS occurrence after DEB-TACE. Results: APS incidence was significantly higher after DEB-TACE than cTACE (46.0% vs. 16.2%, p < 0.001). There was no significant difference in median OS between APS and non-APS groups after DEB-TACE: 50 months (24.6–75.4) versus 26.9 months (19.5–43.2), p = 0.111; median PFS was 15.6 months (4.1–27.1) and 9.5 months (6.8–12.1) for the two groups, respectively, p = 0.065. Risk factors for APS occurrence after DEB-TACE were more than two feeding arteries (OR: 7.25, 95% CI: 1.82–28.95, p = 0.005) and non-selective embolization (OR: 8.02, 95% CI: 2.30–27.95, p = 0.001). Conclusion: APS occurrence was higher in DEB-TACE-treated HCC patients, but it did not significantly affect OS and PFS. More than two feeding arteries and non-selective embolization were significant risk factors for APS occurrence after DEB-TACE.

Depiction rate of feeding arteries of renal cell carcinoma on four-dimensional computed tomography angiography

PurposeTo retrospectively evaluate the depiction rate of feeding arteries in biopsy-proven clear cell renal cell carcinoma (CCRCC) on four-dimensional computed tomography angiography (4D-CTA) images.Materials and methodsThis study included 22 patients with 22 CCRCC and 30 feeding arteries treated with transcatheter renal artery embolization. The depiction rate of the feeding arteries on preprocedural 4D-CTA was evaluated. Images were acquired by 320-row multi-detector computed tomography (CT) 15‒36 s after starting to inject a contrast agent (600 mg/kg iodine) intravenously into patients at 2.1 s intervals (11 phases). Two board-certified radiologists retrospectively assessed the feeder depiction rate in all 11 phases with reference to the procedural images as the gold standard. Discrepancies were resolved by consultation with a third radiologist.ResultsAmong the feeders, 11 (36.7%) were segmental or lobar, and 19 (63.3%) were interlobar or arcuate arteries. The feeder depiction rate was the highest (25 [83.3%] of 30) in the 5th phase (delay, 23.4 s) where the gap in contrast enhancement between the renal artery and cortex was the largest. This was followed by the 6th (23 [76.7%] of 30), 4th (22 [73.3%] of 30]), and 7th (21 [70.0%] of 30) phases. The overall rate of depicting feeding arteries in the 11 phases of 4D-CTA was 28 (93.3%) of 30.ConclusionsThe depiction rate of CCRCC feeding arteries including lobar or smaller artery branches by 4D-CTA was favorable. The feeding arteries were optimally visualized during the phase with the largest contrast gap between the renal artery and cortex.

Application of Spinal Subtraction and Bone Background Fusion CTA in the Accurate Diagnosis and Evaluation of Spinal Vascular Malformations.

