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Gain of function PIK3CA pathogenic variants have been identified in overgrowth syndromes collectively termed "PIK3CA-related overgrowth spectrum" (PROS). There are no previously reported cases of cerebrovascular venous malformations in PROS syndromes, though somatic activating PIK3CA variants have been identified in extracranial venous malformation. This study was approved by the Institutional Review Boar at Boston Children's Hospital. A 14-year-old female mosaic for the de novo p.R108H pathogenic variant in the PIK3CA gene was found to have a large tumor involving the superior sagittal sinus with mass effect on the motor cortex most consistent with a parafalcine meningioma. She underwent surgical resection with pathology demonstrating a venous malformation. PIK3CA pathogenic variants have been identified in nonsyndromic extracranial venous and lymphatic malformations as well in brain tumors, including glioma and meningioma. However, PIK3CA variants have not previously been identified in purely intracranial venous malformations. This distinction is relevant to treatment decisions, given that mTOR inhibitors may provide an alternative option for noninvasive therapy in cases of suspected venous malformation.

Donor vessel quality can impact the outcome of extracranial-intracranial (EC-IC) bypass. External carotid artery (ECA) disease may produce embolism into the anastomosis and cerebral territory and possibly reduce flow in the superficial temporal artery (STA). Previously reported remedies to ECA stenosis include ECA endarterectomy, stenting, and angioplasty. Clinical presentation A middle-aged patient with chronic left MCA occlusion, progressive ischemic symptoms on maximal medical therapy, and imaging confirmation of compromised hemodynamic reserve was evaluated for EC-IC bypass. Angiography demonstrated severe ECA origin stenosis. An ECA-ICA transposition was performed, primarily to eliminate the risk of emboli and secondarily to possibly improve the STA flow. The patient sustained an excellent radiological and clinical outcome, and the STA donor cut-flow was increased modestly by 22% (45 to 55 mL/min). This case is the first report of an ECA to internal carotid artery transposition as an option in the management of ECA stenosis in preparation for an STA-MCA bypass for the purpose of flow augmentation.

BACKGROUND AND PURPOSE Dynamic susceptibility perfusion MR imaging (DSC MRP) has been used to assess changes in cerebral perfusion attributable to vascular stenosis or occlusion that may predict stroke risk. However, DSC MRP is not validated for identifying hemodynamic compromise in the posterior circulation. We investigated the clinical utility of DSC MRP in vertebrobasilar (VB) atherosclerotic disease in the observational VERiTAS study. METHODS VERiTAS enrolled patients with symptomatic ≥50% VB stenosis/occlusion. Posterior circulation hemodynamic status was designated as low or normal based on large vessel flow measured using quantitative magnetic resonance angiography (QMRA) and was predictive of future stroke risk. In this study, DSC MRP conducted concurrently with QMRA was used to evaluate posterior circulation perfusion. The primary outcome was the mean transit time (MTT) and relative cerebral blood volume (rCBV) in the posterior circulation normalized to the anterior circulation, compared between patients with low and normal blood flow as determined on QMRA. RESULTS Twenty-six subjects had 47 DSC MRP studies for review. There was no statistically or clinically significant difference in the rCBV ratio (1.02 vs. .96 P = .89), or MTT ratio (1.04 vs. 1.04 P = .96) relative to normal or low VB territory flow. CONCLUSIONS In this study, we did not find that DSC MRP adequately distinguished between patients with low or normal flow status based on large-vessel flow measurements.

BackgroundEndovascular embolization of cerebral arteriovenous malformations (AVM) with liquid n-butyl cyanoacrylate (n-BCA) serves multiple purposes including AVM occlusion and flow reduction in preparation for other treatment modalities. The objective was to study the clinical, structural, and angiographic factors affecting complications associated with AVM treatment by sequential n-BCA embolizations for nidal occlusion versus quantitative flow reduction in preparation for surgical resection or radiosurgery.MethodsWe performed a retrospective review of all patients who underwent endovascular embolization of cerebral AVM at our institution between 1998 and 2019, during which time the technique of traditional embolization evolved to a strategy of targeted sequential flow reduction guided by serial flow imaging based on quantitative magnetic resonance angiography, in conjunction with a shift away from nidal penetration.ResultsAmong 251 patients, 47.8% of patients presented with ruptured AVM. On average, each patient underwent 2.4 embolizations, for a total of 613 sessions. Major morbidity related to embolization occurred in 18 (7.2%) patients, but this occurred disproportionately in the traditional embolization strategy (n=16, 8%) in contrast with the flow-targeting strategy (n=2, 3.8%). Four patients (1.6%) died in the overall group, and these all occurred with the traditional embolization strategy (2% of 199 patients); no deaths occurred in the flow-targeting strategy (n=52).ConclusionEmbolization with n-BCA targeted to sequential flow reduction and feeder occlusion with limited nidal penetration prior to definitive surgical or radiosurgical treatment can be safely performed with low overall morbidity and mortality.

Object The breadth and complexity of neurovascular pathologies treated with endovascular neurosurgery has expanded dramatically in recent years. Many aneurysms remain difficult to treat safely. Transcirculation (contralateral and/or retrograde) approaches through the circle of Willis are useful alternatives for treating challenging lesions endovascularly. Here, we present a series of patients treated with unconventional transcirculation techniques. Methods A total of six patients were treated: four patients with five aneurysms, one patient with an MCA stroke, and one patient with a meningioma requiring preoperative embolization were initially thought not to be amenable to endovascular treatment. The decision was made to treat these patients with transcirculation approaches. All patients were treated by one interventionist. One aneurysm was located in the cavernous internal carotid artery (ICA), one in the vertebral artery, two in the paraclinoid ICA, and one in a cerebellar AVM feeder vessel were treated. Results Five of six patients (83%) made a full neurologic recovery. Three aneurysms were treated to complete occlusion, one aneurysm was left with small residual neck filling, and one aneurysm was not able to be treated. One patient underwent mechanical thrombectomy of a middle cerebral artery (MCA) embolus and MCA filling was restored after treatment. One patient underwent complete embolization of the deep vascular supply of a meningioma. Conclusions Although many neurovascular pathologies remain unsuitable for endovascular treatment, transcirculation approaches can allow for safe, successful treatment of challenging lesions in select patients.

Machine learning (ML) has been increasingly used in medicine and neurosurgery. We sought to determine whether ML models can distinguish ruptured from unruptured aneurysms and identify features associated with rupture.We performed a retrospective review of patients with intracranial aneurysms detected on vascular imaging at our institution between 2002 and 2018. The dataset was used to train 3 ML models (random forest, linear support vector machine [SVM], and radial basis function kernel SVM). Relative contributions of individual predictors were derived from the linear SVM model.Complete data were available for 845 aneurysms in 615 patients. Ruptured aneurysms (n = 309, 37%) were larger (mean 6.51 mm vs. 5.73 mm; P = 0.02) and more likely to be in the posterior circulation (20% vs. 11%; P0.001) than unruptured aneurysms. Area under the receiver operating curve was 0.77 for the linear SVM, 0.78 for the radial basis function kernel SVM models, and 0.81 for the random forest model. Aneurysm location and size were the 2 features that contributed most significantly to the model. Posterior communicating artery, anterior communicating artery, and posterior inferior cerebellar artery locations were most highly associated with rupture, whereas paraclinoid and middle cerebral artery locations had the strongest association with unruptured status.ML models are capable of accurately distinguishing ruptured from unruptured aneurysms and identifying features associated with rupture. Consistent with prior studies, location and size show the strongest association with aneurysm rupture.

