Pattern of pressure gradient alterations after venous sinus stenting for idiopathic intracranial hypertension predicts stent-adjacent stenosis: a proposed classification system

What should otolaryngologists know about dural venous sinus stenting?

Dural venous sinus stenting is an emerging and exciting area in otolaryngology in collaboration with neurosurgeons and neuroradiologists. The first cases were reported 20 years ago. It is now considered part of the routine treatment of increased intracranial pressure due to transverse sinus stenosis. ENT doctors are the first to see these patients in their clinics, as sinus headaches, pulsating tinnitus, and dizziness are the most common symptoms. Previously, with limited success, high-dose diuretics and intracranial shunts had been the only options for treating these patients. Other methods, such as covering the sigmoid sinuses with graft material, appear to cause a sudden increase in intracranial pressure that can lead to blindness and even death. This overview summarizes the clinical and imaging characteristics of patients who will benefit from endovascular sinus stenting for elevated intracranial pressure.

Stenting for Venous Sinus Stenosis in Patients With Idiopathic Intracranial Hypertension: An Updated Systematic Review and Meta-Analysis of the Literature

BACKGROUND AND OBJECTIVES

Although venous sinus stenting (VSS) improves cerebrospinal fluid reabsorption and decreases intracranial pressure in patients with idiopathic intracranial hypertension (IIH), the underlying pathophysiology of IIH is not well understood. We present a review and meta-analysis of the literature on VSS for IIH treatment, focusing on the rates of restenosis and symptom recurrence.

METHODS

We performed a systematic review of PubMed and Embase databases between January 1, 2011, and December 31, 2021. Articles including ≥5 patients with IIH and venous sinus stenosis treated with VSS and post-treatment rates of restenosis (de novo stenosis at a different anatomic location along the dural sinuses or restenosis within or adjacent to the stent) were selected. Demographic, procedural, and outcomes data were collected and analyzed. Mean values for variables collected were pooled, and a mean value was calculated with a 95% CI.

RESULTS

Twenty-four articles were included, comprising 694 patients and 781 VSS cases. The mean age was 33.9 (CI, 31.5-36.2) years. The mean body mass index was 35.3 (CI, 32.9-37.7) kg/m 2 . Before VSS, 98.8% (CI, 96.8%-100.0%) of patients experienced headaches, 87.7% (CI, 80.6%-95.5%) had visual acuity issues, 78.7% (CI, 69.9%-88.5%) had papilledema, 58.3% (CI, 46.0%-73.9%) had tinnitus, and 98.8% (96.4%-100.0%) had symptoms refractory to previous therapies. After VSS, 77.7% (CI, 71.1%-84.95%) experienced symptom improvement and 22.3% (CI, 15.1%-29.0%) had persistent or worsened symptoms. Pooled restenosis rate was 17.7% (CI, 14.9%-20.9%).

CONCLUSION

VSS is effective in alleviating IIH signs and symptoms, but the associated high rates of restenosis and persistent symptoms highlight the need for further investigation of this procedure and other adjunctive treatments for IIH.

Future Directions and Innovations in Venous Sinus Stenting

This review explores the future role of venous sinus stenting (VSS) in the management of idiopathic intracranial hypertension and pulsatile tinnitus. Despite its favorable safety profile and clinical outcomes compared with traditional treatments, VSS is not yet the standard of care for these conditions, lacking high-level evidence data and guidelines for patient selection and indications. Current and recently completed clinical trials are expected to provide data to support the adoption of VSS as a primary treatment option. Additionally, VSS shows potential in treating other conditions, such as dural arteriovenous fistula and cerebral venous sinus thrombosis, and it is likely that the procedure will continue to see an expansion of its approved indications. The current lack of dedicated venous stenting technology is being addressed with promising advancements, which may improve procedural ease and patient outcomes. VSS also offers potential for expansion into modulation of brain electrophysiology via endovascular routes, offering exciting possibilities for neurodiagnostics and treatment of neurodegenerative disorders.

