Cerebrospinal fluid venous fistula causing spontaneous intracranial hypotension resulting in venous sinus thrombosis and coma.

Cerebrospinal fluid (CSF) fistulas have recently been recognized as a cause of spontaneous intracranial hypotension (SIH), predominantly presenting with headaches, especially positional headaches. Atypical presentations like tinnitus and cranial nerve symptoms have also been reported. SIH has been linked to venous sinus thrombosis; however, to our knowledge, no prior cases describe a CSF venous fistula causing SIH that leads to cerebral venous thrombosis and coma. We report a patient who developed progressive venous sinus thrombosis, leading to coma, and was found to have low intracranial pressure indicative of SIH. Invasive monitoring and imaging confirmed the low intracranial pressure, prompting a dynamic myelogram that revealed a T2/3 CSF venous fistula. The patient underwent transvenous embolization of the fistula, which resulted in the resolution of symptoms and almost immediate improvement in both venous thrombosis and intracranial hypotension. CSF venous fistulae as a cause of SIH is a recently recognized entity, with ongoing research into its treatment through transvenous embolization. Most documented cases focus on patients with headaches. This case highlights a novel presentation, emphasizing the importance of thorough diagnostic workup in patients with cerebral venous thrombosis. Early detection and treatment of this condition can lead to significant clinical improvement, including the resolution of coma.

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

INTRODUCTION: 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. CASES: 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. CONCLUSION: 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.

Occipital venous sinus stenting for idiopathic intracranial hypertension and pulsatile tinnitus: A case series.

Venous sinus stenting for dural venous sinus outflow obstruction due to an intrinsic filling obstruction or extrinsic stenosis is an increasingly popular treatment strategy for idiopathic intracranial hypertension (IIH) and isolated pulsatile tinnitus (PT). The most common site of stenosis is the lateral venous sinus at the transverse-sigmoid junction. Approximately 10% of the population has a persistent occipital venous sinus (OVS), a variant that may be the dominant venous drainage pathway in the setting of a hypoplastic or aplastic transverse sinus. OVS stenosis has been rarely associated with IIH and isolated PT with only a handful published cases. We herein report a retrospective series of OVS stenting in five patients, four of whom presented with non-IIH PT and one with IIH.

The role of surgical disconnection for posterior fossa pial arteriovenous fistulas and dural fistulas with pial supply: an illustrative case series.

BACKGROUND: Pial arteriovenous fistulas (pAVFs) are rare vascular malformations characterized by high-flow arteriovenous shunting involving a cortical arterial supply directly connecting to venous drainage without an intermediate nidus. Dural arteriovenous fistulas (dAVFs) can infrequently involve additional pial feeders which can introduce higher flow shunting and increase the associated treatment risk. In the posterior fossa, arteriovenous fistula (AVF) angioarchitecture tends to be particularly complex, involving either multiple arterial feeders-sometimes from both dural and pial origins-or small caliber vessels that are difficult to catheterize and tend to be intimately involved with functionally critical brainstem or upper cervical cord structures. Given their rarity, published experience on microsurgical or endovascular treatment strategies for posterior fossa pAVFs and dAVFs with pial supply remains limited. METHODS: Retrospective chart review from 2019-2023 at a high-volume center identified six adult patients with posterior fossa pAVFs that were unable to be fully treated endovascularly and required microsurgical disconnection. These cases are individually presented with a technical emphasis and supported by comprehensive angiographic and intraoperative images. RESULTS: One vermian (Case 1), three cerebellopontine angle (Cases 2-4) and two craniovertebral junction (Cases 5-6) posterior fossa pAVFs or dAVFs with pial supply are presented. Three cases involved mixed dural and pial arterial supply (Cases 1, 4, and 6), and one case involved a concomitant microAVM (Case 2). Endovascular embolization was attempted in four cases (Cases 1-4): The small caliber and tortuosity of the main arterial feeder prevented catheterization in two cases (Cases 1 and 3). Partial embolization was achieved in Cases 2 and 4. In Cases 5 and 6, involvement of the lateral spinal artery or anterior spinal artery created a prohibitive risk for endovascular embolization, and surgical clip ligation was pursued as primary management. In all cases, microsurgical disconnection resulted in complete fistula obliteration without evidence of recurrence on follow-up imaging (mean follow-up 27.1 months). Two patients experienced persistent post-treatment sensory deficits without significant functional limitation. CONCLUSIONS: This illustrative case series highlights the technical difficulties and anatomical limitations of endovascular management for posterior fossa pAVFs and dAVFs with pial supply and emphasizes the relative safety and utility of microsurgical disconnection in this context. A combined approach involving partial preoperative embolization-when the angioarchitecture is permissive-can potentially decrease surgical morbidity. Larger studies are warranted to better define the role for multimodal intervention and to assess associated long-term AVF obliteration rates in the setting of pial arterial involvement.