Background The impact of cerebral aneurysm size on distal intracranial hemodynamics such as arterial pressure and Pulsatility Index is not completely understood, either before or after flow diversion. Objective The aim of the study is to assess the impact of aneurysm size on distal Pulsatility Index and pressure before and after flow diversion. Methods From December 2015, prospective measurement of middle cerebral artery pressure and Pulsatility Index was performed in consecutive patients with unruptured cerebral aneurysms in the cavernous to communicating segments of the internal carotid artery, which were treated with single flow diversion. Pressure and Pulsatility Index were recorded at the M1-segment ipsilateral to the cerebral aneurysm. Ratio of middle cerebral artery to radial arterial pressure (pressure ratio) was calculated to control for variations in systemic blood pressure. Correlations between aneurysm size and pressure ratio and Pulsatility Index were assessed before and after treatment. Results A total of 28 aneurysms were treated. The mean aneurysm size was 7.2 mm. Aneurysm size correlated linearly with systolic pressure ratio (1% pressure ratio increase per mm aneurysm size increase, P = 0.002, r2 = 0.33), mean pressure ratio (0.6% per mm, P = 0.03, r2 = 0.17) and Pulsatility Index (5% Pulsatility Index increase per mm, P = 0.003, r2 = 0.43). After flow diversion, aneurysm size preserved a linear correlation with the systolic pressure ratio (1% per mm, P = 0.004, r2 = 0.28), but not with the mean pressure ratio (0.4% per mm, P = 0.15, r2 2 Conclusion Aneurysm size affects distal hemodynamics: patients with larger aneurysms have increased systolic and mean pressure ratio, and increased Pulsatility Index. After flow diversion, mean pressure ratio and Pulsatility Index no longer associate with the aneurysm size, suggesting an effect of the flow diversion also on distal intracranial hemodynamics.

Atherosclerosis of the internal carotid artery and intracranial vessels can compromise cerebral hemodynamics and cause stroke. Cerebral bypass has a half-century history in augmenting or replacing blood flow the brain. Several trials have investigated various applications of cerebral bypass in flow augmentation for atherosclerotic disease. This review discusses the clinical science of cerebrovascular atherosclerosis to provide the context in which cerebral bypass is currently applied. This includes prior clinical trials, ongoing clinical trials, and consensus guidelines, and is complemented by studies in the physiologic science of cerebrovascular flow. The scientific background is supplemented by the description of the technical art of bypass surgery based on a three-decade experience. Successful application of cerebral bypass to augment flow in atherosclerotic cerebrovascular disease requires correct diagnosis of compromised hemodynamic reserve refractory to medical optimization and an appropriate matching of bypass flow with cerebral demand.

Background Perioperative cerebral infarction is a potential complication of glioma resection, of which insular tumors are at higher risk because of the proximity of middle cerebral artery branches, including the lateral lenticulostriates and long insular arteries. In this study, 3 patients received three-dimensional rotational angiography, which was fused with magnetic resonance imaging (MRI) for frameless stereotactic navigation during dominant-hemisphere insular glioma resection. Methods All patients obtained a preoperative catheter angiogram with a three-dimensional rotational acquisition of the ipsilateral internal carotid artery. The pixel-based axial three-dimensional angiography data, thin-cut structural MRI, tractography from diffusion tensor imaging, and expressive language activation from functional MRI were uploaded into the iPlan software (Brainlab, Heimstetten, Germany) and fused. The target tumor, regional blood vessels, adjacent functional areas, and their associated fiber tracts were segmented and overlaid on the appropriate MRI sequence. This image fusion was used preoperatively to visualize the relationship of the mass with the adjacent vasculature and intraoperatively for frameless stereotactic navigation to optimize preservation of arterial structures. Results Three patients aged 27–60 years with excellent baseline functional status presented with seizures and were found to have a large dominant-hemisphere T2 hyperintense nonenhancing insular mass. Surgical resection was performed using multimodality neuronavigation. None sustained a postoperative arterial infarction or a perioperative neurologic deficit. Conclusions Neuronavigation using a fusion of three-dimensional rotational angiography with MRI is a technique that can be used for preoperative planning and during resection of insular gliomas to optimize preservation of adjacent arteries.

OBJECTIVEParaclinoid aneurysms represent approximately 5% of intracranial aneurysms (Drake et al. [1968]). Visual impairment, which occurs in 16%–40% of patients, is among the most common presentations of these aneurysms (Day [1990], Lai and Morgan [2013], Sahlein et al. [2015], and Silva et al. [2017]). Flow-diverting stents, such as the Pipeline Embolization Device (PED), are increasingly used to treat these aneurysms, in part because of their theoretical reduction of mass effect (Fiorella et al. [2009]). Limited data on paraclinoid aneurysms treated with a PED exist, and few studies have compared outcomes of patients after PED placement with those of patients after clipping or coiling.METHODSThe authors performed a retrospective analysis of 115 patients with an aneurysm of the cavernous to ophthalmic segments of the internal carotid artery treated with clipping, coiling, or PED deployment between January 2011 and March 2017. Postoperative complications were defined as new neurological deficit, aneurysm rupture, recanalization, or other any operative complication that required reintervention.RESULTSA total of 125 paraclinoid aneurysms in 115 patients were treated, including 70 with PED placement, 23 with coiling, and 32 with clipping. Eighteen (14%) aneurysms were ruptured. The mean aneurysm size was 8.2 mm, and the mean follow-up duration was 18.4 months. Most aneurysms were discovered incidentally, but visual impairment, which occurred in 21 (18%) patients, was the most common presenting symptom. Among these patients, 15 (71%) experienced improvement in their visual symptoms after treatment, including 14 (93%) of these 15 patients who were treated with PED deployment. Complete angiographic occlusion was achieved in 89% of the patients. Complications were seen in 17 (15%) patients, including 10 (16%) after PED placement, 2 (9%) after coiling, and 5 (17%) after clipping. Patients with incomplete aneurysm occlusion had a higher rate of procedural complications than those with complete occlusion (p = 0.02). The rate of postoperative visual improvement was significantly higher among patients treated with PED deployment than in those treated with coiling (p = 0.01). The significant predictors of procedural complications were incomplete occlusion (p = 0.03), hypertension, (p = 0.04), and diabetes (p = 0.03).CONCLUSIONSIn a large series in which patient outcomes after treatment of paraclinoid aneurysms were compared, the authors found a high rate of aneurysm occlusion and a comparable rate of procedural complications among patients treated with PED placement compared with the rates among those who underwent clipping or coiling. For patients who presented with visual symptoms, those treated with PED placement had the highest rate of visual improvement. The results of this study suggest that the PED is an effective and safe modality for treating paraclinoid aneurysms, especially for patients who present with visual symptoms.

Disease of the vertebral (VA) and basilar arteries (BA) can lead to stroke of the posterior circulation and may warrant management strategies which differ from the anterior circulation. The mechanism and location of the disease determine its natural history and therefore affect the relative risks and benefits of the possible treatment options. Vertebrobasilar (VB) atherosclerotic disease is a source of both hemodynamic and embolic posterior circulation stroke. Advances in medical therapy have decreased the rate of stroke after initial symptomatic presentation. Antiplatelet therapy, blood pressure control, and optimization of secondary risk factors can reduce recurrent stroke risk in both intracranial and extracranial VB disease. However, symptomatic intracranial disease is still associated with a high risk of subsequent stroke, particularly those with hemodynamic compromise who represent a higher risk population. Patients with hemodynamic impairment may benefit from judicious application of endovascular and microsurgical interventions to augment blood flow. Stenting, angioplasty alone, bypass surgery, and endarterectomy, represent endovascular and surgical tools available to address medically refractory VB disease. Apart from atherosclerotic disease, dissection is another etiology of VB stroke, most frequently affecting the extracranial VA. Treatment is predominantly antithrombotic therapy although surgical or endovascular intervention can be required in rare cases of persistent embolism or hemodynamic compromise. In contrast, extrinsic compromise of the VA represents a separate extracranial pathology and is best treated with mechanistically targeted surgeries or extracranial bypass.

