Faculty Bibliography

OBJECTIVE:The carotid web (CW) is an underrecognized source of cryptogenic, embolic stroke in patients younger than 55 years of age, with up to 37% of these patients found to have CW on angiography. Currently, there are little data detailing the best treatment practices to reduce the risk of recurrent stroke in these patients. The authors describe their institutional surgical experience with patients treated via carotid endarterectomy (CEA) for a symptomatic internal carotid artery web. METHODS:A retrospective, observational cohort study was performed including all patients presenting to the authors' institution with CW. All patients who were screened underwent either carotid artery stenting (CAS) or CEA after presentation with ischemic stroke from January 2019 to February 2020. From this sample, patients with suggestive radiological features and pathologically confirmed CW who underwent CEA were identified. Patient demographics, medical histories, radiological images, surgical results, and clinical outcomes were collected and described using descriptive statistics. RESULTS:A total of 45 patients with symptomatic carotid lesions were treated at the authors' institution during the time period. Twenty patients underwent CAS, 1 of them for a CW. Twenty-five patients were treated via CEA, and of these, 6 presented with ischemic strokes ipsilateral to CWs, including 3 patients who presented with recurrent strokes. The mean patient age was 55 ± 12.6 years and 5 of 6 were women. CT angiography or digital subtraction angiography demonstrated the presence of CWs ipsilateral to the stroke in all patients. All patients underwent resection of CWs using CEA. There were no permanent procedural complications and no patients had stroke recurrence following intervention at the latest follow-up (mean 6.1 ± 4 months). One patient developed mild tongue deviation most likely related to retraction, with complete recovery at follow-up. CONCLUSIONS:CEA is a safe and feasible treatment for symptomatic carotid webs and should be considered a viable alternative to CAS in this patient population.

We present a patient who was diagnosed 20 yr prior to current presentation with a spinal arteriovenous malformation. This patient had a 10-yr history of worsening back pain (and underwent lumbar fusion), urinary dysfunction leading to 3-yr dependence on intermittent catheterization, lower extremity paresthesias and pain, and progressive weakness with multiple falls, leading to walker then wheelchair dependence for mobility. Magnetic resonance studies showed extensive thoracic cord expansion and edema with enlarged spinal cord surface veins and flow voids extending from spinal levels T6 to the conus medullaris. Partial embolization at an outside institution elicited transient symptom improvement. Repeated spinal angiogram demonstrated persistent T10 pial arteriovenous fistula (AVF) supplied by the posterior spinal artery arising from the right T11 segmental artery as well as by the anterior spinal artery from the left T10 segmental artery. Because additional embolization carried significant risk, we planned open surgery with fistula resection. Informed consent for the surgery and video recording was obtained. The patient was placed in the prone position, and a radial artery access was obtained for intraoperative angiogram. Following a posterior T9-T11 laminectomy and dural opening, a pial dissection was performed to expose the AVF. Intraoperative indocyanine green angiography was used to assist in identifying the feeders and major drainage of the AVF. Post-AVF resection, a formal intraoperative radial access spinal angiogram demonstrated complete resection of the lesion with no residual shunt or early venous drainage. The patient improved significantly and, on last follow-up, is ambulating without any assistive devices.

Our perspective on anatomy frequently depends on how this anatomy is utilized in clinical practice, and by which methods knowledge is acquired. The thrombectomy revolution, of which the middle cerebral artery (MCA) is the most common target, is an example of a clinical paradigm shift with a unique perspective on cerebrovascular anatomy. This article reviews important features of MCA anatomy in the context of thrombectomy. Recognizing that variation, frequently explained by evolutionary concepts, is the rule when it comes to branching pattern, vessel morphology, territory, or collateral potential is key to successful thrombectomy strategy.

Despite the severity of coronavirus disease 2019 (COVID-19) being more frequently related to acute respiratory distress syndrome and acute cardiac and renal injuries, thromboembolic events have been increasingly reported. We report a unique series of young patients with COVID-19 presenting with cerebral venous system thrombosis. Three patients younger than 41 years of age with confirmed Severe Acute Respiratory Syndrome coronavirus 2 (SARS-Cov-2) infection had neurologic findings related to cerebral venous thrombosis. They were admitted during the short period of 10 days between March and April 2020 and were managed in an academic institution in a large city. One patient had thrombosis in both the superficial and deep systems; another had involvement of the straight sinus, vein of Galen, and internal cerebral veins; and a third patient had thrombosis of the deep medullary veins. Two patients presented with hemorrhagic venous infarcts. The median time from COVID-19 symptoms to a thrombotic event was 7 days (range, 2-7 days). One patient was diagnosed with new-onset diabetic ketoacidosis, and another one used oral contraceptive pills. Two patients were managed with both hydroxychloroquine and azithromycin; one was treated with lopinavir-ritonavir. All patients had a fatal outcome. Severe and potentially fatal deep cerebral thrombosis may complicate the initial clinical presentation of COVID-19. We urge awareness of this atypical manifestation.

