Venous Sinus Stenting in the Management of Patients with Intracranial Hypertension Manifesting with Skull Base Cerebrospinal Fluid Leaks

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.

Intensive care unit admission is not necessary after venous sinus stenting

BACKGROUND

Venous sinus stenting (VSS) has emerged as a safe and effective treatment option for idiopathic intracranial hypertension. Many physicians routinely admit patients to the intensive care unit (ICU) for close monitoring, but little data exists on whether this is necessary.

METHODS

Electronic medical records of consecutive patients who underwent VSS by the senior author from 2016 to 2022 at a single center were reviewed.

RESULTS

214 patients were included. The mean (SD) age was 35.5 (11.6) and 196 (91.6%) patients were female. A total of 166 (77.6%) patients underwent transverse sinus stenting alone; 9 (4.2%) underwent superior sagittal sinus (SSS) stenting alone, 37 (17.3) concomitant transverse and SSS stenting, and 2 (0.9%) underwent stenting at alternate sites. All patients were planned admission to the regular ward (27.6%) or day hospital (72.4%). Twenty (9.3%) patients were discharged to home the same day as the procedure and 182 (85%) patients were discharged the following day. Major periprocedural complications were identified in 2 (0.93%) patients and minor complications were identified in 16 (7.4%). Only one patient with a subdural hematoma identified in the post-anesthesia care unit (PACU) had care escalated to the ICU. No severe complications were identified after the PACU stay. During the next 48 hours after discharge, 4 (1.9%) patients returned to any emergency room to be evaluated without requiring readmission.

CONCLUSION

Routine ICU admission following uncomplicated VSS is unnecessary. Overnight admission to a low-acuity ward, or even same-day discharge in select patients, appears to be a safe and cost-effective strategy.

Dural sinus narrowing in patients with spontaneous anterior skull base cerebrospinal fluid leak

Objectives

Current evidence suggests a link between idiopathic intracranial hypertension (IIH) and spontaneous cerebrospinal fluid (sCSF) leak, as well as between IIH and dural venous sinus (DVS) narrowing. However, there are limited data linking DVS narrowing and sCSF leak. This study aims to determine the prevalence of DVS narrowing in patients with sCSF leak.

Methods

A retrospective review of all patients with sCSF leak that presented to a tertiary academic center from 2008 to 2019. Preoperative imaging was independently reviewed by two neuroradiologists to evaluate for DVS narrowing. Available literature was used to estimate the prevalence of DVS narrowing in the general population to allow for comparison. Data were analyzed using Exact binomial test.

Results

Analysis of 25 patients with appropriate imaging revealed the majority were women (21/25, 84%) with a mean age of 51.89 years (SD 13.96). The majority of these patients were found to have narrowing of the DVS (20/25, 80%). In patient with sCSF leaks, there was a significantly higher proportion of patients with DVS narrowing compared with published literature examining this condition in the general population (80% vs. 40%, CI 0.59-0.93, p < .001).

Conclusion

The prevalence of DVS narrowing in patients with sCSF leaks is substantial and likely greater than the general population. Moreover, there appears to be narrowing in most patients with sCSF leak. Preoperative radiological evaluation of the DVS using MR venography may be useful in patients with sCSF leaks as DVS stenosis may be an underdiagnosed etiology. Further study is needed to evaluate this.

Level of Evidence

IV.

"Idiopathic" intracranial hypertension: An update from neurointerventional research for clinicians

BACKGROUND

The recognition of venous sinus stenosis as a contributing factor in the majority of patients with idiopathic intracranial hypertension coupled with increasing cerebral venography and venous sinus stenting experience have dramatically improved our understanding of the pathophysiologic mechanisms driving this disease. There is now a dense, growing body of research in the neurointerventional literature detailing anatomical and physiological mechanisms of disease which has not been widely disseminated among clinicians.

METHODS

A literature search was conducted, covering the most recent neurointerventional literature on idiopathic intracranial hypertension, the pathophysiology of idiopathic intracranial hypertension, and management strategies (including venous sinus stenting), and subsequently summarized to provide a comprehensive review of the most recently published studies on idiopathic intracranial hypertension pathophysiology and management.

