Tenecteplase versus alteplase before stroke thrombectomy: outcomes after system-wide transitions in Pennsylvania.

INTRODUCTION: United States stroke systems are increasingly transitioning from alteplase (TPA) to tenecteplase (TNK). Real-world data on the safety and effectiveness of replacing TPA with TNK before large vessel occlusion (LVO) stroke endovascular treatment (EVT) are lacking. METHODS: Four Pennsylvania stroke systems transitioned from TPA to TNK during the study period 01/2020-06/2023. LVO stroke patients who received intravenous thrombolysis with TPA or TNK before EVT were reviewed. Multivariate logistic analysis was conducted adjusting for age, sex, National Institute of Health Stroke Scale (NIHSS), occlusion site, last-known-well-to-intravenous thrombolysis time, interhospital-transfer and stroke system. RESULTS: Of 635 patients, 309 (48.7%) received TNK and 326 (51.3%) TPA prior to EVT. The site of occlusion was the M1 middle cerebral artery (MCA) (47.7%), M2 MCA (25.4%), internal carotid artery (14.0%), tandem carotid with M1 or M2 MCA (9.8%) and basilar artery (3.1%). A favorable functional outcome (90-day mRS ≤ 2) was observed in 47.6% of TNK and 49.7% of TPA patients (p = 0.132). TNK versus TPA groups had similar rates of early recanalization (11.9% vs. 8.4%, p = 0.259), successful endovascular reperfusion (93.5% vs. 89.3%, p = 0.627), symptomatic intracranial hemorrhage (3.2% vs. 3.4%, p = 0.218) and 90-day all-cause mortality (23.1% vs. 21.5%, p = 0.491). CONCLUSIONS: This U.S. multicenter real-world clinical experience demonstrated that switching from TPA to TNK before EVT for LVO stroke resulted in similar endovascular reperfusion, safety, and functional outcomes.

Femoral versus radial access for middle meningeal artery embolization for chronic subdural hematomas: multicenter propensity score matched study.

BACKGROUND: With transradial access (TRA) being more progressively used in neuroendovascular procedures, we compared TRA with transfemoral access (TFA) in middle meningeal artery embolization (MMAE) for chronic subdural hematoma (cSDH). METHODS: Consecutive patients undergoing MMAE for cSDH at 14 North American centers (2018-23) were included. TRA and TFA groups were compared using propensity score matching (PSM) controlling for: age, sex, concurrent surgery, previous surgery, hematoma thickness and side, midline shift, and pretreatment antithrombotics. The primary outcome was access site and overall complications, and procedure duration; secondary endpoints were surgical rescue, radiographic improvement, and technical success and length of stay. RESULTS: 872 patients (median age 73 years, 72.9% men) underwent 1070 MMAE procedures (54% TFA vs 46% TRA). Access site hematoma occurred in three TFA cases (0.5%; none required operative intervention) versus 0% in TRA (P=0.23), and radial-to-femoral conversion occurred in 1% of TRA cases. TRA was more used in right sided cSDH (58.4% vs 44.8%; P<0.001). Particle embolics were significantly higher in TFA while Onyx was higher in TRA (P<0.001). Following PSM, 150 matched pairs were generated. Particles were more utilized in the TFA group (53% vs 29.7%) and Onyx was more utilized in the TRA group (56.1% vs 31.5%) (P=0.001). Procedural duration was longer in the TRA group (median 68.5 min (IQR 43.1-95) vs 59 (42-84); P=0.038), and radiographic success was higher in the TFA group (87.3% vs 77.4%; P=0.036). No differences were noted in surgical rescue (8.4% vs 10.1%, P=0.35) or technical failures (2.4% vs 2%; P=0.67) between TFA and TRA. Sensitivity analysis in the standalone MMAE retained all associations but differences in procedural duration. CONCLUSIONS: In this study, TRA offered comparable outcomes to TFA in MMAE for cSDH in terms of access related and overall complications, technical feasibility, and functional outcomes. Procedural duration was slightly longer in the TRA group, and radiographic success was higher in the TFA group, with no differences in surgical rescue rates.

