Faculty Bibliography

We report a case of temporary Solitaire FR stent (Covidien, Mansfield, MA, USA) scaffolding to reduce coil herniation during embolization of a large neck anterior communicating artery aneurysm. In contrast to classic stent-assisted coiling, the fully retrievable stent is recaptured prior to detachment of the last coil. The presented technical nuance hence does not require institution of prolonged antiplatelet coverage. But the door is left open for coil-repositioning in case of coil basket instability. Permanent stent redeployment remains a fall-back option if critical hardware conflict occurs. In comparison to classic balloon remodeling, the presented method may offer easier distal access, particularly in tortuous arterial anatomy. Temporary occlusion of the parent artery, side branches, and perforators is also avoided. Given its specific potential advantages, temporary stent scaffolding using the fully retrievable Solitaire FR device may find its niche as a bailout option, primarily in a very specific subset of distally located wide neck aneurysms.

BACKGROUND AND PURPOSE: Low-porosity endoluminal devices for the treatment of intracranial aneurysms, also known as flow diverters, have been in experimental and clinical use for close to 10 years. Despite rigorous evidence of their safety and efficacy in well-controlled trials, a number of key factors concerning their use remain poorly defined. Among these, none has received more attention to date than the debate on how many devices are optimally required to achieve a safe, effective, and economical outcome. Additional, related questions concern device sizing relative to the parent artery and optimal method of deployment of the devices. While some or all of these issues may be ultimately answered on an empiric basis via subgroup analysis of growing treatment cohorts, we believe that careful in vitro examination of relevant device properties can also help guide its in vivo use. MATERIALS AND METHODS: We conducted a number of benchtop experiments to investigate the varied porosity of Pipeline Embolization Devices deployed in a simulated range of parent vessel diameters and applied these results toward conceptualizing optimal treatment strategies of fusiform and wide-neck aneurysms. RESULTS: The results of our studies confirm a predictable parabolic variability in device porosity based on the respective comparative sizes of the device and recipient artery, as well as device curvature. Even modest oversizing leads to a significant increase in porosity. CONCLUSIONS: The experiments demonstrate various deleterious effects of device oversizing relative to the parent artery and provide strategies for addressing size mismatches when they are unavoidable.

SUMMARY:Does the world need another ICA classification scheme? We believe so. The purpose of proposed angiography-driven classification is to optimize description of the carotid artery from the endovascular perspective. A review of existing, predominantly surgically-driven classifications is performed, and a new scheme, based on the study of NYU aneurysm angiographic and cross-sectional databases is proposed. Seven segments - cervical, petrous, cavernous, paraophthlamic, posterior communicating, choroidal, and terminus - are named. This nomenclature recognizes intrinsic uncertainty in precise angiographic and cross-sectional localization of aneurysms adjacent to the dural rings, regarding all lesions distal to the cavernous segment as potentially intradural. Rather than subdividing various transitional, ophthalmic, and hypophyseal aneurysm subtypes, as necessitated by their varied surgical approaches and risks, the proposed classification emphasizes their common endovascular treatment features, while recognizing that many complex, trans-segmental, and fusiform aneurysms not readily classifiable into presently available, saccular aneurysm-driven schemes, are being increasingly addressed by endovascular means. We believe this classification may find utility in standardizing nomenclature for outcome tracking, treatment trials and physician communication.

BACKGROUND AND PURPOSE: Stent-supported aneurysm coiling has been utilized with increasing frequency over the past few years, particularly for addressing treatment of complex and wide-neck aneurysms. A sizable body of literature describing various experiences with stent-supported coiling now exists. The purpose of this research was to carry out a comprehensive literature survey of stent-supported aneurysm coiling. MATERIALS AND METHODS: A survey of papers reporting results with stent-assisted aneurysm coiling through January 2011 was conducted to identify the prevalence of stent-related and other complications, occlusion rates, and clinical and angiographic follow-up data. RESULTS: Thirty-nine articles with 1517 patients met inclusion criteria for initial analysis, follow-up analysis, or both. Overall, 9% of cases were confounded by a technical stent-related issue, including 4% failure of deployment. The overall procedure complication rate was 19%, with periprocedural mortality of 2.1%. Approximately 45% of aneurysms were completely occluded at first treatment session, increasing to 61% on follow-up. Approximately 3.5% in-stent stenosis and 0.6% stent occlusion were observed at angiographic follow-up. Delayed stroke or transient ischemic attack was reported in 3% of subjects. Within a subset of articles, the incidence of stent-related issues in the first 10 patients was significantly higher than in subsequent subjects, supporting the notion of a procedural "learning curve." CONCLUSIONS: In experienced hands, the morbidity of stent-supported coiling is somewhat higher compared with "traditional" coiling. As might be expected, execution of the procedure appears improved with experience. Complete occlusion rates remain somewhat low. More and longer term angiographic follow-up information is needed to understand delayed stent-related issues and to better define the durability of treatment.

