Aneurysm of the Artery of Wollschlaeger and Wollschlaeger.

The Artery of Wollschlaeger and Wollschlaeger (AWW) is a non-eloquent, tentorial branch of the superior cerebellar artery (SCA). Coursing posteriorly from an intradural origin, the AWW passes through the ambient cistern and supplies the medial tentorium. Due to its small diameter, the AWW is often only identified in the context of secondary dilation from pathologies such as dural arteriovenous fistulas (DAVF). Herein, we report the first case, to our knowledge, of an aneurysm of the AWW associated with a posterior fossa DAVF Swift identification and diagnosis followed by cautious treatment of both the aneurysm and fistula were critical to avert rupture and optimize outcomes, avoiding potential hemorrhagic complications.

Gender parity in neurosurgery residencies: an analysis.

OBJECTIVE: The number of women graduating from United States medical schools has reached parity with that of men. However, persistent inequalities and barriers have slowed the pace toward equity in application and representation in neurosurgery residency despite initiatives to increase female representation. The objective of the present study was to assess the advancement of gender parity within neurosurgery residency programs. Additionally, the study aimed to analyze the pipeline dynamics by investigating the effects of attrition on women in neurosurgery, as well as exploring the patterns of female applications to neurosurgery residency programs versus other surgical specialties. METHODS: Data on the number of active female neurosurgery residents and female applicants to neurosurgery were collected from the Accreditation Council for Graduate Medical Education Data Resource Book from 2007 to 2021 and Electronic Residency Application Service from 2014 to 2022. Linear regression analysis was used to predict the percent of active female residents based on academic year (AY). A Pearson chi-square test was used to determine the odds of a female applying to neurosurgery. RESULTS: The percent of active female residents in neurosurgery increased from 11.0% in 2007 to 21.8% in 2021. Bivariate linear regression analysis using AY as a predictor of the percent of active females showed a statistically significant correlation. On average, the percent of active female residents increased by 0.65% per year. If trends persist, parity for females in neurosurgery will not be reached until 2069. Linear regression analysis of the overall rate of attrition in neurosurgery as a predictor of the percent of active female residents revealed that for every 1% increase in the rate of attrition, the percent of active female residents decreased by 2.91% (p = 0.001). The percent of female applicants to neurosurgery increased from 19.6% in 2014 to 29.8% in 2022 (p = 0.009), yet the odds of a female applying to neurosurgery remain low. CONCLUSIONS: Neurosurgery continues to struggle with the recruitment of female medical students even as parity has been reached for female medical school matriculants. Greater effort is needed to recruit and retain female applicants to neurosurgery, including increased transparency in match and attrition metrics.

Endovascular thrombectomy for posterior cerebral artery strokes in the national inpatient sample (EaT PeCANpIeS) study.

BACKGROUND: Posterior cerebral arteries with acute ischemic strokes (PCA-AISs) comprise around 2% of all acute ischemic strokes and may result in significant long-term deficits. Current guidance regarding endovascular thrombectomy (EVT) for PCA-AIS is insufficient as no published randomized trials exist. METHODS: An analysis of the National Inpatient Sample database compared medical management versus EVT for PCA-AIS. Propensity score matching was applied to adjust for nonrandomization. RESULTS: The study included 19,655 patients. Before matching, the EVT cohort had significantly higher National Institutes of Health Stroke Scale (NIHSS) (10.21 vs. 4.67, p < 0.001), had lower rates of favorable functional outcomes, functional independence, and higher rates of intracranial hemorrhage (ICH) and inpatient mortality. After matching, no differences in functional outcomes were identified, but revealed a higher proportion of ICH in the EVT group (17.45% vs. 8.98%, p < 0.001). However, NIHSS subgroup analysis identified improved functional outcomes associated with the EVT group who presented with an NIHSS between 10 and 19 both in terms of rates of favorable functional outcomes (35.56% vs. 12.09%, p < 0.001) and rates of functional independence (26.67% vs. 9.34%, p < 0.01). On further investigation, the clinical benefit, in the NIHSS 10-19 subgroup, was driven by patients receiving EVT in combination with intravenous thrombolysis (IVT). CONCLUSIONS: This analysis shows that current national practices utilize EVT for more severe PCA strokes. Clinical benefit was only detected in patients with moderate stroke severity (NIHSS 10-19) who were treated with combined EVT and IVT. Further work is needed to investigate the features of PCA-AIS that might benefit from EVT the most.