Eclipse balloon-assisted straight sinus thrombectomy: A novel technique.

Cerebral venous sinus thrombosis comprises 0.5% of all strokes and usually affects young adults. Straight sinus involvement is relatively rare, and it is associated with poor prognosis. Intravenous anticoagulation is considered the first line of treatment. Endovascular approaches such as direct catheter thrombolysis, balloon-assisted thrombolysis, and mechanical thrombectomy may be more efficient and should be considered in cases in which there is involvement of the deep venous system, declining neurological status, or less invasive treatment options have failed. In this work, we describe a novel technique of ECLIPSE 2L balloon (Balt, Irvine, CA) assisted mechanical thrombectomy for straight sinus thrombosis and a review of dural sinus thrombosis management.

Factors Affecting Selection of TraineE for Neurointervention (FASTEN).

BACKGROUND AND IMPORTANCE: Neurointervention is a very competitive specialty in the United States due to the limited number of training spots and the larger pool of applicants. The training standards are continuously updated to ensure solid training experiences. Factors affecting candidate(s) selection have not been fully established yet. Our study aims to investigate the factors influencing the selection process. METHODS: A 52-question survey was distributed to 93 program directors (PDs). The survey consisted of six categories: (a) Program characteristics, (b) Candidate demographics, (c) Educational credentials, (d) Personal traits, (e) Research and extracurricular activities, and (f) Overall final set of characteristics. The response rate was 59.1%. As per the programs' characteristics, neurosurgery was the most involved specialty in running the training programs (69%). Regarding demographics, the need for visa sponsorship held the greatest prominence with a mean score of 5.9 [standard deviation (SD) 2.9]. For the educational credentials, being a graduate from a neurosurgical residency and the institution where the candidate's residency training is/was scored the highest [5.4 (SD = 2.9), 5.4 (SD = 2.5), respectively]. Regarding the personal traits, assessment by faculty members achieved the highest score [8.9 (SD = 1)]. In terms of research/extracurricular activities, fluency in English had the highest score [7.2 (SD = 1.9)] followed by peer-reviewed/PubMed-indexed publications [6.4 (SD = 2.2)]. CONCLUSION: Our survey investigated the factors influencing the final decision when choosing the future neurointerventional trainee, including demographic, educational, research, and extracurricular activities, which might serve as valuable guidance for both applicants and programs to refine the selection process.

Single-center outcomes of Onyx Frontier™ and Resolute Onyx™ drug-eluting balloon-mounted stents for rescue stenting for acute large vessel occlusion.

BACKGROUND: In cases where mechanical thrombectomy (MT) fails, rescue stenting may be necessary to achieve reperfusion; however, the lack of standardized techniques or devices poses a challenge. This series aims to present our early experience with the Onyx Frontier™ and Resolute Onyx™ balloon-mounted drug-eluting stents for rescue stenting. METHODS: A retrospective chart review was performed of all patients who underwent rescue stenting, in the setting of failed MT, using Onyx Frontier™ or Resolute Onyx™ stents at a single institution. Technical details, procedural complications, and patient outcomes were recorded for each case. RESULTS: Twenty-two Onyx Frontier™ and Resolute Onyx™ stents were deployed in 18 patients undergoing rescue stenting. Stent locations included the middle cerebral artery (36.4%), internal carotid artery (18.2%), vertebral artery (22.7%), and basilar artery (22.7%). The average National Institutes of Health Stroke Scale score before MT was 13.8 (range 0-31). The median initial modified Rankin Scale (mRS) score was zero, while the median mRS score at follow-up was three. Successful reperfusion, as assessed by TICI scores, was achieved in 43.8% of patients for TICI 3, 43.8% for TICI 2C, and 12.5% for TICI 2B. Post-revascularization, 16.7% of patients experienced hemorrhage, of which one patient (5.6%) had symptomatic hemorrhage. CONCLUSIONS: Onyx Frontier™ and Resolute Onyx™ stents are well suited for rescue stenting in cases of failed MT. These balloon-mounted drug-eluting stents exhibit excellent navigability, rendering them appropriate for rescue revascularization procedures. Our findings demonstrate that these stents confer a high degree of technical success.

