Dual Layer vs Single Layer Woven EndoBridge Device in the Treatment of Intracranial Aneurysms: A Propensity Score-Matched Analysis.

BACKGROUND: The Woven EndoBridge (WEB) devices have been used for treating wide neck bifurcation aneurysms (WNBAs) with several generational enhancements to improve clinical outcomes. The original device dual-layer (WEB DL) was replaced by a single-layer (WEB SL) device in 2013. This study aimed to compare the effectiveness and safety of these devices in managing intracranial aneurysms. METHODS: A multicenter cohort study was conducted, and data from 1,289 patients with intracranial aneurysms treated with either the WEB SL or WEB DL devices were retrospectively analyzed. Propensity score matching was utilized to balance the baseline characteristics between the two groups. Outcomes assessed included immediate occlusion rate, complete occlusion at last follow-up, retreatment rate, device compaction, and aneurysmal rupture. RESULTS: Before propensity score matching, patients treated with the WEB SL had a significantly higher rate of complete occlusion at the last follow-up and a lower rate of retreatment. After matching, there was no significant difference in immediate occlusion rate, retreatment rate, or device compaction between the WEB SL and DL groups. However, the SL group maintained a higher rate of complete occlusion at the final follow-up. Regression analysis showed that SL was associated with higher rates of complete occlusion (OR: 0.19; CI: 0.04 to 0.8, p = 0.029) and lower rates of retreatment (OR: 0.12; CI: 0 to 4.12, p = 0.23). CONCLUSION: The WEB SL and DL devices demonstrated similar performances in immediate occlusion rates and retreatment requirements for intracranial aneurysms. The SL device showed a higher rate of complete occlusion at the final follow-up.

Evaluating the diagnostic accuracy of 3D contrast-enhanced magnetic resonance angiography versus digital subtraction angiography in spinal dural arteriovenous fistulas.

OBJECTIVE: Spinal dural arteriovenous fistulas (SDAVFs) often go undiagnosed, leading to irreversible spinal cord dysfunction. Although digital subtraction angiography (DSA) is the gold standard for diagnosing SDAVF, DSA is invasive and operator dependent, with associated risks. MR angiography (MRA) is a promising alternative. This study aimed to evaluate the performance of MRA as an equal alternative to DSA in investigating, diagnosing, and localizing SDAVF. METHODS: Prospectively collected data from a single neurosurgeon at a large tertiary academic center were searched for SDAVFs. Eligibility criteria included any patient with a surgically proven SDAVF in whom preoperative DSA, MRA, or both had been obtained. The eligible patients formed a consecutive series, in which they were divided into DSA and MRA groups. DSA and MRA were the index tests that were compared to the surgical SDAVF outcome, which was the reference standard. Accurate diagnosis was considered to have occurred when the imaging report matched the operative diagnosis to the correct spinal level. Comparisons used a two-sample t-test for continuous variables and Fisher-Freeman-Halton's exact test for categorical variables, with p < 0.05 specifying significance. Univariate, bivariate, and multivariate analyses were conducted to investigate group associations with DSA and MRA accuracy. Positive predictive value, sensitivity, and accuracy were calculated. RESULTS: A total of 27 patients with a mean age of 63 years underwent surgery for SDAVF. There were 19 male (70.4%) and 8 female (29.6%) patients, and the mean duration of symptoms at the time of surgery was 14 months (range 2-48 months). Seventeen patients (63%) presented with bowel or bladder incontinence. Bivariate analysis of the DSA and MRA groups further revealed no significant relationships between the characteristics and accuracy of SDAVF diagnosis. MRA was found to be more sensitive and accurate (100% and 73.3%) than DSA (85.7% and 69.2%), with a subanalysis of the patients with both preoperative MRA and DSA showing that MRA had a greater positive predictive value (78.6 vs 72.7), sensitivity (100 vs 72.7), and accuracy (78.6 vs 57.1) than DSA. CONCLUSIONS: In surgically proven cases of SDAVFs, the authors determined that MRA was more accurate than DSA for SDAVF diagnosis and localization to the corresponding vertebral level. Incomplete catheterization at each vertebral level may result in the failure of DSA to detect SDAVF.

Dural arteriovenous fistulas are not observed to convert to a higher grade after partial embolization.