CONCLUSION

Recent studies in the neurointerventional literature have greatly improved our understanding of the pathophysiologic mechanisms causing idiopathic intracranial hypertension and its associated conditions. The ability to make individualized, patient-specific treatment approaches has been made possible by advances in our understanding of how venous sinus stenosis and cerebral venous hypertension fundamentally contribute to idiopathic intracranial hypertension.

A national survey of venous sinus stenting practices for idiopathic intracranial hypertension

Background

Little is currently known about physician opinions and preferences on venous sinus stenting (VSS) for idiopathic intracranial hypertension (IIH), practice patterns, or clinical volumes.

Methods

A 19 question online survey was designed and distributed to physician members of the Society of Neurointerventional Surgery (SNIS).

Results

A total of 107 individual survey responses were obtained (14% of SNIS members). The majority of respondents (85%) indicated that they had performed at least one VSS procedure independently during their careers. Mean (SD) and median (range) career case volumes were 20.9 (33.8) and 10.0 (0.0–200.0), respectively. On a 1–10 scale, most respondents reported a high level of interest in treating IIH patients with VSS (median 8), a high level of comfort/expertise in treating IIH patients with VSS (median 9), and that VSS was effective in the long term reduction of symptoms and papilledema in IIH patients (median 8). Fifty-nine per cent of respondents reported increasing VSS volumes compared with previous years. A major complication during a VSS procedure, including two deaths, was reported by 11% of respondents.

Conclusions

This is the first study designed to understand the opinions and practices of neurointerventionists regarding VSS for IIH. Overall physician opinion on VSS was quite positive, supported by increasing procedural volumes reported by most over the past few years. However, only a small percentage of respondents had substantial experience with VSS and major complications were not rare.

A proposed framework for cerebral venous congestion

BACKGROUND

While venous congestion in the peripheral vasculature has been described and accepted, intracranial venous congestion remains poorly understood. The characteristics, pathophysiology, and management of cerebral venous stasis, venous hypertension and venous congestion remain controversial, and a unifying conceptual schema is absent. The cerebral venous and lymphatic systems are part of a complex and dynamic interaction between the intracranial compartments, with interplay between the parenchyma, veins, arteries, cerebrospinal fluid, and recently characterized lymphatic-like systems in the brain. Each component contributes towards intracranial pressure, occupying space within the fixed calvarial volume. This article proposes a framework to consider conditions resulting in brain and neck venous congestion, and seeks to expedite further study of cerebral venous diagnoses, mechanisms, symptomatology, and treatments.

METHODS

A multi-institution retrospective review was performed to identify unique patient cases, complemented with a published case series to assess a spectrum of disease states with components of venous congestion affecting the brain. These diseases were organized according to anatomical location and purported mechanisms. Outcomes of treatments were also analyzed. Illustrative cases were identified in the venous treatment databases of the authors.

CONCLUSION

This framework is the first clinically structured description of venous pathologies resulting in intracranial venous and cerebrospinal fluid hypertension. Our proposed system highlights unique clinical symptoms and features critical for appropriate diagnostic work-up and potential treatment. This novel schema allows clinicians effectively to approach cases of intracranial hypertension secondary to venous etiologies, and furthermore provides a framework by which researchers can better understand this developing area of cerebrovascular disease.

Prediction of Postoperative Risk of Raised Intracranial Pressure After Spontaneous Skull Base Cerebrospinal Fluid Leak Repair

BACKGROUND

A relationship between idiopathic intracranial hypertension and spontaneous skull base cerebrospinal fluid (CSF) leaks has been proposed, by which CSF leak decreases intracranial pressure (ICP) and masks the symptoms and signs of elevated ICP. These patients are at risk of developing papilledema, symptoms of elevated ICP, or a recurrent CSF leak after CSF leak repair. The objective of this study was to assess whether radiographic signs of raised ICP on preoperative magnetic resonance or computed venography (MRI or CTV) are predictors of postoperative papilledema, recurrence of CSF leak, or need for CSF shunt surgery.

METHODS

We performed a retrospective review of systematically collected demographics, fundus examination, and presurgical brain MRI and magnetic resonance venography/computed tomography venography (MRV/CTV) in patients seen at 1 institution between 2013 and 2019 with spontaneous skull base CSF leak repair. Patients were divided into 2 groups depending on whether they developed papilledema, recurrent CSF leak, or required CSF shunting (Group 1) or not (Group 2).