Curative transvenous embolization for congenital multi-hole pial arteriovenous fistula.

OBJECTIVE: Congenital intracranial pial arteriovenous fistula (PAVF) is a rare cerebral vascular pathology characterized by a direct shunt between one or more pial feeding arteries and a cortical draining vein. Transarterial endovascular embolization (TAE) is widely considered first line therapy. Curative TAE may not be achievable in the multihole variant due to the potential to harbor innumerable small feeding arteries. Transvenous embolization (TVE) may be considered to target the final common outlet of the lesion. Here, we present a series of four patients with complex multi-hole congenital PAVF treated with staged TAE followed by TVE. METHODS: A retrospective review was conducted on patients who underwent treatment for congenital, multi-hole PAVFs treated by a combined TAE/TVE approach at our institution since 2013. RESULTS: We identified four patients with multi-hole PAVF treated by a combined TAE/TVE. Median age was 5.2 (0-14.7) years. Median follow-up of 8 (1-15) months by catheter angiography and 38 (23-53) months by MRI/MRA was obtained. TVE achieved complete occlusion in three patients that proved durable on radiographic follow-up and demonstrated excellent clinical outcomes with a modified Rankin Score (mRS) of 0 or 1. Complete occlusion of the draining vein was not achieved by TVE in one case. This patient is graded as pediatric mRS=5 three years post-procedure. CONCLUSIONS: With thorough technical considerations, our series indicates that TVE of multi-hole PAVF that are refractory to TAE is feasible and effective in arresting the consequences of chronic, high-flow AV shunting produced by this pathology.

Technical advantages of a novel flow diverter in complex flow diversion: patient series.

BACKGROUND: The Surpass Streamline flow diverter (SSFD) possesses 4 attributes that may offer an important advantage in the treatment of complex pathologies: (1) utilization of an over-the-wire (OTW) delivery system, (2) greater device length, (3) larger potential diameter, and (4) propensity to open in tortuosity. OBSERVATIONS: Case 1 leveraged device diameter to embolize a large, recurrent vertebral artery aneurysm. Angiography at 1 year posttreatment showed complete occlusion with a patent SSFD. Case 2 leveraged device length and opening in tortuosity to manage a symptomatic 20-mm cavernous carotid aneurysm. Magnetic resonance imaging at 2 years demonstrated aneurysm thrombosis and patent stents. Case 3 utilized diameter, length, and the OTW delivery system to treat a giant intracranial aneurysm previously treated with surgical ligation and a high-flow bypass procedure. Angiography at 5 months postprocedure demonstrated the return of laminar flow, as the vein graft had healed around the stent construct. Case 4 used diameter, length, and the OTW system to treat a giant, symptomatic, dolichoectatic vertebrobasilar aneurysm. Twelve-month follow-up imaging revealed a patent stent construct with no change to the aneurysm size. LESSONS: Increased awareness of the unique attributes of the SSFD may allow a larger number of cases to be treated with the proven mechanism of flow diversion.

Flow diversion jet: A dangerous mechanism in the flow diversion treatment of giant intracranial aneurysms.