OBJECTIVE: Borden-Shucart type I dural arteriovenous fistulas (dAVFs) lack cortical venous drainage and occasionally necessitate intervention depending on patient symptoms. Conversion is the rare transformation of a low-grade dAVF to a higher grade. Factors associated with increased risk of dAVF conversion to a higher grade are poorly understood. The authors hypothesized that partial treatment of type I dAVFs is an independent risk factor for conversion. METHODS: The multicenter Consortium for Dural Arteriovenous Fistula Outcomes Research database was used to perform a retrospective analysis of all patients with type I dAVFs. RESULTS: Three hundred fifty-eight (33.2%) of 1077 patients had type I dAVFs. Of those 358 patients, 206 received endovascular treatment and 131 were not treated. Two (2.2%) of 91 patients receiving partial endovascular treatment for a low-grade dAVF experienced conversion to a higher grade, 2 (1.5%) of 131 who were not treated experienced conversion, and none (0%) of 115 patients who received complete endovascular treatment experienced dAVF conversion. The majority of converted dAVFs localized to the transverse-sigmoid sinus and all received embolization as part of their treatment. CONCLUSIONS: Partial treatment of type I dAVFs does not appear to be significantly associated with conversion to a higher grade.

Comparative Outcomes of Mechanical Thrombectomy in Acute Ischemic Stroke Patients with ASPECTS 2-3 vs. 4-5.

BACKGROUND: The influence of Alberta Stroke Program Early CT Score (ASPECTS) on outcomes following mechanical thrombectomy (MT) for acute ischemic stroke (AIS) patients with low ASPECTS remains unknown. In this study, we compared the outcomes of AIS patients treated with MT for large vessel occlusion (LVO) categorized by ASPECTS value. METHODS: We conducted a retrospective analysis involving 305 patients with AIS caused by LVO, defined as the occlusion of the internal carotid artery and/or the M1 segments of the middle cerebral artery, stratified into two groups: ASPECTS 2-3 and 4-5. The primary outcome was favorable outcome defined as a 90-day modified Rankin Scale (mRS) score of 0-3. Secondary outcomes were 90-day mRS 0-2, 90-day mortality, any intracerebral hemorrhage (ICH), and symptomatic ICH (sICH). We performed multivariable logistic regression analysis to evaluate the impact of ASPECTS 2-3 vs. 4-5 on outcomes. RESULTS: Fifty-nine patients (19.3%) had ASPECTS 2-3 and 246 (80.7%) had ASPECTS 4-5. Favorable outcomes showed no significant difference between the two groups (adjusted odds ratio [aOR]= 1.13, 95% confidence interval [CI]: 0.52-2.41, p=0.80). There were also no significant differences in 90-day mRS 0-2 (aOR= 1.65, 95% CI: 0.66-3.99, p=0.30), 90-day mortality (aOR= 1.14, 95% CI: 0.58-2.20, p=0.70), any ICH (aOR= 0.54, 95% CI: 0.28-1.00, p=0.06), and sICH (aOR= 0.70, 95% CI: 0.27-1.63, p = 0.40) between the groups. CONCLUSIONS: AIS patients with LVO undergoing MT with ASPECTS 2-3 had similar outcomes compared to ASPECTS 4-5.

The composition of landmark vein of Galen malformation research: the emergence of endovascular treatments.

BACKGROUND: Since the advent of endovascular treatment, the long-term prognosis of vein of Galen malformation (VOGM) has markedly improved; however, the nature of research leading to this point is unclear. The objective of this study was to define the composition of VOGM research to date, by means of a bibliometric analysis of the 100 most cited VOGM articles. METHODS: An electronic search of Elsevier's Scopus database was performed to identify the 100 most cited articles on VOGM screened against predetermined criteria. Data were then compared. RESULTS: The 100 most cited VOGM articles were published between 1974 and 2017 in 38 unique journals and originated from 16 unique countries. Mean citation count and rate were 59.4 citations and 2.9 citations/year, respectively. The USA (n = 42); Hôpital de Bicêtre, France (n = 15); and Dr. Pierre Lasjaunias (n = 16) were the largest individual country, institutional, and author contributors. Compared to the older articles (published < 2000), key differences for newer articles were statistically higher citation rates (P < 0.01), more authors (P < 0.01), higher proportion of endovascular treatment descriptions (P = 0.01), and more originating from Asia Pacific (P < 0.01). CONCLUSIONS: From the 100 most cited VOGM articles to date, there has been a noticeable shift from diagnosing VOGM based on the foundational work by Dr. Lasjaunias to understanding how we can model clinical outcomes now that endovascular treatment has become the standard of care. Significant shifts in prognosis are pending, and the current bibliometric data implicate we are on the precipice of more recent works making an impact in the near future.