RESULTS

Fifty-seven patients were included, among whom 19 were in Group 1. There was no difference in demographic characteristics or clinical features between patients in Group 1 and Group 2. Controlling for other imaging features, bilateral transverse venous sinus stenosis (TVSS) on preoperative imaging increased the odds of being in Group 1 by 4.2 times (95% confidence interval [CI], 1.04-21.2, P = 0.04), optic nerve tortuosity decreased the odds of being in Group 1 by 8.3 times (95% CI: 1.4-74.6, P = 0.02).

CONCLUSION

Imaging of the intracranial venous system with MRV or CTV is warranted before repair of spontaneous CSF leak, as bilateral TVSS is an independent risk factor for postoperative papilledema, CSF leak recurrence, or need for a CSF shunting procedure.

Transverse sinus stenting without surgical repair in idiopathic CSF rhinorrhea associated with transverse sinus stenoses: a pilot study

OBJECTIVE

Based on their clinical and radiological patterns, idiopathic CSF rhinorrhea and idiopathic intracranial hypertension can represent different clinical expressions of the same underlying pathological process. Transverse sinus stenoses are associated with both diseases, resulting in eventual restriction of the venous CSF outflow pathway. While venous sinus stenting has emerged as a promising treatment for idiopathic intracranial hypertension, its efficiency on idiopathic CSF leaks has not been very well addressed in the literature so far. The purpose of this study was to report the results of transverse sinus stenting in patients with spontaneous CSF rhinorrhea associated with transverse sinus stenoses.

METHODS

From a prospectively collected database, the authors retrospectively collected the clinical and radiological features of the patients with spontaneous CSF leakage who were treated with venous sinus stenting.

RESULTS

Five female patients were included in this study. Transverse sinus stenoses were present in all patients, and other radiological signs of idiopathic intracranial hypertension were present in 4 patients. The median transstenotic pressure gradient was 6.5 mm Hg (range 3-9 mm Hg). Venous stenting resulted in the disappearance of the leak in 4 patients with no recurrence and no subsequent meningitis during the follow-up (median 12 months, range 6-63 months).

CONCLUSIONS

According to the authors' results, venous sinus stenting may result in the disappearance of the leak in many cases of idiopathic CSF rhinorrhea. Larger comparative studies are needed to assess the efficiency and safety of venous stenting as a first-line approach in patients with spontaneous CSF rhinorrhea associated with transverse sinus stenoses.

Venous sinus stenting after repair of skull base spontaneous cerebrospinal fluid leaks: A single-center retrospective cohort series with case-control analysis

BACKGROUND

Management of idiopathic intracranial hypertension (IIH) is recommended after surgical repair of spontaneous cerebrospinal fluid leaks (sCSF-leaks) of the skull base for prevention of recurrence.

PURPOSE

To assess the feasibility of venous sinus stenting, a treatment commonly used for the treatment of IIH associated with intracranial venous sinus stenosis (VSS), after sCSF-leaks closure.

MATERIALS AND METHODS

A single-center cohort series of consecutive patients who underwent sCSF-leak closure was retrospectively analyzed. Stenting was considered either for leak recurrence or in prophylactic manner after repair in patients with VSS as confirmed by cerebral venous imaging. Leak recurrence, need for new repair or adjunctive treatment of IIH, meningitis, and stenting complications were determined at the last follow-up. Cases who had prophylactic stenting were compared to historical controls before stenting option.

RESULTS

Twenty-two patients had intracranial venous stenting after sCSF-leak closure. Their median age was 58 years (Q1=45; Q3=68), BMI=31 kg.m^-2 (Q1=27; Q3=36), and female rate=85%. The overall rate of successful repair after stenting was 95% (95% CI = 87-100%) at a median follow-up of 2.4 years (Q1=1.2; Q3=3.3). Adjunctive treatment for IIH was needed in 4 patients (4/22, 18%) including 2 patients without leak recurrence. No meningitis, permanent morbidity or mortality was observed after stenting. Compared to 18 controls, cases had significantly less recurrence (P = 0.03), and a trend for less adjunctive treatment for IIH (P = 0.06).

CONCLUSIONS

Our study suggests that stenting might be a valid option for prevention of sCSF-leak recurrences after repair in patients with intracranial venous sinus stenosis.