BACKGROUND: Cerebral hyperperfusion syndrome (CHS) occurs after the restoration of blood flow to a previously low-flow, low-pressure region of the cerebral vasculature, which subsequently responds with chronic compensatory vasodilation, leading to a dysregulated state. Sudden restoration of normal blood flow can overwhelm the vasculature leading to intracranial hemorrhage (ICH). Separately, the Windkessel phenomenon describes the capacity for elastic vessels to expand with systolic pressure and decompress with diastole, thereby suppressing distal pulse pressure. We encountered a case involving giant basilar aneurysms in which we believe the Windkessel phenomenon precipitated a catastrophic manifestation of CHS at treatment. OBSERVATION: We present a 60-year-old female found to have marked dolichoectasia of the right cervical internal carotid, vertebral, and basilar arteries concurrent with two large vertebrobasilar dissecting-type fusiform aneurysms. Managed conservatively for ten years before developing gait ataxia, new imaging revealed dramatic interval growth of the larger aneurysm. Flow diversion with partial coiling of the aneurysms was pursued. The patient suffered intra-procedural catastrophic thalamic and midbrain hemorrhage with intraventricular extension. A meticulous review of the case data was undertaken. Our findings suggest that giant aneurysms can act as a Windkessel reservoir, depressing the distal pulse pressure. Flow diversion bypasses the reservoir, increasing the distal pulse pressure beyond the autoregulatory capacity, resulting in ICH analogous to CHS. LESSONS: CHS and Windkessel phenomenon can contribute to catastrophic sequelae in the treatment of giant intracranial aneurysms with flow diversion. Awareness of this mechanism can protect future patients from harm.

A review of the top 100 most influential articles on basilar artery aneurysms.

Basilar artery aneurysms account for approximately 5% of all intracranial aneurysms. This bibliometric analysis summarizes the most-cited articles on basilar artery aneurysms and highlights the contributing articles to today's evidence-based practice. In the execution of this bibliometric-based review article, the Scopus database was used to perform a title-specific, keyword-based search for all publications until August 2022. The keyword "basilar artery aneurysm" or "basilar aneurysm" was used. Our results were arranged in descending order based on the article's citation count. The 100 most cited articles were selected for analysis. Parameters included the following: title, citation count, citations per year, authors, specialty of first author, institution, country of origin, publishing journal, Source Normalized Impact Per Paper (SNIP), and Hirsch index. The keyword-based search showed that 699 articles were published between 1888 and 2022. The top 100 articles were published between 1961 and 2019. The top 100 most cited articles collected a total of 8869 citations with an average of 89 citations per paper. The rate of self-citations accounted for an average of 4.85% of the total number of citations. The bibliometric analysis provides a quantitative overview of how medical topics and interventions are analyzed in academic medicine. In the present study, we evaluated the global trends in basilar artery aneurysms by finding the top 100 most cited papers.

Endovascular Management of Pediatric Traumatic Intracranial Pseudoaneurysms: A Systematic Review and Case Series.

OBJECTIVE: This study aims to systematically review the management and outcomes of pediatric patients who develop intracranial pseudoaneurysm (IPA) following head trauma or iatrogenic injury. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic literature review was performed. Additionally, a retrospective analysis was conducted on pediatric patients who underwent evaluation and endovascular treatment for IPA originating from head trauma or iatrogenic injury at a single institution. RESULTS: Two hundred twenty-one articles in the original literature search. Fifty-one met inclusion criteria resulting in a total of 87 patients with 88 IPAs including our institution. Patients ranged in age from 0.5 months to 18 years. Parent vessel reconstruction was used as first-line treatment in 43 cases, parent vessel occlusion in 26, and direct aneurysm embolization (DAE) in 19. Intraoperative complications were observed in 3.00% of procedures. Complete aneurysm occlusion was achieved in 89.61% of cases. 85.54% of cases resulted in favorable clinical outcomes. The mortality rate after treatment was 3.61%. The DAE group had higher rates of aneurysm recurrence than other treatment strategies (P = 0.009). Patients with SAH had overall worse outcomes compared to patients who did not (P = 0.024). There were no differences in favorable clinical outcomes (P = 0.274) or complete aneurysm occlusion (P = 0.13) between primary treatment strategies. CONCLUSIONS: IPAs were successfully obliterated, and favorable neurological outcomes were achieved at a high rate regardless of primary treatment strategy. DAE had a higher rate of recurrence than the other treatment groups. Each described treatment method in our review is safe and viable for the treatment of IPAs in pediatric patients.

