Venous Sinus Stenosis Research Articles

Non-invasive imaging modalities for diagnosing pulsatile tinnitus: a comprehensive review and recommended imaging algorithm.

Pulsatile tinnitus (PT) is a challenging diagnostic condition arising from various vascular, neoplastic, and systemic disorders. Non-invasive imaging is essential for identifying underlying causes while minimizing risks of invasive diagnostic angiography. Although no consensus exists on the primary imaging modality for PT and currently CT, ultrasound, and MRI are used in the diagnostic pathway, MRI is increasingly preferred as the first-line screening test for its diagnostic efficacy and safety. MRI protocols such as time-of-flight, magnetic resonance angiography, diffusion-weighted imaging, and arterial spin labeling can identify serious causes, including vascular shunting lesions, venous sinus stenosis, and tumors. In this narrative review of the current literature we discuss the benefits and limitations of various non-invasive imaging modalities in identifying the characteristic imaging findings of the most common causes of PT and also provide an algorithm that clinicians can use to guide the imaging evaluation.

The effect of blood lipids on the comorbidity of multiple large arachnoid granulations

BackgroundCurrently, studies on the formation mechanism for the enlargement of arachnoid granulation (AG) are lacking. The impact of dyslipidemia on the formation of multiple large arachnoid granulations (LAGs) was studied in this research.MethodsThe study included patients diagnosed with cerebral venous sinus stenosis (CVSS) related to LAG. The number of LAGs was assessed via high-resolution black blood magnetic resonance imaging. The relationships between blood lipids and multiple LAGs were explored to evaluate the effects of dyslipidemia on the formation of multiple LAGs.ResultsA total of 163 participants with a diagnosis of LAG were included. The levels of total cholesterol (TC) (P = 0.004) and low-density lipoprotein cholesterol (LDL-c) (P = 0.01) in the multiple LAGs group were greater than those in the non-multiple LAGs group. Multivariate logistic regression analysis revealed that TC (odds ratio (OR), 2.19; 95% confidence interval (CI), 1.26–3.80; P = 0.006) and LDL-c (OR, 2.18; 95% CI, 1.16–4.07; P = 0.02) were independently associated with multiple LAGs.ConclusionsTC and LDL-c are independently related to multiple LAGs, indicating that dyslipidemia may be a potential cause of CVSS. Therefore, monitoring blood lipids may be necessary for patients with LAGs.

Dural arteriovenous fistula may be occluded through recanalization of impaired venous sinuses.

To investigate the effect and safety of recanalization of stenosed or occluded venous sinuses for dural arteriovenous fistulas (DAVFs) and possible mechanism of DAVF formation, patients with DAVF accompanied by venous sinus stenosis or occlusion treated with balloon angioplasty and/or stenting were retrospectively enrolled. The clinical data, treatment outcomes and complications were analyzed. In 7 patients enrolled, the DAVF was Cognard IIa grade in 3 (42.9% or 3/7) and IIa + b in 4 (57.1% or 4/7) patients, including complex DAVFs in 2 (28.6% or 2/7). The angioplasty procedure was successful in all (100%) patients, including complete cure in 3 (42.9% or 3/7) patients with the initial Cognard grade IIa, transformation from Cognard grade IIa + b to I in 2 (28.6% or 2/7) patients, and unchanged Cognard grade IIa + b in 2 (28.6% or 2/7) patients. The symptoms were all improved. At 3-month angiographic follow-up, 5 (71.4% or 5/7) cases were cured, whereas 2 cases still had grade I fistulas but no clinical symptoms. Staged embolization in 2 patients resulted in significant symptom improvement. At the last follow-up of a median 4 years, no clinical symptoms were present in 5 (71.4% or 5/7) patients, intermittent headache in 1 (14.3% or 1/7), and death from trauma in 1 (14.3% or 1/7). In conclusion, endovascular recanalization of occluded or stenosed venous sinuses using balloon angioplasty and stenting is able to induce occlusion of DAVFs and is a safe and efficient treatment approach for DAVFs which are possibly caused by significant pressure increase.

A narrative review of magnetic resonance imaging findings in pediatric idiopathic intracranial hypertension.