A case of primary central nervous system lymphoma presenting as a shunt complication.

The authors describe an 82-year-old female with a right frontal ventriculoperitoneal (VP) shunt for long-standing normal pressure hydrocephalus (NPH) who presented with worsening incontinence and gait instability. She was found to have right lateral ventricle collapse around the shunt catheter and subsequently underwent shunt revision, which failed to improve her symptoms. Magnetic resonance imaging (MRI) was obtained on postoperative day two, which demonstrated a ventricular lesion. Endoscopic brain biopsy was performed and a diagnosis of primary central nervous system lymphoma (PCNSL) was made. The authors believe this is the first published case of PCNSL presenting as a VP shunt complication in a patient with NPH.

Risk of Early Versus Later Rebleeding From Dural Arteriovenous Fistulas With Cortical Venous Drainage.

BACKGROUND: Cranial dural arteriovenous fistulas with cortical venous drainage are rare lesions that can present with hemorrhage. A high rate of rebleeding in the early period following hemorrhage has been reported, but published long-term rates are much lower. No study has examined how risk of rebleeding changes over time. Our objective was to quantify the relative incidence of rebleeding in the early and later periods following hemorrhage. METHODS: Patients with dural arteriovenous fistula and cortical venous drainage presenting with hemorrhage were identified from the multinational CONDOR (Consortium for Dural Fistula Outcomes Research) database. Natural history follow-up was defined as time from hemorrhage to first treatment, rebleed, or last follow-up. Rebleeding in the first 2 weeks and first year were compared using incidence rate ratio and difference. RESULTS: Of 1077 patients, 250 met the inclusion criteria and had 95 cumulative person-years natural history follow-up. The overall annualized rebleed rate was 7.3% (95% CI, 3.2-14.5). The incidence rate of rebleeding in the first 2 weeks was 0.0011 per person-day; an early rebleed risk of 1.6% in the first 14 days (95% CI, 0.3-5.1). For the remainder of the first year, the incidence rate was 0.00015 per person-day; a rebleed rate of 5.3% (CI, 1.7-12.4) over 1 year. The incidence rate ratio was 7.3 (95% CI, 1.4-37.7; P, 0.026). CONCLUSIONS: The risk of rebleeding of a dural arteriovenous fistula with cortical venous drainage presenting with hemorrhage is increased in the first 2 weeks justifying early treatment. However, the magnitude of this increase may be considerably lower than previously thought. Treatment within 5 days was associated with a low rate of rebleeding and appears an appropriate timeframe.

Multicenter Study for the Treatment of Sidewall versus Bifurcation Intracranial Aneurysms with Use of Woven EndoBridge (WEB).

Background The Woven EndoBridge (WEB) device was explicitly designed for wide-neck intracranial bifurcation aneurysms. Small-scale reports have evaluated the off-label use of WEB devices for the treatment of sidewall aneurysms, with promising outcomes. Purpose To compare the angiographic and clinical outcomes of the WEB device for the treatment of sidewall aneurysms compared with the treatment of bifurcation aneurysms. Materials and Methods A retrospective review of the WorldWideWEB Consortium, a synthesis of retrospective databases spanning from January 2011 to June 2021 at 22 academic institutions in North America, South America, and Europe, was performed to identify patients with intracranial aneurysms treated with the WEB device. Characteristics and outcomes were compared between bifurcation and sidewall aneurysms. Propensity score matching (PSM) was used to match by age, pretreatment ordinal modified Rankin Scale score, ruptured aneurysms, location of aneurysm, multiple aneurysms, prior treatment, neck, height, dome width, daughter sac, and incorporated branch. Results A total of 683 intracranial aneurysms were treated using the WEB device in 671 patients (median age, 61 years [IQR, 53-68 years]; male-to-female ratio, 1:2.5). Of those, 572 were bifurcation aneurysms and 111 were sidewall aneurysms. PSM was performed, resulting in 91 bifurcation and sidewall aneurysms pairs. No significant difference was observed in occlusion status at last follow-up, deployment success, or complication rates between the two groups. Conclusion No significantly different outcomes were observed following the off-label use of the Woven EndoBridge, or WEB, device for treatment of sidewall aneurysms compared with bifurcation aneurysms. The correct characterization of the sidewall aneurysm location, neck angle, and size is crucial for successful treatment and lower retreatment rate. © RSNA, 2022 See also the editorial by Hetts in this issue.