Intrasaccular Flow Disruption: Examining Global Access and Research Trends.

The Woven EndoBridge (WEB) and other intrasaccular flow disruptors show promise in treating intracranial aneurysms. We performed a bibliometric analysis to provide novel insights into the trends and trajectory of these devices. We systematically assessed bibliometric data such as citations, journals, study designs, open access status, and multi-institutional involvement for the top-cited articles on WEB and other disruptors. The top 100 cited studies on the WEB had citations from 7 to 144 (mean±s.d. 35.6 ± 29.5), while only 33 studies were published for other intrasaccular flow disruptors (4.24 ± 8.45). Of the other devices, the Contour has the most publications (n=21). Retrospective reviews were the most common study design for both WEB and other intrasaccular devices. France published the most studies in top 100 WEB papers (n=35), while Germany led for other flow disruptors (n=10). In all studies analyzed, no senior authors from Africa are present. The top 100 WEB publications had a higher mean citation count (35.6 vs. 4.24, p < 0.001), higher mean citations per year (5.24 vs. 1.03, p < 0.01), and a higher proportion of multi-institutional collaborations (44.0% vs. 12.1%, p < 0.01) than other intrasaccular flow disruptors. In conclusion, countries with the most publications on WEB are not necessarily the ones leading the way with newer intrasaccular devices, while study designs remain similar. There is limited contribution to the literature outside of Europe and North America. Our findings identify notable collaborators and trends, providing a snapshot of the field and a roadmap for future research.

The human craniospinal venous system and its influence on postural intracranial pressure: a review.

OBJECTIVE: The cerebral and spinal venous systems have similar functions but unique anatomical and physiological properties. CSF occupies space in the cranial and spinal vaults, is continuously produced, and has many roles, including maintaining a favorable environment for CNS structures. The influence of the cerebrospinal venous system on CSF dynamics has been theorized since the 1940s. Newer studies suggest venous outflow pattern alterations in response to changes in body position. However, the relationship of postural cerebrospinal venous outflow shifts with and their influence on CSF homeostasis is not well understood. METHODS: The authors searched the published literature related to the anatomy and function of vertebral venous plexus (VVP), CSF, and positional cerebral venous flow characteristics. A comprehensive collection of literature was compiled and reviewed, and the relationship between cerebrospinal and venous system changes and alterations in body positions, with an emphasis on the craniocervical system, is discussed. RESULTS: The VVP is a network of valveless veins extending from the sacrum to the cranium that are interconnected with the cranial dural sinuses. The internal VVP occupies space within the extradural spinal canal and functions to return spinal venous blood to the heart, but it has additional properties, including the capability of bidirectional venous flow, an intraspinal dilatory capacity, and a role in cerebral venous outflow. When one rises to the upright position, CSF shifts toward the spinal canal and force vectors change, leading to reduced intracranial CSF pressure; simultaneously, cerebral venous outflow shifts from the jugular vein to the VVP outflow pathway. The venous outflow shift mechanism and its purpose are poorly understood. The authors review the known physiology of the system, identify gaps in knowledge to direct future research, and propose an interpretation of these data, concluding that position-dependent CSF and cerebrospinal venous shifts are part of a complementary positional craniospinal pressure regulation system that must be kept in balance for optimal CNS function. CONCLUSIONS: Current knowledge of the cerebrospinal venous anatomy, dynamic flow characteristics in response to gravity, and the venous system's influence on CSF suggests that the VVP plays a role in influencing CSF pressure, and the authors hypothesize that it plays a role in supporting intracranial pressure in the upright body posture. Further research is needed to better characterize the functional relationship of the VVP to CSF dynamics as well as identify potentially related disease states.

Arteriovenous malformations in the cerebellopontine angle: assessment of the "backdoor resection" technique and microsurgical results in 38 patients.