Background and Purpose: The role of regional hypoperfusion as a contributor to stroke risk in atherosclerotic vertebrobasilar disease has recently been confirmed by the observational VERiTAS (Vertebrobasilar Flow Evaluation and Risk of Transient Ischemic Attack and Stroke) Study. We examined the stability of hemodynamic status over time and its relationship to stroke risk in patients from this prospective cohort. Methods: VERiTAS enrolled patients with recently symptomatic ≥50% atherosclerotic stenosis/occlusion of vertebral and/or basilar arteries. Large vessel flow in the vertebrobasilar territory was assessed using quantitative magnetic resonance angiography, and patients were designated as low or normal flow based on distal territory regional flow, incorporating collateral capacity. Patients underwent standard medical management and follow-up for primary outcome event of vertebrobasilar territory stroke. Quantitative magnetic resonance angiography imaging was repeated at 6, 12, and 24 months. Flow status over time was examined relative to baseline and relative to subsequent stroke risk using a cause-specific proportional hazard model, with flow status treated as a time-varying covariate. Mean blood pressure was examined to assess for association with changes in flow status. Results: Over 19±8 months of follow-up, 132 follow-up quantitative magnetic resonance angiography studies were performed in 58 of the 72 enrolled patients. Of the 13 patients with serial imaging who had low flow at baseline, 7 (54%) had improvement to normal flow at the last follow-up. Of the 45 patients who had normal flow at baseline, 3 (7%) converted to low flow at the last follow-up. The mean blood pressure did not differ in patients with or without changes in flow status. The time-varying flow status remained a strong predictor of subsequent stroke (hazard ratio, 10.3 [95% CI, 2.2–48.7]). Conclusions: There is potential both for improvement and worsening of hemodynamics in patients with atherosclerotic vertebrobasilar disease. Flow status, both at baseline and over time, is a risk factor for subsequent stroke, thus serving as an important prognostic marker. Registration: URL: https://clinicaltrials.gov . Unique identifier: NCT00590980.

Background The impact of cerebral aneurysm size on distal intracranial hemodynamics such as pressure is not completely understood, either before or after flow diversion (FD). Objective To assess the impact of aneurysm size on distal pressure before and after FD.METHODS Beginning in December 2015, prospective measurement of middle cerebral artery (MCA) pressure was completed in consecutive patients with unruptured cerebral aneurysms in the ophthalmic to communicating segments of the internal carotid artery which were treated with a single FD. Pressure was recorded at the M1 segment ipsilateral to the cerebral aneurysm. Ratio of MCA to radial arterial pressure (pressure ratio, PR) controlled for variations in systemic blood pressure. Correlation between aneurysm size and MCA PR was assessed before and after treatment. Results 29 aneurysms were treated in 27 patients. Mean aneurysm size was 7.4 mm (2–27 mm). Aneurysm size correlated linearly with systolic PR (1% per mm, p=0.001, r2=0.33; figure 1A) and mean PR (0.6% per mm, p=0.03, r2=0.17; figure 1B). After FD, aneurysm size continued to have a linear correlation with the systolic PR (1% per mm, p=0.004, r2=0.28; figure 1A), but not with the mean PR (0.4% per mm, p=0.15, r2 Conclusion Aneurysm size affects distal hemodynamics: patients with larger aneurysms have increased systolic and mean MCA PR. After FD, mean MCA PR no longer associates with the aneurysm size, suggesting an effect of the FD on distal intracranial hemodynamics. Disclosures D. Brunozzi: None. A. See: None. A. Alaraj: 1; C; NIH. 2; C; Cerenovus, Siemens.

Introduction/Purpose Historically, spinal dural arteriovenous fistulas (SDAVFs) have been treated with intradural ligation of the draining vein. While endovascular embolization can achieve durable occlusion in a subset of these patients, recent studies have demonstrated a superiority of microsurgical ligation. However, given that spinal angiography is essential in the workup of suspected SDAVFs, we and others have demonstrated the utility of an ‘endovascular-first’ approach to SDAVFs. One limiting factor to the success of endovascular therapies has been the reliability of casting and occluding the draining vein using Onyx. In contrast, we have observed that n-butyl-2-cyanoacrylate (nBCA) glue can readily penetrate and cast the fistula and vein. We therefore sought to compare the efficacy of nBCA and Onyx embolization in the treatment of SDAVFs. Material and Methods We performed a retrospective analysis of our endovascular database from 4/2007 to 4/2019 to identify patients treated for SDAVFs. We extracted demographic, clinical, treatment, and radiographic information data. We considered a ‘durable cure’ of the SDAVF to include complete obliteration of the fistula following endovascular treatment, demonstrated clinical improvement, and follow-up radiographic studies demonstrating improvement of spinal cord edema and flow voids on MRI/MRA and/or persistent obliteration on follow-up angiograms. We compared our results using Onyx and nBCA embolysate. Results We performed 40 endovascular treatments for SDAVFs in 38 patients. The embolysates utilized were Onyx without any other embolysate (22), NBCA without any other liquid embolysate (16), and a combination of nBCA and Onyx (2). For the 22 treatments in which Onyx was the only embolysate used, endovascular treatment resulted in a durable cure in 11 cases (50%) (mean follow-up 20.8 months). For 10 of these 22 (45.5%), a complete obliteration of the fistula with casting of the vein was not achieved and these patients were referred for microsurgical ligation. For 1 of these 22 treatments, a complete obliteration of the fistula was noted on immediate post-procedure angiography. However, 4.2 months after treatment, he was found to have a recurrence. For the 16 treatments in which nBCA was the only liquid embolysate used, endovascular treatment resulted in a complete obliteration of the fistula following treatment in all 16 (100%) patients. None of these patients underwent subsequent microsurgical treatment. Follow-up data were available for 13 of these patients (81.3%). Of these 13, all (100%) achieved a durable cure (mean follow-up 19.6 months) without clinical or radiographic recurrence. A durable cure was achieved more frequently in patients treated with nBCA (100%) relative to those treated with Onyx only (50%) (p Conclusion NBCA embolization of SDAVFs is superior to Onyx embolization. NBCA embolization is safe and effective for a subset of SDAVFs with results in this population comparable to microsurgical ligation. Disclosures J. Baranoski: None. J. Catapano: None. T. Cole: None. N. Majmundar: None. B. Hendricks: None. D. Wilkinson: None. A. See: None. D. Cavalcanti: None. B. Flores: None. A. Ducruet: None. F. Albuquerque: None.