Challenges in the use of Venous Sinus Stenting in the Treatment of Idiopathic Intracranial Hypertension and Pulsatile Tinnitus

Although numerous case series and meta-analyses have shown the efficacy of venous sinus stenting (VSS) in the treatment of idiopathic intracranial hypertension and idiopathic intracranial hypertension-associated pulsatile tinnitus, there remain numerous challenges to be resolved. There is no widespread agreement on candidacy; pressure gradient and failed medical treatment are common indications, but not all clinicians require medical refractoriness as a criterion. Venous manometry, venography, and cerebral angiography are essential tools for patient assessment, but again disagreements exist regarding the best, or most appropriate, diagnostic imaging choice. Challenges with the VSS technique also exist, such as stent choice and deployment. There are considerations regarding postprocedural balloon angioplasty and pharmacologic treatment, but there is insufficient evidence to formalize postoperative decision making. Although complications of VSS are relatively rare, they include in-stent stenosis, hemorrhage, and subdural hematoma, and the learning curve for VSS presents specific challenges in navigating venous anatomy, emphasizing the need for wider availability of high-quality training. Recurrence of symptoms, particularly stent-adjacent stenosis, poses challenges, and although restenting and cerebrospinal fluid-diverting procedures are options, there is a need for clearer criteria for retreatment strategies. Despite these challenges, when comparing VSS with traditional cerebrospinal fluid-diverting procedures, VSS emerges as a favorable option, with strong clinical outcomes, lower complication rates, and cost-effectiveness. Further research is necessary to refine techniques and indications and address specific aspects of VSS to overcome these challenges.

Idiopathic Intracranial Venous Hypertension: Toward a Better Understanding of Venous Stenosis and the Role of Stenting in Idiopathic Intracranial Hypertension

BACKGROUND

Venous sinus stenosis, typically at the junction of the transverse and sigmoid sinus, is increasingly recognized as a contributor to the pathophysiology of idiopathic intracranial hypertension (IIH), whether it be the intrinsic type that does not reverse with normalization of intracranial pressure or the extrinsic type, which does. Efforts to treat the stenosis and reduce the associated transstenotic gradient through placement of a stent at the site of stenosis have been studied over the past 2 decades, primarily through retrospective studies, with variable emphasis on formal visual testing and direct assessment of poststent opening pressure. Most studies have presented evidence for utilization of stenting as an alternative to cerebrospinal fluid shunting or optic nerve sheath fenestration in patients with IIH who harbor the stenosis and are refractory to or intolerant of intracranial pressure-lowering medications, but an assessment of the current data is needed to better understand the role of stenting for this patient population.

EVIDENCE ACQUISITION

A search in PubMed was made for "IIH," "papilledema," and "venous stenting." Data pre and post stenting, including symptoms attributable to IIH, intracranial pressure, papilledema, retinal nerve fiber layer thickening on optical coherence tomography, and visual field assessment (mean deviation), were collected. Need for retreatment and complications were assessed among all studies. Studies using stenting for special circumstances, such as cerebrospinal leaks or for stenosis along anomalous vessels, were reviewed.

RESULTS

In total, 49 studies (45 retrospective and 4 prospective) and 18 case reports (with 3 or less patients) were found and included in the analysis, for a total of 1,626 patients. In 250 patients in whom poststent intracranial pressure was measured, the mean value was 19.7 cm H 2 O, reduced from a mean of 33 cm H 2 O. Transient visual obscurations resolved in 79.6% of 201 patients who complained of it, pulsatile tinnitus resolved in 84.7% of 515, diplopia resolved in 93% of 86 patients, and nonspecific visual symptoms such as "blurry vision" improved in 76.2% of 537 patients. Headaches resolved in 36% and improved in a further 40.7% of 1,105 patients in whom they were documented before stenting. Of 1,116 with papilledema, 40.8% demonstrated resolution and 38.2% improvement. The mean retinal nerve fiber layer thickness improved from 170.2 µm to 89.2 µm among 402 eyes in which optical coherence tomography was used to measure it. Among 135 eyes in which formal visual fields were performed pre and post stenting, the prestent average mean deviation of -7.35 dB improved to -4.72 dB after stenting. Complications associated with stenting included in-stent stenosis or thrombosis, subdural hematoma, intracerebral hematoma, cerebral edema, stent migration, and death. A recurrence of symptoms requiring a follow-up surgical intervention occurred in 9%.

