Transorbital Microsurgery: An Anatomical Description of a Minimally Invasive Corridor to the Anterior Cranial Fossa and Paramedian Structures.

Objectives Transorbital neuroendoscopic surgery (TONES) has ignited interest in the transorbital access corridor, increasing its use for single and multi-portal skull base interventions. However, the crowding of a small corridor and two-dimensional viewing restrict this access portal. Design Cadaveric qualitative study to assess the feasibility of transorbital microsurgery (TMS). Setting Anatomical dissection steps and instrumentation were recorded for homogeneous methodology. Participants Six cadaveric specimens were systematically dissected using TMS to the anterior cranial fossa and paramedian structures. Main Outcome Measures Anatomical parameters of the TMS craniectomy were established, and the visible and accessible neuroanatomy was highlighted. Results A superior lid crease incision achieved essential orbital rim exposure and preseptal dissection. The orbital roof craniectomy is defined by three boundaries: (1) frontozygomatic suture to the frontosphenoid suture, (2) frontal sinus and cribriform plate, and (3) frontal sinus and orbital rim. The mean (standard deviation) craniectomy was 440 mm 2 (78 mm 2 ). Exposing the ipsilateral optic nerve and internal carotid artery obviated the need for frontal lobe retraction to identify the A1-M1 bifurcation as well as near-complete visualization of the M1 artery. Conclusion TMS is a feasible corridor for intracranial access. Mobilization of orbital contents is imperative for maximal intracranial access and protection of the globe. TMS enables access to the frontal lobe base, ipsilateral optic nerve, and most of the ipsilateral anterior circulation. This cosmetically satisfactory approach causes minimal destruction of the anterior skull base with satisfactory exposure of the anterior cranial fossa floor without sinus invasion.

A taxonomy for cerebellar cavernous malformations: subtypes of cerebellar lesions.

OBJECTIVE: An anatomical taxonomy has been established to guide surgical approach selection for resecting brainstem and deep and superficial cerebral cavernous malformations (CMs). The authors propose a novel taxonomy for cerebellar CMs, introduce 6 distinct neuroanatomical subtypes, and assess their clinical outcomes. METHODS: This bi-institutional, 2-surgeon cohort study included 143 cerebellar CMs that were microsurgically treated over a 25-year period. The proposed taxonomy classifies cerebellar CMs into 6 subtypes on the basis of anatomical location as identified on preoperative MR imaging. Neurological outcomes were assessed using the modified Rankin Scale (mRS), and outcomes were compared among the subtypes, with favorable outcomes defined as mRS scores ≤ 2. RESULTS: A total of 143 cerebellar CMs were resected in 140 patients. The mean (SD) age was 42.3 (15.2) years; 86 (60%) of the cerebellar CMs were in women, and 57 (40%) were in men. Cerebellar subtypes were suboccipital (17%, 25/143); tentorial (9%, 13/143); petrosal (43%, 62/143); vermian (13%, 18/143); tonsillar (2%, 3/143); and deep nuclear (15%, 22/143). Overall, 78 of 143 (55%) cerebellar CMs presenting to a cerebellar surface were resected without tissue transgression, and the remaining CMs (65/143, 45%) required translobular or transsulcal approaches. Complete resection was achieved in 134 of 143 cases (94%). Favorable outcomes were achieved in 91% (129/141) of cases with follow-up at a mean (SD) follow-up duration of 37.4 (53.8) months. Relative outcomes were unchanged or improved relative to the preoperative baseline in 93% (131/141) of cases with follow-up, without differences between subtypes. CONCLUSIONS: Most cerebellar CMs are convexity lesions that do not require deep dissection. However, transsulcal and fissural approaches are used for those beneath the cerebellar surface to minimize tissue transgression and preserve associated function. Complete resection without any new deficit is accomplished in most patients. The proposed taxonomy for cerebellar CMs (suboccipital, tentorial, petrosal, vermian, tonsillar, and deep nuclear) guides the selection of craniotomy and approach to enhance patient safety and optimize neurological outcomes.