International controlled study of revascularization and outcomes following COVID-positive mechanical thrombectomy.

BACKGROUND AND PURPOSE: Previous studies suggest that mechanisms and outcomes in patients with COVID-19-associated stroke differ from those in patients with non-COVID-19-associated strokes, but there is limited comparative evidence focusing on these populations. The aim of this study, therefore, was to determine if a significant association exists between COVID-19 status with revascularization and functional outcomes following thrombectomy for large vessel occlusion (LVO), after adjustment for potential confounding factors. METHODS: A cross-sectional, international multicenter retrospective study was conducted in consecutively admitted COVID-19 patients with concomitant acute LVO, compared to a control group without COVID-19. Data collected included age, gender, comorbidities, clinical characteristics, details of the involved vessels, procedural technique, and various outcomes. A multivariable-adjusted analysis was conducted. RESULTS: In this cohort of 697 patients with acute LVO, 302 had COVID-19 while 395 patients did not. There was a significant difference (p < 0.001) in the mean age (in years) and gender of patients, with younger patients and more males in the COVID-19 group. In terms of favorable revascularization (modified Thrombolysis in Cerebral Infarction [mTICI] grade 3), COVID-19 was associated with lower odds of complete revascularization (odds ratio 0.33, 95% confidence interval [CI] 0.23-0.48; p < 0.001), which persisted on multivariable modeling with adjustment for other predictors (adjusted odds ratio 0.30, 95% CI 0.12-0.77; p = 0.012). Moreover, endovascular complications, in-hospital mortality, and length of hospital stay were significantly higher among COVID-19 patients (p < 0.001). CONCLUSION: COVID-19 was an independent predictor of incomplete revascularization and poor functional outcome in patients with stroke due to LVO. Furthermore, COVID-19 patients with LVO were more often younger and had higher morbidity/mortality rates.

Hematologic Complications Associated With Intra-arterial Chemotherapy for Retinoblastoma Treatment: A Single Institution Experience.

Retinoblastoma (RB) is the most common intraocular pediatric malignancy. Advancements in intra-arterial chemotherapy (IAC) for treatment of RB have resulted in dramatic improvement in eye salvage rates. Data regarding IAC outcomes and associated hematologic toxicities are limited. The objective of this retrospective study was to analyze baseline characteristics, efficacy, and hematologic complications associated with IAC treatment in children with RB at a single international referral institution. Ninety-five sessions of IAC were performed in 28 patients. Mean age at RB diagnosis was 12.5 months (SD, 9.2 mo). Fourteen patients had bilateral RB. IAC agents included melphalan, carboplatin, and topotecan. The most common regimens were triple-agent IAC and single-agent melphalan (66.3% and 15.8%, respectively). Median number of IAC sessions was 3 (mean: 3.39, range: 1 to 9). Eye salvage rate was 83.7% with an overall survival rate of 100% at a median follow-up of 29 months (mean: 29.8 mo, range: 1 to 63 mo). A total of 26 patients (92.9%) experienced at least 1 hematologic toxicity during their treatment course Prevalence of neutropenia, anemia, and thrombocytopenia were 89.3%, 85.7%, and 25%, respectively. While IAC is effective in salvaging most eyes with advanced intraocular RB, over half of patients experienced clinically significant neutropenia and anemia. Clinicians should be vigilant in monitoring patients for IAC-related complications.

The impact of embolization on radiosurgery obliteration rates for brain arteriovenous malformations: a systematic review and meta-analysis.