Idiopathic intracranial hypertension (IIH) is a rare neurological disorder in the pediatric population which is defined as an increase in intracranial pressure (ICP) without the presence of brain parenchymal lesions, hydrocephalus, or central nervous system infection. In this study, we have determined the magnetic resonance imaging (MRI) findings in IIH patients. A comprehensive literature search was conducted using the electronic databases including Web of Sciences, Scopus, and Pubmed to identify suitable and relevant articles using keyword search methods. The search included keywords such as "idiopathic intracranial hypertension," "pseudotumor cerebri," "MRI," and "pediatrics." The search was limited to the available publications up to January 2024. MRI plays a crucial role in diagnosing IIH by excluding secondary causes and revealing neuroimaging findings associated with elevated ICP. Despite fewer studies in children compared to adults, MRI serves as a cornerstone in identifying traditional neuroradiological markers such as empty sella turcica, posterior globe flattening, optic nerve tortuosity, optic nerve sheath distension, and transverse venous sinus stenosis. Additional subtle markers include increased Meckel's cave length, cerebellar tonsillar herniation, and slit-like ventricles, although these are less reliable. Diffusion-weighted imaging does not typically show cerebral ADC value changes indicative of cerebral edema in pediatric IIH. MRI findings provide valuable non-invasive diagnostic indicators that facilitate early detection, clinical management, and potential surgical intervention in pediatric IIH. The reliability of these MRI markers underscores their importance in clinical practice.

Association between laboratory markers, clinical and radiological findings in patients with idiopathic intracranial hypertension: case–control study

BackgroundIdiopathic intracranial hypertension (IIH) is a disease of raised intracranial pressure. Contribution of inflammatory mediators has been suggested in IIH pathophysiology. The aim of this study was to estimate certain serum inflammatory markers in IIH patients compared to normal subjects. Also, to examine the correlation between these laboratory parameters and the clinical and radiological characteristics of IIH patients.ResultsBody mass index (BMI) was significantly higher among IIH patients compared to controls. Serum LDH, CRP, NLR and PLR were significantly higher, whereas serum iron was significantly lower in IIH patients compared to healthy controls. IIH patients with stenosis in brain MRV had significantly higher mean serum CRP compared with patients with normal MRV. There was a statistically significant positive correlation between serum CRP and the presence of stenosis in MRV, between serum LDH level and grade of papilledema, and between CRP, TIBC, and NLR with BMI.ConclusionsThere is a significant elevation of inflammatory markers in IIH patients. Moreover, cerebral venous sinus stenosis and BMI were positively associated with higher markers of inflammation as CRP, LDH and NLR indicating the role of inflammation in thrombosis and obesity associated with IIH.

Analysis of cerebral venous sinus stenosis by flat panel angiographic CT (FP-CT) to guide treatment for idiopathic intracranial hypertension.

Cerebral venous sinus stenting (CVSS) is an effective treatment for idiopathic intracranial hypertension (IIH) secondary to dural venous sinus stenosis. Traditional selection of patients for CVSS has been made by microcatheter manometry, but pressure measurements are often equivocal. Here we present the results of a series of cases in which venous flat-panel CT (FP-CT) was used as an adjunct to microcatheter manometry to improve decision making and precise stent placement during CVSS. Ten consecutive patients with IIH underwent angiography with microcatheter manometry and venous FP-CT, with CVSS if indicated by the results. Cross-sectional measurements of the narrowed sinus were obtained on FP-CT before and after stenting. After the procedure, clinical outcomes were tracked. Follow-up with quantitative MRA with sinus flow measurements was also performed, when available. There was an exponential correlation between measured pressure gradient and degree of stenosis calculated using venous FP-CT. All patients with both a high degree of stenosis measured by FP-CT and a high pressure gradient across the stenosis showed a clinical benefit from stenting. True measurement of the cross-sectional area of the dural sinus, made by venous phase FP-CT, has a high degree of correlation with elevated venous pressure gradient across the point of stenosis. Even in a limited series of cases, we found an exponential decrease in flow with increasing severity of stenosis. Furthermore, patients with both an elevated venous pressure gradient and critical stenosis of the sinus on FP-CT showed symptomatic improvement after stenting.