A Bibliometric Analysis of the Top 50 Most Influential Articles on External Ventricular Drains.

OBJECTIVE: External ventricular drains (EVDs) are commonly used to remove cerebrospinal fluid and monitor intracranial pressure in patients with neurological dysfunction. Often the first invasive procedure learned in training, ventricular drain placement is the quintessential neurosurgical procedure. This bibliometric analysis highlights the top contributing EVD articles in current evidence-based practice. METHODS: The Scopus database was used to perform a title-specific, keyword-based search for all publications until September 2022. The keywords "external ventricular drain" or "EVD" or "external ventriculostomy" were used. The 50 most cited articles were selected for analysis. Parameters included the following: title, citation count, citations per year, authors, specialty of first author, institution, country of origin, publishing journal, Source Normalized Impact per Paper, and Hirsch index. RESULTS: The keyword-based search showed that 8464 articles on EVDs were published between 1991 and 2022. The top 50 articles were published between 1999 and 2019. The top 50 articles acquired a total of 3343 citations with an average of 66.86 citations per paper. The rate of self-citations accounted for an average of 5.16% of the total number of citations. A majority of the top 50 articles focused on EVD infection and placement accuracy. The first and second most cited papers were authored by Zabramski et al and Fried et al, respectively. CONCLUSIONS: The bibliometric analysis provides a quantitative overview of how topics and interventions are analyzed in academic medicine. In the present study, we evaluated the global trends in EVDs by analyzing the top 50 most cited papers.

An Analysis of Landmark Articles Regarding Aneurysms of the Middle Cerebral Artery.

OBJECTIVE: Aneurysms located on the middle cerebral artery (MCA) range from 22% to 31.5% in prevalence of all aneurysms in the anterior cerebral circulation. This bibliometric analysis summarizes the most cited articles on MCA aneurysms and highlights the landmark publications that contributed to evidence-based practice. METHODS: In the execution of this bibliometric-based review article, the Scopus database was used to perform a title-specific, keyword-based search for all publications until August 2022. The keyword "(middle cerebral artery OR MCA) AND aneurysm" was used. Our results were arranged in descending order based on the citation count of the article. The 100 most cited articles were selected for analysis. Parameters included the following: title, citation count, citations per year, authors, specialty of first author, institution, country of origin, publishing journal, Source Normalized Impact per Paper, and Hirsch index. RESULTS: The keyword-based search showed that 1206 articles on MCA aneurysms were published up to August 2022. The top 100 articles were published between 1940 and 2019. The top 100 most cited articles collected a total of 6232 citations with an average of 62.3 citations per article. The rate of self-citations accounted for an average of 5.75% of the total number of citations. CONCLUSIONS: The bibliometric analysis provides a quantitative overview of how medical literature and interventions are analyzed in academic medicine. In the present study, we evaluated the global trends in research regarding MCA aneurysms by finding the top 100 most cited articles.

A Bibliometric Analysis of the Top 100 Most Influential Articles on Cerebral Cavernous Malformations.