OBJECTIVE: Posterior fossa arteriovenous malformations (AVMs) represent 7% to 15% of all intracranial AVMs and are associated with an increased risk of hemorrhage, morbidity, and mortality compared with supratentorial AVMs, thus prompting urgent and definitive treatment. Cerebellopontine angle (CPA) AVMs are a unique group of posterior fossa AVMs incorporating characteristics of brainstem and cerebellar lesions, which are particularly amenable to microsurgical resection. This study reports the clinical, radiological, operative, and outcome features of patients with CPA AVMs in a large cohort. METHODS: The authors conducted a single-surgeon, 2-institution retrospective cohort study of all consecutive patients with CPA AVMs treated with microsurgical resection during a 25-year period. RESULTS: CPA AVMs represented 22% (38 of 176) of all infratentorial AVMs resected by the senior author. Overall, 38 patients (22 [58%] male and 16 [42%] female) met the study inclusion criteria and were analyzed. Most patients presented with hemorrhage (n = 29, 76%). The median age at surgery was 56 (range 6-82) years. Subtypes included 22 (58%) petrosal cerebellar AVMs, 11 (29%) lateral pontine AVMs, and 5 (13%) AVMs involving both the brainstem and cerebellum. Most AVM niduses were small (< 3 cm; n = 35, 92%) and compact (n = 31, 82%). Fourteen (37%) patients harbored flow-related aneurysms. Twenty (53%) patients underwent preoperative embolization. Complete angiographic obliteration was achieved with microsurgery in 35 (92%) patients. Five (13%) patients with poor neurological conditions at presentation died before hospital discharge. Of the 7 (18%) patients with new postoperative neurological deficits, 5 had transient deficits. The median (interquartile range) follow-up was 1.7 (0.5-3.2) years; 32 (84%) patients were alive at last follow-up, and 30 (79%) had achieved a favorable neurological outcome (modified Rankin Scale [mRS] score 0-2). The only independent predictor of unfavorable postoperative outcome (mRS score 3-6) was the preoperative mRS score (p = 0.002). CONCLUSIONS: CPA AVMs are unique posterior fossa lesions, including petrosal cerebellar and lateral pontine AVMs. The "backdoor resection" technique provides a safe and efficient strategy with high obliteration rates and a low risk of treatment-related morbidity. Microsurgical resection should be considered the frontline treatment for most CPA AVMs, except for those with a significant diffuse brainstem component.

Urgent carotid endarterectomy with distal mechanical thrombectomy.

We review the technique for carotid endarterectomy (CEA) and direct carotid access for distal thrombectomy after attempted proximal thrombectomy in the setting of tandem occlusions. A patient in their 70s presented with right facial droop and drooling and was found to have critical left carotid stenosis with filling defect in the cavernous segment of the left internal carotid artery consistent with vessel occlusion, Thrombolysis in Cerebral Infarction (TICI) 0, and left M2 middle cerebral artery (MCA) occlusion. After multiple attempts with different wire shapes guided by microcatheter injections within the carotid bulb, we were unable to cross the occlusion. Conversion to open CEA with distal thrombectomy was elected. Following closure of the arteriotomy, direct carotid access using a 5Fr radial artery sheath was achieved within the open surgical field for distal thrombectomy. A 5Fr aspiration catheter was navigated to the left M2 MCA where a stent retriever was then recaptured and TICI 2B reperfusion was achieved.

Transcirculation retrograde placement of a Pipeline embolization device for treatment of a vertebrobasilar junction aneurysm.