Radiological signs supporting idiopathic intracranial hypertension in symptomatic patients with lumbar puncture opening pressure < 250 mm

Lumbar puncture opening pressure (LPOP) exceeding 250mmH2O is key in diagnosing idiopathic intracranial hypertension (IIH), per revised Friedman’s criteria. Some patients do not meet LPOP criteria (with or without papilledema), despite having IIH-related symptoms and neuroimaging findings. This study aimed to investigate the radiological findings and clinical symptoms in patients suspected of having IIH without meeting the LPOP criteria. We retrospectively evaluated cerebral venous sinus stenosis using the conduit Farb score (CFS) and other radiological findings suggestive of IIH by computed tomography venography and magnetic resonance venography in females ≥ 18 years-old with chronic headaches, suspected IIH, and LPOP < 250 mm. Eighty-eight women (56 with LPOP < 200 mm H2O and 32 with LPOP ranging between 200 and 250mmH2O) were included. Among patients with LPOP 200–250mmH2O, 40% (12) exhibited three or more radiological findings supporting IIH, compared to 17% (8) in the LPOP < 200 mmH2O group (p = 0.048). Cerebral venous stenosis (CFS ≤ 5) was observed in 80% (24) of those with LPOP 200–250 mmH2O, contrasting with 40% (19) of those with LPOP < 200 mmH2O (p < 0.001). Cerebral venous stenosis was significantly more common in patients with LPOP 200–250 mmH2O than < 200 mmH2O, suggesting that they may benefit from IIH treatment.

Outcomes of Pulsatile Tinnitus After Cerebral Venous Sinus Stenting: Systematic Review and Pooled Analysis of 616 Patients

Pulsatile tinnitus (PT) is a debilitating condition with substantial morbidity related to quality of life. Cerebral venous sinus stenosis has recently emerged as a noninfrequent cause of PT, either in the setting of concurrent idiopathic intracranial hypertension (IIH) or due to primary venous stenosis. Venous sinus stenting (VSS) is an endovascular technique that can be used to treat venous stenosis. However, it is unclear if outcomes are different between patients with primary venogenic PT and IIH associated PT. A systematic literature review and pooled analysis was completed to evaluate the clinical outcomes of PT in patients undergoing cerebral VSS. Outcome measures included: Improved PT, complete resolution of PT, and PT recurrence at follow-up. Subgroup analysis between patients with IIH and primary PT was completed. In total, 28 studies were identified with 616 patients. The proportion of improved PT symptoms after VSS had an overall pooled rate of 91.7% (confidence interval [CI]:88.1%-95.2%; I2= 65%) and no difference between subgroups (P= 0.12). Complete resolution after VSS had an overall pooled rate of 88.6% (CI: 84.0%-93.3%; I2= 68%) and no significant difference between subgroups (P= 0.35). Recurrent PT after stenting occurred in 6.5% of cases (CI: 1.7%-11.3%; I2= 62%). Furthermore, subgroup analysis demonstrated that IIH patients had a significantly higher recurrence rate (10.6%; CI: 5.2%-16.1%; I2= 26%) compared to patients treated with venous stenting for PT as the primary indication (2.0%; CI: 0.8%-4.7%; I2= 0%) (P < 0.0001). Venous stenting in patients with PT results in a substantial decrease and often complete resolution of symptoms. PT is more likely to recur in patients with IIH-associated PT.

Treatment of tumor-induced cerebral venous sinus stenosis: Technical note and review of the literature.

Tumors that invade or compress the venous sinuses have the potential to impair venous drainage. Rarely, this may be so severe as to induce intracranial hypertension. Other studies have previously described venous sinus stenting (VSS) for the treatment of these symptomatic lesions. In this report, we present our series of eight cases of VSS for symptomatic tumor-induced venous sinus stenosis and review the existing literature. Eight patients with mostly intracranial tumors were found to have symptomatic venous sinus stenosis with the most common presenting symptom being elevated intracranial pressure. Six of the eight (75%) patients presented with papilledema on neuro-ophthalmological exam. The most affected locations were the transverse and sigmoid sinuses in four patients, followed by the superior sagittal sinus in three patients. All eight patients underwent VSS with no adverse events. In total, 6 out of 8 (75%) of patients had complete resolution of their symptoms, while the remaining patients experienced at least partial improvement. Tumors that cause symptomatic venous sinus stenosis may be successfully managed with VSS to improve venous drainage. This may facilitate continued conservative management of meningiomas or allow for treatment with noninvasive means, such as stereotactic radiosurgery. Depending on the size of the target stenosis, balloon-mounted coronary stents may be a suitable option to treat these lesions.

