Faculty Bibliography

Adoption of middle meningeal artery embolization in the management of chronic subdural hematomas has led to a renewed interest in dural vascular anatomy. The readily identifiable major dural arteries and potential hazards associated with their embolization are well described. Less emphasized are several levels of intrinsic dural angioarchitecture, despite their more direct relationship to dural based diseases, such as subdural hematoma and dural fistula. Fortunately, microvascular aspects of dural anatomy, previously limited to ex vivo investigations, are becoming increasingly accessible to in vivo visualization, setting the stage for synthesis of the old and the new, and providing a rationale for the endovascular approach to subdural collections in particular. In contrast with traditional anatomical didactics, where descriptions advance from larger trunks to smaller pedicles, we present a strategic approach that proceeds from a fundamental understanding of the dural microvasculature and its relationship to larger vessels.

OBJECTIVE:Cerebral aneurysms in the pediatric population are rare and optimal treatment strategies are not as well characterized as in adults. The Pipeline embolization device (PED) is an endoluminal flow diverter that is commonly used to treat aneurysms in adults, but experience with this device in children is limited. The authors sought to further characterize PED use and outcomes in this specific population by performing both a systematic review of patient-level data from studies reporting the use of the PED to treat pediatric aneurysms and a retrospective review of their experience. METHODS:A systematic review of the PubMed, Embase, and Scopus databases was performed to identify studies reporting the use of the PED in pediatric patients (age ≤ 18 years). Disaggregated data regarding demographics, aneurysm characteristics, treatment, and outcomes were collected. Retrospective data from the authors' two institutions were also included. RESULTS:Thirty studies comprising patient-level data on 43 pediatric patients with 47 aneurysms were identified. An additional 9 patients with 9 aneurysms were included from the authors' institutions for a total of 52 patients with 56 aneurysms. The mean patient age was 11.1 years. Presentations included aneurysm rupture (17.3%) and symptomatic mass effect (23.1%). Aneurysms were located in the anterior circulation in 55.4% of cases, and 73.2% were described as nonsaccular. Imaging follow-up was available for 89.3% with a mean follow-up of 13.3 months. Aneurysm occlusion was reported in 75%, with 1 case each (1.8%) demonstrating significant in-stent stenosis and parent vessel occlusion. Clinical follow-up was reported in 90.4% with a mean follow-up of 14.7 months. Good functional outcomes (modified Rankin Scale score of 0-1 or Glasgow Outcome Scale score of 5) were reported in 65.4% of the total population. Two major complications were reported, including 1 death. CONCLUSIONS:Despite substantial differences in aneurysm location and type between published pediatric and adult patient populations treated with the PED, the use of the PED in the pediatric population appears to be safe. While the short-term effectiveness is also similar to that of adults, additional studies are needed to further characterize the long-term outcomes and better define the use of this device in pediatric patients.

BACKGROUND:In the post-Carotid Occlusion Surgery Study (COSS) era, multiple reviews suggested subset groups of patients as potential candidates for superficial temporal artery to middle cerebral artery (STA-MCA) bypass. Among them are patients with recurrent strokes despite optimal medical therapy. There is a paucity of data on the outcome of bypass in these specific patients. OBJECTIVE:To examine the safety and efficacy of direct STA-MCA bypass in patients with nonmoyamoya, symptomatic steno-occlusive disease with impaired distal perfusion, who failed optimal medical management or endovascular treatment. METHODS:A retrospective review was performed to identify patients with cerebrovascular steno-occlusive disease who underwent bypass after symptomatic recurrent or rapidly progressive strokes, despite optimal conservative or endovascular treatment. RESULTS:A total of 8 patients (mean age 60 ± 6 yr) underwent direct or combined direct/indirect STA-MCA bypass between 2016 and 2019. All anastomoses were patent. One bypass carried slow flow. There were no procedure-related permanent deficits. One patient developed seizures which were controlled by medications. A total of 7 out of 8 patients were stable or improved clinically at last follow-up (mean 27.3 ± 13.8 mo) without recurrent strokes. One patient did not recover from their presenting stroke, experienced severe bilateral strokes 4 mo postoperatively, and subsequently expired. Modified Rankin Scale (mRS) improved in 6 patients (75%), remained stable in 1 patient (12.5%), and deteriorated in 1 (12.5%). Good long-term functional outcome was achieved in 5 patients (63%, mRS ≤ 2). CONCLUSION/CONCLUSIONS:Patients with symptomatic, hypoperfused steno-occlusive disease who fail optimal medical or endovascular treatment may benefit from cerebral revascularization. Direct or combined STA-MCA bypass was safe and provided favorable outcomes in this small series.

