Blind spots on western blots: Assessment of common problems in western blot figures and methods reporting with recommendations to improve them.

Western blotting is a standard laboratory method used to detect proteins and assess their expression levels. Unfortunately, poor western blot image display practices and a lack of detailed methods reporting can limit a reader's ability to evaluate or reproduce western blot results. While several groups have studied the prevalence of image manipulation or provided recommendations for improving western blotting, data on the prevalence of common publication practices are scarce. We systematically examined 551 articles published in the top 25% of journals in neurosciences (n = 151) and cell biology (n = 400) that contained western blot images, focusing on practices that may omit important information. Our data show that most published western blots are cropped and blot source data are not made available to readers in the supplement. Publishing blots with visible molecular weight markers is rare, and many blots additionally lack molecular weight labels. Western blot methods sections often lack information on the amount of protein loaded on the gel, blocking steps, and antibody labeling protocol. Important antibody identifiers like company or supplier, catalog number, or RRID were omitted frequently for primary antibodies and regularly for secondary antibodies. We present detailed descriptions and visual examples to help scientists, peer reviewers, and editors to publish more informative western blot figures and methods. Additional resources include a toolbox to help scientists produce more reproducible western blot data, teaching slides in English and Spanish, and an antibody reporting template.

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.

Localized conditional induction of brain arteriovenous malformations in a mouse model of hereditary hemorrhagic telangiectasia.

BACKGROUND: Longitudinal mouse models of brain arteriovenous malformations (AVMs) are crucial for developing novel therapeutics and pathobiological mechanism discovery underlying brain AVM progression and rupture. The sustainability of existing mouse models is limited by ubiquitous Cre activation, which is associated with lethal hemorrhages resulting from AVM formation in visceral organs. To overcome this condition, we developed a novel experimental mouse model of hereditary hemorrhagic telangiectasia (HHT) with CreER-mediated specific, localized induction of brain AVMs. METHODS: Hydroxytamoxifen (4-OHT) was stereotactically delivered into the striatum, parietal cortex, or cerebellum of R26CreER; Alk12f/2f (Alk1-iKO) littermates. Mice were evaluated for vascular malformations with latex dye perfusion and 3D time-of-flight magnetic resonance angiography (MRA). Immunofluorescence and Prussian blue staining were performed for vascular lesion characterization. RESULTS: Our model produced two types of brain vascular malformations, including nidal AVMs (88%, 38/43) and arteriovenous fistulas (12%, 5/43), with an overall frequency of 73% (43/59). By performing stereotaxic injection of 4-OHT targeting different brain regions, Alk1-iKO mice developed vascular malformations in the striatum (73%, 22/30), in the parietal cortex (76%, 13/17), and in the cerebellum (67%, 8/12). Identical application of the stereotaxic injection protocol in reporter mice confirmed localized Cre activity near the injection site. The 4-week mortality was 3% (2/61). Seven mice were studied longitudinally for a mean (SD; range) duration of 7.2 (3; 2.3-9.5) months and demonstrated nidal stability on sequential MRA. The brain AVMs displayed microhemorrhages and diffuse immune cell invasion. CONCLUSIONS: We present the first HHT mouse model of brain AVMs that produces localized AVMs in the brain. The mouse lesions closely resemble the human lesions for complex nidal angioarchitecture, arteriovenous shunts, microhemorrhages, and inflammation. The model's longitudinal robustness is a powerful discovery resource to advance our pathomechanistic understanding of brain AVMs and identify novel therapeutic targets.

Cerebrospinal Fluid Biomarkers for Diagnosis and the Prognostication of Acute Ischemic Stroke: A Systematic Review.