Dural venous sinus angioplasty and stenting for treatment of idiopathic intracranial hypertension: a single-center experience with 20 consecutive cases

Background: Dural venous sinus stenosis has been shown to be a potential cause or aggravating factor of idiopathic intracranial hypertension (IIH). Endovascular therapy for angioplasty of venous sinus stenosis is emerging as a potential alternative to treat IIH. Objective: This article aims to present the results of a cases series representing the experience of a single center in treating this disease. Materials and Methods: We retrospectively reviewed the angiographic and manometric data of patients undergoing angioplasty and stenting for the treatment of IIH with venous sinus stenosis on magnetic resonance angiography. All patients had failed conventional medical treatment. Data on demographic features, clinical and radiologic presentation, and outcomes were collected retrospectively. Results: 20 female patients, with persistent headache and papilledema, underwent venous sinus angioplasty and stenting. Mean age was 35.9 (SD, 10) years. Eighteen patients (90%) had clinical improvement after the procedure. Of these, all showed resolution (17 patients, 94%) or partial improvement (1 patient, 6%) of papilledema within 6 months. Two patients had persistent moderate-to-severe headache (intensity &gt; 6 on a 10-point pain scale), with continued papilledema despite stable visual acuity on visual field testing. The mean pre-procedure lumbar puncture opening pressure was 30.1 (SD, 4) mm Hg, decreasing to 16.2 (SD, 4) mm Hg after the procedure. Only 4 patients experienced complications directly or indirectly related to the procedure, with no impact on outcome. Conclusion: Angioplasty and stenting of the stenotic segment may effectively and safely treat IIH associated with focal venous sinus stenosis, with a high technical success rate and an acceptable complication rate.

Magnetic Resonance Imaging Signs of Idiopathic Intracranial Hypertension

The magnetic resonance imaging (MRI) criteria currently used to diagnose idiopathic intracranial hypertension (IIH) are based on expert opinion and have limited accuracy. Additional neuroimaging signs have been proposed and used with contradictory results; thus, prospective evidence is needed to improve diagnostic accuracy. To provide evidence-based, accurate MRI signs for IIH diagnosis. This prospective cohort study was conducted from January 2018 to May 2021 with 3 validation cohorts at 2 Danish headache centers and with 3 independent international cohorts. Consecutive patients with suspected IIH were enrolled. Eligibility required the clinical suspicion of IIH, age 18 years or older, and written informed consent. The validation cohorts comprised patients with confirmed IIH from Austria and the US, and patients without IIH from the US. Data analysis was performed from December 2021 to August 2023. Standardized diagnostic workup was performed to classify cases according to current criteria, and blinded evaluation of cerebral radiological diagnostics and papilledema was performed. The primary outcomes were MRI signs associated with IIH as assessed by univariate analyses. An MRI score estimating papilledema was calculated using machine learning. Internal validation of associations with lumbar puncture opening pressure and outcome and external validation of accuracy were performed in 3 cohorts. Of 192 eligible patients (185 women [96.4%]; median [IQR] age, 28.0 [23.0-35.0] years), 110 were classified as having IIH, 4 as having probable IIH, and 1 as having suspected IIH without papilledema; 77 did not have IIH and served as controls, with corresponding age, sex, and weight. Papilledema at diagnosis was associated with perioptic subarachnoid space distension (56 patients [68.3%] vs 21 patients [41.2%]), posterior globe flattening (53 patients [66.3%] vs 10 patients [21.3%]), optic nerve disc protrusion (35 patients [30.4%] vs 2 patients [2.3%]), and transverse sinus venous stenosis (75 patients [79.8%] vs 29 patients [46.8%]). The papilledema-estimating MRI score showed optimal balance between sensitivity (49%) and specificity (87%) when 2 of the 3 latter signs were present and was associated with the lumbar puncture opening pressure and ophthalmological outcome. The score showed strong diagnostic accuracy in the external validation cohorts (587 patients; area under the receiver operating characteristic curve, 0.86) and outperformed the current (2013) diagnostic MRI criteria. The findings of this cohort study of patients with IIH and controls suggest that an evidence-based MRI score including posterior globe flattening, optic nerve disc protrusion, and transverse sinus stenosis can estimate the presence of papilledema more accurately than the current diagnostic criteria.