Background Atherosclerotic vertebrobasilar disease is a significant etiology of posterior circulation stroke. The prospective observational VER i TAS (Vertebrobasilar Flow Evaluation and Risk of Transient Ischemic Attack and Stroke) study demonstrated that distal hemodynamic status is a robust predictor of subsequent vertebrobasilar stroke risk. We sought to compare predictive models using thresholds for posterior circulation vessel flows standardized to age and vascular anatomy to optimize risk prediction. Methods and Results VER i TAS enrolled patients with recent vertebrobasilar transient ischemic attack or stroke and ≥50% atherosclerotic stenosis/occlusion in vertebral and/or basilar arteries. Quantitative magnetic resonance angiography measured large‐vessel vertebrobasilar territory flow, and patients were designated as low or normal flow based on a prespecified empiric algorithm considering distal territory regional flow and collateral capacity. For the present study, post hoc analysis was performed to generate additional predictive models using age‐specific normalized flow measurements. Sensitivity, specificity, and time‐to‐event analyses were compared between the algorithms. The original prespecified algorithm had 50% sensitivity and 79% specificity for future stroke risk prediction; using a predictive model based on age‐normalized flows in the basilar and posterior cerebral arteries, standardized to vascular anatomy, optimized flow status thresholds were identified. The optimized algorithm maintained sensitivity and increased specificity to 84%, while demonstrating a larger and more significant hazard ratio for stroke on time‐to‐event analysis. Conclusions These results indicate that flow remains a strong predictor of stroke across different predictive models, and suggest that prediction of future stroke risk can be optimized by use of vascular anatomy and age‐specific normalized flows.

BackgroundBlebs are rupture risk factors in intracranial aneurysms (IAs), but their prevalence, distribution, and associations with clinical factors as well as their causes and effects on aneurysm vulnerability remain unclear.MethodsA total of 122 blebs in 270 IAs selected for surgery were studied using patient-specific vascular reconstructions from 3D angiographic images. Bleb geometry, location on the aneurysm, and frequency of occurrence in aneurysms at different locations were analyzed. Associations between gender, age, smoking, hypertension, hormone therapy, dental infection, and presence of blebs were investigated.ResultsOf all aneurysms with blebs, 77% had a single bleb and 23% had multiple blebs. Only 6% of blebs were at the neck, while 46% were in the body and 48% in the dome. Aneurysms with blebs were larger (pConclusionsBlebs are common in IAs, and most aneurysms harboring blebs have a single bleb. Blebs in the aneurysm neck are rare, but they are equally common in the body and dome. The presence of blebs in IAs was associated with dental infection, and negatively associated with hormone replacement therapy.

Functional magnetic resonance imaging (fMRI) is increasingly used for preoperative counseling and planning, and intraoperative guidance for tumor resection in the eloquent cortex. Although there have been improvements in image resolution and artifact correction, there are still limitations of this modality. In this review, we discuss clinical fMRI's applications, limitations and potential solutions. These limitations depend on the following parameters: foundations of fMRI, physiologic effects of the disease, distinctions between clinical and research fMRI, and the design of the fMRI study. We also compare fMRI to other brain mapping modalities which should be considered as alternatives or adjuncts when appropriate, and discuss intraoperative use and validation of fMRI. These concepts direct the clinical application of fMRI in neurosurgical patients., Highlights • fMRI is increasingly used for presurgical brain mapping for surgical planning. • Understanding of the limitations of fMRI is critical for its clinical use. • Clinical fMRI's challenges and potential solutions are discussed. • Intraoperative use and validation of fMRI are discussed.

Background Giant hypervascular intracranial tumors represent a formidable challenge because their size limits surgical control of the blood supply and debulking poses the risk of critical blood loss. Embolization facilitates resection but carries the risk of life-threatening tumor infarction, hemorrhage, or swelling if performed preoperatively. Endovascular intraoperative embolization avoids the fatal risk and allows the surgeon to attend instantly if any complication occurs. Methods and Results We report 2 cases in which combining intraoperative embolization with microsurgical resection in the hybrid operating room was used to safely and successfully remove giant hypervascular tumors. Conclusions Intraoperative embolization facilitates the safe resection of giant hypervascular tumors and mitigates the consequences of potential tumor infarction, hemorrhage, or swelling from embolization. These cases exemplify the benefits of combining expertise in endovascular and microsurgical techniques with the capabilities of modern hybrid operating rooms allowing for their simultaneous application.

BACKGROUND AND IMPORTANCE Aneurysms affecting double origin (DO) posterior inferior cerebellar artery (PICA) variants are rare. Most reports describe endovascular occlusion of the affected branch to treat the aneurysm, but we describe a patient in which open surgical sacrifice of 1 branch resulted in insufficient perfusion. CLINICAL PRESENTATION We report the only case of open surgical treatment of an aneurysm affecting a leg of a DOPICA. A 42-year-old woman presenting with the worst headache of her life was found to have a DOPICA aneurysm and initially treated by trapping the aneurysm. Intraoperative indocyanine green imaging revealed insufficient perfusion through the caudal branch, which was remediated by end-to-end anastomosis to preserve flow through both origins. The patient made a full recovery. CONCLUSION Treating a DOPICA aneurysm by sacrificing 1 of the origins is not possible for all patients. This first report of open surgical treatment of a DOPICA leg aneurysm suggests that 1 or both branches may be required for sufficient perfusion, and the unique embryology of DOPICA development suggests a possible mechanism.

Coil migration following cerebral aneurysm treatment has been described and may result in stroke, recurrent aneurysm, or local mass effect. Cerebral coil embolization is also applied in arteriovenous malformations and arteriovenous fistulas, but these pathologies are relatively rare and coil migration is not as well described. Furthermore, these cases are more commonly treated with combinations of multiple modalities to achieve cure. Embolization, surgery, and radiation each have risks and benefits and combinations may have synergistic risks and benefits not seen in monotherapy. We report a case of extravascular and extra-corporeal coil migration after embolization and craniectomy to treat a patient with hemorrhage from an arteriovenous fistula. Electronic supplementary material The online version of this article (10.1007/s00701-018-3689-3) contains supplementary material, which is available to authorized users.

Hyponatremia occurs commonly in patients with aneurysmal subarachnoid hemorrhage (aSAH). Our objective was to determine the time course of, and factors associated with, hyponatremia after aSAH. We performed a retrospective review of 259 patients with ruptured aneurysms at a single institution. Multivariate regression analysis was performed to determine the factors associated with hyponatremia. Increasing age was significantly associated with lower initial sodium (p=0.04) and incidence of delayed hyponatremia (p=0.01) while smoking was associated with longer duration of hyponatremia (p=0.02). Older patients should therefore be monitored closely for hyponatremia and patients who smoke should be treated more aggressively for hyponatremia given the greater frequency and longer duration of hyponatremia in these two groups, respectively.

Objective In early-generation hybrid biplane endovascular operating rooms, switching from surgical to angiographic position is cumbersome. In this report, we highlight the unique design of a new hybrid neuroendovascular operating suite that allows surgical access to the head while keeping the biplane system over the lower body of the patient. Current and future hybrid neuroendovascular operating suite applications are discussed. Methods We collaborated with engineers to implement the following modifications to the design of the angiographic system: translation of the bed toward the feet to allow biplane cerebral imaging in the head-side position and the biplane left-side position; translation of the base of the A-plane C-arm away from the feet to allow increased operator space at the head of the bed and to allow cerebral imaging in both the head-side and left-side positions; use of a specialized boom mount for the display panel to increase mobility; and use of a radiolucent tabletop with attachments for the headrest or radiolucent head clamp system. Results The modified hybrid neuroendovascular operating suite allows for seamless transition between surgical and angiographic positions within seconds, improving workflow efficiency and decreasing procedure time as compared with early-generation hybrid rooms. Conclusions Combined endovascular and surgical applications are facilitated by co-locating their respective technologies and refining the ergonomics of the system to ease transition between both sets of technologies. In so doing, hybrid neuroendovascular operating suites can be anticipated to improve patient outcomes, generate novel treatment paradigms, and improve time and cost efficiency.