Despite the high incidence and burden of stroke, biological biomarkers are not used routinely in clinical practice to diagnose, determine progression, or prognosticate outcomes of acute ischemic stroke (AIS). Because of its direct interface with neural tissue, cerebrospinal fluid (CSF) is a potentially valuable source for biomarker development. This systematic review was conducted using three databases. All trials investigating clinical and preclinical models for CSF biomarkers for AIS diagnosis, prognostication, and severity grading were included, yielding 22 human trials and five animal studies for analysis. In total, 21 biomarkers and other multiomic proteomic markers were identified. S100B, inflammatory markers (including tumor necrosis factor-alpha and interleukin 6), and free fatty acids were the most frequently studied biomarkers. The review showed that CSF is an effective medium for biomarker acquisition for AIS. Although CSF is not routinely clinically obtained, a potential benefit of CSF studies is identifying valuable biomarkers from the pathophysiologic microenvironment that ultimately inform optimization of targeted low-abundance assays from peripheral biofluid samples (e.g., plasma). Several important catabolic and anabolic markers can serve as effective measures of diagnosis, etiology identification, prognostication, and severity grading. Trials with large cohorts studying the efficacy of biomarkers in altering clinical management are still needed.

Emerging pathogenic mechanisms in human brain arteriovenous malformations: a contemporary review in the multiomics era.

A variety of pathogenic mechanisms have been described in the formation, maturation, and rupture of brain arteriovenous malformations (bAVMs). While the understanding of bAVMs has largely been formulated based on animal models of rare hereditary diseases in which AVMs form, a new era of "omics" has permitted large-scale examinations of contributory genetic variations in human sporadic bAVMs. New findings regarding the pathogenesis of bAVMs implicate changes to endothelial and mural cells that result in increased angiogenesis, proinflammatory recruitment, and breakdown of vascular barrier properties that may result in hemorrhage; a greater diversity of cell populations that compose the bAVM microenvironment may also be implicated and complicate traditional models. Genomic sequencing of human bAVMs has uncovered inherited, de novo, and somatic activating mutations, such as KRAS, which contribute to the pathogenesis of bAVMs. New droplet-based, single-cell sequencing technologies have generated atlases of cell-specific molecular derangements. Herein, the authors review emerging genomic and transcriptomic findings underlying pathologic cell transformations in bAVMs derived from human tissues. The application of multiple sequencing modalities to bAVM tissues is a natural next step for researchers, although the potential therapeutic benefits or clinical applications remain unknown.

Electroencephalography for detection of vasospasm and delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage: a retrospective analysis and systematic review.

OBJECTIVE: Good functional outcomes after aneurysmal subarachnoid hemorrhage (aSAH) are often dependent on early detection and treatment of cerebral vasospasm (CVS) and delayed cerebral ischemia (DCI). There is growing evidence that continuous monitoring with cranial electroencephalography (cEEG) can predict CVS and DCI. Therefore, the authors sought to assess the value of continuous cEEG monitoring for the detection of CVS and DCI in aSAH. METHODS: The cerebrovascular database of a quaternary center was reviewed for patients with aSAH and cEEG monitoring between January 1, 2017, and July 31, 2019. Demographic data, cardiovascular risk factors, Glasgow Coma Scale score at admission, aneurysm characteristics, and outcomes were abstracted from the medical record. Patient data were retrospectively analyzed for DCI and angiographically assessed CVS. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and odds ratio for cEEG, transcranial Doppler ultrasonography (TCDS), CTA, and DSA in detecting DCI and angiographic CVS were calculated. A systematic literature review was conducted in accordance with PRISMA guidelines querying the PubMed, Cochrane Controlled Trials Register, Web of Science, and Embase databases. RESULTS: A total of 77 patients (mean age 60 years [SD 15 years]; female sex, n = 54) were included in the study. Continuous cEEG monitoring detected DCI and angiographically assessed CVS with specificities of 82.9% (95% CI 66.4%-93.4%) and 94.4% (95% CI 72.7%-99.9%), respectively. The sensitivities were 11.1% (95% CI 3.1%-26.1%) for DCI (n = 71) and 18.8% (95% CI 7.2%-36.4%) for angiographically assessed CVS (n = 50). Furthermore, TCDS detected angiographically determined CVS with a sensitivity of 87.5% (95% CI 71.0%-96.5%) and specificity of 25.0% (95% CI 7.3%-52.4%). In patients with DCI, TCDS detected vasospasm with a sensitivity of 85.7% (95% CI 69.7%-95.2%) and a specificity of 18.8% (95% CI 7.2%-36.4%). DSA detected vasospasm with a sensitivity of 73.9% (95% CI 51.6%-89.8%) and a specificity of 47.8% (95% CI 26.8%-69.4%). CONCLUSIONS: The study results suggest that continuous cEEG monitoring is highly specific in detecting DCI as well as angiographically assessed CVS. More prospective studies with predetermined thresholds and endpoints are needed to assess the predictive role of cEEG in aSAH.