There exists no consensus in the literature regarding the impact of pre-stereotactic radiosurgery (SRS) embolization on obliteration rates and clinical outcome after radiosurgery treatment of intracranial arteriovenous malformations (AVM). We performed a systematic review of four databases and included studies with at least 10 patients evaluating obliteration rates of intracranial AVMs treated with SRS alone (SRS cohort) and combined pre-SRS embolization followed by SRS (E + SRS cohort). Meta-analytic results were pooled together via random-effects models. A total of 43 studies, with 7103 patients, were included in our analysis. Among our included patients, complete obliteration was achieved in 51.5% (964/1871) of patients in the E + SRS cohort as compared to 61.5% (3217/5231) of patients in the SRS cohort. Meta-analysis of the pooled data revealed that obliteration was significantly lower in the E + SRS cohort (pooled OR = 0.64, 95% CI = 0.54-0.75, p < 0.0001). The use of pre-SRS embolization was significantly associated with lower AVM obliteration rates when compared to treatment with SRS alone. Our analysis seeks to provide a macroscopic insight into the complex interaction between pre-SRS embolization and brain AVM obliteration rates and prognosis. Pre-SRS embolization may still be beneficial in select patients, and further studies are needed to identify patients who benefit from neoadjuvant AVM embolization.

Interplay between vascular hemodynamics and the glymphatic system in the pathogenesis of idiopathic normal pressure hydrocephalus, exploring novel neuroimaging diagnostics.

As the aging population continues to grow, so will the incidence of age-related conditions, including idiopathic normal pressure hydrocephalus (iNPH). The pathogenesis of iNPH remains elusive, and this is due in part to the poor characterization of cerebral spinal fluid (CSF) dynamics within the brain. Advancements in technology and imaging techniques have enabled new breakthroughs in understanding CSF physiology, and therefore iNPH pathogenesis. This includes understanding the hemodynamic and microvascular components involved in CSF influx and flow. Namely, the glymphatic system appears to be the great mediator, facilitating perivascular CSF flow via astrocytic aquaporin channels located along the endothelium of the pial vasculature. The interplay between glymphatics and both arterial pulsatilty and venous compliance has also been recently demonstrated. It appears then that CSF flow, and therefore glymphatic function, are highly dependent on cardiocirculatory and vascular factors. Impairment in any one component, whether it be related to arterial pulsatility, microvascular changes, reduced venous drainage, or astrogliosis, contributes greatly to iNPH, although it is likely a combination thereof. The strong interplay between vascular hemodynamics and CSF flow suggests perfusion imaging and cerebral blood flow quantification may be a useful diagnostic tool in characterizing iNPH. In addition, studies detecting glymphatic flow with magnetic resonance imaging have also emerged. These imaging tools may serve to both diagnose iNPH and help delineate it from other similarly presenting disease processes. With a better understanding of the vascular and glymphatic factors related to iNPH pathogenesis, physicians are better able to select the best candidates for treatment.

Treatment-Associated Stroke in Patients Undergoing Endovascular Therapy in the ARUBA Trial.

Background and Purpose: Since the publication of ARUBA trial (A Randomized Trial of Unruptured Brain Arteriovenous Malformations), outcomes in treated and untreated patients with unruptured arteriovenous malformation have been thoroughly compared. However, no prior analysis of ARUBA patients has sought to identify risk factors for perioperative stroke. Improved understanding of risks within the ARUBA cohort will help clinicians apply the study's findings in a broader context. Methods: The National Institute of Neurological Disorders and Stroke database was queried for all data relating to ARUBA patients, including demographics, interventions undertaken, and timing of stroke. Retrospective cohort analysis was performed with the primary outcome of perioperative stroke in patients who underwent endovascular intervention, and stroke risk was modeled with multivariate analysis. Results: A total of 64 ARUBA patients were included in the analysis. One hundred and fifty-ninth interventions were performed, and 26 (16%) procedures resulted in stroke within 48 hours of treatment. Posterior cerebral artery supply (adjusted odds ratio, 4.42 [95% CI, 1.23­15.9], P=0.02) and Spetzler-Martin grades 2 and 3 arteriovenous malformation (adjusted odds ratio, 7.76 [95% CI, 1.20­50.3], P=0.03; 9.64 [95% CI, 1.36­68.4], P=0.04, respectively) were associated with increased perioperative stroke risk in patients who underwent endovascular intervention. Patients treated in the United States or Germany had a significantly lower stroke risk than patients treated in other countries (adjusted odds ratio, 0.18 [95% CI, 0.04­0.82], P=0.02). Conclusions: Knowing patient and lesion characteristics that increase risk during endovascular treatment can better guide clinicians managing unruptured brain arteriovenous malformation. Our analysis suggests risk of perioperative stroke is dependent on Spetzler-Martin grade and posterior-circulation arterial supply. Differences in regional treatment paradigms may also affect stroke risk.