CONCLUSIONS

A growing body of evidence supports the use of venous sinus stenting as a viable option for medically refractory IIH, especially when papilledema threatens visual function. Complication and failure rates seem to be similar to alternative surgical approaches, although serious neurological sequalae can rarely occur. Emerging studies evaluating stent type, including novel stents designed for use in the venous system, may help improve ease of the procedure and long-term success rates. Prospective head-to-head studies are needed to better understand the performance of stenting compared with other interventions.

Neuro-ophthalmological evaluation including optical coherence tomography surrounding venous sinus stenting in idiopathic intracranial hypertension with papilledema: a case series

Venous sinus stenting (VSS) for idiopathic intracranial hypertension (IIH) has been demonstrated to achieve significant symptom improvement while harboring a low periinterventional morbidity profile. Comprehensive neuro-ophthalmological monitoring represents a cornerstone of disease monitoring. The value of optical coherence tomography (OCT) requires further exploration. Patients with IIH and papilledema who underwent VSS between 04/2018 and 02/2021 were retrospectively reviewed. Clinical and radiological were analyzed. Neuro-ophthalmological data included visual acuity, visual fields, fundoscopy categorized via Frisén scale, and OCT obtained retinal nerve fiber layer (RNFL) thickness were analyzed. Of 39 IIH patients who underwent cerebral angiography with transverse-sigmoid sinus pressure evaluation, 18 patients with IIH and papilledema underwent 21 transverse-sigmoid sinus stenting (TSST) procedures. After TSST, manometry showed a significant reduction of maximum transverse sinus pressures and trans-stenotic gradient pressures (p = 0.005 and p < 0.001, respectively). Chronic headaches, visual disturbance resolved and pulsatile tinnitus improved significantly. Visual fields remained similar, while papilledema Frisén scales and visual acuity significantly improved. The OCT calculated RNFL thickness significantly decreased in all patients. Stratification according to a minimal-low degree (Frisén 1-2) and moderate-marked degree (Frisén 3-4) papilledema demonstrated a significant reduction of RNFL thickness in both groups. Venous sinus stenting provides favorable clinical and neuro-ophthalmological outcomes. This study demonstrates that neuro-ophthalmologic testing augmented with OCT evaluation provides objective data that can be used as a biomarker for treatment success for managing patients with different extents of papilledema and may inform patient management.

The Case of a Patient with Idiopathic Intracranial Hypertension Who Required Additional Stenting for Stent-Adjacent Stenosis

Objective

We report the case of a patient with recurred idiopathic intracranial hypertension (IIH) with transverse sinus (TS) stenosis after initial stenting, which was treated with additional stent placed in tandem to the secondarily occurred stent-adjacent stenosis (SAS).

Case Presentation

A 41-year-old woman complained of reduced visual acuity and blurred vision, and presented with papilledema. Lumbar puncture revealed an opening pressure of 36 cmH₂O. MRI revealed no space-occupying lesions, and the patient was diagnosed with IIH based on the modified Dandy criteria. MR venography revealed stenosis in the right and hypoplastic left TS. The patient complained of headache and neck pain after each lumbar puncture for examination. Venous sinus stenting (VSS) was performed in the right TS. One month after stenting, follow-up angiography revealed stenosis in the remaining parts of TS. Five months after stenting, IIH recurred, and SAS was detected on angiography. An additional stenting procedure was performed. Three months after the second treatment, her symptoms disappeared and cerebrospinal fluid pressure was normalized.

Conclusion

Patients with post-VSS recurrent IIH may develop restenosis in the remaining parts of TS at variable progression speeds. In this case, angiography revealed gradually advancing stenosis that seemed to form SAS at the time of recurrence. If the initial VSS is effective for IIH, SAS can also be treated effectively and less invasively with a second stent placement covering the entire TS length.

Associations among Audiometric, Doppler Hydroacoustic, and Subjective Outcomes of Venous Pulsatile Tinnitus

OBJECTIVE

Venous pulsatile tinnitus (PT) has received increasing attention recently. As analyses of psychophysical and neuropsychological dimensions of venous PT are lacking, this study aimed to quantitatively and qualitatively investigate the correlation among audiometric, hydroacoustic, and subjective outcomes in patients with PT.

METHODS

Fifty-five venous PT patients, with or without sigmoid sinus wall anomalies (SSWAs), were subdivided into SSWAs (n = 30) and non-SSWAs (n = 25) groups. Audiometric and hemodynamic evaluations were assessed. Questionnaires including the Tinnitus Handicap Inventory, Hospital Anxiety and Depression Scale (HADS), and Athens Insomnia Scale (AIS) were deployed to evaluate the psychological impacts of PT.

