Faculty Bibliography

BACKGROUND AND PURPOSE/OBJECTIVE:Flow diversion is being increasingly used to treat bifurcation aneurysms. Empiric approaches have generally led to encouraging results, and a growing body of animal and ex vivo literature addresses the fate of target aneurysms and covered branches. Our prior investigations highlighted the dynamic nature of metal coverage provided by the Pipeline Embolization Device and suggested strategies for creating optimal single and multidevice constructs. We now address the geometric and hemodynamic aspects of jailing branch vessels and neighboring target aneurysms. MATERIALS AND METHODS/METHODS:Fundamental electric and fluid dynamics principles were applied to generate equations describing the relationships between changes in flow and the degree of vessel coverage in settings of variable collateral support to the jailed territory. Given the high complexity of baseline and posttreatment fluid dynamics, in vivo, we studied a simplified hypothetic system with minimum assumptions to generate the most conservative outcomes. RESULTS:In the acute setting, Pipeline Embolization Devices modify flow in covered branches, principally dependent on the amount of coverage, the efficiency of collateral support, and intrinsic resistance of the covered parenchymal territory. Up to 30% metal coverage of any branch territory is very likely to be well-tolerated regardless of device or artery size or the availability of immediate collateral support, provided, however, that no acute thrombus forms to further reduce jailed territory perfusion. CONCLUSIONS:Basic hemodynamic principles support the safety of branch coverage during aneurysm treatment with the Pipeline Embolization Device. Rational strategies to build bifurcation constructs are feasible.

Background/UNASSIGNED:Variations in aortic arch anatomy have been extensively described from multiple perspectives including gross anatomy, embryology, associated cardiac and other anomalies, early life presentation, and cross-sectional diagnosis. There is however a paucity of literature with an emphasis on safe and timely catheterization, particularly when the variants are found during emergent or other catheter angiographic procedures without benefit of prior cross-sectional vascular imaging. The purpose of this review is to try to fill this gap. Methods/UNASSIGNED:A review of past 1,000 diagnostic and therapeutic catheterizations was performed to identify arch variants, which are presented in order of frequency encountered at our institutions. Results/UNASSIGNED:The variants are presented as illustrations and catheter angiographic images, with emphasis on safe and efficient intraprocedural diagnosis and catheterization. Conclusion/UNASSIGNED:Familiarity with more and less common arch variants, along with low threshold for performance of pigtail aortic arch angiography and comfort in use of general purpose and recurved catheters, will ensure success in the vast majority of encountered variations.

BACKGROUND AND PURPOSE/OBJECTIVE:Our aim was to propose a conceptually new angioarchitectural model of some dural arteriovenous fistulas based on subset analysis of transverse and sigmoid type lesions. The "common collector" notion argues for convergence of multiple smaller caliber arterial vessels on a common arterial collector vessel within the sinus wall. Communication of this single collector (or constellation of terminal collectors) with the sinus proper defines the site of arteriovenous fistula, which can be closed by highly targeted embolization, preserving the sinus and avoiding unnecessary permeation of indirect arterial feeders. MATERIALS AND METHODS/METHODS:One hundred consecutive dural arteriovenous shunts were examined. Thirty-six transverse/sigmoid fistulas were identified within this group and analyzed for the presence of a common arterial collector as well as other parameters, including demographics, grade, treatment approach, and outcome. RESULTS:A common collector was identified in nearly all Cognard type I lesions (15 fistulas with 14 single collector vessels seen) and progressively less frequently in higher grade fistulas. Identification of the common collector requires careful angiographic analysis, including supraselective and intraprocedural angiographies during treatment, and final embolic material morphology. CONCLUSIONS:Detailed evaluation of imaging studies allows frequent identification of a vascular channel in the sinus wall, which we argue reflects a compound, common arterial channel (rather than a venous collector) with 1 or several discrete fistulous points between this vessel and the sinus proper. Targeted closure of this channel is often feasible, with sinus preservation and avoidance of embolic material penetration into arteries remote from fistula site.

BACKGROUND AND PURPOSE/OBJECTIVE:Spinal arterial aneurysms are a rare cause of spinal subarachnoid hemorrhage (SAH). We performed a retrospective review of spinal arterial aneurysms not associated with spinal arteriovenus shunts from three institutions in order to better understand the clinical and imaging characteristics of these lesions. MATERIALS AND METHODS/METHODS:We performed a retrospective review of spinal arterial aneurysms managed at three North American institutions. For each patient, the following information was collected: demographic data, clinical presentation, comorbidities, imaging findings, and neurological status at the last follow-up. Treatment strategies and outcomes were reported. RESULTS:11 patients were included; 7 were women and median age was 60 years. The most common presentation was sudden back pain (81.8%). We found 3 aneurysms on the radiculomedullary artery and 8 along the radiculopial arteries. Of the 3 aneurysms on the radiculomedullary artery, 1 was treated conservatively, 1 was treated with coiling of the aneurysm and sacrifice of the radiculomedullary artery, and 1 was treated with surgical trapping. The 8 aneurysms on the radiculopial artery were treated endovascularly in 4 cases, surgically in 1 case, and conservatively in 3 cases. One surgically treated patient had a spinal subdural hematoma. There were no other complications. Mean clinical follow-up time was 20 months, and 87.5% of patients were functionally independent. CONCLUSIONS:Spinal arterial aneurysms are lesions which commonly present with sudden back pain and spinal SAH. Conservative, surgical, and endovascular treatment options are safe and effective. Long term outcomes in these patients are generally good.