Flow diverter surface modifications for aneurysm treatment: A review of the mechanisms and data behind existing technologies.

Flow diversion (FD) has become a mainstay treatment for large wide-necked aneurysms. Despite excellent safety and efficacy, the risk of thromboembolic complications necessitates the use of dual antiplatelet therapy (DAPT). The use of DAPT makes hemorrhagic complications of stenting carry high morbidity and mortality. Additionally, DAPT usage carries a risk of "nuisance" complications that do not directly impact intracranial circulation but need to be managed nonetheless. To circumvent this issue, the most recent generation of flow diverters have undergone surface modification with various compounds to confer blood compatibility to limit clotting and thrombosis. While these newer generation flow diverters are marketed to enhance ease of deployment, the goal is to eventually facilitate single antiplatelet use with flow diverter treatment. This generation of FDs have potential to expand indications beyond unruptured wide-necked aneurysms to include ruptured intracranial aneurysms without the necessity of DAPT. Currently, no comprehensive review details the molecular mechanisms and pre-clinical and clinical data on these modifications. We seek to fill this gap in the literature by consolidating information on the coating technology for four major FDs currently in clinical use-PipelineTM Flex and Vantage Shield TechnologyTM, FREDTMX, p48/64 hydrophilic coating, and Acandis Dervio® 2heal-to serve as a reference guide in neurointerventional aneurysm treatment. Although the Balt silkTM was one of the first FDs, it is uncoated, thus we will not cover this device in our review. A literature review was performed to obtain information on each coating technology for the major flow diverters currently on the market using international databases (PUBMED, Embase, Medline, Google Scholar). The search criteria used the keywords for each coating technology of interest "phosphorylcholine," "poly 2-methoxyethyl acrylate," "hydrophilic polymer coating," and "fibrin-heparin" Keywords related to the device names "Pipeline Shield," "Pipeline Shield with Flex Technology," "FRED," "FREDX," "p64," "p64-HPC," "Derivo 2heal" were also used. Studies that detailed the mechanism of action of the coating, any pre-clinical studies with surface-modified intravascular devices, and any clinical retrospective series, prospective series, or randomized clinical trials with surface-modified devices for aneurysm treatment were included.

Extreme lateral infracondylar approach for internal jugular vein compression syndrome: A case series with preliminary clinical outcomes.

BACKGROUND AND OBJECTIVES: Internal jugular vein (IJV) stenosis is associated with several neurological disorders including idiopathic intracranial hypertension (IIH) and pulsatile tinnitus. In cases of extreme bony compression causing stenosis in the infracondylar region, surgical decompression might be necessary. We aim to examine the safety and efficacy of surgical IJV decompression. METHODS: We retrospectively reviewed patients who received surgical IJV decompression via the extreme lateral infracondylar (ELI) approach between July 2020 and February 2022. RESULTS: Fourteen patients with IJV stenosis were identified, all with persistent headache and/or tinnitus. Six patients were diagnosed with IIH, three of whom failed previous treatment. Of the eight remaining patients, two failed previous treatment. All underwent surgical IJV decompression via styloidectomy, release of soft tissue, and removal of the C1 transverse process (TP). Follow-up imaging showed significant improvement of IJV stenosis in eleven patients and mild improvement in three. Eight patients had significant improvement in their presenting symptoms, and three had partial improvement. Two patients received IJV stenting after a lack of initial improvement. Two patients experienced cranial nerve paresis, and one developed a superficial wound infection. CONCLUSION: The ELI approach for IJV decompression appears to be safe for patients who are not ideal endovascular candidates due to bony anatomy. Confirming long-term efficacy in relieving debilitating clinical symptoms requires longer follow-up and a larger patient cohort. Carefully selected patients with symptomatic bony IJV compression for whom there are no effective medical or endovascular options may benefit from surgical IJV decompression.