Outcome Following Hemorrhage From Cranial Dural Arteriovenous Fistulae: Analysis of the Multicenter International CONDOR Registry.

Background and Purpose: Dural arteriovenous fistulae can present with hemorrhage, but there remains a paucity of data regarding subsequent outcomes. We sought to use the CONDOR (Consortium for Dural Arteriovenous Fistula Outcomes Research), a multi-institutional registry, to characterize the morbidity and mortality of dural arteriovenous fistula­related hemorrhage. Methods: A retrospective review of patients in CONDOR who presented with dural arteriovenous fistula­related hemorrhage was performed. Patient characteristics, clinical follow-up, and radiographic details were analyzed for associations with poor outcome (defined as modified Rankin Scale score ≥3). Results: The CONDOR dataset yielded 262 patients with incident hemorrhage, with median follow-up of 1.4 years. Poor outcome was observed in 17.0% (95% CI, 12.3%­21.7%) at follow-up, including a 3.6% (95% CI, 1.3%­6.0%) mortality. Age and anticoagulant use were associated with poor outcome on multivariable analysis (odds ratio, 1.04, odds ratio, 5.1 respectively). Subtype of hemorrhage and venous shunting pattern of the lesion did not affect outcome significantly. Conclusions: Within the CONDOR registry, dural arteriovenous fistula­related hemorrhage was associated with a relatively lower morbidity and mortality than published outcomes from other arterialized cerebrovascular lesions but still at clinically consequential rates.

Effect of Hispanic Status in Mechanical Thrombectomy Outcomes After Ischemic Stroke: Insights From STAR.

Background and Purpose: Epidemiological studies have shown racial and ethnic minorities to have higher stroke risk and worse outcomes than non-Hispanic Whites. In this cohort study, we analyzed the STAR (Stroke Thrombectomy and Aneurysm Registry) database, a multi-institutional database of patients who underwent mechanical thrombectomy for acute large vessel occlusion stroke to determine the relationship between mechanical thrombectomy outcomes and race. Methods: Patients who underwent mechanical thrombectomy between January 2017 and May 2020 were analyzed. Data included baseline characteristics, vascular risk factors, complications, and long-term outcomes. Functional outcomes were assessed with respect to Hispanic status delineated as non-Hispanic White (NHW), non-Hispanic Black (NHB), or Hispanic patients. Multivariate analysis was performed to identify variables associated with unfavorable outcome or modified Rankin Scale ≥3 at 90 days. Results: Records of 2115 patients from the registry were analyzed. Median age of Hispanic patients undergoing mechanical thrombectomy was 60 years (72­84), compared with 63 years (54­74) for NHB, and 71 years (60­80) for NHW patients (P<0.001). Hispanic patients had a higher incidence of diabetes (41%; P<0.001) and hypertension (82%; P<0.001) compared with NHW and NHB patients. Median procedure time was shorter in Hispanics (36 minutes) compared to NHB (39 minutes) and NHW (44 minutes) patients (P<0.001). In multivariate analysis, Hispanic patients were less likely to have favorable outcome (odds ratio, 0.502 [95% CI, 0.263­0.959]), controlling for other significant predictors (age, admission National Institutes Health Stroke Scale, onset to groin time, number of attempts, procedure time). Conclusions: Hispanic patients are less likely to have favorable outcome at 90 days following mechanical thrombectomy compared to NHW or NHB patients. Further prospective studies are required to validate our findings.

Medical Adjuvants in the Treatment of Surgically Refractory Arteriovenous Malformations of the Head and Face: Case Report and Review of Literature.