Transcirculation catheterization, also known as the retrograde approach, involves the navigation of a catheter or other endovascular device from one arterial circulation to the other (right to left, or anterior to posterior).1-4 We present a case of a complex vertebrobasilar junction aneurysm previously treated by bilateral vertebral artery deconstruction, precluding antegrade access (video 1). Following the creation of a protective occipital artery to posterior inferior cerebellar artery (PICA) bypass, the patient was treated with transcirculation placement of a Pipeline embolization device (PED).5-9 The right internal carotid artery was accessed with a guide catheter using a transradial approach. The microwire-microcatheter combination was then tracked through the right posterior communicating artery, down the basilar trunk, and to the left PICA. The PED was successfully deployed from the left vertebral artery to the mid-basilar artery. At 3-month follow-up, the aneurysm was completely obliterated. The nuances of transcirculation technique, especially for flow diversion, are discussed. (Used with permission from Barrow Neurological Institute, Phoenix, Arizona, USA.)neurintsurg;jnis-2023-021363v1/V1F1V1Video 1Transcirculation retrograde placement of a Pipeline embolization device for treatment of a vertebrobasilar junction aneurysm previously treated by bilateral vertebral artery deconstruction, precluding antegrade access.

Intraoperative Ionizing Radiation Exposure Awareness and Associated Morbidity in Neurosurgery: A Nationwide Survey.

BACKGROUND: Neurosurgeons often use radiation to visualize blood vessels and implants intraoperatively. However, high exposure to radiation increases one's cancer risk. This study aims to investigate intraoperative ionizing radiation exposure awareness and associated morbidity among neurosurgeons. METHODS: An anonymized 30-question survey about their intraoperative radiation exposure, protective measures, radiation knowledge, and any conditions that can arise from protracted radiation exposure was disseminated to 3344 American Association of Neurological Surgeons members. RESULTS: A total of 227 (6.8%) neurosurgeons completed the survey. Most neurosurgeons (61, 27%) performed 2-4 surgeries per week necessitating radiation (61, 27%), did not use a dosimeter (134, 59%), and wore a lead apron (89%) and a thyroid shield (75%). Only 7 (3%) of respondents could correctly identify the safety limit for occupational radiation. One hundred and thirty-four (59%) respondents correctly identified the relationship between distance and radiation dose reduction. Two hundred and thirteen (94%) neurosurgeons reported concern about occupational radiation exposure. No significant association was found between occupational radiation exposure and the rate of cataracts, combined cancer, and skin cancer. Multivariate logistic regression adjusting for age and cancer history found that the likelihood of developing leukemia (P = 0.02) and nonmalignant thyroid nodular disease (P = 0.01) is positively associated with increased total occupational radiation exposure. CONCLUSIONS: There is a need for improved radiation safety awareness among neurosurgeons, especially in the context of rising usage of minimally invasive surgery. This can allow for a greater understanding of radiation-associated risks among neurosurgeons and guide the implementation of safer practices.

Superficial Temporal Artery to Superior Cerebellar Artery STA (E-S*) s2 Bypass for Dolichoectatic Superior Cerebellar Artery Aneurysm After Failed Flow Diversion: 2-Dimensional Operative Video.

Flow diversion is a unique interventional tool with evolving roles in the treatment of intracranial aneurysms.1 Although flow diversion strategies can be highly effective in appropriately selected patients, their off-label use is controversial. As flow diversion indications have expanded, so has the incidence of treatment failure, resulting in an evolving subgroup of patients with atypical lesions that require complex salvage strategies, such as cerebrovascular bypass.2,3 We report a residual dolichoectatic superior cerebellar artery aneurysm in which flow diversion failed, which was treated through superficial temporal artery to superior cerebellar artery bypass.4,5 Being a single case report, institutional review board approval was not needed. Patient consent was obtained. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Multicenter US clinical experience with the Scepter Mini balloon catheter.