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.

Hemodynamic outcomes of stenting for vertebrobasilar insufficiency in patients with a low flow state.

INTRODUCTION: The Vertebrobasilar Flow Evaluation and Risk of Transient Ischemic Attack and Stroke (VERiTAS) study determined patients with low flow in their vertebrobasilar (VB) system are at increased risk of recurrent stroke. Endovascular interventions such as angioplasty and stenting are reserved for patients with refractory symptoms; however, few series to date have demonstrated either hemodynamic or clinical outcomes in this high-risk patient group. We present our combined institutional series of patients with symptomatic VB atherosclerotic disease and low-flow state who underwent angioplasty and stenting. METHODS: Retrospective chart review of patients undergoing angioplasty and stenting for symptomatic VB atherosclerotic disease at two institutions was performed. Clinical and radiographical outcomes were collected including flow rates using quantitative MRA (QMRA) pre- and post-stenting. RESULTS: Seventeen patients underwent angioplasty and stenting for symptomatic VB atherosclerotic disease and met VERiTAS low-flow state criteria. There were four cases (23.5%) of periprocedural stroke, two of which were minor and transient. The stent was placed intracranially in 82.4% of patients. Basilar and bilateral posterior cerebral artery (PCA) flows significantly improved post-stenting (p < 0.05) and normalized based upon VERiTAS criteria in all patients. Fourteen patients had delayed QMRA at mean follow-up 20 months demonstrating appropriate patency and flow post-stenting. Two patients (10%) had recurrent stroke, one from medication nonadherence and in-stent thrombosis, and the other from a procedural dissection that subsequently became symptomatic. CONCLUSIONS: Our series demonstrates angioplasty and stenting significantly improve intracranial flow over long-term. Angioplasty and stenting may improve the natural history of low-flow VB atherosclerotic disease.

Combined surgical repair and venous sinus stenting for patients with skull base encephaloceles secondary to dural venous sinus stenosis.

BACKGROUND: Chronically elevated intracranial pressure (ICP) seen in idiopathic intracranial hypertension (IIH) can cause the development of skull base encephaloceles and cerebrospinal fluid (CSF) leaks. Surgical repair and ventriculoperitoneal shunt (VPS) placement are mainstays of treatment. Venous sinus stenting (VSS) is a newly accepted treatment modality. The goal of this study was thus to determine if VSS can be used to treat symptoms and prevent recurrence after surgical encephalocele repair. METHODS: Retrospective chart review of patients that had surgical repair of encephaloceles followed by VSS for symptomatic stenosis with elevated pressure gradient. RESULTS: A total of 13 patients underwent a combined encephalocele repair and VSS. Seventy-two percent were female; 46% had headaches, 69% pulsatile tinnitus, and 92% CSF rhinorrhea or otorrhea. One had seizures. Mean lumbar opening pressure was 23.3 ± 2.6 cm H2O; the average sagittal-to-jugular pressure gradient was 12.7 ± 1.8 cmH2O and was elevated in all patients. Four patients had middle fossa craniotomy for repair of tegmen defect (one bilateral); one had a retrosigmoid craniotomy for repair of a sigmoid plate defect. Eight had an endoscopic endonasal repair for sphenoid or cribriform plate encephalocele. There were no VSS procedural complications or complications associated with dual antiplatelet therapy. One patient had meningitis after endoscopic repair that was treated with antibiotics. One patient had recurrence of both CSF leak and venous stenosis adjacent to the stent requiring repeat repair and VSS. There was no further recurrence. CONCLUSION: In patients with dural sinus stenosis and encephaloceles requiring repair, VSS can be performed safely within weeks of surgery for relief of symptoms, resolution of underlying pathology, and prevention of CSF leak recurrence.

A comparison of endovascular coil systems for the treatment of small intracranial aneurysms.

