Recommendations for the selection and treatment of patients with idiopathic intracranial hypertension for venous sinus stenting

INTRODUCTION

Although venous sinus stenting (VSS) has emerged as a promising treatment option for patients with idiopathic intracranial hypertension (IIH) and associated venous sinus stenosis, there is considerable ambiguity regarding patient selection criteria, treatment protocols, and management strategies.

METHODS

An extensive literature review was performed to identify all reports of VSS in patients with IIH using PubMed. Recommendations for the selection and treatment of patients with IIH with VSS are outlined as determined based on author opinion from supporting studies. Due to the lack of randomized trials and few published prospective studies, standard grading scales for recommendations and level of evidence are not fully applicable and therefore a revised grading scale has been provided for recommendations.

RESULTS

The literature review identified a total of eight systematic reviews or meta-analyses and 29 published patient series on VSS. Recommendations for patient selection for diagnostic catheter angiography, angiography procedural considerations, stenting procedural considerations, and retreatment are provided based on the literature. Recommendations that were considered strong included: performance of venous sinus manometry to assess candidacy for treatment prior to stenting; administration of antiplatelet agents prior to stenting and for a follow-up period of at least 3-6 months; performance of post-stenting manometry to confirm resolution of pressure gradient; and performance of repeat angiography and manometry on patients with recurrence of symptoms after resolution with stenting to evaluate for recurrent stenosis.

CONCLUSION

VSS for patients with IIH with venous sinus stenosis is now an established and effective treatment option. These recommendations have been provided, based on a summative review of the available published literature, to assist in standardizing care for patients with IIH undergoing VSS.

Unexpected occlusion of the contralateral transverse sinus after stenting for idiopathic intracranial hypertension

A woman in her thirties with intracranial hypertension underwent stenting of the right transverse-sigmoid (TS) junction with resolution of the pressure gradient. Due to persisting symptoms at follow-up, she underwent a repeat study showing a patent right TS stent but the non-dominant left transverse sinus, patent on initial studies, was now completely occluded. According to the positive feedback loop hypothesis, stenting of the right transverse sinus should have resulted in a reduction in intracranial pressures (confirmed by post-stenting lumbar puncture), but also an increase in left transverse sinus diameter, opposed to the occlusion seen on venography. This unexpected finding can be explained by the positive feedback loop hypothesis if a revision is made accounting for intramural venous pressures as an opposing force of venous sinus stenosis, as venous outflow obstruction in the dominant venous sinus pathway provided an increased intramural venous pressure in the non-dominant sinus facilitating patency against extramural pressures.

Correlation between angiographic stenosis and physiologic venous sinus outflow obstruction in idiopathic intracranial hypertension

Introduction

The relationship between degree of angiographic venous sinus stenosis and the trans-stenosis pressure gradient magnitude in idiopathic intracranial hypertension (IIH) is poorly understood. The present study aimed to assess the utility of angiography, venography, and non-invasive imaging (MRV or CTV) for the diagnosis and characterization of clinically significant VSS.

Methods

Retrospective analysis of a prospectively collected database was performed to identify patients with medically refractory IIH who were evaluated by angiography and venous manometry for the presence of VSS with associated clinically significant pressure gradient. Angiographic stenosis was measured by two independent raters using novel methodology.

Results

Thirty-seven patients met inclusion criteria for the study. In total, 70% of patients had clinically significant pressure gradients and were selected for stenting. The optimal percentage stenosis for detection of a significant pressure gradient was 34% stenosis on venous phase arteriography (sensitivity 0.81 and specificity 0.91) and 31% stenosis on venography (0.92 and 0.73). For every 10% increase in stenosis, an approximate increase in pressure gradient of 3.5 mmHg is seen. MRV/CTV had a calculated sensitivity of 0.42, and a negative predictive value of 22%.

Conclusion

The degree of stenosis predictive of a clinically significant pressure gradient (30–35%) in the venous sinuses is considerably lower than the arterial stenosis at which pathologic hemodynamic alterations occur. While highly predictive of a venous pressure gradient when a stenosis is identified, non-invasive imaging does not appear to be a suitable diagnostic evaluation for the purpose of ruling out clinically significant cerebral VSS.