INTRODUCTION: Distal navigability and imprecise delivery of embolic agents are two limitations encountered during liquid embolization of cerebrospinal lesions. The dual-lumen Scepter Mini balloon (SMB) microcatheter was introduced to overcome these conventional microcatheters' limitations with few small single-center reports suggesting favorable results. METHODS: A series of consecutive patients undergoing SMB-assisted endovascular embolization were extracted from prospectively maintained registries in seven North-American centers (November 2019 to September 2022). RESULTS: Fifty-four patients undergoing 55 embolization procedures utilizing SMB were included (median age 58.5; 48.1% females). Cranial dural arteriovenous fistula embolization was the most common indication (54.5%) followed by cranial arteriovenous malformation (27.3%). Staged/pre-operative embolization was done in 36.4% of cases; and 83.6% of procedures using Onyx-18. Most procedures utilized a transarterial approach (89.1%), and SMB-induced arterial-flow arrest concurrently with transvenous embolization was used in 10.9% of procedures. Femoral access/triaxial setups were utilized in the majority of procedures (65.5% and 60%, respectively). The median vessel diameter where the balloon was inflated of 1.8 mm, with a median of 1.5 cc of injected embolic material per procedure. Technical failures occurred in 5.5% of cases requiring aborting/replacement with other devices without clinical sequelae in any of the patients, with SMB-related procedural complications of 3.6% without clinical sequelae. Radiographic imaging follow-up was available in 76.9% of the patients (median follow-up 3.8 months), with complete occlusion (100%) or >50% occlusion in 92.5% of the cases, and unplanned retreatments in 1.8%. CONCLUSION: The SMB microcatheter is a useful new adjunctive device for balloon-assisted embolization of cerebrospinal lesions with a high technical success rate, favorable outcomes, and a reasonable safety profile.

Posterior Interhemispheric Approach for Occlusion of a Galenic (Type 1) Tentorial Dural Arteriovenous Fistula: 2-Dimensional Operative Video.

Galenic dural arteriovenous fistulas account for 1 of the 6 types of tentorial dural arteriovenous fistulas (type I). These fistulas are located around the great cerebral vein of Galen, with dural arterial supply through the tentorial arteries of Bernasconi and Cassinari or other posterior fossa branches, such as the posterior meningeal artery. In this case, a man in his 60s presented with a headache and was found to have this high-risk lesion, which was Borden grade III and Cognard grade IV. The lesion persisted despite embolization through the middle meningeal artery. This video discusses the microsurgical management of this lesion through a torcular craniotomy and a posterior interhemispheric approach for clipping. Because this is a single case report, institutional review board approval was not needed. The patient consented to the procedure. Used with permission from Barrow Neurological Institute, Phoenix, Arizona. Images at 7:19 and 7:49 in Surgical Video are used with permission from Lawton, Michael T.; Sanchez-Mejia, Rene O.; Pham, Diep; Tan, Jeffrey; Halbach, Van V. Tentorial Dural Arteriovenous Fistulae: Operative Strategies and Microsurgical Results for Six Types. Operative Neurosurgery 62(3): 110-125, 2008.

External Validation of the Modified Southwestern Aneurysm Severity Index in the Barrow Ruptured Aneurysm Trial Surgical Cohort.

BACKGROUND AND OBJECTIVES: Predicting functional outcomes after surgical management of ruptured aneurysms is essential. This study sought to validate the modified Southwestern Aneurysm Severity Index (mSASI), which predicts functional outcomes 1 year after treatment. METHODS: The surgical arm of a randomized controlled trial, the Barrow Ruptured Aneurysm Trial, was used to validate the mSASI model. mSASI scores incorporating the Hunt and Hess scale, Non-Neurological American Society of Anesthesiologists Physical Classification Status, imaging findings, and other modifiers were assigned and evaluated against the Glasgow Outcome Scale (GOS) score at 1 year. The model's performance was assessed for discrimination and calibration. Similar evaluations were constructed using the modified Rankin Scale (mRS) as the 1-year functional outcome measurement. Long-term outcomes (3, 6, 10 years) were also evaluated. RESULTS: Of 280 clinical trial patients treated surgically, 242 met the inclusion criteria. The mean age was 54.1 ± 12.9 years; 31% were men. Favorable GOS score (4-5) and mRS score (0-2) at 1 year were observed in 73.6% and 66.1% of patients, respectively. The mSASI model predicted unfavorable GOS score at 1 year with fair to good discrimination (area under the curve = 0.75, 95% CI = 0.68-0.82) and accurate calibration (R2 = 0.98). Similar results were obtained when mRS was used as the outcome measure (area under the curve = 0.75, 95% CI = 0.68-0.82; R2 = 0.95). CONCLUSION: The mSASI model was externally validated in our cohort to predict functional outcomes using the GOS or mRS scores 1 year after surgery. This index may be used for prognosticating outcomes of patients undergoing surgery for ruptured aneurysms at short-term and long-term intervals.