Acute ischemic stroke (AIS) in children has been difficult to diagnose, treat and study, due to atypical clinical presentation, imaging challenges and the rarity of large-vessel embolic occlusion as the etiology of acute neurological change in children. With endovascular thrombectomy showing success in randomized trials of adult AIS, the technique is increasingly being extrapolated to pediatric stroke. However, there is little evidence regarding the safety or efficacy of applying in children these devices developed and tested in adults. There is concern about a vessel-to-device size mismatch that may result in a different complication and benefit profile than typically seen. We report on the successful application in pediatric stroke of a newer-generation, smaller stent retriever, designed to be delivered through relatively smaller and more navigable microcatheters than the prior generation of this device.

The literature has long attempted distinct classifications of arteriovenous fistulae and arteriovenous malformations of the spine.1-3 It is worth noting that lesions can become more complex during recurrence and may not adhere to traditional definitions. In these cases, recognizing the principles of pathology and pathophysiology can guide management and treatment. We present the case of a spinal arteriovenous malformation with recurrence after prior treatment that is managed in the setting of a second opinion with a multidisciplinary approach. This case demonstrates (1) an evolution of recurrent arteriovenous shunting pathology observed both in the endovascular suite, and under direct microscopic visualization and (2) considerations in multimodal treatment with endovascular devices during microsurgical dissection and extirpation. This manuscript was prepared with informed assent provided by the patient (a minor) and with informed consent by the parent of the patient, who is their legal representative and health-care proxy.

Objective Preoperative embolization may facilitate skull base meningioma resection, but its safety and efficacy in the Onyx era have not been investigated. In this retrospective cohort study, we evaluated the outcomes of preoperative embolization of skull base meningiomas using Onyx as the primary embolysate. Methods We queried an endovascular database for patients with skull base meningiomas who underwent preoperative embolization at our institution in 2007–2017. Patient, tumor, procedure, and outcome data were analyzed. Results Twenty-eight patients (28 meningiomas) underwent successful preoperative meningioma embolization. The mean patient age ± SD was 56 ± 13 years, and 18 patients (64%) were women. The mean tumor size was 49 cm3. There were 1, 2, or 3 arterial pedicles embolized in 21 cases (75%), 6 cases (21%), and 1 case (4%), respectively. The embolized pedicles included branches of the middle meningeal artery in 19 cases (68%), the internal maxillary artery in 8 cases (29%), the ascending pharyngeal artery in 2 cases (7%), and the posterior auricular, ophthalmic, occipital, and anterior cerebral arteries in 1 case each (4%). The embolysates used were Onyx alone in 20 cases (71%), n-butyl cyanoacrylate alone in 3 cases (11%), coils/particles and Onyx/n-butyl cyanoacrylate in 2 cases each (7%), and Onyx and coils in 1 case (4%). The median degree of tumor devascularization was 60%. Significant neurologic morbidity occurred in 1 patient (4%) who developed symptomatic peritumoral edema after Onyx embolization. Conclusions For appropriately selected skull base meningiomas supplied by dura mater–based arterial pedicles without distal cranial nerve supply, preoperative embolization with current embolysate technology affords substantial tumor devascularization with a low complication rate.

This study uses diffuse correlation spectroscopy (DCS) to monitor blood flow during mechanical thrombectomy, a novel catheter-based treatment in acute ischemic stroke patients, to assist the surgeons observing the flow changes in realtime, towards a personalized therapy.

Purpose: Cardiac myxomas are common tumors of the heart with disproportionate impact on young patients, occasionally with dramatic systemic dissemination of tumor emboli with catastrophic multiorgan system ischemia. The coincident comorbidities can increase the risk of traditional treatments for tumor embolus in each region. Case report: A young patient with previously unknown cardiac myxoma presented with seizure and was found to have stress cardiomyopathy, multiple cerebral large vessel occlusions with acute ischemic stroke, bilateral lower extremity tumor emboli and rhabdomyolysis, and renal tumor embolus with acute tubular necrosis. We describe a multidisciplinary approach applying cerebrovascular stent retriever devices in tumor embolectomy of the renal artery of a young patient with systemic morbidity, preventing safe laparotomy for open surgical tumor embolectomy. Conclusion: We describe 2-month renal function outcomes and the considerations in applying a neuroendovascular mechanical thrombectomy device within the renal artery. This was a radiographically successful technique and her renal function appears to be improving at the 2-month follow-up, although this is complicated by other renal insults and support.

Effective treatment of cerebral arteriovenous malformations (AVMs) requires a multidisciplinary approach that appropriately applies the complementary modalities of microsurgical resection, endovascular embolization, and radiosurgery. Embolization is most commonly used as an adjunct to reduce the arterial supply to the AVM before surgery or radiosurgery. Additional indications for embolization include an attempt to achieve complete AVM obliteration, targeted treatment to eliminate high-risk features, and subtotal occlusion to palliate symptoms caused by an otherwise incurable AVM. In all cases, the risks and benefits of treatment must be weighed carefully when formulating a treatment strategy. For optimal management of cerebral AVMs, patients should have access to physicians experienced in open cerebrovascular surgery, endovascular embolization, and radiosurgery.

OBJECTIVEPatients with paraclinoid aneurysms commonly present with visual impairment. They have traditionally been treated with clipping or coiling, but flow diversion (FD) has recently been introduced as an alternative treatment modality. Although there is still initial aneurysm thrombosis, FD is hypothesized to reduce mass effect, which may decompress the optic nerve when treating patients with visually symptomatic paraclinoid aneurysms. The authors performed a meta-analysis to compare vision outcomes following clipping, coiling, or FD of paraclinoid aneurysms in patients who presented with visual impairment.METHODSA systematic literature review was performed using the PubMed and Web of Science databases. Studies published in English between 1980 and 2016 were included if they reported preoperative and postoperative visual function in at least 5 patients with visually symptomatic paraclinoid aneurysms (cavernous segment through ophthalmic segment) treated with clipping, coiling, or FD. Neuroophthalmological assessment was used when reported, but subjective patient reports or objective visual examination findings were also acceptable.RESULTSThirty-nine studies that included a total of 2458 patients (520 of whom presented with visual symptoms) met the inclusion criteria, including 307 visually symptomatic cases treated with clipping (mean follow-up 26 months), 149 treated with coiling (mean follow-up 17 months), and 64 treated with FD (mean follow-up 11 months). Postoperative vision in these patients was classified as improved, unchanged, or worsened compared with preoperative vision. A pooled analysis showed preoperative visual symptoms in 38% (95% CI 28%–50%) of patients with paraclinoid aneurysms. The authors found that vision improved in 58% (95% CI 48%–68%) of patients after clipping, 49% (95% CI 38%–59%) after coiling, and 71% (95% CI 55%–84%) after FD. Vision worsened in 11% (95% CI 7%–17%) of patients after clipping, 9% (95% CI 2%–18%) after coiling, and 5% (95% CI 0%–20%) after FD. New visual deficits were found in patients with intact baseline vision at a rate of 1% (95% CI 0%–3%) for clipping, 0% (95% CI 0%–2%) for coiling, and 0% (95% CI 0%–2%) for FD.CONCLUSIONSTo the authors’ knowledge, this is the first meta-analysis to assess vision outcomes after treatment for paraclinoid aneurysms. The authors found that 38% of patients with these aneurysms presented with visual impairment. These data also demonstrated a high rate of visual improvement after FD without a significant difference in the rate of worsened vision or iatrogenic visual impairment compared with clipping and coiling. These findings suggest that FD is an effective option for treatment of visually symptomatic paraclinoid aneurysms.