Wide-neck bifurcation aneurysms of the middle cerebral artery and basilar apex treated by endovascular techniques: a multicentre, core lab adjudicated study evaluating safety and durability of occlusion (BRANCH)

Background and purpose

BRANCH (wide-neck bifurcation aneurysms of the middle cerebral artery and basilar apex treated by endovascular techniques) is a multicentre, retrospective study comparing core lab evaluation of angiographic outcomes with self-reported outcomes.

Materials and methods

Consecutive patients were enrolled from 10 US centres, aged between 18 and 85 with unruptured wide-neck middle cerebral artery (MCA) or basilar apex aneurysms treated endovascularly. Patient demographics, aneurysm morphology, procedural information, mortality and morbidity data and core lab and self-reported modified Raymond Roy (RR) outcomes were obtained.

Results

115 patients met inclusion criteria. Intervention-related mortality and significant morbidity rates were 1.7% (2/115) and 5.8% (6/103) respectively. Core lab adjudicated RR1 and 2 occlusion rates at follow-up were 30.6% and 32.4% respectively. The retreatment rate within the follow-up window was 10/115 (8.7%) and in stent stenosis at follow-up was 5/63 (7.9%). Self-reporting shows a statistically significant direction to angiographic RR one outcomes at follow-up compared with core lab evaluation, with OR 1.75 (95% CI 1.08 to 2.83).

Conclusion

Endovascular treatment of wide-neck MCA and basilar apex aneurysms resulted in a core lab adjudicated RR1 occlusion rate of 30.6%. Self-reported results at follow-up favour better angiographic outcomes, with OR 1.75 (95% CI 1.08 to 2.83). These data demonstrate the need for novel endovascular devices specifically designed to treat complex intracranial aneurysms, as well as the importance of core lab adjudication in assessing outcomes in such a trial.

The burden of neurothrombectomy call: a multicenter prospective study

INTRODUCTION

Neurothrombectomy frequency is increasing, and a better understanding of the neurothrombectomy call burden is needed.

METHODS

Neurointerventional physicians at nine participating stroke centers prospectively recorded time requirements for all neurothrombectomy (NT) consultations over 30 consecutive 24 hour call periods.

RESULTS

Data were collected from a total of 270 days of call. 214 NT consultations were reported (mean 0.79 per day), including 130 'false positive' consultations that ultimately did not lead to thrombectomy (mean 0.48 per day). 84 NT procedures were performed at the nine centers (0.32 per day, or 1 every 3 days). Most (59.8%) consultations occurred between 5pm and 7am. 30% of thrombectomy procedures resulted in delays in scheduled cases; treating physicians had to emergently travel to the hospital for 51.2% of these cases. A median of 27 min was spent on each false positive consultation and 171 min on each thrombectomy. Overall, the median physician time spent on NT responsibilities per 24 hour call period was 69 min (mean 85 min; IQR 16-135 min).

CONCLUSIONS

NT consultations are frequent and often disrupt physician schedules, requiring physicians to commute in from home after hours in the majority of cases. As procedural and consultation volumes increase, it is crucial to understand the significant burden of call on neurointerventional physicians and develop strategies that reduce the potential for burnout. Importantly, this study was performed prior to the completion of the DAWN and DEFUSE3 trials; NT consultations are expected to continue to increase in the future.

Lifting the veil on stroke outcomes: revisiting stroke centers' transparency through public reporting of metrics

Public reporting of healthcare metrics provides transparency that allows patients and emergency medical providers to make informed decisions about where patients should receive care. Most previous reports about public reporting of health metrics have demonstrated significant improvements in outcome metrics after implementation. However, no mechanism exists, voluntary or otherwise, for the public reporting of outcomes of stroke care. We review the components of public reporting of health outcomes data and its limited history in stroke outcomes. We summarize the literature on public reporting in cardiovascular interventions, particularly percutaneous coronary interventions, as a close corollary to mechanical neurothrombectomy. The benefits, limitations, and controversies associated with reporting of cardiovascular outcomes are reviewed with a focus on the development of risk-avoidant behaviors. This article serves as a primer for discussion of the potential benefits, limitations, and unintended consequences of public reporting of stroke data.