Regulation of the Receptor Tyrosine Kinase AXL in Response to Therapy and Its Role in Therapy Resistance in Glioblastoma.

The receptor tyrosine kinase AXL (RTK-AXL) is implicated in therapy resistance and tumor progression in glioblastoma multiforme (GBM). Here, we investigated therapy-induced receptor modifications and how endogenous RTK-AXL expression and RTK-AXL inhibition contribute to therapy resistance in GBM. GBM cell lines U118MG and SF126 were exposed to temozolomide (TMZ) and radiation (RTX). Receptor modifications in response to therapy were investigated on protein and mRNA levels. TMZ-resistant and RTK-AXL overexpressing cell lines were exposed to increasing doses of TMZ and RTX, with and without RTK-AXL tyrosine kinase inhibitor (TKI). Colorimetric microtiter (MTT) assay and colony formation assay (CFA) were used to assess cell viability. Results showed that the RTK-AXL shedding product, C-terminal AXL (CT-AXL), rises in response to repeated TMZ doses and under hypoxia, acts as a surrogate marker for radio-resistance. Endogenous RTX-AXL overexpression leads to therapy resistance, whereas combination therapy of TZM and RTX with TKI R428 significantly increases therapeutic effects. This data proves the role of RTK-AXL in acquired and intrinsic therapy resistance. By demonstrating that therapy resistance may be overcome by combining AXL TKI with standard treatments, we have provided a rationale for future study designs investigating AXL TKIs in GBM.

Advanced Surgical Techniques for Dural Venous Sinus Repair: A Comprehensive Literature Review.

The dural venous sinus (DVS) is a thin-walled blood channel composed of dura mater that is susceptible to injury during common neurosurgical approaches. DVS injuries are highly underreported, which is reflected by a lack of literature on the topic. Neurosurgeons should be familiar with appropriate techniques to successfully repair an injured DVS and prevent associated complications. This study presents a literature review on the surgical techniques for DVS repair after DVS injury during common neurosurgical approaches. The databases PubMed and Scopus were queried using the terms "cranial sinuses," "superior sagittal sinus," "transverse sinuses," "injury," and "surgery." A total of 117 articles underwent full-text review and were analyzed for surgical approach, craniotomy, lesion location, lesion characteristics, and surgical repair techniques. A literature review was performed, and a comprehensive summary is presented. Data from publications describing DVS lacerations related to pathological conditions (eg, meningioma) were excluded. A total of 9 techniques aiding with bleeding control, hemostasis, and sinus repair and reconstruction were identified, including compression, hemostatic agents, bipolar cautery, dural tenting and tack-up suturing, dural flap, direct suturing, autologous patch, venous bypass, and ligation. The advantages and drawbacks of each technique are described. Multiple options to treat DVS injuries are available to the neurosurgeon. Treatment type is based on anatomic location, complexity of the laceration, cardiovascular status, the presence of air embolism, and the dexterity and experience of the surgeon.

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.

Fenestrated Aneurysm Clip Trigeminal Decompression after CyberKnife Treatment Failure.

Objective This article describes a novel technique for trigeminal nerve decompression in the setting of refractory trigeminal neuralgia (TN). Design Technical note with an illustrative case example and operative video. Setting Outpatient, inpatient, and operating room of a quaternary neurosurgical referral center. Participant A woman in her early 70s who had previously undergone linear accelerator-based stereotactic radiotherapy (i.e., CyberKnife) and achieved 2 years of partial pain relief. However, facial pain, numbness, and parasympathetic dysfunction returned and became unbearable. Main Outcome Measure Durable relief of TN. Results Microvascular decompression was recommended for refractory TN. Intraoperatively, the trigeminal nerve was markedly attenuated from previous irradiation, with the superior cerebellar artery (SCA) loop embedded in the nerve at its root entry zone. The arterial loop was mobilized into a new position superior to the nerve, thus liberating it from the impingement. The tentorium was incised, and a fenestrated aneurysm clip was positioned such that the SCA loop was transmitted via the fenestration. The clip was applied across the tentorium, thus suspending the artery in a kink-free orientation that made no contact with the nerve. Conclusion This procedure provided excellent neurovascular decompression without placing mechanical strain on the nerve, relieving the patient's persistent postirradiation TN. The technique could have broader applications for other challenging or atypical microvascular decompression procedures.