Accurate pretreatment diagnosis and assessment of spinal vascular malformations using spinal CTA are crucial for patient prognosis, but the postprocessing reconstruction may not be able to fully depict the lesions due to the complexity inherent in spinal anatomy. Our purpose was to explore the application value of the spinal subtraction and bone background fusion CTA (SSBBF-CTA) technique in precisely depicting and localizing spinal vascular malformation lesions. In this retrospective study, patients (between November 2017 and November 2022) with symptoms similar to those of spinal vascular malformations were divided into diseased (group A) and nondiseased (group B) groups. All patients underwent spinal CTA using Siemens dual-source CT. Multiplanar reconstruction; routine bone subtraction, and SSBBF-CTA images were obtained using the snygo.via and ADW4.6 postprocessing reconstruction workstations. Multiple observers researched the following 3 aspects: 1) preliminary screening capability using original images with multiplanar reconstruction CTA, 2) the accuracy and stability of the SSBBF-CTA postprocessing technique, and 3) diagnostic evaluation of spinal vascular malformations using the 3 types of postprocessing images. Diagnostic performance was analyzed using receiver operating characteristic analysis, while reader or image differences were analyzed using the Wilcoxon signed-rank test or the Kruskal-Wallis rank sum test. Forty-nine patients (groups A and B: 22 and 27 patients; mean ages, 44.0 [SD, 14.3] years and 44.6 [SD,15.2] years; 13 and 16 men) were evaluated. Junior physicians showed lower diagnostic accuracy and sensitivity using multiplanar reconstruction CTA (85.7% and 77.3%) than senior physicians (93.9% and 90.9%, 98% and 95.5%). Short-term trained juniors achieved SSBBF-CTA image accuracy similar to that of experienced physicians (P > .05). In terms of the visualization and localization of spinal vascular malformation lesions (nidus/fistula, feeding artery, and drainage vein), both multiplanar reconstruction and SSBBF-CTA outperformed routine bone subtraction CTA (P = .000). Compared with multiplanar reconstruction, SSBBF-CTA allowed less experienced physicians to achieve superior diagnostic capabilities (comparable with those of experienced radiologists) more rapidly (P < .05). The SSBBF-CTA technique exhibited excellent reproducibility and enabled accurate pretreatment diagnosis and assessment of spinal vascular malformations with high diagnostic efficiency, particularly for junior radiologists.

Acquired Uterine Arteriovenous Malformation: Treatment With Uterine Artery Embolization

Enhanced myometrial vascularity/uterine arteriovenous malformations (EVM/AVM) are a rare cause of vaginal bleeding that can result in life-threatening hemorrhage if left untreated. Enhanced myometrial vascularity/uterine arteriovenous malformations arise from an abnormal connection between arteries and veins without an intervening capillary network and can be acquired as a result of retained products of conception, uterine trauma, or surgical intervention. Enhanced myometrial vascularity/uterine arteriovenous malformations are typically present in women of childbearing age with intermittent to profuse vaginal bleeding symptoms. The diagnosis is typically made by transabdominal or transvaginal ultrasound with color Doppler followed by computed tomography angiography or magnetic resonance imaging to assess the extent of the malformation and visualize any feeding arteries. Treatment varies based on symptoms, age, patient preferences, and desire for future fertility and includes conservative therapy, uterine artery embolization, and hysterectomy. We report 3 cases of EVM/AVM, which were imaged and diagnosed utilizing ultrasonography and successfully treated with uterine artery embolization.

Pulmonary AVM Embolization

Pulmonary arteriovenous malformations (PAVMs) are rare fistulous connections between pulmonary arteries and veins that, as in our case, are commonly associated with hereditary hemorrhagic telangiectasia (HHT). Embolotherapy, the mainstay of treatment for PAVMs, is a procedure in which the feeding arteries of a malformation are endovascularly occluded under fluoroscopic guidance. Effective and well-tolerated, embolotherapy has been shown to decrease right-to-left shunting following treatment and decrease risks of paradoxical embolization and lung hemorrhage and to improve pulmonary gas exchange and lung function. Patients are selected for treatment according to clinical suspicion for the presence of a PAVM and feeding artery diameter. The occlusion of PAVMs with arteries that exceed 2-3 mm in diameter is recommended. Diagnostic contrast-enhanced pulmonary angiography is performed via injection of contrast through a percutaneous catheter to characterize and confirm PAVMs suitable for embolization. Lesions are then treated by catheter-directed placement of embolic material— vascular plugs in our case—into the feeding artery, terminating blood flow to the area of the lesion. Although multiple PAVMs may be embolized during a single session, in patients with HHT, who may present with large numbers of PAVMs, treatment is limited by maximum contrast dosage, and additional sessions may be performed if PAVMs remain perfused.