Middle meningeal artery patency after surgical evacuation for chronic subdural hematoma.

BACKGROUND: Chronic subdural hematoma (CSDH) often requires surgical evacuation, but recurrence rates remain high. Middle meningeal artery (MMA) embolization (MMAE) has been proposed as an alternative or adjunct treatment. There is concern that prior surgery might limit patency, access, penetration, and efficacy of MMAE, such that some recent trials excluded patients with prior craniotomy. However, the impact of prior open surgery on MMA patency has not been studied. METHODS: A retrospective analysis was conducted on patients who underwent MMAE for cSDH (2019-2022), after prior surgical evacuation or not. MMA patency was assessed using a six-point grading scale. RESULTS: Of the 109 MMAEs (84 patients, median age 72 years, 20.2% females), 58.7% were upfront MMAEs, while 41.3% were after prior surgery (20 craniotomies, 25 burr holes). Median hematoma thickness was 14 mm and midline shift 3 mm. Hematoma thickness reduction, surgical rescue, and functional outcome did not differ between MMAE subgroups and were not affected by MMA patency or total area of craniotomy or burr-holes. MMA patency was reduced in the craniotomy group only, specifically in the distal portion of the anterior division (p = 0.005), and correlated with craniotomy area (p < 0.001). CONCLUSION: MMA remains relatively patent after burr-hole evacuation of cSDH, while craniotomy typically only affects the frontal-distal division. However, MMA patency, evacuation method, and total area do not affect outcomes. These findings support the use of MMAE regardless of prior surgery and may influence future trial inclusion/exclusion criteria. Further studies are needed to optimize the timing and techniques for MMAE in cSDH management.

Endovascular biopsy in neurointerventional surgery: A systematic review.

INTRODUCTION: Endothelial cells (ECs) continuously line the cerebrovasculature. Molecular aberrations in the ECs are hallmarks and contributory factors to the development of cerebrovascular diseases, including intracranial aneurysms and arteriovenous malformations (AVMs). Endovascular biopsy has been introduced as a method to harvest ECs and obtain relevant biologic information. We aimed to summarize the literature on endovascular biopsy in neurointerventional surgery. METHODS: We conducted a comprehensive literature search in multiple databases, identifying eligible studies focusing on neurosurgical applications of endovascular biopsy. The systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The relevant information was collected, including study characteristics, biopsy techniques, and key findings. RESULTS: Nine studies met the inclusion criteria and were included. The studies involved the collection of ECs using various endovascular devices including coils, guide wires, different stents, and forceps. Endothelial-enrichment techniques, such fluorescence-activated cell sorting (FACS), collected ECs and facilitated downstream applications of bulk or single-cell RNA sequencing (scRNAseq). The studies provided insights into gene expression profiles and identified potential biomarkers associated with intracranial aneurysms. However, challenges were observed in obtaining an adequate number of ECs and identifying consistent biomarkers. CONCLUSION: Endovascular biopsy of endothelial cells (ECs) in cerebrovascular pathologies shows promise for gene expression profiling. However, many studies have been limited in sample size and underpowered to identify "signature genes" for aneurysm growth or rupture. Advancements in minimally invasive biopsy methods have potential to facilitate applications of precision medicine in the treatment of cerebrovascular disorders.

Microsurgical Resection of Brainstem Cavernous Malformations in Older Adults: A Multicenter, 30-Year Experience.