Academic productivity and career trajectory of international medical graduates in US neurosurgery residency programs.

OBJECTIVE: The objective of this study was to review and compare the research experiences and career outcomes of international medical graduates (IMGs) with those of US medical graduates (USMGs). METHODS: Neurosurgery graduates from 2018 to 2020 were evaluated on the basis of medical school, degree, residency program, publications before and during residency, postresidency fellowships, and career progression. Publications were further categorized by author order and type (laboratory, comprehensive clinical, or short communication). RESULTS: Of 550 neurosurgery graduates, 39 (7%) were IMGs, with the largest percentages from India (8/39, 21%) and in a residency position in Pennsylvania (5/39, 13%). Prior to residency, IMGs had a higher median number of all publications (4 vs 1, p < 0.001), first-author articles (2 vs 0, p < 0.001), comprehensive clinical articles (1 vs 0, p = 0.002), and short communication articles (1 vs 0, p < 0.001) than USMGs. Similarly, the median number of papers published by IMGs during residency was also higher compared with that of USMGs for all publications (20 vs 9, p = 0.004), laboratory articles (1 vs 0, p < 0.001), and short communication articles (4 vs 3, p = 0.04). The percentage of early academic appointments was higher for IMGs (25/39, 64%) than for USMGs (232/511, 45%) (p = 0.03). No significant difference was observed between the percentages of postresidency clinical fellowships completed by IMGs (28/39, 72%) and USMGs (302/511, 59%) (p = 0.15). No statistical significance was found between the ranking of neurosurgery residency programs attended by IMGs and USMGs (p = 0.65). CONCLUSIONS: The results indicate that IMGs often exhibit higher academic productivity than USMGs. Although there was no discernible difference in residency program rankings or postresidency fellowships completed, early academic appointments were more prevalent among IMGs.

Association between sociodemographic variables and delayed patient presentation among surgical neuro-oncology patients in Mexico City: a single institution experience.

PURPOSE: Mexico has the second highest incidence of central and peripheral nervous system cancer cases in Latin America, but clinical and research resources to improve oncologic care are biased towards high-income countries. We carried out a retrospective study to identify sociodemographic factors associated with more severe clinical presentation among surgical neuro-oncology who underwent surgery at a major public referral hospital in Mexico City. METHODS: The hospital electronic medical record was reviewed to identify all surgical neuro-oncology patients who underwent surgery between January 1 and December 31, 2022. Descriptive statistics were used to characterize the patient population and outcomes; statistical analysis was performed to determine association between sociodemographic variables and advanced clinical presentation. RESULTS: A total of 366 neuro-oncology patients underwent surgery during the study period. The median patient age was 48 (IQR 17-83). The majority of patients were female (60.1, n = 220), single (51.4%, n = 188), and 29.2% (n = 107) endorsed being the primary provider for their family. The median number of dependents per patient was 4 (IQR 2-50), while the median monthly income was 10269 Mexican pesos (MXN) (IQR 2000-13500] and the median travel distance to INNN was 49 km (IQR 22-174). On multivariate analyses, having a higher number of dependents was associated with increased odds of presenting with longer symptom duration (p = 0.01). Divorced/separated status was associated with increased odds of presenting with tumors > 35mL in volume (p = 0.04). Primary provider (p = 0.01) and higher average monthly income (p = 0.03) was associated with decreased odds of presenting with tumors > 35mL. CONCLUSIONS: This is the first study to recognize that certain sociodemographic factors are associated with more severe clinical presentation among surgical neuro-oncology patients. Further studies are needed in order to decern specific causes for delayed presentation in this patient population in order to create targeted interventions and decrease delays in care.

Deep learning detection of hand motion during microvascular anastomosis simulations performed by expert cerebrovascular neurosurgeons.