Posterior Interhemispheric-Transtentorial Approach for Resection of an Arteriovenous Malformation of the Superior Medullary Velum and Fourth Ventricle: 2-Dimensional Operative Video.

Brain arteriovenous malformations (AVMs) of the fourth ventricle represent a rare subtype associated with an aggressive natural course.1,2 In this case, a woman in her early 50s presented with dizziness. An AVM was diagnosed in the left superior cerebellar peduncle extending into the fourth ventricle. The AVM was supplied by superior cerebellar artery branches and classified as a Spetzler-Martin grade III and a Lawton-Young grade III, with a supplemented grade of 6.3,4 Being a single case report, institutional review board approval was not needed. Patient consent was obtained. The lesion was accessed through a torcular craniotomy and posterior interhemispheric-transtentorial approach, employing gravity to naturally retract the parietooccipital lobe.5-7 Dissection continued into the quadrigeminal and ambient cisterns, where the tentorium was incised parallelling the straight sinus to reach the superior vermis. Partial resection of the lingual and central lobules of the vermis facilitated access to the superior medullary velum. The superior cerebellar artery feeders were divided and followed to the superior cerebellar peduncle and through the superior medullary vellum. A vertical incision in the superior medullary velum facilitated entry into the fourth ventricle, where the AVM nidus was dissected circumferentially and resected en bloc. Intraoperative indocyanine green videoangiography and postoperative digital subtraction angiography confirmed complete obliteration of the AVM. After surgery, the patient experienced mild ataxia, but motor symptoms greatly improved during 3-month follow-up. This video illustrates resection of a complex fourth ventricular AVM through a posterior interhemispheric-transtentorial approach, highlighting pivotal considerations of patient positioning and approach selection to optimize treatment outcome for complex posterior fossa AVM resection.

Dolichoectatic Posterior Inferior Cerebellar Artery Aneurysm Treated With Excision and Posterior Inferior Cerebellar Artery Double Reimplantation Bypass: 2-Dimensional Operative Video.

Posterior inferior cerebellar artery (PICA) aneurysms account for 0.3% of all intracranial aneurysms, and they commonly present with a complex fusiform morphology that necessitates unique bypass strategies.1-5 An adolescent boy with a familial predisposition to aneurysmal subarachnoid hemorrhage was identified as harboring a fusiform aneurysm of the right distal PICA, characterized by 2 outflow branches. Our recommended treatment strategy involved a right far lateral craniotomy, followed by P1 PICA reanastomosis and P2 PICA reimplantation. Informed written consent was obtained. On exposure, the aneurysm was trapped, and the inflow and 2 outflow PICA branches were excised. Revascularization was established through a P1 PICA end-to-end reanastomosis using running continuous suturing techniques, followed by P2 PICA end-to-side reimplantation into a more distal portion of PICA. Subsequent indocyanine green videoangiography confirmed patency of the P2 PICA reimplantation; however, the initial P1 PICA reanastomosis was noted to be thrombosed. After several unsuccessful attempts to dissolve the thrombus, the decision was made to proceed with a P2 PICA side-to-side in situ reimplantation into the V4 segment of the vertebral artery. Indocyanine green videoangiography and postoperative digital subtraction angiography confirmed patency of the PICA double reimplantation bypass. The patient tolerated the procedure well and was discharged home at his neurological baseline. This video showcases the microsurgical treatment of a complex dolichoectatic, distal PICA aneurysm using a double reimplantation technique, in addition to highlighting bypass decision-making processes for managing complex PICA aneurysms.