BACKGROUND AND OBJECTIVES: Microsurgical resection is the only curative intervention for symptomatic brainstem cavernous malformations (BSCMs), but the management of these lesions in older adults (≥65 years) is not well described. This study sought to address this gap by examining the safety and efficacy of BSCM resection in a cohort of older adults. METHODS: Records of patients who underwent BSCM resection over a 30-year period were reviewed retrospectively. Baseline characteristics and outcomes were compared between older (≥65 years) and younger (<65 years) patients. RESULTS: Of 550 patients with BSCM who met inclusion criteria, 41 (7.5%) were older than 65 years. Midbrain (43.9% vs 26.1%) and medullary lesions (19.5% vs 13.6%) were more common in the older cohort than in the younger cohort (P = .01). Components of the Lawton BSCM grading system (ie, lesion size, crossing axial midpoint, developmental venous anomaly, and timing of hemorrhage) were not significantly different between cohorts (P ≥ .11). Mean (SD) Elixhauser comorbidity score was significantly higher in older patients (1.86 [1.06]) than in younger patients (0.66 [0.95]; P < .001). Older patients were significantly more likely than younger patients to have poor outcomes at final follow-up (28.9% vs 13.8%, P = .01; mean follow-up duration, 28.7 [39.1] months). However, regarding relative neurological outcome (preoperative modified Rankin Scale to final modified Rankin Scale), rate of worsening was not significantly different between older and younger patients (23.7% vs 14.9%, P = .15). CONCLUSION: BSCMs can be safely resected in older patients, and when each patient's unique health status and life expectancy are taken into account, these patients can have outcomes similar to younger patients.

Microsurgical Resection of a Lateral Pontine Arteriovenous Malformation Masquerading as a Cavernous Malformation: 2-Dimensional Operative Video.

Although cavernous malformations (CMs) often demonstrate characteristic T2 heterogeneity and gadolinium enhancement, whereas arteriovenous malformations (AVMs) appear as tangles of T2 hypointense flow voids, small lesions in deep locations may have equivocal features on preoperative imaging.1-4 This video presents an unusual case of a lateral pontine AVM masquerading as a CM. The patient presented with sudden-onset headache, dizziness, double vision, and left facial numbness. Diagnostic imaging findings suggested a hemorrhagic left lateral pontine mass lesion, most consistent with brainstem CM. Resection through a left extended retrosigmoid craniotomy was recommended. Patient consent was obtained. During dissection, a prominent petrosal vein tributary was noted to be arterialized, which was concerning for AVM. Indocyanine green videoangiography (ICG-VA) was performed to confirm the diagnosis, and the intraoperative plan was dynamically adjusted in accordance with the principles of AVM resection. The small superficial feeding arteries were identified and disconnected, and the nidus was dissected circumferentially with the pial resection technique. After dearterialization, the draining petrosal vein was noted to darken, and repeat ICG-VA confirmed complete occlusion of the AVM without residual shunting. The patient recovered well, with no neurological deficits, and postoperative angiography confirmed complete resection of the Spetzler-Martin grade III AVM. Key learning points for this unusual case include the importance of dynamic interpretation of intraoperative findings, openness to alterations of the surgical plan when integrating new diagnostic information, and the integration of ICG-VA as a critical tool for differentiating CMs and AVMs during microsurgical resection. Images in Surgical Video © 2024 Barrow Neurological Institute. Used with permission.

Sex differences in patients with and without high-risk factors associated with aneurysmal subarachnoid hemorrhage.