OBJECTIVE: Deep learning enables precise hand tracking without the need for physical sensors, allowing for unsupervised quantitative evaluation of surgical motion and tasks. We quantitatively assessed the hand motions of experienced cerebrovascular neurosurgeons during simulated microvascular anastomosis using deep learning. We explored the extent to which surgical motion data differed among experts. METHODS: A deep learning detection system tracked 21 landmarks corresponding to digit joints and the wrist on each hand of 5 expert cerebrovascular neurosurgeons. Tracking data for each surgeon was analyzed over long and short time intervals to examine gross movements and micromovements, respectively. Quantitative algorithms assessed the economy and flow of motion by calculating mean movement distances from the baseline median landmark coordinates and median times between sutures, respectively. RESULTS: Tracking data correlated with specific surgical actions observed in microanastomosis video analysis. Economy of motion during suturing was calculated as 19, 26, 29, 27, and 28 pixels for surgeons 1, 2, 3, 4, and 5, respectively. Flow of motion during microanastomosis was 31.96, 29.40, 28.90, 7.37, and 47.21 secs for surgeons 1, 2, 3, 4, and 5, respectively. CONCLUSIONS: Hand tracking data showed similarities among experts, with low movements from baseline, minimal excess motion, and rhythmic suturing patterns. The data revealed unique patterns related to each expert's habits and techniques. The results showed that surgical motion can be correlated with hand motion and assessed using mathematical algorithms. We also demonstrated the feasibility and potential of deep learning-based motion detection to enhance surgical training.

Presentation and management of cerebral proliferative angiopathy: a systematic review and meta-analysis on treatment outcomes.

Cerebral Proliferative Angiopathy (CPA) is a rare brain vascular malformation, similar to Arteriovenous Malformations (AVM) but lacking of early venous drainage. Presentation and treatment outcomes were investigated, examining for morbidity, mortality and complications. A meta-analysis was conducted according to PRISMA guidelines. PubMed, Embase and Web Of Science were searched with keywords such as "cerebral proliferative angiopathy" and "management". We pooled and meta-analyzed outcomes on documented CPA cases. 11,079 studies were pooled as a result of manual citation searching, 50 studies were included, adding up to 115 CPA cases. The majority of patients were females (1.38:1), with a mean age of presentation of 26.9 (19.4) years. Headache (46%) and seizures (34%) were the most common presenting symptoms. 37% of patients presented with focal neurologic deficit. Patients managed conservatively from the surgical standpoint (i.e. nonoperative management) did not undergo homogenous treatment strategies, and major complications were at 47% (95% CI: 17%, 76%), with a 1% mortality (95% CI: 0%, 6%). Surgical and embolization interventions presented the highest proportion of major complications, 66% (95% CI: 33%, 99%) and 73% (95% CI: 42%, 100%), respectively. The embolization subgroup led in mortality, with 3% (95% CI: 0%, 10%). No death was documented in patients undergoing surgery. CPA has a similar presentation to brain arteriovenous malformations, but its treatment outcomes are potentially worse. This difference is not attributable to heterogeneity in assigning patient treatment strategies. This highlights the need for more accurate diagnostic methods.

Exploring arterial anatomy of the internal capsule: an analysis of the deep vascular structures and related white matter pathways.