Initially developed for large and giant wide-necked aneurysms of the internal carotid artery, flow diverter devices are now used in almost every location safely and with effectiveness.1-5 This video demonstrates a unique case of a giant aneurysm of the right petrous internal carotid artery in a 20-yr-old patient. This is an extremely rare location, and most of patients are asymptomatic.3-6 Signs of compression of the seventh and eight cranial nerves can be present and even Horner syndrome and lower cranial nerves neuropathies. Nevertheless, rupture can lead to epistaxis and otorrhagia, and ultimately to hemorrhagic shock. The patient in the current report was otherwise healthy but presented with lightheadedness and dizziness for 10 d. The patient consented to the procedure. There was no history of major trauma or head and neck infection. A transradial endovascular flow diversion embolization of a giant aneurysm of the petrous internal carotid artery is herein demonstrated in a stepwise manner. A triaxial system was used to deploy 3 overlapping devices. Concepts of J-wire technique, multiple coverage,1 and the so-called weld technique are emphasized. The role of adjunctive coiling and main reasons for failure are also discussed.7,8 Brief cases of flow diversion embolization of aneurysms of different morphologies at different locations are used to highlight the importance of assessing vessel wall apposition and follow-up imaging.

BACKGROUND AND IMPORTANCE/BACKGROUND:Spinal cord infarction is rare but can be extremely disabling. Prompt diagnosis and treatment of these infarcts is important for patient outcomes. While intravenous thrombolytic therapy is a well-established form of treatment in circumstances of cerebral stroke, it has only recently been successfully used in a few incidents of spinal cord ischemia. We present a case of anterior spinal artery (ASA) territory ischemia treated with ASA intra-arterial thrombolytic therapy. CLINICAL PRESENTATION/METHODS:A 52-year-old male presented with acute onset of severe lumbar pain, rapidly progressing paraplegia and loss of pain and temperature sensation, with preservation of proprioception and vibratory sensation at the L1 level and below on the right and at the L3 level and below on the left. MRI showed restricted diffusion involving the cord at and below L1 level, with normal cord T2 signal. Digital subtraction spinal angiography showed ASA cutoff in the descending limb at the level of L1. Intra-arterial tissue plasminogen activator (t-PA) combined with verapamil and eptifibatide was administered within the ASA and the patient had significant neurological improvement immediately postoperatively and at 8-month clinical follow-up. CONCLUSION/CONCLUSIONS:Direct ASA intra-arterial thrombolysis is feasible, and this drug combination might be an effective therapy for spinal stroke.

INTRODUCTION/BACKGROUND:The carotid web is a compelling potential mechanism of embolic ischemic stroke. In this study, we aim to determine the prevalence of ipsilateral carotid web in a cohort of ischemic stroke patients and to perform a systematic review and meta-analysis of similar cohorts. PATIENTS & METHODS/METHODS:We performed a retrospective, observational, cohort study of acute ischemic stroke patients admitted to a comprehensive stroke center from June 2012 to September 2017. Carotid web was defined on computed tomography angiography (CTA) as a thin shelf of non-calcified tissue immediately distal to the carotid bifurcation. We described the prevalence of carotid artery webs in our cohort, then performed a systematic review and meta-analysis of similar cohorts in the published literature. RESULTS:We identified 1,435 potentially eligible patients of whom 879 met criteria for inclusion in our analysis. An ipsilateral carotid web was detected in 4 out of 879 (0.45%) patients, of which 4/4 (1.6%) were in 244 patients with cryptogenic stroke and 3/4 were in 66 (4.5%) patients <60 years old with cryptogenic stroke. Our systematic review yielded 3,192 patients. On meta-analysis, the pooled prevalence of ipsilateral carotid web in cryptogenic stroke patients <60 was 13% (95% CI: 7%-22%; I2 = 66.1%). The relative risk (RR) of ipsilateral versus contralateral carotid web in all patients was 2.5 (95% CI 1.5-4.2, p = 0.0009) whereas in patients less than 60 with cryptogenic stroke it was 3.0 (95% CI 1.6-5.8, p = 0.0011). DISCUSSION/CONCLUSIONS:Carotid webs are more common in young patients with cryptogenic stroke than in other stroke subtypes. Future studies concerning the diagnosis and secondary prevention of stroke associated with carotid web should focus on this population.