This case demonstrates a rare pathology of basilar artery pial arteriovenous shunting presenting with acutely progressive symptoms of brainstem compression, in which we applied a polytetrafluoroethylene-coated embolic device to achieve short-segment upper mid-basilar artery sacrifice. In addition to presenting a rare form of basilar arteriovenous fistula (AVF) (likely related to hereditary hemorrhagic telangiectasia) and discussing the extreme management challenges, this case demonstrates the unusual but successful application of a novel neurovascular device. Unanswered questions include the mechanism of development of this pathology and the optimum post-embolization anticoagulation plan. Reports of pial arteriovenous fistulas (AVFs) that occur in the posterior fossa are quite rare, occasionally appearing in general pial AVF case series or as individual case reports;1–6 in particular, direct AVFs originating off the basilar artery have not previously been reported. We present the case of a child with a basilar pial AVF with mass effect and progressively accelerating neurological decline and report on its management and outcome. A 3-year-old child with a history of ocular albinism and normal neurological milestones (walking at 10 months, speaking in full sentences) was noted to have several months of progressive gait instability, bilateral hand tremor, dysarthria, drooling, and intermittent esotropia, with accelerating worsening over the most recent 3 weeks. Her parents and three siblings were all healthy. On examination she had left eye intorsion and limitation of upgaze. She ambulated with a hyper-plantarflexed gait and became progressively unsteady on her feet, with axial ataxia. She had intention tremors bilaterally in the upper extremities. Over the course of observation of several days she developed swallowing difficulties and, as a result, had her oral intake progressively restricted, and showed progressive loss of motor and speech milestones. On MRI brain she was found to have an AVF that appeared to originate directly off the upper mid-basilar artery, with …

OBJECTIVELiquid embolic agents have revolutionized endovascular management of arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs). Nonetheless, since 2005, the US FDA has received more than 100 reports of microcatheter breakage or entrapment related to Onyx embolization, including 9 deaths. In 2014, the Apollo detachable-tip microcatheter became the first of its kind available in the US. Since then, few reports on its safety have been published.METHODSThe authors conducted a retrospective review of endovascular cases by searching the patient databases at 2 tertiary cerebrovascular centers (Barrow Neurological Institute and University of Pittsburgh Medical Center). Patients who underwent endovascular embolization of an AVM or AVF using the Apollo microcatheter were identified. Patient demographics and lesion characteristics were collected. The authors analyzed Apollo-specific endovascular variables, such as number of microcatheterizations, sessions, and pedicles embolized; microcatheter tip detachment status; obliteration rate; and endovascular- and microcatheter-related morbidity and mortality.RESULTSFrom July 2014 to October 2016, a total of 177 embolizations using the Apollo microcatheter were performed in 61 patients (mean age 40.3 years). The most frequent presentation was hemorrhage (22/61, 36.1%). Most lesions were AVMs (51/61, 83.6%; mean diameter 30.6 mm). The mean Spetzler-Martin grade was 2.4. Thirty-nine (76.5%) of 51 patients with AVMs underwent resection. Microcatheterization was successful in 172 pedicles. Most patients (50/61, 82%) underwent a single embolization session. The mean number of pedicles per session was 2.5 (range 1–7). Onyx-18 was used in 103 (59.9%), N-butyl cyanoacrylate (NBCA) in 44 (25.6%), and Onyx-34 in 25 (14.5%) of the 172 embolizations. In 45.9% (28/61) of the patients, lesion obliteration of 75% or greater was achieved. Tip detachment occurred in 19.2% (33/172) of microcatheters. Fifty-three (86.9%) of the 61 patients who underwent embolization with the Apollo microcatheter had good functional outcomes (modified Rankin Scale score 0–2). No unintended microcatheter fractures or related morbidity was observed. One patient died of intraprocedural complications unrelated to microcatheter selection. In the univariate analysis, microcatheter tip detachment (p = 0.12), single embolized pedicles (p = 0.12), and smaller AVM nidus diameter (p = 0.17) correlated positively with high obliteration rates (> 90%). In the multivariate analysis, microcatheter tip detachment was the only independent variable associated with high obliteration rates (OR 9.5; p = 0.03).CONCLUSIONSThe use of the Apollo detachable-tip microcatheter for embolization of AVMs and AVFs is associated with high rates of successful catheterization and obliteration and low rates of morbidity and mortality. The microcatheter was retrieved in all cases, even after prolonged injections in distal branch pedicles, often with significant reflux. This study represents the largest case series on the application of the Apollo microcatheter for neurointerventional procedures.

Introduction: Paraclinoid aneurysms commonly present with visual impairment. They were traditionally treated with clipping or coiling, but flow diversion has recently been introduced as an alternative treatment modality. Although there is still initial aneurysm thrombosis, flow diversion is hypothesized to reduce mass effect, which may decompress the optic nerve when treating visually symptomatic paraclinoid aneurysms. We performed a meta-analysis to compare vision outcomes following clipping, coiling, or flow diversion of paraclinoid aneurysms in patients presenting with visual impairment. Methods: A systematic literature review was performed using the PubMed and Web of Science databases. Studies written in English between 1980-2016 were included if they reported preoperative and postoperative visual function in at least 5 patients with visually symptomatic paraclinoid aneurysms (cavernous segment through ophthalmic segment) treated with clipping, coiling, or flow diversion. Neuro-ophthalmologic assessment was used when reported. Results: Thirty-nine studies totaling 2458 patients (20%, 510 of whom presented with visual symptoms) met our inclusion criteria, including 309 visually symptomatic cases treated with clipping (mean follow-up, 25.9 mo), 138 treated with coiling (17.1 mo), and 63 treated with flow diversion (11 mo). Postoperative vision in these patients was classified as improved, unchanged, or declined compared to preoperative vision. We found that vision improved in 57% (95% CI 47-67) of patients after clipping, 45% (34-57) after coiling, and 73% (56-88) after flow diversion. Vision worsened in 11% (7-17) of patients after clipping, 8% (2-17) after coiling, and 7% (0-27) after flow diversion. New visual deficits were found in patients with intact baseline vision at a rate of 0.69% (0-2) for clipping, 0.53% (0-3) for coiling, and 0.80% (0-3) for flow diversion. Conclusion: Our data demonstrates a high rate of visual improvement and a low rate of iatrogenic vision impairment for patients with paraclinoid aneurysms treated with flow diversion. Further analysis is needed to compare flow diversion to clipping and coiling and inform clinical management of visually symptomatic paraclinoid aneurysms.

Developmental venous anomalies (DVAs, also known as venous angiomas) are rare, asymptomatic congenital remnants of fetal venous vasculature. As persistent fetal veins, they provide critical venous drainage for the brain parenchyma, and resection or embolization is associated with significant morbidity from venous infarction. They are often incidentally discovered in association with cavernomas, which are more frequently symptomatic. They do not independently progress and therefore do not require follow-up when discovered incidentally. However, in rare circumstances, they can present with arteriovenous shunting from adjacent arteriovenous malformations, which then alters the venous drainage pattern and evolution of symptoms. Core principles in defining the risk and management plan of a DVA are attribution of presenting symptoms to DVA or another source, identifying mechanism of DVA symptomatology for indirect treatment of these symptoms as an alternative to the DVA, and defining the DVA flow pattern.

Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults, and radiation is one of the main treatment modalities. However, cure rates remain low despite best available therapies. Immunotherapy is a promising modality that could work synergistically with radiation, which has been shown to increase antigen presentation and promote a proinflammatory tumor microenvironment. Programmed-death-1 (PD-1) is a surface receptor expressed on activated and exhausted T cells, which mediate T cell inhibition upon binding with its ligand PD-L1, expressed on many tumor types including human GBMs. We tested the combination of anti-PD-1 immunotherapy with stereotactic radiosurgery in a mouse orthotopic GBM model.We performed intracranial implantation of mouse glioma cell line GL261 transfected with luciferase into C57BL/6 mice. Mice were stratified into 4 treatment groups: (1) control; (2) radiation only; (3) anti-PD-1 antibody only; and (4) radiation plus anti-PD-1 antibody. Overall survival was quantified. The mice were killed on day 21 after implantation to assess immunologic parameters in the brain/tumor, cervical lymph nodes, and spleen.Improved survival was demonstrated with combination anti-PD-1 therapy plus radiation compared with either modality alone: median survival was 25 days in the control arm, 27 days in the anti-PD-1 antibody arm, 28 days in the radiation arm, and 53 days in the radiation plus anti-PD-1 therapy arm (P.05 by log-rank Mantle-Cox). Long-term survival was seen only in the combined treatment arm, with a fraction (15%-40%) of animals alive at day 180+ after treatment. Immunologic data on day 21 after implantation showed increased tumor infiltration by cytotoxic T cells (CD8+/interferon-γ+/tumor necrosis factor-α+) and decreased regulatory T cells (CD4+/FOXP3) in the combined treatment group compared with the single modality arms.The combination of PD-1 blockade and localized radiation therapy results in long-term survival in mice with orthotopic brain tumors. These studies provide strong preclinical evidence to support combination trials in patients with GBM.

Object Patients with trigeminal neuralgia due to multiple sclerosis (TN-MS) and idiopathic TN (ITN) who underwent glycerol rhizotomy (GR) and radiofrequency thermocoagulation with glycerol rhizotomy (RFTC-GR) were compared to investigate the effectiveness of these percutaneous ablative procedures in the TN-MS population. Methods Between 1998 and 2010, 822 patients with typical TN were evaluated; 63 (8%) had TN-MS and 759 (92%) had ITN. Pain relief comparisons were made between 22 GR procedures in patients with TN-MS and 470 GR procedures in patients with ITN; 50 RFTC-GR procedures in patients with TN-MS and 287 RFTC-GR procedures in patients with ITN were compared. Analysis of time to recurrence included only procedures that achieved complete pain relief without medications. Results After 15 of the GR procedures (68%) in patients with TN-MS and 315 of the procedures (67%) in those with ITN, the patients were pain free without medications (p = 0.736). After 36 of the RFTC-GR procedures (72%) in patients with TN-MS and 210 of the procedures (73%) in those with ITN, the patients were pain free without medications (p = 0.657). The difference in pain relief between GR and RFTC-GR for patients with TN-MS was not significant (p = 0.447). The median time to failure of GR was 20 months in patients with TN-MS compared with 25 months in those with ITN (p = 0.403). The median time to failure of RFTC-GR was 26 months in the TN-MS population compared with 21 months in the ITN population (p = 0.449). Patients with TN-MS experienced similar times to recurrence whether they were treated with GR or RFTC-GR (p = 0.431). Conclusions Pain relief and durability of relief outcomes of GR and RFTC-GR were similar in patients with TN-MS and ITN, reinforcing their use as preferred treatments of TN-MS. The GR and RFTC-GR achieved comparable outcomes in patients with TN-MS, suggesting that both can be used to good effect.

Successful application of endovascular neurosurgery depends on high-quality imaging to define the pathology and the devices as they are being deployed. This is especially challenging in the treatment of complex cases, particularly in proximity to the skull base or in patients who have undergone prior endovascular treatment. The authors sought to optimize real-time image guidance using a simple algorithm that can be applied to any existing fluoroscopy system. Exposure management (exposure level, pulse management) and image post-processing parameters (edge enhancement) were modified from traditional fluoroscopy to improve visualization of device position and material density during deployment. Examples include the deployment of coils in small aneurysms, coils in giant aneurysms, the Pipeline embolization device (PED), the Woven EndoBridge (WEB) device, and carotid artery stents. The authors report on the development of the protocol and their experience using representative cases.The stent deployment protocol is an image capture and post-processing algorithm that can be applied to existing fluoroscopy systems to improve real-time visualization of device deployment without hardware modifications. Improved image guidance facilitates aneurysm coil packing and proper positioning and deployment of carotid artery stents, flow diverters, and the WEB device, especially in the context of complex anatomy and an obscured field of view.

Vertebral artery dissection (VAD) is an important cause of ischemic stroke and subarachnoid hemorrhage (SAH). Dissections presenting with ischemia rarely cause SAH after more than a few hours, especially without radiographic evidence of pseudoaneurysm. We successfully treated a patient for persistent vessel injury presenting with SAH 7 years after presenting with extracranial subocclusive dissection of the right vertebral artery and an associated right posterior inferior cerebellar artery stroke. This is one of only three reported cases of delayed SAH occurring more than 2 weeks after an initial ischemic presentation of a VAD, and the only one without radiographic evidence of pseudoaneurysm at standard follow-up duration.

Haussen et al1 present an interesting series demonstrating an improvement in TICI (Thrombolysis in Cerebral Infarction) 3 revascularization using the push and fluff technique (PFT) for deploying the Trevo Retriever device (Stryker, MI) over standard unsheathing technique. PFT is an interesting technique which seems to be an adaptation of techniques first described in the pipeline embolization device, but there are distinct differences in the response of a braided stent and a closed cell laser-cut stent. The authors propose to increase radial force and clot capture of the stent by increasing coaxial force (pushing and fluffing). Although the authors suggest concerns regarding excessive radial force resulting in arterial rupture, we propose that …

OBJECT Moyamoya can cause cerebral ischemia and stroke in Down syndrome (DS) patients. In this study, the authors defined a surgically treated population of patients with DS and moyamoya and compared their clinical presentation, response to surgical treatment, and long-term prognosis with those of the general population of patients with moyamoya but without DS. METHODS This study was a retrospective review of a consecutive operative series of moyamoya patients with DS treated at Boston Children’s Hospital from 1985 through 2012. RESULTS Thirty-two patients, average age 9.7 years (range 1.8–29.3 years), underwent surgery for moyamoya in association with DS. The majority presented with ischemic symptoms (87% stroke, 42% transient ischemic attacks). Twenty-four patients (75%) had congenital heart disease. Nineteen patients (59%) had bilateral moyamoya on presentation, and 13 presented with unilateral disease, of which 2 progressed to surgery on the opposite side at a later date. Patients were followed for a median of 7.5 years (1–20.2 years) after surgery, with no patients lost to follow-up. Follow-up arteriography demonstrated Matsushima Grade A collaterals in 29 of 39 (74%) hemispheres, Grade B in 5 (13%), and Grade C in 5 (13%). Complications included postoperative strokes in 2 patients, which occurred within 48 hours of surgery in both; one of these patients had arm weakness and the other confusion (both had recovered completely at follow-up). Seizures occurred in 5 patients perioperatively, including one who had a new seizure disorder related to hypocalcemia. CONCLUSIONS Moyamoya disease is a cause of stroke in patients with DS. Both the incidence of preoperative stroke (87% vs 67%) and the average age at diagnosis for children under age 21 (8.4 vs 6.5 years) were greater in patients with DS and moyamoya than in the general moyamoya surgical population, suggesting a possible delay in reaching a correct diagnosis of the cause of cerebral ischemia in the DS patient population. Pial synangiosis provided long-term protection from stroke in all patients treated.