BACKGROUND AND OBJECTIVES: The internal capsule is supplied by perforators originating from the internal carotid artery, middle cerebral artery, anterior choroidal artery and anterior cerebral artery. The aim of this study is to examine the vascular anatomy of the internal capsule, along with its related white matter anatomy, in order to prevent potential risks and complications during surgical interventions. METHODS: Twenty injected hemispheres prepared according to the Klingler method were dissected. Dissections were photographed at each stage. The findings obtained from the dissections were illustrated to make them more understandable. Additionally, the origins of the arteries involved in the vascularization of the internal capsule, their distances to bifurcations, and variations in supplying territories have been thoroughly examined. RESULTS: The insular cortex and the branches of the middle cerebral artery on the insula and operculum were observed. Following decortication of the insular cortex, the extreme capsule, claustrum, external capsule, putamen and globus pallidus structures were exposed. The internal capsule is shown together with the lenticulostriate arteries running on the anterior, genu and posterior limbs. Perforators supplying the internal capsule originated from the middle cerebral artery, anterior cerebral artery, internal carotid artery and anterior choroidal artery. The internal capsule's vascular supply varied, with the medial lenticulostriate arteries (MLA) and lateral lenticulostriate arteries (LLA) being the primary arteries. The anterior limb was most often supplied by the MLA, while the LLA and anterior choroidal artery dominated the genu and posterior limb. The recurrent artery of Heubner originated mostly from the A2 segment. The distance from the ICA bifurcation to the origin of the first LLA on M1 is 9.55 ± 2.32 mm, and to the first MLA on A1 is 5.35 ± 1.84 mm. MLA branching from A1 and proximal A2 ranged from 5 to 9, while LLA originating from the MCA ranged from 7 to 12. CONCLUSION: This study provides comprehensive understanding of the arterial supply to the internal capsule by combining white matter dissection. The insights gained from this study can help surgeons plan and execute procedures including oncological, psychosurgical, and vascular more accurately and safely. The illustrations derived from the dissections serve as valuable educational material for young neurosurgeons and other medical professionals.

Predictors of neurological outcomes in patients with poor Glasgow Coma Scale scores 1 week after aneurysmal subarachnoid hemorrhage.

BACKGROUND: This study assessed neurological outcomes and variables associated with favorable outcomes in aSAH patients with low functional status (Glasgow Coma Scale [GCS] score ≤8) on postbleed day 7 (PBD7). METHODS: A retrospective analysis was conducted of all patients in the Barrow Ruptured Aneurysm Trial (January 1, 2014-July 31, 2019) treated for a ruptured aneurysm and who had a GCS score ≤8 on PBD7. The primary outcome was a favorable neurological outcome (modified Rankin Scale score ≤2) at last follow-up. RESULTS: Of 312 patients, 63 had low GCS scores at PBD7. These patients had a significantly greater proportion of poor Hunt and Hess scale grades (≥4) (44/63 [70%] vs 49/249 [19.7%], P < 0.001) and poor Fisher grades (grade=4) (58/63 [92%] vs 174/249 [69.9%], P < 0.001) compared to patients who did not have low GCS scores on PBD7, but no differences were found in age, sex, anterior location, aneurysm size, or type of treatment. Of the 63 patients, 7 (11%) experienced a favorable neurological outcome. On univariate analysis, none of the physical examination reflexes predicted a favorable neurological outcome. The middle cerebral artery aneurysm territory was the only significant predictor of a favorable neurological outcome by multivariate analysis (odds ratio, 10.8; 95% confidence interval, 1.16-100], P = 0.04). CONCLUSIONS: This study yielded no significant physical examination findings that predict a favorable outcome in patients with GCS score ≤8 on PBD7. This finding may inform the decision of whether to prolong hospital management or arrange for end-of-life care.

Minimally invasive keyhole craniotomies for microsurgical clipping of cerebral aneurysms: comparative meta-analysis of the mini-pterional and supraorbital keyhole approaches.