RESULTS

Among 55 subjects, PT frequency-related pure-tone audiometry (PTA) was significantly different between ipsilesional non-PT frequency-related PTA (p < 0.01), ipsilateral jugular vein compression PTA (p < 0.01), and contralesional ear PTA (p < 0.01). In contrast with the pulsatility index and flow velocity, bilateral EOET and flow volume were significantly different (p < 0.01). Of the 3 questionnaire types, there was a strong correlation between HADS anxiety and AIS scores (r = 0.658, p < 0.01). The duration of PT was not correlated with subjective outcomes, and there was no statistical significance found among audiometric, hemodynamic, and subjective outcomes between SSWAs and non-SSWAs groups.

CONCLUSIONS

(1) The duration of PT was irrelevant to the increase of PTA. (2) Venous PT is the perception of vascular flow sound, in which hydroacoustic characteristics can be highly independent. (3) Anxiety, depression, and sleep disorders commonly prevail among PT patients.

Dural venous sinus stenting in the treatment of idiopathic intracranial hypertension: A systematic review and critique of literature

Idiopathic intracranial hypertension (IIH) is increased intracranial pressure without a known cause. Dural venous sinus stenting (DVSS) is a relatively new intervention for treatment of IIH refractory to medical therapy and lifestyle modifications. In this review, we outline various hypotheses of IIH pathogenesis and describe the role of venous sinus stenosis and the technical details of DVSS. We also present a summary and critique of the available evidence describing the outcomes of DVSS in IIH and review the evidence-based guidelines for this procedure. We conclude that, although many studies have shown generally favorable outcomes of DVSS in patients with IIH, most have serious limitations, the most common one being paucity of pre- and postprocedure ophthalmological data. Thus, there is not enough available evidence to conclude whether DVSS is an effective procedure for treatment of IIH. We also present the most commonly used indications for DVSS as described in the literature and stress the importance of neuro-ophthalmological assessment before and after the procedure to monitor response and potential complications.

Predicting the need for retreatment in venous sinus stenting for idiopathic intracranial hypertension

BACKGROUND

Idiopathic intracranial hypertension is a disease of raised intra-cranial pressure of unknown etiology. Lateral cerebral venous sinus stenosis (VSS) has been increasingly reported in these patients, and stenting has emerged as an alternative treatment for medically refractory symptoms. Treatment efficacy on meta-analysis appears promising, but identifying which patients are likely to benefit most, and which are likely to require repeat procedures, is currently unclear.

METHODS

We retrospectively reviewed a prospectively collected database of 79 patients treated with venous sinus stenting at a single academic center with minimum follow-up of 18 months. We extracted baseline clinical data, as well as manometry at lumbar puncture and during angiography, and used logistic regression to identify parameters that could predict stent failure.

RESULTS

Retreatment rate after successful VSS was 13.9%. Lumbar puncture opening pressure (OP) was shown to significantly predict treatment failure (ß=0.06; OR=1.064 (1.003-1.135); P=0.039). This effect remained significant when age, sex and body mass index were added to the model (ß=0.06; OR=1.066 (1.002-1.140); P=0.043). OP was correlated with venous sinus manometry readings in the superior sagittal and transverse sinus pre-stent placement, as well trans-stenotic gradient (P<0.001).

CONCLUSIONS

Higher lumbar puncture OP was associated with an increased risk of stent failure in transverse sinus stenting for idiopathic intracranial hypertension, although the performance of this model as a linear discriminator was poor. Further studies are required to better assess which patients are at greatest risk of treatment failure.