BACKGROUND Injury to the greater occipital nerve (GON) during suboccipital/retrosigmoid craniectomy (SOC) has been postulated as an etiology of postoperative headaches (HAs). We hypothesized that severe postoperative HAs may be due to the division of the GON during dissection. OBJECTIVE To determine whether the GON plays an important role in the development of postoperative HAs. METHODS A retrospective review of prospectively accrued patients undergoing SOC by 1 neurosurgeon at Johns Hopkins from 1995 to 2009 was performed. A total of 280 patients were included in the study. HA was categorized into 3 groups according to the severity and impact on daily activities. Data were analyzed using a stepwise multivariate logistic regression analysis to identify independent factors associated with HA development. Patients with a history of preoperative HAs and migraine were excluded from the analysis. RESULTS In this cohort, new postoperative severe HAs at last follow-up visit were found in 19% of patients. By multivariate analysis, only GON preservation (relative risk: 1.49; 95% confidence interval: 1.00-2.34; P = 0.05) and wound infection (relative risk: 2.29; 95% confidence interval: 0.91-4.25; P = 0.07) were statistically significant. By univariate analysis, positive dependent associations included GON preservation (P < .01), reconstruction of the porus with hydroxyapatite cement (P = 0.02), and wound infection (P < 0.01). Statistically significant differences in the incidence of HA after surgery were found in patients in whom the GON was preserved compared with patients in whom the GON was divided (P = 0.035). CONCLUSION Postoperative debilitating HAs are a common complication after SOC. Although these HAs are probably multifactorial in nature, preservation of the GON during SOC is independently associated with postoperative debilitating HAs.

Supratentorial arteriovenous malformations in eloquent territories can be difficult to resect. This video presents the treatment of a patient with a symptomatic 3-cm arteriovenous malformation in the left motor strip. At the authors’ institution, per the surgeon’s discretion, preoperative angiography is performed to evaluate the need for preoperative embolization. Multimodality treatment reduced the microsurgical risk by allowing early occlusion of a draining vein, by decreasing overall intraoperative hemorrhage, and by allowing minimal pial dissection in the deep aspect of the arteriovenous malformation that abutted the corticospinal tract. The choice of embolysate was an additional nuance of the embolization.The video can be found here: https://youtu.be/HWZ0RjgPEXg.

Occlusion of the basilar artery can be treated with endovascular thrombectomy, although the results have not been well studied. Persistent fetal cerebrovascular anatomy can lead to unusual presentation of carotid atherosclerotic disease and can be a barrier to successful mechanical thrombectomy if not recognized. This case presents a rare persistent carotico–basilar anastomosis which resulted in basilar occlusion via the persistent hypoglossal artery and coincident absence of contralateral vertebral arterial access due to a left vertebral artery terminating in the left posterior inferior cerebellar artery. Preoperative recognition of this anatomy afforded by review of cross-sectional imaging was critical to success during this emergent procedure.

Background Stenosing flexor tenosynovitis of the digital flexor tendon (trigger digit) is a common condition encountered by hand surgeons. Our purpose was to determine the efficacy of corticosteroid injections and review the demographic profile of patients with trigger digits. Methods We reviewed the records of 362 patients (577 trigger digits) treated with steroid injections (8 mg of triamcinolone acetonide in 1 % lidocaine) from 1998 through 2011. Follow-up (intervention to last visit) averaged 66.4 months. We assessed patient demographics (e.g., gender, age, diabetes mellitus, hand dominance, trigger digit distribution) and determined recurrence rate and injection duration of efficacy. If one injection failed, additional injections or surgical A1 pulley release were offered. Results were analyzed with Student's t test or Fisher's exact test (significance, pResults Women (258, 71.3 %) were affected significantly ( pConclusions Injection therapy is safe and highly effective (79.7 %). Women were affected by trigger digits more often than men and at a younger age. Surgical release provides a definitive therapeutic option if corticosteroid injection fails.

Introduction Aneurysms of the paraclinoid region of the internal carotid artery (ICA) and the interventions used to treat them often result in visual impairment. Because of the proximity of these aneurysms to the optic nerve and the ophthalmic artery, between 16% and 53% of patients present with visual deficits. While flow diversion is increasingly used throughout endovascular neurosurgery, few studies have reported the visual outcomes of treating paraclinoid aneurysms with this technique or compared it to coiling or clipping. Hypothesis In order to satisfy demand for data on the visual outcomes for this new endovascular treatment modality and inform the contemporary management of paraclinoid aneurysms, we performed a retrospective analysis of patients with paraclinoid aneurysms treated at our site with a Pipeline embolization device (PED). Methods We compiled visual outcome data for 20 patients presenting with 26 paraclinoid aneurysms and treated at our site with flow diversion, 10 of whom (totaling 13 aneurysms) presented with visual impairment. We then reviewed vision outcomes in these patients at discharge and at 6 months, noting improved, unchanged, deteriorated, or newly impaired vision. We also performed an extensive literature review to compile data (1447 cases from 21 sites) on vision outcomes for paraclinoid aneurysms treated with clips (534 cases), coils (638), or flow diverters (275). Results Of twenty patients with 26 paraclinoid aneurysms treated at our site with a PED, ten patients (totaling 13 aneurysms with an average diameter of 7.1 mm) presented with preoperative visual impairment. Visual deficits were improved in 8 patients (80%) and unchanged in 2 (20%) following treatment. No patients experienced sustained worsening of their existing visual impairment, however one patient acquired postoperative iatrogenic vision impairment (5%). A literature review of paraclinoid aneurysm treatment revealed visual improvement rates of approximately 41% for clipping, 54% for coiling, and 73% for flow diversion, visual deterioration rates of approximately 14%, 23%, and 2%, and newly impaired vision rates of 9%, 3%, and 4%. Conclusion Compared to clipping and coiling, flow diversion demonstrates a higher rate of visual improvement and a lower rate of visual decline in patients with visually symptomatic paraclinoid aneurysms, with comparable risk of iatrogenic vision impairment. We report strong visual outcomes in patients treated at our site for paraclinoid aneurysms with a PED, including small aneurysms. Our results suggest that this new treatment modality yields improved vision outcomes in patients with paraclinoid aneurysms compared to clipping and coiling. Disclosures M. Silva: None. A. See: None. H. Dasenbrock: None. P. Khandelwal: None. N. Patel: None. M. Aziz-Sultan: 2; C; Covidien.

The dynamic, hemodynamic impact of a cervical dissection on an ipsilateral, intracranial saccular aneurysm has not been well illustrated. This 45-year-old female was found to have a small, supraclinoid aneurysm ipsilateral to a spontaneous cervical internal carotid artery dissection. With healing of the dissection, the aneurysm appeared to have significantly enlarged. Retrospective review of the magnetic resonance imaging (MRI) at the time of the initial dissection demonstrated thrombus, similar in overall morphology to the angiographic appearance of the "enlarged" aneurysm. As the dissection healed far proximal to the intradural portion of the internal carotid artery, this suggested that the aneurysm was likely a typical, saccular posterior communicating artery aneurysm that had thrombosed and then recanalized secondary to flow changes from the dissection. The aneurysm was coiled uneventfully, in distinction from more complex treatment approaches such as flow diversion or proximal occlusion to treat an enlarging, dissecting pseudoaneurysm. This case illustrates that flow changes from cervical dissections may result in thrombosis of downstream saccular aneurysms. With healing, these aneurysms may recanalize and be misidentified as enlarging dissecting pseudoaneurysms. Review of an MRI from the time of the dissection facilitated the conclusion that the aneurysm was a saccular posterior communicating artery aneurysm, influencing treatment approach.