OBJECTIVE: Axel Perneczky is responsible for conceptualizing the "keyhole" philosophy as a new paradigm of minimal invasiveness within cranial neurosurgery. Keyhole neurosurgery aims to limit approach-related traumatization and minimize brain retraction while still enabling the neurosurgeon to achieve operative goals. The supraorbital keyhole craniotomy (SOKC) and minipterional (pterional keyhole, PKC) approaches have become mainstays for clipping intracranial aneurysms. While studies have compared these approaches to the traditional pterional craniotomy for clipping cerebral aneurysms, head-to-head comparisons of these workhorse keyhole approaches remain limited. METHODS: The authors queried three databases per PRISMA guidelines to identify all studies comparing the SOKC to the PKC for microsurgical clipping of cerebral aneurysms. Of 148 unique studies returned on initial query, a total of 5 studies published between 2013 and 2019 met inclusion criteria. Where applicable, quantitative meta-analysis was performed via the Mantel-Haenszel method using Review Manager v5.4 (Nordic Cochrane Centre, Cochrane Collaboration, Copenhagen, Denmark). Risk of bias (ROB) was assessed using the Cochrane ROBINS-I tool, and all studies were assigned a Level of Evidence (I-V). RESULTS: Across all five studies, the mean age ranged from 53.0 to 57.5 years old, and the cohort consisted of more females (n = 403, 60.6%) than males. The proportion of patients presenting with ruptured aneurysmal SAH was comparable between the SOKC and PKC cohorts (p = 0.43). Clipping rate [defined as the rate of successful aneurysm clip deployment with successful intraoperative occlusion] (OR 1.52 [0.49, 4.71], I2 = 0%, p = 0.47), final occlusion rates (OR 1.27 [0.37, 4.32], p = 0.70), and operative durations (SMD 0.33 [-0.83. 1.49], I2 = 97%, p = 0.58) were comparable regardless of approach used. Furthermore, rates of intraoperative rupture (OR 1.51 [0.64, 3.55], I2 = 0, p = 0.34), postoperative hemorrhage (OR 1.49 [0.74, 3.01], I2 = 0, p = 0.26), postoperative vasospasm (OR 0.94 [0.49, 1.80], I2 = 63, p = 0.86), and postoperative infection (OR 0.70 [0.16, 2.99], I2 = 0%, p = 0.63) were equivocal across SOKC and PKC cohorts. CONCLUSION: The PKC and SOKC approaches appear to afford comparable outcomes when used for open microsurgical clipping of cerebral aneurysms in select patients with both ruptured and unruptured aneurysms. Both are associated with excellent clipping and occlusion rates, minimal perioperative complication profiles, and favorable postoperative neurologic outcomes. Further investigations are merited so clinicians can further parse out the indications and contraindications for each keyhole approach.

STA-MCA Double-Barrel Bypass: A Systematic Review of Technique and Single-Arm Meta-Analysis of Outcomes.

INTRODUCTION: Conventionally, one branch of the superficial temporal artery (STA) is utilized to revascularize the middle cerebral artery (MCA). However, there is the possibility of utilizing both branches of the STA when performing the bypass, characterizing the double-barrel (DB) STA-MCA bypass. Notably, a lack of studies evaluating this technique led the authors to conduct a systematic review and single-arm meta-analysis. METHODS: PubMed, Embase and Web of Science were searched systematically for publications of DB-STA-MCA bypass on November 1st, 2023. The findings were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Case reports were not included for statistical analysis purposes. RESULTS: The review included 408 patients and 534 bypasses from 34 studies. The main etiology was Moyamoya disease (64.6%), followed by cerebral ischemia (22.2%) and aneurysms (12.5%). The median of the mean follow-ups of each study was 12.8 months (range 1.5-87.9). The postoperative patency was 100%. The follow-up patency was 98% (95% CI: 96%-100%; I2 = 0%). The procedure-related mortality was 0% (95% CI: 0%-1%; I2 = 0%). Aneurysms obtained 87% (95% CI: 72%-100%; I2 = 4%) of good clinical outcomes, while Moyamoya disease yielded a rate of 70% (95% CI: 10%-100%; I2 = 97%). Ischemic complications occurred at a rate of 6% (95% CI: 2%-11%; I2 = 36%), while hemorrhagic occurred at 6% (95% CI: 1%-11%; I2 = 56%). Hyperperfusion syndrome rate was calculated as 18% (7%-30%; I2 = 55%) for Moyamoya disease. CONCLUSIONS: The procedure appears to be safe, with excellent patency rates. The clinical efficacy for ischemic and Moyamoya diseases warrants further standardized robust investigation with a broader number of patients, and aneurysm studies are required to enhance sample sizes. The main complication for the Moyamoya subgroup is hyperperfusion syndrome.