A systematic review of surgical treatments of idiopathic intracranial hypertension (IIH)

Idiopathic intracranial hypertension denotes raised intracranial pressure in the absence of an identifiable cause and presents with symptoms relating to elevated ICP, namely headaches and visual deterioration. Treatment of IIH aims at reducing intracranial pressure, relieving headache and salvaging patients' vision. Surgical interventions are recommended for medically refractory IIH and include CSF diversion techniques, optic nerve sheath fenestration, bariatric surgery and venous sinus stenting. Prospective studies on the surgical options for IIH are scant and no evidence-based guidelines for the surgical management of medically refractory IIH have been established. A search in Cochrane Library, MEDLINE and EMBASE from 1 January 1985 to 19 April 2019 for controlled or observational studies on the surgical treatment of IIH (defined in accordance with the modified Dandy or the modified Friedman criteria) in adults yielded 109 admissible studies. VSS improved papilledema, visual fields and headaches in 87.1%, 72.7% and 72.1% of the patients respectively, with a 2.3% severe complication rate and 11.3% failure rate. CSF diversion techniques diminished papilledema, visual field deterioration and headaches in 78.9%, 66.8% and 69.8% of the cases and are associated with a 9.4 severe complication rate and a 43.4% failure rate. ONSF ameliorated papilledema, visual field defects and headaches in 90.5, 65.2% and 49.3% of patients. Severe complication rate was 2.2% and failure rate was 9.4%. This is currently the largest systematic review for the available operative modalities for IIH. VSS provided the best results in headache resolution and visual outcomes, with low failure rates and a very favourable complication profile. In light of this, VSS ought to be regarded as the first-line surgical modality for the treatment of medically refractory IIH.

Exploring The Current Management Idiopathic Intracranial Hypertension, And Understanding The Role Of Dural Venous Sinus Stenting

Idiopathic Intracranial Hypertension (IIH) is a debilitating disorder characterised by raised intracranial pressure (ICP), papilloedema with the potential risk of permanent visual loss, and headaches that are profoundly disabling and reduce the quality of life. The first consensus guidelines have been published on investigation and management of adult IIH and one key area of uncertainty is the utility of dural venous sinus stenting for the management of headache and visual loss. There are an increasing number of series published and to help understand the successes and complications. During a patient physician priority setting, the understanding of the best type of intervention to treat IIH was assigned to the top 10 of most desired research questions for the disease. Ultimately randomised clinical trials (RCTs) in neurovascular stenting for IIH would be instructive, as the literature to date may suffer from publication bias. Due to the increasing incidence of IIH, there is no better time to systematically investigate interventions that may reverse the disease process and achieve remission. In this review we discuss the pathophysiology of IIH in relation to venous sinus stenosis, the role of venous sinus stenting with a review of the relevant literature, the advantages and disadvantages of stenting compared with other surgical interventions, and the future of stenting in the treatment of IIH.

Long-term Outcomes of Cerebral Venous Sinus Stenosis Corrected by Stenting

Background and Purpose:

Cerebral Venous Sinus Stenosis (CVSS) usually results in severe Intracranial Hypertension (IH), which can be corrected by stenting immediately. However, there is a lack of evidence of the long-term good outcomes in patients with CVSS who underwent stenting.

Methods:

A total of 62 patients with imaging confirmed non-thrombotic and non-external compression CVSS were enrolled into this single center real-world cohort study after undergoing stenting, and were continuously followed up for more than 12 years. The symptoms and signs of IH prior to stenting and post-stenting and the incidence of restenosis after stenting were analyzed.

Results:

The mean age of the 62 patients (range, 13 to 62) was 40 years old, and the mean body mass index was 26 (range 23 to 40). Females accounted for 67.7% (42/62). Headache was the most common symptom (79%). Transient visual obscurations occurred in 69% of the patients. 42% of the patients suffered from visual loss, 11.3% pulsatile tinnitus, and 96.8% Papilledema before stenting. The mean trans-stenotic pressure gradients were 6~43 mmHg prior to stenting and returned to 0~4 mmHg after stent placement. During the following 12~126 months (the median was 62) after stenting of the follow-up, 91.9% (57/62) of the patients obtained good outcomes. Headaches disappeared in 96% (47/49) of the patients and papilledema was attenuated in 98.3% (59/60). However, There were still 8.0 % (5/62) of the patients with poor outcomes, including optic disc atrophy in 3 patients and stent-interior thrombosis in 2 patients, which occurred 6.3 months after stenting.