Pulsatile Tinnitus: Differential Diagnosis and Approach to Management.

The purpose of this review is to provide an updated approach to the evaluation and management of pulsatile tinnitus (PT), an uncommon but often treatable subtype of tinnitus. Secondary PT can be due to either vascular or non-vascular etiologies, including, but not limited to: neoplasm, arteriovenous malformation or fistula, idiopathic intracranial hypertension, dural venous sinus stenosis, otoacoustic etiologies (e.g., otosclerosis, patulous eustachian tube) and bony defects (e.g., superior semicircular canal dehiscence). Computed tomography (CT) and magnetic resonance imaging (MRI) imaging have comparable diagnostic yield, though each may be more sensitive to specific etiologies. If initial vascular imaging is negative and a vascular etiology is strongly suspected, digital subtraction angiography (DSA) may further aid in the diagnosis. Many vascular etiologies of PT can be managed endovascularly, often leading to PT improvement or resolution. Notably, venous sinus stenting is an emerging therapy for PT secondary to idiopathic intracranial hypertension with venous sinus stenosis. Careful history and physical exam can help establish the differential diagnosis for PT and guide subsequent evaluation and management. Additional studies on the efficacy and long-term outcome of venous sinus stenting for venous stenosis are warranted.

Tortuous occipital emissary vein combined with dural venous sinus stenosis in contrast-enhanced MRV for evaluation of idiopathic intracranial hypertension.

Venous outflow impediment is increasingly recognized in idiopathic intracranial hypertension (IIH). We aim to search for the value of tortuous occipital emissary vein (OEV) in IIH by integrating measurable transverse sinus (TS) stenosis in contrast-enhanced MR venography (CE-MRV). Twenty-one IIH patients were evaluated with CE-MRV. Each patient had high LP opening pressure (> 25cm.H2O), and presented papilledema. Age- and sex-matched 21 control subjects who underwent cranial CE-MRV were selected. The OEV and the following features: intraosseous diameter of more than 3mm, twisted course, and continuous with prominent sub-occipital extracranial veins were named tortuous OEV. TS stenosis was measured by utilizing the coronal T1-VIBE series to calculate quantitative metrics such as TS max./min.. The tortuous OEV and TS max./min. were registered to create a bivariate logistic regression model to assess the performance of tortuous OEV for IIH when accompanied by TS stenosis. Six (29%) tortuous OEVs were observed in the IIH group, while no tortuous OEV was identified in the control group (p = 0.021). The mean TSmax./min. was 2.48 ± 1.19 in patients with IIH and 1.23 ± 0.33 in the control group (p < 0.001). According to regression analysis, tortuous OEV is not predictive of IIH (p = 0.999), while the higher TSmax./min. (> 1.69) is predictive of IIH (p = 0.022, OR: 8.9; %95 CI; 1.4-59.0) when accompanied together. Tortuous occipital emissary vein is more frequently seen in patients with IIH. However, the tortuous appearance alone does not predict idiopathic intracranial hypertension unless associated with measurable transverse sinus narrowing in CE-MRV.

Assessment of cerebral venous sinus: Anatomical and functional diagnostic performance of three-dimensional reconstruction models based on venous sinus MRI and CT images

Venous sinus stenosis is commonly observed in patients presenting with pulsatile tinnitus (PT). While magnetic resonance imaging (MRI) and computed tomography (CT) are commonly used for assessing venous sinus geometries, the preferred modality remains unclear. In this study, we reconstructed the three-dimensional (3D) geometries of the venous sinus using MRI and CT imaging data from 20 PT patients. We conducted comparisons of the anatomical features of the venous sinus through case-wise analysis and anatomic geometrical parameter-wise analysis. Our findings indicate that by taking the geometries from CT as a reference, MRI could provide a better illustration of venous structure, primarily due to a stronger flow signal concentrated in the vascular tree. We observed high agreements in anatomic parameters measured from 3D geometries reconstructed based on CT and MRI in 19 out of 20 cases. Notably, the cross-sectional area of the sinus and segment length displayed the highest consistency, with a mean difference of -5.01% and 6.5% between modalities, respectively. In addition, we noticed that 55% of cases exhibited consistency in analyzing the confluence of the sinus, while variants of connectivity and collateral branching were observed between CT and MRI. Importantly, CT-based geometric reconstruction provided better detail of inflow side branches in the straight sinus, whereas MRI preserved more side branches of outflow in the downstream sinus. It is important to note that CT-based evaluation may be affected by the bone structures surrounding the venous sinus, whereas MRI-based evaluation focuses on blood flow to the segments, potentially indicating both anatomical and functional abnormalities.