International Hackathon as a Tool to Augment Education, Collaboration, and Innovation in Global Neurosurgery.

BACKGROUND AND OBJECTIVES: Health care providers' exposure to global surgical disparities is limited in current nursing and/or medical school curricula. For instance, global health is often associated with infectious diseases or maternal health without acknowledging the growing need for surgical care in low- and middle-income countries (LMICs). We propose an international virtual hackathon based on neurosurgical patient cases in under-resourced settings as an educational tool to bring awareness to global surgical disparities and develop relationships among trainees in different countries. METHODS: Participants were recruited through email listservs, a social media campaign, and prize offerings. A 3-day virtual hackathon event was administered, which included workshops, mentorship, keynote panels, and pitch presentations to judges. Participants were presented with real patient cases and directed to solve a barrier to their care. Surveys assessed participants' backgrounds and event experience. The hackathon was executed through Zoom at Harvard Innovation Lab in Boston, MA, on March 25 to 27, 2022. Participants included medical students, with additional participants from business, engineering, or current health care workers. RESULTS: Three hundred seven applications were submitted for 100 spots. Participants included medical students, physicians, nurses, engineers, entrepreneurs, and undergraduates representing 25 countries and 82 cities. Fifty-one participants previously met a neurosurgeon, while 39 previously met a global health expert, with no difference between LMIC and high-income countries' respondents. Teams spent an average of 2.75 hours working with mentors, and 88% of postevent respondents said the event was "very" or "extremely conducive" to networking. Projects fell into 4 categories: access, language barriers, education and training, and resources. The winning team, which was interdisciplinary and international, developed an application that analyzes patient anatomy while performing physical therapy to facilitate remote care and clinical decision-making. CONCLUSION: An international virtual hackathon can be an educational tool to increase innovative ideas to address surgical disparities in LMICs and establish early collaborative relationships with medical trainees from different countries.

Surgical clipping and endovascular treatments for small or very small anterior communicating artery aneurysms: A comparative pooled analysis.

INTRODUCTION: Small and very small anterior communicating artery (ACoA) aneurysms pose a complex challenge in neurosurgery and interventional neuroradiology due to their critical location and potential for severe consequences upon rupture. Surgical clipping has been a traditional approach, but it presents challenges requiring precision and expertise. Endovascular treatment has emerged as an alternative, offering minimally invasive techniques with potential advantages. This study aims to comprehensively compare outcomes and efficacy between surgical clipping and endovascular treatment for small or very small ACoA aneurysms. OBJECTIVES: We aimed to perform a meta-analysis of small or very small anterior communicating artery aneurysms comparing surgical clipping and endovascular treatments. METHODS: A systematic review and meta-analysis were conducted, including studies reporting on both treatment modalities. Eligible studies were identified through PubMed, Cochrane Library, and Embase databases. Pooled analyses with 95% confidence intervals were used to compare treatment effects, and statistical analysis followed PRISMA guidelines. RESULTS: Thirteen studies with 637 patients were included. Endovascular treatment, predominantly coiling, was performed in 60.3% of patients, while 39.7% underwent surgical management. Endovascular treatment exhibited an 18% retreatment rate, contrasting with 0% in the surgery group. Mortality rates were 3% and 6% for endovascular and surgical treatments, respectively. Overall complications occurred in 1.8% of patients, with intraoperative rupture and cerebral infarction being the most common. CONCLUSION: In summary, our study indicates a comparable outcome between surgical clipping and endovascular treatment for small ACoA aneurysms, with the former showing a lower retreatment rate. Decision factors include surgeon expertise, healthcare context, and patient age. Further research is needed to refine treatment strategies, considering variations in aneurysm status and evolving techniques.

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.

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.

Assessing the Relationship between Surgical Timing and Postoperative Seizure Outcomes in Cavernoma-Related Epilepsy: A Single-Institution Retrospective Analysis of 63 Patients with a Review of the Literature.