Unexpected early radiographic findings associated with a ruptured blister-like carotid wall aneurysm

A 33-year-old man presented with aneurysmal subarachnoid hemorrhage from a ruptured, blister-type sidewall internal carotid artery (ICA) aneurysm. Balloon-assisted coiling was performed with residual neck. He subsequently developed severe vasospasm requiring intra-arterial therapies on multiple occasions, during which it was noted that despite widespread vasospasm, a focal segment of the ICA at the site of the aneurysm showed no significant spasm, suggesting underlying vessel abnormality. He was discharged without deficit and scheduled for flow diversion given concern over this potentially pathologic segment of vessel. At time of scheduled flow diversion 6 weeks later, a de novo unstable-appearing 6 mm stalk-like pseudoaneurysm was identified in this segment. Both aneurysms and the diseased vessel were successfully treated with Pipeline stenting, with excellent clinical and angiographic result. This case highlights the need for close angiographic follow-up when there is a heterogeneous vasospastic response in arterial segments adjacent to a ruptured aneurysm.

Venous waveform morphological changes associated with treatment of symptomatic venous sinus stenosis

Introduction

Venous outflow obstruction is recognized as a contributing factor in a subset of patients with idiopathic intracranial hypertension (IIH). Little is known about venous sinus waveform morphology or how it changes after stenting.

Methods

Fifteen patients with IIH underwent waveform recording during catheter venography and manometry. Ten patients (Group A) with venous sinus stenosis and pressure gradient ≥7 mm Hg underwent waveform recording during awake venography and during stenting under general anesthesia. Five control IIH patients (Group B) without a gradient underwent awake recording only.

Results

Group A patients underwent successful stenting with reduction of their gradient from 15.1±6.19 mm Hg to 1.2±0.60 mm Hg. This resulted in an amplitude reduction from 8.3 mm Hg to 2.8 mm Hg (P=0.02). Qualitative evaluation of the waveform yielded a number of novel findings. In Group A before stenting, the observed waveform progressed from an intracranial pressure (ICP)-dominated to central venous pressure (CVP)-dominated waveform. Stenting abolished the high amplitude waveform and smoothed the transition from the intracranial to central venous measurement points. Group B displayed primarily CVP-influenced waveforms distal and proximal to the transverse-sigmoid junction along with respiratory variability of the waveform, absent in 8/10 Group A patients. General anesthesia appeared to blunt the waveform in 5/10 Group A patients.

Conclusion

The cerebral venous waveform appears to be influenced by both the ICP and CVP waveforms. As measurement moves proximally, the waveform progressively changes to mirror the CVP waveform. Venous sinus stenosis results in a high amplitude waveform which improves with treatment of the stenosis.

Incorporation of a Physical Education and Nutrition Program Into Neurosurgery: A Proof of Concept Pilot Program

BACKGROUND

Balancing the demands of a busy medical career with personal wellness can be daunting, and there is little education on these principles available to physicians in training.

OBJECTIVE

To implement a voluntary wellness initiative in our neurosurgery department to promote healthy lifestyle choices. This report details the baseline data collected as part of this quality improvement initiative.

METHODS

The wellness initiative was implemented in July 2015 and available to all faculty and resident physicians in the Department of Neurological Surgery in collaboration with the Medical University of South Carolina Wellness Center. All participants were provided a Fitbit Surge HR wrist monitor (Fitbit, Boston, Massachusetts) and underwent baseline physical and psychological testing.

RESULTS

Six faculty physicians and 9 residents participated. Overall physical fitness levels varied widely between subjects. Health screening demonstrated abnormalities in 80% of participants (elevated systolic blood pressure in 60%, elevated diastolic in 47%, elevated serum low-density lipoprotein in 53%). Body composition analysis demonstrated body weight higher than ideal in 69% (47% overweight; 13% obese). Recommended average body fat mass reduction was 25.4 pounds. Seventy-nine percent reported below-average quality of life compared with the average healthy adult. All subjects reported wanting more time for personal health.