During the coronavirus disease 2019 (COVID-19) pandemic, the World Health Organization recommended measures to mitigate the outbreak such as social distancing and confinement. Since these measures have been put in place, anecdotal reports describe a decrease in the number of endovascular therapy (EVT) treatments for acute ischemic stroke due to large vessel occlusion. The purpose of our study was to determine the effect on EVT for patients with acute ischemic stroke during the COVID-19 confinement. In this retrospective, observational study, data were collected from November 1, 2019, to April 15, 2020, at 17 stroke centers in countries where confinement measures have been in place since March 2020 for the COVID-19 pandemic (Switzerland, Italy, France, Spain, Portugal, Germany, Canada, and United States). This study included 1600 patients treated by EVT for acute ischemic stroke. Date of EVT and symptom onset-to-groin puncture time were collected. Mean number of EVTs performed per hospital per 2-week interval and mean stroke onset-to-groin puncture time were calculated before confinement measures and after confinement measures. Distributions (non-normal) between the 2 groups (before COVID-19 confinement versus after COVID-19 confinement) were compared using 2-sample Wilcoxon rank-sum test. The results show a significant decrease in mean number of EVTs performed per hospital per 2-week interval between before COVID-19 confinement (9.0 [95% CI, 7.8-10.1]) and after COVID-19 confinement (6.1 [95% CI, 4.5-7.7]), (P<0.001). In addition, there is a significant increase in mean stroke onset-to-groin puncture time (P<0.001), between before COVID-19 confinement (300.3 minutes [95% CI, 285.3-315.4]) and after COVID-19 confinement (354.5 minutes [95% CI, 316.2-392.7]). Our preliminary analysis indicates a 32% reduction in EVT procedures and an estimated 54-minute increase in symptom onset-to-groin puncture time after confinement measures for COVID-19 pandemic were put into place.

BACKGROUND AND PURPOSE/OBJECTIVE:Tentorial sinus venous channels within the tentorium cerebelli connecting various cerebellar and supratentorial veins, as well as the basal vein, to adjacent venous sinuses are a well-recognized entity. Also well-known are "dural lakes" at the vertex. However, the presence of similar channels in the supratentorial dura, serving as recipients of the Labbe, superficial temporal, and lateral and medial parieto-occipital veins, among others, appears to be underappreciated. Also under-recognized is the possible role of these channels in the angioarchitecture of certain high-grade dural fistulas. MATERIALS AND METHODS/METHODS:A retrospective review of 100 consecutive angiographic studies was performed following identification of index cases to gather data on the angiographic and cross-sectional appearance, location, length, and other features. A review of 100 consecutive dural fistulas was also performed to identify those not directly involving a venous sinus. RESULTS:Supratentorial dural venous channels were found in 26% of angiograms. They have the same appearance as those in the tentorium cerebelli, a flattened, ovalized morphology owing to their course between 2 layers of the dura, in contradistinction to a rounded cross-section of cortical and bridging veins. They are best appreciated on angiography and volumetric postcontrast T1-weighted images. Ten dural fistulas not directly involving a venous sinus were identified, 6 tentorium cerebelli and 4 supratentorial. CONCLUSIONS:Supratentorial dural venous channels are an under-recognized entity. They may play a role in the angioarchitecture of dural arteriovenous fistulas that appear to drain directly into a cortical vein. We propose "dural venous channel" as a unifying name for these structures.