Background: Patients with supratentorial cavernous malformations (SCMs) commonly present with seizures. First-line treatments for cavernoma-related epilepsy (CRE) include conservative management (antiepileptic drugs (AEDs)) and surgery. We compared seizure outcomes of CRE patients after early (≤6 months) vs. delayed (>6 months) surgery. Methods: We compared outcomes of CRE patients with SCMs surgically treated at our large-volume cerebrovascular center (1 January 2010-31 July 2020). Patients with 1 sporadic SCM and ≥1-year follow-up were included. Primary outcomes were International League Against Epilepsy (ILAE) class 1 seizure freedom and AED independence. Results: Of 63 CRE patients (26 women, 37 men; mean ± SD age, 36.1 ± 14.6 years), 48 (76%) vs. 15 (24%) underwent early (mean ± SD, 2.1 ± 1.7 months) vs. delayed (mean ± SD, 6.2 ± 7.1 years) surgery. Most (32 (67%)) with early surgery presented after 1 seizure; all with delayed surgery had ≥2 seizures. Seven (47%) with delayed surgery had drug-resistant epilepsy. At follow-up (mean ± SD, 5.4 ± 3.3 years), CRE patients with early surgery were more likely to have ILAE class 1 seizure freedom and AED independence than those with delayed surgery (92% (44/48) vs. 53% (8/15), p = 0.002; and 65% (31/48) vs. 33% (5/15), p = 0.03, respectively). Conclusions: Early CRE surgery demonstrated better seizure outcomes than delayed surgery. Multicenter prospective studies are needed to validate these findings.

Sex-dependent characteristics and outcomes after clipping of unruptured intracranial aneurysms: a multicenter propensity score-matched study.

OBJECTIVE: Disparities in the epidemiology and growth rates of aneurysms between the sexes are known. However, little is known about sex-dependent outcomes after microsurgical clipping of unruptured intracranial aneurysms (UIAs). The aim of this study was to examine sex differences in characteristics and outcomes after microsurgical clipping of UIAs and to perform a propensity score-matched analysis using an international multicenter cohort. METHODS: This retrospective cohort study involved the participation of 15 centers spanning four continents. It included adult patients who underwent clipping of UIAs between January 2016 and December 2020. Patients were stratified according to their sex and analyzed for differences in morbidities and aneurysm characteristics. Based on this stratification, female patients were matched to male patients in a 1:1 ratio with a caliper width of 0.1 using propensity score matching. Endpoints included postoperative complications, neurological performance, and aneurysm occlusion at discharge and 24 months after clip placement. RESULTS: A total of 2245 patients with a mean age of 57.3 (range 20-87) years were included. Of these patients, 1675 (74.6%) were female. Female patients were significantly older (mean 57.6 vs 56.4 years, p = 0.03) but had fewer comorbidities. Aneurysms of the internal carotid artery (7.1% vs 4.2%), posterior communicating artery (6.9% vs 1.9%), and ophthalmic artery (6.0% vs 2.8%) were more commonly treated surgically in females, while clipping of aneurysms of the anterior communicating artery was more frequent in males (17.0% vs 25.3%; all p < 0.001). After propensity score matching, female patients were found to have had significantly fewer pulmonary complications (1.4% vs 4.2%, p = 0.01). However, general morbidity (24.5% vs 25.2%, p = 0.72) and mortality (0.5% vs 1.1%, p = 0.34), as well as neurological performance (p = 0.58), were comparable at discharge in both sexes. Lastly, rates of aneurysm occlusion at the time of discharge (95.5% vs 94.9%, p = 0.71) and 24 months after surgery (93.8% vs 96.1%, p = 0.22) did not significantly differ between male and female patients. CONCLUSIONS: Despite overall differences between male and female patients in demographics, comorbidities, and treated aneurysm location, sex did not relevantly affect surgical performance or perioperative complication rates.