BACKGROUND: Arteriovenous malformations (AVMs) of the brain and face present unique challenges for clinicians. Cerebral AVMs may induce hemorrhage or form aneurysms, while facial AVMs can cause significant disfigurement and pain. Moreover, facial AVMs often draw blood supply from arteries providing critical blood flow to other important structures of the head which may make them impossible to treat curatively. Medical adjuvants may be an important consideration in the management of these patients. SUMMARY: We conducted a systematic review of the literature to identify other instances of molecular target of rapamycin (mTOR) inhibitors used as medical adjuvants for the treatment of cranial and facial AVMs. We also present 2 cases from our own institution where patients were treated with partial embolization, followed by adjuvant therapy with rapamycin. After screening a total of 75 articles, 7 were identified which described use of rapamycin in the treatment of inoperable cranial or facial AVM. In total, 21 cases were reviewed. The median treatment duration was 12 months (3-24.5 months), and the highest recorded dose was 3.5 mg/m2. 76.2% of patients demonstrated at least a partial response to rapamycin therapy. In 2 patients treated at our institution, symptomatic and radiographic improvement were noted 6 months after initiation of therapy. Key Messages: Early results have been encouraging in a small number of patients with inoperable AVM of the head and face treated with mTOR inhibitors. Further study of medical adjuvants such as rapamycin may be worthwhile.

Minimally invasive resection of intracranial lesions using tubular retractors: a large, multi-surgeon, multi-institutional series.

PURPOSE: Lesions located in subcortical areas are difficult to safely access. Tubular retractors have been increasingly used successfully with low complication profile to access lesions by minimizing brain retraction trauma and distributing pressure radially. Both binocular operative microscope and monocular exoscope are utilized for lesion visualization through tubular retractors. We present the largest multi-surgeon, multi-institutional series to determine the efficacy and safety profile of a transcortical-transtubular approach for intracranial lesion resections with both microscopic and exoscopic visualization. METHODS: We reviewed a multi-surgeon, multi-institutional case series including transcortical-transtubular resection of intracranial lesions using either BrainPath (NICO, Indianapolis, Indiana) or ViewSite Brain Access System (VBAS, Vycor Medical, Boca Raton, Florida) tubular retractors (n = 113). RESULTS: One hundred thirteen transtubular resections for intracranial lesions were performed. Patients presented with a diverse number of pathologies including 25 cavernous hemangiomas (21.2%), 15 colloid cysts (13.3%), 26 GBM (23.0%), two meningiomas (1.8%), 27 metastases (23.9%), 9 gliomas (7.9%) and 9 other lesions (7.9%). Mean lesion depth below the cortical surface was 4.4 cm, and mean lesion size was 2.7 cm. A gross total resection was achieved in 81 (71.7%) cases. Permanent complication rate was 4.4%. One patient (0.8%) experienced one early postoperative seizure (< 1 week postop). No patients experienced late seizures (> 1 week follow-up). Mean post-operative hospitalization length was 4.1 days. CONCLUSION: Tubular retractors provide a minimally invasive operative corridor for resection of intracranial lesions. They provide an effective tool in the neurosurgical armamentarium to resect subcortical lesions with a low complication profile.

Prolonged Heightened Blood Pressure Following Mechanical Thrombectomy for Acute Stroke is Associated with Worse Outcomes.