CONCLUSION

Baseline health and psychological screenings in our department demonstrated alarmingly prevalent, previously undiagnosed abnormalities on cardiovascular and body weight screenings. Obstacles to leading a healthier lifestyle have been identified and solutions have been incorporated into the program. This quality improvement initiative may serve as a template for other programs seeking to improve physician physical and mental well-being.

ABBREVIATIONS

BMI, body mass indexESS, Epworth Sleepiness ScaleHR, heart rate.

Unexpected early radiographic findings associated with a ruptured blister-like carotid wall aneurysm

A 33-year-old man presented with aneurysmal subarachnoid hemorrhage from a ruptured, blister-type sidewall internal carotid artery (ICA) aneurysm. Balloon-assisted coiling was performed with residual neck. He subsequently developed severe vasospasm requiring intra-arterial therapies on multiple occasions, during which it was noted that despite widespread vasospasm, a focal segment of the ICA at the site of the aneurysm showed no significant spasm, suggesting underlying vessel abnormality. He was discharged without deficit and scheduled for flow diversion given concern over this potentially pathologic segment of vessel. At time of scheduled flow diversion 6 weeks later, a de novo unstable-appearing 6 mm stalk-like pseudoaneurysm was identified in this segment. Both aneurysms and the diseased vessel were successfully treated with Pipeline stenting, with excellent clinical and angiographic result. This case highlights the need for close angiographic follow-up when there is a heterogeneous vasospastic response in arterial segments adjacent to a ruptured aneurysm.

Bibliometric indices: defining academic productivity and citation rates of researchers, departments and journals

There has been an increasing focus on academic productivity for the purposes of promotion and funding within departments and institutions but also for comparison of individuals, institutions, specialties, and journals. A number of quantitative indices are used to investigate and compare academic productivity. These include various calculations attempting to analyze the number and citations of publications in order to capture both the quality and quantity of publications, such as the h index, the e index, impact factor, and Eigenfactor score. The indices have varying advantages and limitations and thus a basic knowledge is required in order to understand their potential utility within academic medicine. This article describes the various bibliometric indices and discusses recent applications of these metrics within the neurological sciences.

A review and comparison of three neuronavigation systems for minimally invasive intracerebral hemorrhage evacuation

Advances in stereotactic navigation technology have helped to improve the ease, reliability, and workflow of neurosurgical intraoperative navigation. These advances have also allowed novel, minimally invasive neurosurgical techniques to emerge. Minimally invasive techniques for intracerebral hemorrhage (ICH) evacuation, including endoscopic evacuation and passive catheter drainage, are notable examples, and as these gain support in the literature and their use expands, stereotactic navigation will take on an increasingly important and central role. Each neurosurgical navigation system has unique characteristics. Operators may find that certain aspects are more important than others, depending on the environment in which the evacuation is performed and operator preferences. This review will describe the characteristics of three popular stereotactic neuronavigation systems and compare their advantages and disadvantages as they relate to minimally invasive ICH evacuation.

A multicenter study evaluating the frequency and time requirement of mechanical thrombectomy

Introduction

There are few published data evaluating the incidence of mechanical thrombectomy among stroke centers or the times at which they occur.

Methods

A multicenter retrospective study was performed to identify all patients undergoing emergent thrombectomy for acute ischemic stroke during a 3-month period (June through August 2016). Consultations that did not undergo thrombectomy were not included.

Results

Ten institutions participated in the study. During the 92-day study period, a total of 189 patients underwent mechanical thrombectomy. The average number of procedures per hospital over the study period was 18.9 (average of 0.2 cases per day per or 75.6 cases per year). This ranged from 0.09 cases per day at the lowest volume center to 0.49 cases per day at the highest volume center. Procedures were more common on weekdays (p<0.001) and during non-work hours (p<0.001). The most common period for thrombectomy procedures was between 20:00 and 21:00 hours. The median time from notification to groin puncture was 84 min (IQR 56–145 min) and from puncture to closure was 57 min (IQR 33–80 min). The median time from imaging completion to procedural start was 52 min longer for non-work hours than during work hours (p<0.001). There were no differences in procedural length based on day of the week or time of day.

Conclusions

These findings indicate that the majority of mechanical thrombectomy cases occur during non-work hours, with associated off-hours delays, which has important operational implications for hospitals implementing stroke call coverage.