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.

Magnetic Resonance-Guided Laser Interstitial Thermal Therapy for Recurrent Glioblastoma and Radiation Necrosis: A Single-Surgeon Case Series.

OBJECTIVE: To evaluate long-term clinical outcomes among patients treated with laser interstitial thermal therapy (LITT) for predicted recurrent glioblastoma (rGBM). METHODS: Patients with rGBM treated by LITT by a single surgeon (2013-2020) were evaluated for progression-free survival (PFS), overall survival (OS), and OS after LITT. RESULTS: Forty-nine patients (33 men, 16 women; mean [SD] age at diagnosis, 58.7 [12.5] years) were evaluated. Among patients with genetic data, 6 of 34 (18%) had IDH-1 R132 mutations, and 7 of 21 (33%) had MGMT methylation. Patients underwent LITT at a mean (SD) of 23.8 (23.8) months after original diagnosis. Twenty of 49 (40%) had previously undergone stereotactic radiosurgery, 37 (75%) had undergone intensity-modulated radiation therapy, and 49 (100%) had undergone chemotherapy. Patients had undergone a mean of 1.2 (0.7) previous resections before LITT. Mean preoperative enhancing and T2 FLAIR volumes were 13.1 (12.8) cm3 and 35.0 (32.8) cm3, respectively. Intraoperative biopsies confirmed rGBM in 31 patients (63%) and radiation necrosis in 18 patients (37%). Six perioperative complications occurred: 3 (6%) cases of worsening aphasia, 1 (2%) seizure, 1 (2%) epidural hematoma, and 1 (2%) intraparenchymal hemorrhage. For the rGBM group, median PFS was 2.0 (IQR, 4.0) months, median OS was 20.0 (IQR, 29.5) months, and median OS after LITT was 6.0 (IQR, 10.5) months. For the radiation necrosis group, median PFS was 4.0 (IQR, 4.5) months, median OS was 37.0 (IQR, 58.0) months, and median OS after LITT was 8.0 (IQR, 23.5) months. CONCLUSIONS: In a diverse rGBM cohort, LITT was associated with a short duration of posttreatment PFS.

Eloquent noneloquence: redefinition of cortical eloquence based on outcomes of superficial cerebral cavernous malformation resection.

OBJECTIVE: Cerebral cavernous malformations (CMs) are pathological lesions that cause discrete cortical disruption with hemorrhage, and their transcortical resections can cause additional iatrogenic disruption. The analysis of microsurgically treated CMs might identify areas of "eloquent noneloquence," or cortex that is associated with unexpected deficits when injured or transgressed. METHODS: Patients from a consecutive microsurgical series of superficial cerebral CMs who presented to the authors' center over a 13-year period were retrospectively analyzed. Neurological outcomes were measured using the modified Rankin Scale (mRS), and new, permanent neurological or cognitive symptoms not detected by changes in mRS scores were measured as additional functional decline. Patients with multiple lesions and surgical encounters for different lesions within the study interval were represented within the cohort as multiple patient entries. Virtual object models for CMs and approach trajectories to subcortical lesions were merged into a template brain model for subtyping and Quicktome connectomic analyses. Parcellation outputs from the models were analyzed for regional cerebral clustering. RESULTS: Overall, 362 CMs were resected in 346 patients, and convexity subtypes were the most common (132/362, 36.5%). Relative to the preoperative mRS score, 327 of 362 cases (90.3%) were in patients who improved or remained stable, 35 (9.7%) were in patients whose conditions worsened, and 47 (13.0%) were in patients who had additional functional decline. Machine learning analyses of lesion objects and trajectory cylinder mapping identified 7 hotspots of novel eloquence: supplementary motor area (bilateral), anterior cingulate cortex (bilateral), posterior cingulate cortex (bilateral), anterior insula (left), frontal pole (right), mesial temporal lobe (left), and occipital cortex (right). CONCLUSIONS: Transgyral and transsulcal resections that circumvent areas of traditional eloquence and navigate areas of presumed noneloquence may nonetheless result in unfavorable outcomes, demonstrating that brain long considered by neurosurgeons to be noneloquent may be eloquent. Eloquent hotspots within multiple large-scale networks redefine the neurosurgical concept of eloquence and call for more refined dissection techniques that maximize transsulcal dissection, intracapsular resection, and tissue preservation. Human connectomics, awareness of brain networks, and prioritization of cognitive outcomes require that we update our concept of cortical eloquence and incorporate this information into our surgical strategies.