Conclusion:

Our data suggest that stenting may be a promising therapy for CVSS correcting. Patients with CVSS may get long-term benefit from stenting, especially when they are accompanied with severe IH

Concurrent Venous Stenting of the Transverse and Occipito-Marginal Sinuses: An Analogy with Parallel Hemodynamic Circuits

Nonthrombotic intracranial venous occlusive disease (NIVOD) has been implicated in the pathophysiology of idiopathic intracranial hypertension (IIH) and various non-IIH headache syndromes. Endovascular stenting of stenotic, dominant transverse sinuses (TSs) may reduce trans-stenosis pressure gradients, decrease intracranial pressure, and alleviate symptoms in a subset of NIVOD patients. We present a case in which concurrent stenting of the occipito-marginal sinus obliterated the residual trans-stenosis pressure gradient across an initially stented dominant TS. We hypothesize that this observation may be explained using an electric-hydraulic analogy, and that this patient's dominant TS and occipito-marginal sinus may be modeled as a parallel hemodynamic circuit. Neurointerventionalists should be aware of parallel hemodynamic drainage patterns and consider manometry and possibly additional stenting of stenotic, parallel venous outflow pathways if TS stenting alone fails to obliterate the trans-stenosis pressure gradient.

Intracranial Venous Sinus Stenting: A Review of Idiopathic Intracranial Hypertension and Expanding Indications

Idiopathic intracranial hypertension (IIH) is a functionally limiting disorder secondary to increased intracranial pressures (ICPs) with a prevalence of one per 100,000 persons. It is estimated to cost >$400 million per year in productively. Symptoms classically consist of chronic headaches, papilledema, and visual loss. The pathophysiology is unknown but postulated to involve increased resistance to cerebrospinal fluid (CSF) absorption. Traditional treatments involve weight loss, acetazolamide, CSF diversion, or optic nerve fenestration. More recent technology has allowed exploration of venous sinus stenosis. Through venous sinus stenting (VSS), the ICPs and venous sinus pressures decrease. After treatment, >75% exhibit an improvement in headaches, ~50% improvement in tinnitus, and ~50 % improvement in ophthalmologic testing. Complications are rare but involve stent stenosis, femoral pseudoaneurysm, and hemorrhages. Future studies will look into controlled studies for VSS as well as expansion to other venous structures of the intracranial circulation.

Development of an Intracranial Dural Arteriovenous Fistula after Venous Sinus Stenting for Idiopathic Intracranial Hypertension

We report a case in which an intracranial dural arteriovenous fistula (DAVF) developed after endovascular treatment of a patient with idiopathic intracranial hypertension with venous sinus stenting (VSS). The pathogenesis may involve hemodynamic alterations secondary to increased poststenting venous sinus pressure, which may cause new arterial ingrowth into the fistulous sinus wall without capillary interposition. Despite administration of dual antiplatelet therapy, there may also be subclinical cortical vein thrombosis that contributed to DAVF formation. In addition to the aforementioned mechanisms, increased inflammation induced by VSS may upregulate vascular endothelial growth factor and platelet-derived growth factor expression and also promote DAVF pathogenesis. Since VSS has been used to obliterate DAVFs, DAVF formation after VSS may seem counterintuitive. Previous stents have generally been closed cell, stainless steel designs used to maximize radial compression of the fistulous sinus wall. In contrast, our patient's stent was an open cell, self-expandable nitinol design (Protégé Everflex). Neurointerventionalists should be aware of this potential, although rare complication of DAVF formation after VSS.

Development of an intracranial dural arteriovenous fistula after venous sinus stenting for idiopathic intracranial hypertension

We report a case in which an intracranial dural arteriovenous fistula (DAVF) developed after endovascular treatment of a patient with idiopathic intracranial hypertension with venous sinus stenting (VSS). The pathogenesis may involve hemodynamic alterations secondary to increased poststenting venous sinus pressure, which may cause new arterial ingrowth into the fistulous sinus wall without capillary interposition. Despite administration of dual antiplatelet therapy, there may also be subclinical cortical vein thrombosis that contributed to DAVF formation. In addition to the aforementioned mechanisms, increased inflammation induced by VSS may upregulate vascular endothelial growth factor and platelet-derived growth factor expression and also promote DAVF pathogenesis. Since VSS has been used to obliterate DAVFs, DAVF formation after VSS may seem counterintuitive. Previous stents have generally been closed cell, stainless steel designs used to maximize radial compression of the fistulous sinus wall. In contrast, our patient's stent was an open cell, self-expandable nitinol design (Protégé Everflex). Neurointerventionalists should be aware of this potential, although rare complication of DAVF formation after VSS.