The authors present the unusual case of a complex unruptured basilar artery terminus (BAT) aneurysm in a 42-year-old symptomatic female patient presenting with symptoms of mass effect. Due to the fusiform incorporation of both the BAT and left superior cerebellar artery (SCA) origin, simple surgical or endovascular treatment options were not feasible in this case. A 2-staged (combined deconstructive/reconstructive) procedure was successfully performed: first occluding the left SCA with a Pipeline embolization device (PED) coupled to a microvascular plug (MVP) in the absence of antiplatelet coverage, followed by reconstruction of the BAT by deploying a second PED from the right SCA into the basilar trunk. Six-month follow-up angiography confirmed uneventful aneurysm occlusion. The patient recovered well from her neurological symptoms. This case report illustrates the successful use of a combined staged deconstructive/reconstructive endovascular approach utilizing 2 endoluminal tools, PED and MVP, to reconstruct the BAT and occlude a complex aneurysm.

Background/UNASSIGNED:Scarce reports exist of permanent deployment of Solitaire FR™ devices for arterial steno-occlusive disease as it is primarily indicated for temporary deployment for thrombectomy in large-vessel, anterior-circulation ischemic strokes. Even more scarce are reports describing permanent deployment of the Solitaire device for posterior circulation strokes. Summary/UNASSIGNED:We present 2 cases where the Solitaire device was electrolytically detached to re-establish flow in an occluded or stenotic basilar artery in acutely symptomatic patients. In both cases, a 4 × 15 mm Solitaire device was positioned across the stenotic or occluded portion of the basilar artery and electrolytically detached to maintain vessel patency. Both cases had good clinical outcomes with a National Institutes of Health Stroke Scale (NIHSS) score of 1 (from 24) on 90-day follow-up and an NIHSS score of 2 (from 7) on 30-day follow-up. Key Messages/UNASSIGNED:Permanent deployment of the Solitaire device may potentially be a safe and effective means of maintaining vessel patency in an occluded or stenotic basilar artery.

Background/UNASSIGNED:We investigated low-dose aspirin (ASA) efficacy and safety in subjects with silent brain infarcts (SBIs) in preventing new cerebrovascular (CVD) events as well as cognitive impairment. Methods/UNASSIGNED:We included subjects aged ≥45 years, with at least one SBI and no previous CVD. Subjects were followed up to 4 years assessing CVD and SBI incidence as primary endpoint and as secondary endpoints: (a) cardiovascular and adverse events and (b) cognitive impairment. Results/UNASSIGNED:Thirty-six subjects received ASA while 47 were untreated. Primary endpoint occurred in 9 controls (19.1%) versus 2 (5.6%) in the ASA group (p=0.10). Secondary endpoints did not differ in the two groups. Only baseline leukoaraiosis predicts primary [OR 5.4 (95%CI 1.3-22.9, p=0.022)] and secondary endpoint-a [3.2 (95%CI 1.1-9.6, p=0.040)] occurrence. Conclusions/UNASSIGNED:is registered with EudraCT Number: 2005-000996-16; Sponsor Protocol Number: 694/30.06.04.

Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease characterized by degeneration of both upper and lower motor neuron located in the spinal cord and brainstem. Diagnosis of ALS is predominantly clinical, nevertheless, electromyography and Magnetic Resonance Imaging (MRI) may provide support. Several advanced MRI techniques have been proven useful for ALS diagnosis and, indeed, the combination of different MRI techniques demonstrated an improvement in sensitivity and specificity as far as 90%. This review focus on the imaging techniques currently used in the diagnosis and management of ALS with brief considerations on future applications.

OBJECTIVE The Pipeline Embolization Device (PED) is now a well-established option for the treatment of giant or complex aneurysms, especially those arising from the anterior circulation. Considering the purpose of such treatment is to maintain patency of the parent vessel, postembolization occlusion of the parent artery can be regarded as an untoward outcome. Antiplatelet therapy in the posttreatment period is therefore required to minimize such events. Here, the authors present a series of patients with anterior circulation aneurysms treated with the PED who subsequently experienced parent vessel occlusion (PVO). METHODS The authors performed a retrospective review of all anterior circulation aneurysms consecutively treated at a single institution with the PED through 2014, identifying those with PVO on follow-up imaging. Aneurysm size and location, number of PEDs used, and follow-up digital subtraction angiography results were recorded. When available, pre- and postembolization platelet function testing results were also recorded. RESULTS Among 256 patients with anterior circulation aneurysms treated with the PED, the authors identified 8 who developed PVO after embolization. The mean aneurysm size in this cohort was 22.3 mm, and the number of PEDs used per case ranged from 2 to 10. Six patients were found to have asymptomatic PVO discovered incidentally on routine follow-up imaging between 6 months and 3 years postembolization, 3 of whom had documented "delayed" PVO with prior postembolization angiograms confirming aneurysm occlusion and a patent parent vessel at an earlier time. Two additional patients experienced symptomatic PVO, one of which was associated with early discontinuation of antiplatelet therapy. CONCLUSIONS In this large series of anterior circulation aneurysms, the authors report a low incidence of symptomatic PVO, complicating premature discontinuation of postembolization antiplatelet or anticoagulation therapy. Beyond the subacute period, asymptomatic PVO was more common, particularly among complex fusiform or very large-necked aneurysms, highlighting an important phenomenon with the use of PED for the treatment of anterior circulation aneurysms, and suggesting that extended periods of antiplatelet coverage may be required in select complex aneurysms.