The carotid web is a proposed stroke mechanism that may underlie cryptogenic stroke, particularly in younger patients without vascular risk factors. The web appears as a shelf-like projection into the lumen of the proximal cervical internal carotid artery without evidence of calcification. It is pathologically defined as intimal fibromuscular dysplasia. Altered haemodynamics distal to the web cause flow stagnation and remote embolisation of fibrin-based clots. It is best demonstrated and diagnosed on CT angiography (CTA) of the neck because of its ability to resolve calcium and create multiplanar reconstructions. Although they can be readily visualised on CTA, carotid webs may be missed or misinterpreted because they do not typically cause haemodynamically significant stenosis and can mimic arterial dissection, non-calcified atherosclerotic plaque and intraluminal thrombus. Options for management include antiplatelet therapy, carotid endarterectomy and carotid artery stenting. Modern management strategies for cryptogenic stroke include long-term cardiac monitoring, further investigation for structural cardiac disease and a diagnostic workup for arterial hypercoagulability, however, these strategies are not likely to capture the possibility of a carotid web. Carotid webs should be suspected in a young patient presenting with recurrent unihemispheric strokes particularly when conventional vascular risk factors are not present.

BACKGROUND:Attainment of basic microsurgical skills in neurosurgery presents a departmental challenge worldwide. Models for teaching are either not readily available or expensive, and are incompatible with a resident's busy schedule, requiring lengthy and proper setup. OBJECTIVE:Presenting a model and a set of measurable tasks, based upon a fruit (orange) which is cheap, easy to setup instantly when desired and can be used for training of basic microsurgical skills. METHODS:Basic microsurgical skills were identified necessitating hand-eye coordination working with the microscope. The goal was to dissect an orange segment, while preserving adjacent segments. Assessment was based on the number of side tears and task completion duration. Task was repeated in sequential manner (N=10), for validation purposes, for 3 operators at different seniority levels. RESULTS:trial, p<0.01), as well as duration of time required for task completion (mean initial duration of 28:16+-19:00 minutes to a duration of 16:33+-10:50 minutes in the last attempt ,p<0.01)was observed. Daily practice scores and time gradually improved, and seniority level of operators was correlated with scoring between individuals. CONCLUSION/CONCLUSIONS:The orange model is an easily accessible, cheap model enables the acquisition of basic micro-neurosurgical skills. In this work, we validated and defined reproducible tasks that can be scored and tracked, correlated with operator's proficiency and experience. This model can be incorporated into a resident's workflow environment and provides a platform for attainment of elementary microsurgical skills for neurosurgical residents.

BACKGROUND AND PURPOSE/OBJECTIVE:Mechanical thrombectomy (MT) has helped many patients achieve functional independence. The effect of time-to-treatment based in specific epochs and as related to Alberta Stroke Program Early CT Score (ASPECTS) has not been established. The goal of the study was to evaluate the association between last known normal (LKN)-to-puncture time and good functional outcome. METHODS:We conducted a retrospective cohort study of prospectively collected acute ischemic stroke patients undergoing MT for large vessel occlusion. We used binary logistic regression models adjusted for age, Modified Treatment in Cerebral Ischemia score, initial National Institutes of Health Stroke Scale, and noncontrast CT ASPECTS to assess the association between LKN-to-puncture time and favorable outcome defined as Modified Rankin Score 0-2 on discharge. RESULTS:Among 421 patients, 328 were included in analysis. Increased LKN-to-puncture time was associated with decreased probability of good functional outcome (adjusted odds ratio [aOR] ratio per 15-minute delay = .98; 95% confidence interval [CI], .97-.99; P = .001). This was especially true when LKN-puncture time was 0-6 hours (aOR per 15-minute delay = .94; 95% CI, .89-.99; P = .05) or ASPECTS 8-10 (aOR = .98; 95% CI, .97-.99; P = .002) as opposed to when LKN-puncture time was 6-24 hours (aOR per 15-minute delay = .99; 95% CI, .97-1.00; P = .16) and ASPECTS <8 (aOR = .98; 95% CI, .93-1.03; P = .37). CONCLUSION/CONCLUSIONS:Decreased LKN-groin puncture time improves outcome particularly in those with good ASPECTS presenting within 6 hours. Strategies to decrease reperfusion times should be investigated, particularly in those in the early time window and with good ASPECTS.