Intracranial venous sinus stenting for the treatment of lateral sinus stenoses: An analysis of 200 patients

PURPOSE

The purpose of this study was to analyze the long-term efficacy and safety of intracranial venous sinus stenting in a large cohort of patients with any type of presentation of primary lateral venous sinus stenosis (VSS).

MATERIALS AND METHODS

A retrospective cohort study was performed including patients treated by venous sinus stenting for symptomatic VSS from 2012 to 2019. Successful primary resolution of symptoms without adjunctive treatment or recurrence, and complications after stenting were analyzed at the last follow-up time point.

RESULTS

Two-hundred patients were included. There were 14 men and 186 women with a mean age of 39±14 (SD) years (age range: 13-75 years). Presenting symptoms included venous pulsatile tinnitus in 168 patients (168/200; 84%), idiopathic intracranial hypertension in 100 patients (100/200; 50%) and/or spontaneous cerebrospinal fluid leak in 35 patients (35/200; 17%). The overall rate of successful primary resolution of any typical presenting symptoms was 79% (95% CI: 73-85%). This rate ranged from 74% to 93% depending on the symptom with no significant difference between patients with and those without idiopathic intracranial hypertension (P=0.08). Recurrence rate was 10% (95% CI: 6-14%). No death or permanent morbidity were observed during a median follow-up of 2.2 years (Q1, Q3: 1.4, 3.3; range: 1-7.7 years).

CONCLUSION

Our study shows that venous sinus stenting has a low morbidity and high success rate at long-term follow-up for the treatment of idiopathic intracranial hypertension, venous pulsatile tinnitus or spontaneous cerebrospinal fluid leak associated with VSS. The excellent safety suggests considering this treatment as first-line treatment when medical management is ineffective or poorly tolerated.

A Unique Subset: Idiopathic Intracranial Hypertension Presenting as Spontaneous CSF Leak of the Anterior Skull Base

Introduction Spontaneous cerebrospinal fluid (CSF) leaks represent a unique clinical presentation of idiopathic intracranial hypertension (IIH), lacking classical features of IIH, including severe headaches, papilledema, and markedly elevated opening pressures.

Methods Following a single-institution retrospective review of patients undergoing spontaneous CSF leak repair, we performed a literature review of spontaneous CSF leak in patients previously undiagnosed with IIH, querying PubMed.

Results Our literature review yielded 26 studies, comprising 716 patients. Average age was 51 years with 80.8% female predominance, and average body mass index was 35.5. Presenting symptoms included headaches (32.5%), visual disturbances (4.2%), and a history of meningitis (15.3%). Papilledema occurred in 14.1%. An empty sella was present in 77.7%. Slit ventricles and venous sinus stenosis comprised 7.7 and 31.8%, respectively. CSF leak most commonly originated from the sphenoid sinus (41.1%), cribriform plate (25.4%), and ethmoid skull base (20.4%). Preoperative opening pressures were normal at 22.4 cm H2O and elevated postoperatively to 30.8 cm H2O. 19.1% of patients underwent shunt placement. CSF leak recurred after repair in 10.5% of patients, 78.6% involving the initial site. A total of 85.7% of these patients were managed with repeat surgical intervention, and 23.2% underwent a shunting procedure.

Conclusion Spontaneous CSF leaks represent a distinct variant of IIH, distinguished by decreased prevalence of headaches, lack of visual deficits, and normal opening pressures. Delayed measurement of opening pressure after leak repair may be helpful to diagnose IIH. Permanent CSF diversion may be indicated in patients exhibiting significantly elevated opening pressures postoperatively, refractory symptoms of IIH, or recurrent CSF leak.

Do Most Patients With a Spontaneous Cerebrospinal Fluid Leak Have Idiopathic Intracranial Hypertension?

BACKGROUND

The association between cerebrospinal fluid (CSF) leaks at the skull base and raised intracranial pressure (ICP) has been reported since the 1960s. It has been suggested that spontaneous CSF leaks might represent a variant of idiopathic intracranial hypertension (IIH). We review the evidence regarding the association between spontaneous CSF leaks and IIH, and the role of ICP in the pathophysiology of nontraumatic skull base defects. We also discuss the management of ICP in the setting of CSF leaks and IIH.

EVIDENCE ACQUISITION

References were identified by searches of PubMed from 1955 to September 2018 with the terms "idiopathic intracranial hypertension" and "cerebrospinal fluid leak." Additional references were identified using the terms "pseudotumor cerebri," "intracranial hypertension," "benign intracranial hypertension," and by hand search of relevant articles.