A survey of intracranial aneurysm treatment practices among United States physicians

Background

Recent surveys have failed to examine cerebrovascular aneurysm treatment practices among US physicians.

Objective

To survey physicians who are actively involved in the care of patients with cerebrovascular aneurysms to determine current aneurysm treatment preferences.

Methods

A 25-question SurveyMonkey online survey was designed and distributed electronically to members of the Society of NeuroInterventional Surgery, Society of Vascular and Interventional Neurology, and the American Association of Neurological Surgeons/Congress of Neurological Surgeons Combined Cerebrovascular Section.

Results

211 physicians completed the survey. Most respondents recommend endovascular treatment as the first-line management strategy for most ruptured (78%) and unruptured (71%) aneurysms. Thirty-eight per cent of respondents indicate that they routinely treat all patients with subarachnoid hemorrhage regardless of grade. Most physicians use the International Study of Unruptured Intracranial Aneurysms data for counseling patients on natural history risk (80%); a small minority (11%) always or usually recommend treatment of anterior circulation aneurysms of <5 mm. Two-thirds of respondents continue to recommend clipping for most middle cerebral artery aneurysms, while most (51%) recommend flow diversion for wide-necked internal carotid artery aneurysms. Follow-up imaging schedules are highly variable. Neurosurgeons at academic institutions and those practicing longer were more likely to recommend clipping surgery for aneurysms (p<0.05).

Conclusions

This survey demonstrates considerable variability in patient selection for intracranial aneurysm treatment, preferred treatment strategies, and follow-up imaging schedules among US physicians.

External ventricular drain practice variations: results from a nationwide survey

OBJECTIVE While guidelines exist for many neurosurgical procedures, external ventricular drain (EVD) insertion has yet to be standardized. The goal of this study was to survey the neurosurgical community and determine the most frequent EVD insertion practices. The hypothesis was that there would be no standard practices identified for EVD insertion or methods to avoid EVD-associated infections. METHODS The American Association of Neurological Surgeons membership database was queried for all eligible neurosurgeons. A 16-question, multiple-choice format survey was created and sent to 7217 recipients. The responses were collected electronically, and the descriptive results were tabulated. Data were analyzed using the chi-square test. RESULTS In total, 1143 respondents (15.8%) completed the survey, and 705 respondents (61.6%) reported tracking EVD infections at their institution. The most common self-reported infection rate ranged from 1% to 3% (56.1% of participants), and 19.7% of respondents reported a 0% infection rate. In total, 451 respondents (42.7%) indicated that their institution utilizes a formal protocol for EVD placement. If a respondent's institution had a protocol, only 258 respondents (36.1%) always complied with the protocol. Protocol utilization for EVD insertion was significantly more frequent among residents, in academic/hybrid centers, in ICU settings, and if the institution tracked EVD-associated infection rates (p < 0.05). A self-reported 0% infection rate was significantly more commonly associated with a higher level of training (e.g., attending physicians), private center settings, a clinician performing 6 to 10 EVD insertions within the previous 12 months, and prophylactic continuous antibiotic utilization (p < 0.05). CONCLUSIONS This survey demonstrated heterogeneity in the practices for EVD insertion. No standard practices have been proposed or adopted by the neurosurgical community for EVD insertion or complication avoidance. These results highlight the need for the nationwide standardization of technique and complication prevention measures.

Vessel perforation during stent retriever thrombectomy for acute ischemic stroke: technical details and clinical outcomes

BACKGROUND

Vessel perforation during stent retriever thrombectomy is a rare complication; typically only single instances have been reported.

OBJECTIVE

To report on a series of patients whose stent retriever thrombectomy was complicated by intraprocedural vessel perforation and discuss its potential mechanisms, rescue treatment strategies, and clinical significance.

METHODS

Cases with intraprocedural vessel perforation, where a stent retriever was used either as a primary treatment approach or as a part of a direct aspiration first pass technique (ADAPT), were included in the final analysis. Clinical data, procedural details, radiographic and clinical outcomes were collected from nine participating centers.