BACKGROUND: Controversy remains regarding the appropriate screening for intracranial aneurysms or for the treatment of aneurysmal subarachnoid hemorrhage (aSAH) for patients without known high-risk factors for rupture. This study aimed to assess how sex affects both aSAH presentation and outcomes for aSAH treatment. METHOD: A retrospective cohort study was conducted of all patients treated at a single institution for an aSAH during a 12-year period (August 1, 2007-July 31, 2019). An analysis of women with and without high-risk factors was performed, including a propensity adjustment for a poor neurologic outcome (modified Rankin Scale [mRS] score > 2) at follow-up. RESULTS: Data from 1014 patients were analyzed (69% [n = 703] women). Women were significantly older than men (mean ± SD, 56.6 ± 14.1 years vs 53.4 ± 14.2 years, p < 0.001). A significantly lower percentage of women than men had a history of tobacco use (36.6% [n = 257] vs 46% [n = 143], p = 0.005). A significantly higher percentage of women than men had no high-risk factors for aSAH (10% [n = 70] vs 5% [n = 16], p = 0.01). The percentage of women with an mRS score > 2 at the last follow-up was significantly lower among those without high-risk factors (34%, 24/70) versus those with high-risk factors (53%, 334/633) (p = 0.004). Subsequent propensity-adjusted analysis (adjusted for age, Hunt and Hess grade, and Fisher grade) found no statistically significant difference in the odds of a poor outcome for women with or without high-risk factors for aSAH (OR = 0.7, 95% CI = 0.4-1.2, p = 0.18). CONCLUSIONS: A higher percentage of women versus men with aSAH had no known high-risk factors for rupture, supporting more aggressive screening and management of women with unruptured aneurysms.

Mandibular Fossa Approach to Petroclival and Anterior Pontine Lesions.

Objective To describe the anatomy related to a novel approach to the petroclival region through the mandibular fossa for the treatment of petroclival and anterior pontine lesions. Design Five dry skulls were examined for surgical approach. Three adult cadaveric heads underwent bilateral dissection. One cadaveric head was evaluated with computed tomography after dissection. Setting This study was performed in an academic medical center. Participants Neurosurgical anatomy researchers performed this study using dry skulls and cadaveric heads. Main Outcome Measurements This was a proof-of-concept anatomical study. Results The mandibular fossa approach uses a vertical preauricular incision above the facial nerve branches. Removal of the temporomandibular joint exposes the mandibular fossa. The anterior boundary is the mandibular nerve at the foramen ovale, and the posterior boundary is the jugular foramen. The chorda tympani, eustachian tube, and tensor tympani muscle are sectioned. The carotid artery is transposed out of the petrous canal, and a petrosectomy is performed from Meckel's cave to the foramen magnum and anterior occipital condyle. Dural opening exposes the anterior pons, vertebrobasilar junction, bilateral vertebral arteries, and the ipsilateral anterior and posterior inferior cerebellar arteries. At completion, the temporomandibular joint is reconstructed with a prosthetic joint utilizing a second incision along the mandible. Conclusions The mandibular fossa approach is a new trajectory to the petroclival region and the anterior pons. It combines the more anterior angle of endoscopic approaches along with the enhanced control of open approaches. Further study is necessary before this approach is used clinically.

Readability of cerebrovascular diseases online educational material from major cerebrovascular organizations.

INTRODUCTION: The internet is an essential resource for patients and their loved ones to understand their medical conditions, and professional medical organizations have taken great strides to develop educational material targeting patients. The average American reads at a seventh to eighth grade reading level, hence it is important to understand the readability of this medical information to ensure patients comprehend what is being presented. METHODS: In January 2023, online patient education material was downloaded from major cerebrovascular healthcare organizations and assessed using eight assessments, including Bormuth Cloze Mean, Bormuth Grade Placement, Coleman-Liau (grade levels), Coleman-Liau (predictive cloze scores), Flesch Reading Ease (FRE), and Fry. RESULTS: A total of 32 files were extracted from six organizations and analyzed across 15 readability measures. None of the organizations met the federal government guidelines for grade-level readability. This held constant across all measured tests. Two organizations had above a postgraduate level. The FRE graphs do not identify any organizations with material below a ninth grade reading level, while the American Association of Neurological Surgeons (AANS) and the Society of Interventional Radiology (SIR) have a postgraduate readability level. The Fry graphs show similar results, with AANS/CNS Cerebrovascular Section, Society of NeuroInterventional Surgery (SNIS), SIR, and AANS having college-level readability. The lowest readability across all measures is only at an early seventh grade reading level. CONCLUSIONS: Current health literacy content for cerebrovascular patients is far above the recommended readability level. We provide straightforward suggestions for how major professional organizations should improve their informational material on cerebrovascular diseases to improve patient understanding.