BACKGROUND: Most data evaluating the relationship of post-mechanical thrombectomy (MT) blood pressure (BP) management and outcomes of patients with large vessel occlusion (LVO) focus on early BP control within the first 24 h. We investigated the correlation of daily BP trends up to the third day following MT with patient outcomes. METHODS: We retrospectively reviewed our prospectively maintained database for LVO patients treated with MT from February 2015 to December 2017. Recorded BP values for 72 h post-reperfusion were reviewed. Daily peak systolic and diastolic blood pressures (SBP, DBP) were extracted for each day post-procedure. The association and importance between BP increments of 10 mmHg and mortality, hemorrhage, and functional independence (FI = mRS ≤ 2) was analyzed in a multivariable logistic regression and random forest (RF) analyses modeling. RESULTS: A total of 212 thrombectomies were included. An increase in peak 24-h SBP was independently associated with higher likelihood of symptomatic hemorrhage (OR 1.2, p = 0.048) and decreased functional independence (OR 0.85, p = 0.03). Higher day 2 and day 3 peak SBP was strongly correlated with decreased functional independence and higher mortality. Third day SBP < 140 was independently associated with higher likelihood of functional independence (OR 4.3, p = 0.0004). Post-MT patients with and without functional independence demonstrated a similar relative decrease in peak SBP between the first 2 days following thrombectomy (p = 0.26); however, those without functional independence experienced a significant rebound increase in peak SBP on the third day following MT (mean change from day 2 to 3: FI - 3.5 mmHg, non-FI + 3.9 mmHg; p = 0.005). CONCLUSION: High daily maximum SBP and a rebound SBP on the third day following MT is independently associated with increased likelihood of functional dependence.

Mechanical Thrombectomy for Large Vessel Occlusions in Cocaine Associated Acute Ischemic Stroke: Small Case Series and Review of the Literature.

INTRODUCTION: Cocaine through multifactorial pathogenetic mechanisms causes small and large vessel occlusions (LVO) leading to acute ischemic stroke. The optimal treatment for cocaine related LVO remains unknown. Mechanical thrombectomy (MT) poses a unique challenge, and successful MT are not widely reported. MATERIAL AND METHODS: We report three patients with no other risk factors and a common history of cocaine metabolites found on presentation drug screen who underwent MT for MCA occlusions with subsequent failed recanalization or vessel re-occlusion due to persistent thrombosis and severe vasospasm.Two patients initially had good revascularization but then developed severe vasospasm and reoccluded, and the remaining patient had persistent severe distal vasospasm. Rescue therapy either with balloon angioplasty with stent placement or intraarterial vasodilator was used in all patients and was ineffective. All patient had large hemispheric strokes and developed malignant cerebral edema requiring hemicraniectomy in two of them. We also did literature review and summarized previously reported cases of cocaine associated vasospasm in MT and other endovascular procedures. CONCLUSION: In this case series, cocaine induced vasospasm contributed to unsuccessful recanalization and reocclusion in patients undergoing MT with poor outcomes. Further studies are needed to ascertain strategies for improved outcomes in patients with LVO related to cocaine use.

Risk of Brain Arteriovenous Malformation Hemorrhage Before and After Stereotactic Radiosurgery.

Background and Purpose- Understanding the hemorrhage risks associated with brain arteriovenous malformations (AVMs) before and after stereotactic radiosurgery (SRS) is important. The aims of this multicenter, retrospective cohort study are to evaluate and compare the rates of pre- and post-SRS AVM hemorrhage and identify risk factors. Methods- We pooled AVM SRS data from 8 institutions participating in the International Radiosurgery Research Foundation. Predictors of post-SRS hemorrhage were determined using a multivariate logistic regression model. Pre- and post-SRS hemorrhage rates were compared using Fisher exact test. Ruptured and unruptured AVMs were matched in a 1:1 ratio using propensity scores, and their outcomes were compared. Results- The study cohort comprised 2320 AVM patients who underwent SRS. Deep AVM location (odds ratio, 1.86; 95% CI, 1.19-2.92; P=0.007), the presence of an AVM-associated arterial aneurysm (odds ratio, 2.44; 95% CI, 1.63-3.66; P<0.001), and lower SRS margin dose (odds ratio, 0.93; 95% CI, 0.88-0.98; P=0.005) were independent predictors of post-SRS hemorrhage. The post-SRS hemorrhage rate was lower for obliterated versus patent AVMs (6.0 versus 22.3 hemorrhages/1000 person-years; P<0.001). The AVM hemorrhage rate decreased from 15.4 hemorrhages/1000 person-years before SRS to 11.9 after SRS ( P=0.001). The outcomes of the matched ruptured versus unruptured AVM cohorts were similar. Conclusions- SRS appears to reduce the risk of AVM hemorrhage, although this effect is predominantly driven by obliteration. Deep-seated AVMs are more likely to rupture during the latency period after SRS. AVM-associated aneurysms should be considered for selective occlusion before SRS of the nidus to ameliorate the post-SRS hemorrhage rate of these lesions.