Hemodynamic Study of Cerebral Arteriovenous Malformation: Newtonian and Non-Newtonian Blood Flow

ObjectiveArteriovenous malformation is a disease of the vascular system that occurs mainly in the cerebral arteries and spine. Numerical simulation as a powerful method is used to investigate the Cerebral Arteriovenous Malformation hemodynamic after occlusion of the abnormality step by step by embolization. MethodsThe CT Angiographic imaging data of two patients are used and a geometric model is extracted by the Mimics software. Numerical simulation of blood flow is performed in both Newtonian and non-Newtonian models. The Navier–Stokes, and continuity governing equations are solved by finite element method using the COMSOL Multiphysics software (the commercial computational fluid dynamics (CFD) simulation software). To validate the numerical results, the real data on blood flow rate in the feeding artery and draining veins are used, as well as angiographic images at different times. ResultsRegarding the comparison of pressure contours for different occlusions of 0, 30, 50, and 90%, by increasing the amount of occlusion in the nidus, there is an increase in the blood pressure. Regarding the comparison of the blood flow velocity in the feeding artery, draining veins, and inside the AVM nidus for Newtonian and non-Newtonian models, there is a significant difference between these two simulations in vessels with smaller dimensions (such as vessels inside the nidus). ConclusionBy increasing the amount of nidus occlusion, the blood pressure is increased, so the blood supply process is better. According to a significant difference between the Newtonian and non-Newtonian simulations in vessels with smaller dimensions (such as vessels inside the nidus), therefore, non-Newtonian simulation should be done for different occlusions of 30, 50, and 90%.

Abstract TMP6: Dural Arteriovenous Fistulas With Cognitive Impairment: Angiographic Characteristics and Treatment Outcomes

Background: Anecdotal cases of rapidly progressing dementia in patients with dural arteriovenous fistulas (dAVFs) and cortical venous drainage have been reported in small series. However, a comprehensive description of the angiographic features of this dAVFs is lacking. We conducted an analysis of the largest cohort of dAVFs presenting with cognitive impairment (dAVFs-CI), aiming to provide a better characterization of this subset of dAVFs. Methods: The CONDOR Consortium, a multicenter repository comprising 1077 dAVFs, served as the study population. Among the dAVFs, patients with dAVFs-CI were analyzed. A propensity scores matching analysis was conducted to compare dAVFs-CI with Borden type II and type III dAVFs without cognitive impairment (controls). Logistic regression was employed to identify angiographic characteristics specific to dAVFs-CI. Post-treatment outcomes were analyzed. Results: A total of 60 patients with dAVFs-CI and 60 control dAVFs were included. Outflow obstruction leading to venous hypertension was observed in all dAVFs-CI. Sinus stenosis was significantly associated with dAVFs-CI (OR 2.85, 95% CI: 1.16-7.55, p = 0.027). dAVFs-CI were more likely to have a higher number of arterial feeders (OR 1.56, 95% CI 1.22-2.05, p &lt; 0.001) and draining veins (OR 2.05, 95% CI 1.05-4.46, p = 0.004). Venous ectasia increased the risk of dAVFs-CI (OR 2.38, 95% CI 1.13-5.11, p = 0.024). A trend toward achieving asymptomatic status at follow-up was observed in patients with successful closure of dAVFs (OR 2.86, 95% CI 0.85-9.56, p = 0.09). Discussion: Venous hypertension is a key angiographic feature dAVFs-CI. dAVFs-CI exhibit a complex angioarchitecture characterized by an increased number of arteriovenous connections and stenosed sinuses. The presence of venous ectasia further exacerbates the impaired drainage and contributes to the development of dAVFs-CI. Notably, closure of the dAVF has the potential to reverse symptoms in certain cases (Figure).

The correlation of cerebral arteriovenous malformation flow measured by quantitative MR angiography on MR-detected arteriovenous malformation microhemorrhage.