Revisiting the Pathophysiology of Intracranial Hemorrhage in Fetuses with Chiari II Malformation: Novel Imaging Biomarkers of Disease Severity?

Intracranial hemorrhage (ICH) has emerged as a notable concern in Chiari II malformation (CM II), yet its origins and clinical implications remain elusive. This study aims to validate the in utero prevalence of ICH in CM II and investigate contributing factors, and visualize the findings in a network format. A single-center retrospective review of fetal MRI scans obtained in fetuses with CM II (presenting January 2007 to December 2022) was performed for ICH utilizing EPI-T2* blood-sensitive sequence. Fetuses with aqueduct stenosis (AS) were included as a control group. The incidence of ICH and corresponding gestational ages were compared between CM II and AS cases, and morphometric measurements (inner/outer CSF spaces, posterior fossa, venous structure) were compared among the 4 1:1 age-matched groups: CM II+ICH, CM II-ICH, AS+ICH, and AS-ICH. Additionally, a co-occurrence network was constructed to visualize associations between phenotypic features in ICH cases. A total of 101 fetuses with CM II and 90 controls with AS at a median gestational age of 24.4 weeks and 22.8 weeks (P = .138) were included. Prevalence of ICH in fetuses with CM II was higher compared with the AS cases (28.7% versus 18.9%, P = .023), accompanied by congested veins (deep vein congestion mainly in young fetuses, and cortical veins may also be affected in older fetuses). ICH was notably correlated with specific anatomic features, essentially characterized by reduced outer CSF spaces and clivus-supraocciput angle. The co-occurrence network analysis reveals complex connections including bony defects, small posterior fossa dimensions, vermis ectopia, reduced CSF spaces, as well as venous congestion and venous sinus stenosis as pivotal components within the network. The high prevalence of ICH-detected by fetal MRI-among fetuses with CM emphasizes the pathophysiologic importance of venous congestion, ICH, and vasogenic edema. As indicators of disease severity, these features may serve as helpful additional imaging biomarkers for the identification of potential candidates for fetal surgery.

Novel Approach to Venous Stenting: Tigertriever Temporary Stenting for the Evaluation of Pulsatile Tinnitus

Objective Pulsatile tinnitus can be significantly functionally debilitating, with venous sinus stenosis being a largely underrecognized etiology. Establishing a direct cause‐effect relationship can be particularly challenging in pulsatile tinnitus cases without idiopathic intracranial hypertension, and with multifocal, bilateral venous sinus stenoses. Case Presentation Herein, we present a patient with pulsatile tinnitus and bilateral transverse‐sigmoid sinus stenoses on diagnostic angiogram. Temporary stenting using a Tigertreiver was utilized to localize the symptomatic segment. Patient reported resolution of pulsatile tinnitus after deploying the temporary stentriever within the left sigmoid sinus. Subsequently, permanent stenting of the left sigmoid sinus was preformed resulting in complete resolution of symptoms. Conclusion We highlight the diagnostic challenges of patients presenting with pulsatile tinnitus and venous sinus stenoses, without idiopathic intracranial hypertension. While more experience is needed, temporary stenting may provide an improved method for assessing venous stenting efficacy in patients with pulsatile tinnitus.

Intravascular ultrasound characteristics of different types of stenosis in idiopathic intracranial hypertension with venous sinus stenosis

BackgroundIn this study, we analyzed the characteristics of different stenosis types in idiopathic intracranial hypertension (IIH) patients with venous sinus stenosis (VSS) using intravascular ultrasound (IVUS).MethodsWe retrospectively reviewed data from...