A taxonomy for superficial cerebral cavernous malformations: subtypes of cortical and subcortical lesions.

OBJECTIVE: A taxonomy for superficial cerebral cavernous malformations (CMs), those based cortically in gyral gray matter or subcortically in underlying white matter, is proposed to build on the comprehensive, systematic characterization of CMs in the entire brain. METHODS: Patients with superficial cerebral CMs were retrospectively analyzed from a consecutive surgical series between November 2008 and June 2021 at the authors' center. Superficial cerebral CMs were categorized into 4 subtypes based on their cortical location or, if subcortical, proximity to the nearest cerebral surface: convexity, medial, basal, and sylvian. Lobar location was also included for subtyping: frontal, temporal, parietal, and occipital. RESULTS: A total of 362 CMs were resected in 346 patients. CM subtypes were as follows: 132 (36.5%) convexity, 78 (21.5%) medial, 72 (19.9%) basal, and 80 (22.1%) sylvian. Frontal CMs were most common (155 [42.8%]), followed by parietal (89 [24.6%]), temporal (87 [24.0%]), and occipital (31 [8.6%]). Of all CMs, 302 (83.4%) were cortical and 60 (16.6%) were subcortical. The mean subcortical depth of deep lesions was 2.97 cm, and the mean lesion volume was 4.68 cm3. Overall, 228 lesions (63.0%) were resected through a transgyral approach, and 134 (37.0%) were resected through a transsulcal approach. Good outcomes (modified Rankin Scale [mRS] score ≤ 2) were observed in 314 patients (86.7%) and poor outcomes (mRS score > 2) in 25 patients (6.9%), and 23 patients (6.4%) were lost to late follow-up (mean follow-up duration 11.5 months). Relative outcomes were good (unchanged or improved mRS score) in 327 patients (90.3%) and poor (worse or died) in 35 patients (9.7%). CONCLUSIONS: Superficial cerebral CMs were resected through a gyrus or sulcus to open the subarachnoid dissection corridors, traversing the full extent of sulci to deepen the approach and minimize tissue transgression. Transgyral dissection avoids associated arteries but is inherently transgressive, whereas transsulcal dissection preserves cortical tissue and may reduce morbidity. Superficial cerebral CMs occupy the largest territory of the 7 types, and the size and surface complexity of the cerebrum make taxonomic subtyping valuable for clear anatomical description.

Anatomic Feasibility of a Superficial Temporal Artery to Distal Anterior Cerebral Artery Bypass With a Parietal Branch Interposition Graft: The Superficial Temporal Artery Telescope Bypass.

BACKGROUND AND OBJECTIVES: Revascularizing the postcommunicating segment of the anterior cerebral artery (ACA) using extracranial donor sites requires long interposition grafts. The superficial temporal artery (STA) is frequently used for extracranial-intracranial ACA revascularization. However, the length of either STA branch is not sufficient to reach the ACA with a proper caliber match, so an interposition graft is required. The aim of this study was to evaluate a bypass that uses the 2 main branches of the STA to reach the A3 (pericallosal) segment of the ACA. METHODS: The frontal and parietal branches of the STA were dissected from 10 cadaveric specimens. The middle internal frontal artery (MIFA) was exposed through an anterior interhemispheric approach. An interposition graft technique was applied using the parietal branch of the STA (pSTA) to connect the frontal branch of the STA (fSTA) with the MIFA. The bypass code is fSTA (E-Ec) pSTA + pSTA (E-Sc) MIFA. Measurements of length and caliber were taken at the anastomotic sites for the distal branches of the STA and the MIFA. RESULTS: The mean (SD) diameter of the MIFA measured 1.4 (0.2) mm, similar to the calibers of the frontal and parietal branches of the STA. The mean (SD) length of the end-to-side STA-MIFA bypass was 145.5 (7.4) mm, and the mean (SD) length of the donor-graft construct measured 204.2 (27.9) mm. This bypass design resulted in a surplus donor graft length of 38%. CONCLUSION: Using the pSTA as an interposition graft proved to be a successful technique for creating an STA-MIFA bypass, yielding excess donor graft length that facilitated an unstrained bypass construct. This approach offers several advantages, including a single skin incision, ample graft length, caliber compatibility, and a straightforward technical execution.