BACKGROUND: Endovascular coiling of small, intracranial aneurysms remains controversial and difficult, despite advances in technology. METHODS: We retrospectively reviewed data for 62 small aneurysms (<3.99 mm) in 59 patients. Occlusion rates, complications rates, and coil packing densities were compared between subgroups based upon coil type and rupture status. RESULTS: Ruptured aneurysms predominated (67.7%). Aneurysms measured 2.99 ± 0.63 mm by 2.51 ± 0.61 mm with an aspect ratio of 1.21 ± 0.34 mm. Brands included Optima (Balt) (29%), MicroVention Hydrogel (24.2%), and Penumbra SMART (19.4%) coil systems. Average packing density was 34.3 ± 13.5 mm3. Occlusion rate was 100% in unruptured aneurysms; 84% utilized adjuvant devices. For ruptured aneurysms, complete occlusion or stable neck remnant was achieved in 88.6% while recanalization occurred in 11.4%. No rebleeding occurred. Average packing density (p = 0.919) and coil type (p = 0.056) did not impact occlusion. Aspect ratio was smaller in aneurysms with technical complications (p = 0.281), and aneurysm volume was significantly smaller in those with coil protrusion (p = 0.018). Complication rates did not differ between ruptured and unruptured aneurysms (22.6 vs. 15.8%, p = 0.308) or coil types (p = 0.830). CONCLUSION: Despite advances in embolization devices, coiling of small intracranial aneurysms is still scrutinized. High occlusion rates are achievable, especially in unruptured aneurysms, with coil type and packing density suggesting association with complete occlusion. Technical complications may be influenced by aneurysm geometry. Advances in endovascular technologies have revolutionized small aneurysm treatment, with this series demonstrating excellent aneurysm occlusion especially in unruptured aneurysms.

Ghost infarct core: A systematic review of the frequency, magnitude, and variables of CT perfusion overestimation.

BACKGROUND AND PURPOSE: CT perfusion (CTP) imaging is now widely used to select patients with large vessel occlusions for mechanical thrombectomy. Ghost infarct core (GIC) phenomenon has been coined to describe CTP core overestimation and has been investigated in several retrospective studies. Our aim is to review the frequency, magnitude, and variables associated with this phenomenon. METHODS: A primary literature search resulted in eight studies documenting median time from symptom onset to CTP, median estimated core size, median final infarct volume, median core overestimation of the GIC population, recanalization rates, good outcomes, and collateral status for this systematic review. RESULTS: All the studies investigated patients who underwent CTP within 6 hours of symptom onset, ranging from median times of 105 to 309 minutes. The frequency of core overestimation varied from 6% to 58.4%, while the median estimated ischemic core and final infarction volume ranged from 7 to 27 mL and 12 to 31 mL, respectively. The median core overestimation ranged from 3.6 to 30 mL with upper quartile ranges up to 58 mL. GIC was found to be a highly time-and-collateral-dependent process that increases in frequency and magnitude as the time from symptom onset to imaging decreases and in the presence of poor collaterals. CONCLUSIONS: CTP ischemic core overestimation appears to be a relatively common phenomenon that is most frequent in patients with poor collaterals imaged within the acute time window. Early perfusion imaging should be interpreted with caution to prevent the inadvertent exclusion of patients from highly effective reperfusion therapies.

Angiographic Evaluation of Cranial Venous Outflow Patterns in Patients With and Without Idiopathic Intracranial Hypertension.