The objective of this study was to assess the relationship of arteriovenous malformation (AVM) blood flow measured by quantitative MR angiography (QMRA) in nonruptured AVMs with MR-detected microhemorrhage. All patients with unruptured AVMs who received baseline QMRA and gradient echo or susceptibility-weighted MRI were retrospectively reviewed (2004-2022). Imaging data, clinical history, and AVM angioarchitectural and flow features were collected and assessed. AVM flow was calculated from the difference of flow within primary arterial feeders from their contralateral counterparts. A review of the MR images determined the presence of microhemorrhages. Analysis of descriptive statistics, chi-square test, and binomial logistic regression were performed. Of 634 patients with cerebral AVMs at a single center, 89 patients met the inclusion criteria (54 with microhemorrhage and 35 without microhemorrhage). The calculated AVM flow was significantly higher in the group with a microhemorrhage (447.9 ± 193.1 ml/min vs 287.6 ± 235.7 ml/min, p = 0.009). In addition, the presence of venous anomaly, arterial ectasia, and diffuse nidus was significantly associated with microhemorrhage (p = 0.017, p = 0.041, and p = 0.041, respectively). Binary logistic regression found that higher flow predicted the presence of microhemorrhage (OR 1.002, 95% CI 1.000-1.004; p = 0.031). The highest AVM flow quartile significantly predicted the presence of venous anomaly (OR 3.840, 95% CI 1.037-14.213; p = 0.044), diffuse nidus (OR 6.800, 95% CI 1.766-25.181; p = 0.005), and arterial ectasia (OR 13.846, 95% CI 1.905-122.584; p = 0.018). This study represents the first to examine the association between flow measurements on QMRA with microhemorrhage in unruptured AVMs. Higher AVM flow, venous anomaly, arterial ectasia, and diffuse AVM nidus were related to a higher likelihood of AVM microhemorrhage. Higher AVM flow was present in AVMs with venous anomalies, a diffuse nidus, and arterial ectasia, indicating a possible interaction between these angioarchitectural findings, AVM flow, and microhemorrhage. These findings suggest a relationship between higher AVM flow and the risk of microhemorrhage.

Abstract TP215: Endovascular and Medical Management Strategies for Caroticocavernous Fistulae: A Single Center Retrospective Safety and Efficacy Analysis

Background: Caroticocavernous fistulae (CCF) are a rare subtype of intracranial arteriovenous fistulae with variable clinical and angiographic presentations. This study aimed to describe the clinical outcomes in a cohort of CCF patients and identify clinical and angiographic features differentiating patients more likely to benefit from endovascular intervention. Methods: A single-center, retrospective analysis was performed to identify all patients with angiographically-confirmed CCF between 2000 and 2022. Pertinent data, including clinical symptoms, angiographic findings, treatment strategies, recurrence rates, and complications, was collected. Results: A total of 84 patients were included, of whom 67 (80%) underwent endovascular intervention and 17 (20%) were conservatively managed. Primary endovascular techniques were transvenous coil embolization (78%), feeder artery embolization (16%), and ICA flow diversion (8%). High-risk clinical symptoms, such as reduced visual acuity, and angiographic features, such as cortical and ophthalmic venous reflux, were more common in the intervention group (p&lt;0.05). All direct (Barrow Type A) CCFs underwent endovascular intervention (32% vs 0%, p=0.005), while indirect (Barrow types B-D) CCFs were common in the conservatively managed group (100% vs 68%, p=0.005). 31% of treated CCFs required retreatment, which primarily occurred with Barrow type D CCFs and following transvenous coil embolization. Procedure-related complications occurred in 10% of cases and consisted of cranial nerve palsies (n=5), asymptomatic intracranial dissection (n=1), and asymptomatic distal thromboembolic occlusion (n=1). Conclusion: High-risk symptoms and angiographic features favor endovascular intervention. Various embolization techniques, including transvenous coil embolization, proved safe and effective. In select CCF patients without high-risk clinical or angiographic features, conservative observation is a safe and effective alternative to endovascular embolization. Complications were rare, and most were transient, emphasizing the safety of endovascular management. Longitudinal angiographic surveillance is essential for monitoring fistula persistence or recurrence.