Flow diversion for basilar quadrifurcation aneurysms.

BACKGROUND: Flow-diverting devices (FDDs), such as the Pipeline Embolization Device, have been gaining traction for treating challenging posterior circulation aneurysms. Few previous studies have focused on using FDDs to treat aneurysms of the basilar quadrifurcation. METHODS: We retrospectively reviewed the use of FDDs to treat patients with basilar quadrifurcation aneurysms. Patients were assessed for aneurysm type, previous aneurysm treatment, technical success, periprocedural complications, and long-term aneurysm occlusion. RESULTS: 34 patients were assessed; aneurysms of the basilar apex (n=23) or superior cerebellar artery (SCA) (n=7), or both (n=1), and posterior cerebral artery (PCA) (n=3). The mean (SD) largest aneurysm dimension was 8.7 (6.1) mm (range 1.9-30.8 mm). 14 aneurysms were previously surgically clipped or endovascularly coiled. All aneurysms had a saccular morphology. Complete or near-complete occlusion was achieved in 30 of 34 patients (88%) at final angiographic follow-up, a mean (SD) of 6.6 (5.4) months (range 0-19 months) postoperatively. No patient experienced postoperative symptomatic occlusions of the SCA or PCA; 4 patients developed asymptomatic posterior communicating artery occlusions; 28 patients (82%) experienced no complications; whereas 3 (9%) experienced major complications and 3 (9%) experienced minor complications; and 1 patient died as a result of subarachnoid hemorrhage. CONCLUSION: Flow diversion may be a safe and effective option to treat basilar quadrifurcation aneurysms. Previously treated basilar quadrifurcation aneurysms with recurrence or residual lesion may benefit from additional treatment with an FDD. Further prospective studies should be directed toward validating these findings.

Optimal PHASES Scoring for Risk Stratification of Surgically Treated Unruptured Aneurysms.

OBJECTIVE: The PHASES (Population, Hypertension, Age, Size, Earlier subarachnoid hemorrhage, Site) score was developed to facilitate risk stratification for management of unruptured intracranial aneurysms (UIAs). This study aimed to identify the optimal PHASES score cutoff for predicting neurologic outcomes in patients with surgically treated aneurysms. METHODS: All patients who underwent microneurosurgical treatment for UIA at a large quaternary center from January 1, 2014, to December 31, 2020, were retrospectively reviewed. Inclusion criteria included a modified Rankin Scale (mRS) score of ≤2 at admission. The primary outcome was 1-year mRS score, with a "poor" neurologic outcome defined as an mRS score >2. RESULTS: In total, 375 patients were included in the analysis. The mean (SD) PHASES score for the entire study population was 4.47 (2.67). Of 375 patients, 116 (31%) had a PHASES score ≥6, which was found to maximize prediction of poor neurologic outcome. Patients with PHASES scores ≥6 had significantly higher rates of poor neurologic outcome than patients with PHASES scores <6 at discharge (58 [50%] vs. 90 [35%], P = 0.005) and follow-up (20 [17%] vs. 18 [6.9%], P = 0.002). After adjusting for age, Charlson Comorbidity Index score, nonsaccular aneurysm, and aneurysm size, PHASES score ≥6 remained a significant predictor of poor neurologic outcome at follow-up (odds ratio, 2.75; 95% confidence interval, 1.42-5.36, P = 0.003). CONCLUSIONS: In this retrospective analysis, a PHASES score ≥6 was associated with significantly greater proportions of poor outcome, suggesting that awareness of this threshold in PHASES scoring could be useful in risk stratification and UIA management.

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.