BACKGROUND: Several collateral venous pathways exist to assist in cranial venous drainage in addition to the internal jugular veins. The important extrajugular networks (EJN) are often readily identified on diagnostic cerebral angiography. However, the angiographic pattern of venous drainage through collateral EJN has not been previously compared among patients with and without idiopathic intracranial hypertension (IIH). OBJECTIVE: To quantify EJN on cerebral angiography among patients both with and without IIH and to determine whether there is a different EJN venous drainage pattern in patients with IIH. METHODS: Retrospective imaging review of 100 cerebral angiograms (50 IIH and 50 non-IIH patients) and medical records from a single academic medical center was performed by 2 independent experienced neuroendovascular surgeons. Points were assigned to EJN flow from 0 to 6 using an increasing scale (with each patient's dominant internal jugular vein standardized to 5 points to serve as the internal reference). Angiography of each patient included 11 separately graded extrajugular networks for internal carotid and vertebral artery injections. RESULTS: Patients in the IIH group had statistically significant greater flow in several of the extrajugular networks. Therefore, they preferentially drained through EJN compared with the non-IIH group. Right transverse-sigmoid system was most often dominant in both groups, yet there was a significantly greater prevalence of codominant sinus pattern on posterior circulation angiograms. CONCLUSION: Patients with IIH have greater utilization of EJN compared with patients without IIH. Whether this is merely an epiphenomenon or possesses actual cause-effect relationships needs to be determined with further studies.

Hypoperfusion Intensity Ratio is Associated with Stroke Mechanism in Patients Undergoing Mechanical Thrombectomy.

BACKGROUND: Hypoperfusion Intensity Ratio (HIR), defined as Tmax >10s/Tmax >6s on computed tomography perfusion (CTP), and stroke mechanisms have been independently correlated with angiographic collaterals and patient outcomes. Slowly developing atherosclerotic stenosis may foster collateral development, whereas cardioembolic occlusion may occur before collaterals mature. We hypothesized that favorable HIR is associated with large artery atherosclerosis (LAA) stroke mechanism and good clinical outcome. METHODS: Retrospective study of consecutive endovascularly-treated stroke patients with intracranial ICA or MCA M1/M2 occlusions, who underwent CTP before intervention, between January 2018 and August 2021. Patients were dichotomized into LAA+ or LAA- based on presence of LAA on angiography. HIR was dichotomized into favorable (HIR+) or unfavorable (HIR-) groups based on published thresholds. Good early outcome was defined as discharge mRS of 0-2. Bivariate and multivariable logistic regression were performed. RESULTS: 143 patients met inclusion. 21/143 were LAA+ (15%) and 65/143 (45%) were HIR+. HIR+ was significantly more frequent in LAA+ patients (67% vs. 42%, p= 0.035). Controlling for demographics, stroke severity, imaging findings, and medical comorbidities, LAA+ remained independently associated with HIR+ (OR 5.37 [95% CI 1.43 - 20.14]; p=0.013) as did smaller infarction core volume (<30 mL of CBF <30%: OR 7.92 [95% CI 2.27 - 27.64]; p = 0.001). HIR+ was not associated with good clinical outcome. CONCLUSIONS: Large artery atherosclerosis was independently associated with favorable HIR in patients undergoing mechanical thrombectomy. While favorable HIR was associated with smaller pre-treatment core infarcts, reflecting more robust collaterals, it was not associated with good clinical outcome.

The resolute Onyx drug eluting stent for neurointervention: A technical series.

INTRODUCTION: Current methods for angioplasty and stenting of the intracranial vasculature for neurointervention are limited. The Wingspan Stent System is Food and Drug Administration (FDA) approved with human device exemption for a limited patient group and despite numerous prospective registries and trials demonstrating reasonable safety, still carries warnings from the FDA for its use. Given these limitations, we present the technical nuances and outcomes of the off-label use of the Resolute Onyx drug-eluting stent (DES) for neurointerventional purposes. METHODS: Retrospective chart review of all patients undergoing a neurointerventional procedure with the Resolute Onyx DES was done from January 2017-2021. The Resolute Onyx is a coronary balloon-mounted drug-eluting (zotarolimus) single wire laser cut stent. Technical details and procedural outcomes were collected. RESULTS: In total 40 patients had attempted placement of the Resolute Onyx DES with procedural success in 95% of patients. The most common vessel stented was the basilar artery, 30% (12/40). The most common indication was intracranial atherosclerotic disease in 62.5% (25/40) patients, followed by acute stroke in 17.5% (7/40) of patients. The technical and procedural outcomes were excellent with only one technical complication (2.5%). CONCLUSIONS: This series describes the initial technical safety and utility of utilizing a new generation balloon-mounted drug-eluting stent for neurointerventional purposes. This stent offers the potential for improved navigability, delivery, and outcomes compared to current neurointerventional options and warrants further study.