OBJECTIVE:Middle meningeal artery (MMA) embolization may be an effective means of inhibiting neovascularization of the subdural capsular membrane and preventing hematoma maintenance. We sought to better understand how the MMA may affect subdural hematoma physiology and how this process may be modified by embolization. METHODS:A retrospective review was done. We studied 27 patients with 29 SDHs who underwent MMA embolization from July 2018 to May 2019. Eight of these patients had post-embolization DynaCT imaging and were included. RESULTS:Average patient age was 75 years old. Baseline non-contrast head CT showed the presence of a hematoma membrane in all 8 patients. Post-embolization DynaCTs in all patients demonstrated enhancement of all four components (dura, capsular membrane, septations, and subdural hematoma fluid). All patients had a minimum 60-day imaging and clinical follow-up. There was an average 87% decrease in SDH volume at last follow-up compared to baseline. There was a significant difference between the average baseline and average last follow-up SDH volume (paired t-test, p < 0.0001) in all patients. Average last follow-up scan was 89 days (range 61-122 days) from the date of procedure. No patient experienced post-embolization complications, subsequent SDH drainage, or mortality. CONCLUSIONS:Our data lends support to the theory of contiguous vascular networks between the MMA and SDH membranes. Targeting these leaky vascular networks may remove the source of hematoma accumulation. This adds to the pathophysiological understanding of the disease and suggests potential insight into the mechanism of action of MMA embolization.

BACKGROUND:Verification of complete occlusion or resection of neurovascular lesions is often done with intraoperative angiography. Surgery for spinal vascular lesions such as arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs) is typically performed in the prone position making intraoperative angiography difficult. There is no standardized protocol for intraoperative angiography in spinal surgeries performed in the prone position. OBJECTIVE:We describe our experience with using radial artery access for intraoperative angiography in thoracic spinal neurovascular procedures performed with patients in the prone position. METHODS:We reviewed all patients who underwent surgical resection of spinal vascular lesions in the prone position with radial artery vascular access for intraoperative angiography. Patients were treated in a hybrid endovascular operating room. RESULTS:4 patients were treated in the pone position utilizing transradial artery access intraoperative angiography for confirmation of complete resection of the vascular lesions. 2 patients were operated for dural AVFs, one patient had a pial AVF, and one patient had an AVM of the filum terminale. None of the patients faced any procedural complications. CONCLUSION/CONCLUSIONS:Radial artery access for intraoperative angiography in spinal neurovascular procedures in which selective catheterization of a thoracic branch is necessary, is feasible, safe, and practical.

INTRODUCTION/BACKGROUND:The glial-lymphatic pathway is a fluid-clearance pathway consisting of a para-arterial route for the flow of cerebrospinal fluid along perivascular spaces and subsequently toward the brain interstitium. In this case series we aim to investigate an empirical demonstration of glymphatic clearance of extravasated iodine following perforation incurred during endovascular therapy on serial CT. METHODS AND RESULTS/RESULTS:Six consecutive cases of endovascular perforation during thrombectomy performed between 2005 and 2018 were retrospectively collected by searching our internal database of total 446 thrombectomies. Two cases were excluded because care was withdrawn shortly following the procedure and no follow-up imaging was available. One case was excluded because a ventricular drain was placed. Three cases were hence included in this analysis. All three cases demonstrated progressive absorption of contrast by the brain parenchyma with eventual contrast disappearance. CONCLUSION/CONCLUSIONS:We described a likely in vivo CT correlate of the glymphatic system in a cohort of patients who sustained intraprocedural extravasation during thrombectomy for acute ischemic stroke.

BACKGROUND:Spinal epidural lipomatosis (SEL) is a rare condition defined as pathological overgrowth of the normally present epidural fat within the spinal canal. SEL is associated with Cushing disease, obesity and chronic corticosteroid therapy. Diabetes mellitus type 1 (DM1) has not known to be a risk factor for SEL. The neurological symptoms of SEL are attributed mainly to mechanical compression on the spinal cord and the cauda equina. METHODS:A retrospective chart review of patients evaluated at NYU Multiple Sclerosis Care Center identified three diabetic patients with progressive myelopathy associated with SEL. We report the clinical course, diagnostic workup and outcomes in these three patients with SEL-associated myelopathy. RESULTS:Three patients (2 females and 1 male) had long-standing DM1 and developed progressive myelopathy in their early 40's. All were found to have thoracic SEL (extensive extradural T1, T2 hyperintense signal; biopsy confirmed in one case) with associated extensive abnormal cord signal in lower cervical/upper thoracic spinal cord. A comprehensive evaluation for metabolic, infectious, autoimmune and vascular causes of myelopathy that included serologies, cerebrospinal fluid analyses, and spinal angiography did not reveal an alternative cause for myelopathy. One of the patients underwent a surgical decompression of SEL with subsequent clinical and radiologic improvement. CONCLUSIONS:Our case series suggest that patients with DM1 and myelopathy of unknown cause should be evaluated for SEL. Timely diagnosis and appropriate intervention may forestall progression of neurological disability and even result in neurologic improvement. SEL should be considered on the short list of diagnoses that cause potentially reversible progressive myelopathy.