OBJECTIVE: Cerebral cavernous malformations (CCMs) or cavernomas, are low-flow sinusoidal vascular anomalies of the central nervous system comprised of capillary networks filled with blood in various stages of thrombosis. This bibliometric analysis summarizes the most-cited articles on CCM and highlights the contributing articles to today's evidence-based practice. METHODS: In the execution of this bibliometric-based review article, the Scopus database was used to perform a title-specific, keyword-based search for all publications until June 2022. The keyword "cerebral cavernous malformations" OR "cerebral cavernous hemangioma" OR "cerebral cavernous angioma" OR "cerebral cavernoma." was used. Our results were arranged in descending order based on the article's citation count. The 100 most-cited articles were selected for analysis. Parameters included the following: title, citation count, citations per year, authors, specialty of first author, institution, country of origin, publishing journal, Source Normalized Impact per Paper, and Hirsch index were collected. RESULTS: The keyword-based search showed that 806 articles were published between 1974 and 2022 on CCMs. The top 100 articles were published between 1980 and 2018. The top 100 most cited articles collected a total of 12,928 citations with an average of 129.3 citations per paper. The rate of self-citations accounted for an average of 2.79% of the total number of citations. CONCLUSIONS: The bibliometric analysis provides a quantitative overview of how medical topics and interventions are analyzed in academic medicine. In the present study, we evaluated the global trends in CCMs by analyzing the top 100 most cited papers.

Ruptured aneurysm of the artery of Davidoff and Schechter: illustrative case.

BACKGROUND: The artery of Davidoff and Schechter (ADS) is an uncommonly encountered meningeal branch originating from the posterior cerebral artery typically identified in the setting of pathology, often dural arteriovenous fistulas (DAVFs). Here, the authors describe the first reported case of an ADS aneurysm, discovered in the setting of subarachnoid hemorrhage (SAH) and complicating a high-grade DAVF. OBSERVATIONS: A 57-year-old female presented after experiencing the worst headache of her life. Noncontrast computed tomography scanning of the head demonstrated SAH. Angiography revealed a high-grade DAVF centered around the anterior straight sinus, consistent with the Galenic subtype of tentorial DAVF. Predominant arterial supply was from the bilateral middle meningeal and occipital arteries. Vertebral artery imaging revealed a 12-mm irregular aneurysm. The prospect that the target artery represented the noneloquent ADS was confirmed by Wada testing. Given the fusiform nature of the aneurysm, treatment required concomitant coil embolization of the aneurysm and parent artery sacrifice. A week later, the DAVF was treated with liquid embolic. The patient tolerated treatment without neurological compromise. LESSONS: The authors describe the first reported case of an ADS aneurysm discovered in the setting of SAH complicating a high-grade DAVF and the lessons learned during our experience managing this unique pathology.

Treatment Options for Pseudoaneurysm After Carotid Endarterectomy: A Systematic Review and Illustrative Case.

BACKGROUND: The goal of this study was to systematically review the management and outcomes of patients who developed pseudoaneurysm (PA) after carotid endarterectomy (postendarterectomy PA [PEPA]). METHODS: Following the PRISMA guidelines, a systematic literature review was performed using PubMed, Scopus, and Web of Science databases from date of inception to June 2022. Studies were selected based on predetermined inclusion and exclusion criteria. Simultaneously, a retrospective review was conducted of patients who underwent neurosurgical evaluation of suspected PEPA at our institution. RESULTS: Of the 321 articles in the original literature search, 62 were selected. A total of 143 patients (93 men, 27 women; mean age, 70.7 years) diagnosed with PEPA were included. Mean time from carotid endarterectomy to PA diagnosis was 41.8 months. Primary repair data were available for 135 patients, including 19 with primary closures, 112 with patch or graft repairs, and 4 with eversion procedures. Fifty-five patients with PA (39%) presented with infection. Staphylococcal species were the most common causative organism. Of infected PAs, 89.1% were treated with open procedures. Overall complication rates of PAs treated via open, endovascular, and hybrid methods were 31%, 15.4%, and 0%, respectively. Open ligation (42.9%) and aneurysmectomy with grafting (36.4%) resulted in the highest rates of complications. CONCLUSIONS: Despite higher complication rates after open repair strategies, use of these techniques remains a viable option in situations requiring removal of infected patches or evacuation of large extravascular collections. Endovascular treatment options are associated with low numbers of complications and can be considered for primary PEPA treatment when infection is not present.