RESULTS

A CSF leak entails the egress of CSF from the subarachnoid spaces of the skull base into the surrounding cavitary structures. Striking overlaps exist regarding demographic, clinical, and radiological characteristics between IIH patients and those with spontaneous CSF leaks, suggesting that some (if not most) of these patients have IIH. However, determining whether a patient with spontaneous CSF leak may have IIH may be difficult, as signs and symptoms of raised ICP may be obviated by the leak. The pathophysiology is unknown but might stem from progressive erosion of the thin bone of the skull base by persistent pulsatile high CSF pressure. Currently, there is no consensus regarding the management of ICP after spontaneous CSF leak repair when IIH is suspected.

CONCLUSIONS

IIH is becoming more widely recognized as a cause of spontaneous CSF leaks, but the causal relationship remains poorly characterized. Systematic evaluation and follow-up of patients with spontaneous CSF leaks by neuro-ophthalmologists will help clarify the relation between IIH and spontaneous CSF leaks.

Spontaneous cerebrospinal fluid leak and idiopathic intracranial hypertension

PURPOSE OF REVIEW

To review the most recent literature on the relationship of spontaneous cerebrospinal fluid (CSF) leak with idiopathic intracranial hypertension (IIH) and considerations in management of these conditions.

RECENT FINDINGS

A link has been proposed between spontaneous CSF leak and IIH based on similar demographics, radiologic, and clinical findings in these patients, and on a plausible mechanism of skull base erosion in the setting of high CSF pressure over time. IIH patients with CSF leak may not present with classic IIH signs and symptoms as the leak can alleviate excess pressure; however, they may develop these after a leak is repaired. There may also be a higher risk of leak recurrence if intracranial hypertension is not treated postoperatively.

SUMMARY

A growing body of evidence supports an association between IIH and spontaneous CSF leak. However, this relationship is still not fully elucidated, and there is no current agreement on how to incorporate screening, management, or counseling guidelines for CSF leak into the care of IIH patients. There are also no specific guidelines for evaluation/management of IIH in patients with spontaneous CSF leak. Further interdisciplinary research is needed to explore this connection and to establish screening, evaluation, and management guidelines.

Risk Factors for Cerebrospinal Fluid Leak Following Anterior Cervical Discectomy and Fusion

STUDY DESIGN/SETTING

This was a retrospective cohort study.

PURPOSE

The purpose of this study was to examine the association between postoperative cerebrospinal fluid (CSF) leak and anterior cervical discectomy and fusion (ACDF). Specifically, we evaluated: (1) demographic risk factors; (2) comorbid risk factors; (3) indications for surgery; and (4) lengths of stay.

SUMMARY OF BACKGROUND DATA

CSF leak is a rare but serious complication of ACDF. Currently, there is a paucity of literature describing the risk factors for CSF leak following ACDF.

METHODS

The Nationwide Inpatient Sample was used to identify all patients who underwent cervical fusion using the anterior approach with excision of intervertebral disc between 1998 and 2010. Patients who had a diagnosis of ossification of the posterior longitudinal ligament in the cervical region were excluded. All patients who had a CSF leak were identified. Demographics and comorbidities were compared via χ analysis, and logistic regression to calculate the odds of having a CSF leak.

RESULTS

Of the 1,261,140 patients identified, 3048 patients (0.24%) had a postoperative CSF leak. Patients who were between the ages of 55 and 69 years (P=0.038) and 70 years or older (P=0.001) were at an increased risk of CSF leak compared with patients who were aged 40-54 years. Non-white race (P=0.021), obesity, (P<0.001) and hypertension (P=0.025) were associated with an increased risk of CSF leak, but diabetes (P=0.966) and hyperlipidemia (P=0.226) were not. Herniated disc diagnosis was associated with decreased risk of CSF leak (P=0.032), but cervical spondylosis with myelopathy patients had an increased risk (P<0.001). Patients with CSF leak had a mean length of stay of 6.0 days compared with 2.1 days among controls.

CONCLUSIONS

Surgical candidates who are older and non-white should be counseled of their increased risk for CSF leak in preoperative planning. Patients who are obese and have hypertension may benefit from medical optimization before surgery.

LEVEL OF EVIDENCE

Level III.