RESULTS

Intraprocedural vessel perforation during stent retriever thrombectomy occurred in 16 (1.0%) of 1599 cases. 63% of intraprocedural perforations occurred at distal locations. Endovascular rescue techniques (most commonly, intracranial balloon occlusion for tamponade) were attempted in 50% of cases. Procedure was aborted without any rescue attempts in 44% of cases. Mortality during hospitalization and at 3 months was 56% and 63%, respectively. 25% of patients achieved good functional outcome at 3 months after the procedure.

CONCLUSIONS

Intraprocedural perforations during stent retriever thrombectomy were rare, but when they occurred were associated with high mortality. Perforations most commonly occurred at distal occlusion sites and were often characterized by difficulty traversing the occlusion with a microcatheter or microwire, or while withdrawing the stent retriever. Nevertheless, 25% of patients had a favorable functional outcome, suggesting that in some patients with this complication good neurological recovery is achievable.

Comparison of venous sinus manometry gradients obtained while awake and under general anesthesia before venous sinus stenting

Introduction

Venous sinus stenting is a popular treatment strategy for patients with high venous sinus pressure gradients across a site of outflow obstruction. Little is known about the effect of anesthesia on venous sinus pressure measurements.

Objective

To compare venous manometry performed in patients under general anesthesia and while awake.

Methods

A prospective database was accessed to retrospectively identify patients who had undergone venous sinus stenting. Pressure gradients were compared between those patients who underwent manometry while awake and before stenting under general anesthesia.

Results

Thirty patients with both general anesthesia and awake pressure recordings were identified. Pressure measurements were highly variable but overall were higher under general anesthesia by an average of 5.8 mm Hg (1.7; p=0.002). A significant difference between awake and general anesthesia pressure measurements was detected in the sigmoid sinus (5.8 mm Hg (2.0); p=0.005) and the jugular vein (8.1 mm Hg (3.9); p=0.040). Only 11/30 (36.7%) pressure gradients remained within 5 mm Hg of the original awake gradient when repeated under general anesthesia; 9/30 (30%) patients had gradients that were at least 10 mm Hg different across procedures.

Conclusions

Calculated pressure gradients were markedly affected by anesthesia. These findings suggest that candidacy for stenting should be determined with venous manometry while patients are awake owing to the unpredictable and highly variable effect of general anesthesia on pressure measurements and an apparent tendency to underestimate the degree of venous outflow obstruction.

Impact of ASPECT scores and infarct distribution on outcomes among patients undergoing thrombectomy for acute ischemic stroke with the ADAPT technique

Objective

To investigate the associations between Alberta Stroke Program Early CT Score (ASPECTS) or distribution and sidedness of acute infarction and clinical outcomes following intervention with a direct aspiration first pass technique (ADAPT).

Methods

A review was performed of patients who had undergone thrombectomy with ADAPT for emergent large vessel occlusions of the middle cerebral artery (MCA) between December 2012 and May 2015. Preintervention CT scans were reviewed by a blinded radiologist to calculate ASPECTS and determine the distribution of infarction. Clinical outcomes were compared for subsets of patients depending upon ASPECTS and regional infarction distribution (cortical, subcortical, or both).

Results

One hundred and fifty-four patients (50% female, mean age 67) underwent thrombectomy using ADAPT for MCA emergent large vessel occlusion. The median presenting National Institute of Health Stroke Scale score was 15. Fifty-five per cent of patients had left-side occlusions. Similar good outcomes were achieved for patients with perfect and non-perfect ASPECTS (modified Rankin Scale (mRS) 0–2: 63% vs 51%, respectively; p=0.20). Similar outcomes were also achieved for patients with ‘poor’ ASPECTS (≤6) compared with those with ASPECTS >6 (mRS 0–2: 52% vs 53%, respectively; p=0.91). Regional distribution and sidedness of core infarction on preintervention CT also did not correlate with worse outcomes.

Conclusions

Patients with moderate-sized core infarcts involving various distributions in either hemisphere can potentially achieve similar good outcomes compared with those with no core infarction at presentation. A treatment algorithm for acute ischemic stroke, which employs hardline ASPECTS thresholds or excludes patients with basal ganglia infarcts, might preclude patients who would potentially benefit from mechanical thrombectomy with ADAPT.