Foundations of the Diagnosis and Management of Idiopathic Intracranial Hypertension and Pulsatile Tinnitus

Venous sinus stenosis has garnered increasing academic attention as a potential etiology of idiopathic intracranial hypertension (IIH) and pulsatile tinnitus (PT). The complex anatomy of the cerebral venous sinuses and veins plays a crucial role in the pathophysiology of these conditions. Venous sinus stenosis, often found in the superior sagittal or transverse sinus, can lead to elevated intracranial pressure (ICP) and characteristic IIH symptoms. Stenosis, variations in dural venous anatomy, and flow dominance patterns contribute to aberrant flow and subsequent PT. Accurate imaging plays a vital role in diagnosis, and magnetic resonance (MR) venography is particularly useful for detecting stenosis. Management strategies for IIH and PT focus on treating the underlying disease, weight management, medical interventions, and, in severe cases, surgical or endovascular procedures. Recently, venous sinus stenting has gained interest as a minimally invasive treatment option for IIH and PT. Stenting addresses venous sinus stenosis, breaking the feedback loop between elevated ICP and stenosis, thus reducing ICP and promoting cerebrospinal fluid outflow. The correction and resolution of flow aberrances can also mitigate or resolve PT symptoms. While venous sinus stenting remains an emerging field, initial results are promising. Further research is needed to refine patient selection criteria and evaluate the long-term efficacy of stenting as compared to traditional treatments.

416 Redefining Treatment Expectations: Exploring Long-Term Outcomes of Venous Sinus Stenting in Idiopathic Intracranial Hypertension

INTRODUCTION: Idiopathic intracranial hypertension (IIH) is a condition characterized by various symptoms such as pulsatile tinnitus, chronic headaches, and papilledema. Venous sinus stenosis has been associated with IIH, and venous sinus stenting (VSS) has emerged as a potential treatment option. However, there is a lack of standardized outcome definitions and limited long-term data on the effectiveness of VSS in current literature. METHODS: In this study, we analyzed the long-term outcomes of 178 patients with medically-refractory IIH who underwent VSS by the senior author. Demographic information, pressure gradients, symptom improvement, recurrence, and persistence were recorded. Quality of life and symptom severity scores were assessed using standardized HIT-6, WHO-BREF, and pulsatile tinnitus surveys. Follow-up duration and patient-reported outcomes were also considered. RESULTS: Among the VSS cohort, 52.8% reported initial symptom relief followed by recurrence, and 13.5% experienced persistent symptoms without improvement. Overall failure rate of VSS was found to be 66.3%. Repeat procedures, such as lumbar puncture or additional stenting occurred in many patients. Survey data showed varying degrees of improvement in symptom severity and quality of life, and these changes were found to be statistically insignificant long-term. CONCLUSIONS: Our study challenges the prevailing notion of favorable outcomes in VSS suggests a need for reevaluation of the procedure as a long-term treatment option for severe IIH. High rates of symptom recurrence, persistence, and the need for repeat interventions indicate limitations in the efficacy of VSS. Improved understanding of the underlying factors contributing to poor outcomes and the development of alternative interventions are essential for better management of this debilitating condition.

Angulation of the dural venous sinuses of the posterior cranial fossa: Anatomical study with clinical and surgical applications.

Cerebral vein and dural venous sinus thromboses (CVST) account for 0.5%-1% of all strokes. Some structural factors associated with a potentially higher risk for developing CVST have been described. However, angulation of the dural venous sinuses (DVS) has yet to be studied as a structural factor. The current study was performed because this variable could be related to alterations in venous flow, thus predisposing to a greater risk of CVST development. Additionally, such information could help shed light on venous sinus stenosis (VSS) at or near the transverse-sigmoid junction. The angulations formed in the different segments of the grooves of the transverse (TS), sigmoid (SS), and superior sagittal sinuses (SSS) were measured in 52 skulls (104 sides). The overall angulation of the TS groove was measured using two reference points. Other variables were examined, such as the communication pattern at the sinuses' confluence and the sinus grooves' lengths and widths. The patterns of communication between sides were compared statistically. The most typical communication pattern at the sinuses' confluence was a right-dominant TS groove (82.98%). The mean angulations of the entire left TS groove at two different points (A and B) were 46° and 43°. Those of the right TS groove were 44° and 45°. The median angulations of the left and right SSS-transverse sinus junction grooves were 127° and 124°. The mean angulations of the left and right TS-SSJsv grooves were 111° (range 82°-152°) and 103° (range 79°-130°). Differentiating normal and abnormal angulations of the DVSs of the posterior cranial fossa can help to explain why some patients are more susceptible to pathologies affecting the DVSs, such as CVST and VSS. Future application of these findings to patients with such pathologies is now necessary to extrapolate our results.