Purpose: To evaluate safety and effectiveness of Pipeline Embolization Device for the treatment of complex intracranial aneurysms. Materials and Methods: 108 patients with large and giant, wide neck aneurysms involving the petrous, cavernous, and paraclinoid segments of the internal carotid artery were enrolled in this prospective, multicenter, single arm study. All subjects but one underwent successful treatment of the target aneurysm with Pipeline. Clinical follow-up was performed at 30 days, 180 days, and 1 year post treatment. Angiographic follow-up was obtained at 180 days (n=99) and 1 year (n=91). Completeness of aneurysm occlusion was assessed by a core laboratory. The results were compared to a predefined target aneurysm occlusion rate derived from exhaustive literature review. Safety outcomes were similarly compared to a historically defined threshold. Results: Complete aneurysm occlusion was observed in a high proportion of cases at both time points of angiographic assessments, representing a highly statistically significant result as compared to the predefined target complete occlusion rate. The safety profile of the device was acceptable, with primary safety events statistically significantly below the predefined threshold. Conclusion: Pipeline Embolization Device is effective and safe for treatment of petrous, cavernous, and paraclinoid aneurysms

Dural arteriovenous fistulas are characterized by abnormal arteriovenous shunting localized to the pachymeninges. Fistulae venous drainage is essential to their classification, symptomatology, and treatment. Endovascular therapy is rapidly progressing to an adjunct or even alternative treatment to microsurgical resection. Several techniques, such as transarterial or transvenous embolization with metallic coils, NBCA, or Onyx, have been used successfully in several studies. The long-term clinical and radiographic outcomes of endovascular therapy for the treatment of dural arteriovenous fistulas are satisfactory, and future studies are underway for the refinement of these techniques

PURPOSE: Conventional noncontrast CT (NCCT) is insensitive to hyperacute cerebral infarction in the first 3 h. Our aim was to determine if CT perfusion (CTP) can improve diagnostic accuracy over NCCT for patients presenting with stroke symptoms in the 3-hour window. METHODS: Consecutive patients presenting to our emergency department with symptoms of ischemic stroke <3 h old and receiving NCCT and CTP as part of their triage evaluation were retrospectively reviewed. Patients with follow-up diffusion-weighted MRI (DWI) <7 days from ictus were included. Two readers rated the NCCT and CTP for evidence of acute infarct and its vascular territory. CTP selectively covered 24 mm of brain centered at the basal ganglia with low relative cerebral blood volume in a region of low cerebral blood flow or elevated time to peak as the operational definition for infarction. A third reader rated all follow-up DWI for acute infarct and its vascular territory as the reference standard. Sensitivity, specificity, and predictive values were calculated. An exact McNemar test and generalized estimating equations from a binary logistic regression model were used to assess the difference in detection rates between modalities. A two-sided p value <0.05 was considered significant. RESULTS: 100 patients were included. Sixty-five (65%) patients had follow-up DWI confirmation of acute infarct. NCCT revealed 17 (26.2%) acute infarcts without false positives. CTP revealed 42 (64.6%) acute infarcts with one false positive. Of the 23 infarcts missed on CTP, 10 (43.5%) were outside the volume of coverage while the remaining 13 (56.5%) were small cortical or lacunar type infarcts (<or=15 mm in size). CTP was significantly more sensitive (64.6 vs. 26.2%, p < 0.0001) and accurate (76.0 vs. 52%, p < 0.0001) and had a better negative predictive value (59.6 vs. 42.2%, p = 0.032) than NCCT. CONCLUSION: In a retrospective cohort of 100 patients with symptoms of hyperacute stroke in the 3-hour window, CTP provided improved sensitivity and accuracy over NCCT

BACKGROUND AND PURPOSE: Concurrent temporary inflation of a nondetachable balloon in the parent artery has been reported to be useful during endovascular coiling of complex, wide-neck aneurysms, facilitating truer coil reconstruction of the native vessel. Nevertheless, there exists concern that adjunctive use of balloon assistance may lead to increased adverse events during aneurysm coiling. MATERIALS AND METHODS: A literature search of all of the unassisted and balloon-remodeling studies published between 1997 and 2006 was conducted with application of strict selection criteria based on the reporting of complication incidence and outcome. The final cohort was analyzed to determine rates and clinical outcomes of iatrogenic aneurysm rupture and thromboembolism. Additional data were collected on the degree of initial and follow-up aneurysm occlusion rates. RESULTS: A total of 83 potential studies (4973 patients) were identified, from which 23 articles reporting results for 867 traditional-unassisted and 273 balloon-assisted coiled aneurysms met inclusion criteria for the analysis of thromboembolic complications, and 21 articles with 993 routinely coiled and 170 balloon-remodeled aneurysms were eligible for iatrogenic perforation analysis. No statistically significant difference was found in the rates of thromboembolism. Iatrogenic perforation rates were also comparable, though the overall numbers were too few for meaningful statistical analysis. Both initial and follow-up aneurysm occlusion rates were higher in balloon-assisted cases. CONCLUSION: This largest-to-date literature review and meta-analysis did not demonstrate a higher incidence of thromboembolic events or iatrogenic rupture with the use of adjunctive balloon remodeling compared with unassisted coiling. Balloon remodeling appears to result in higher initial and follow-up aneurysm occlusion rates

OBJECTIVE: The purposes of this article are to summarize recent developments and concerns in endovascular aneurysm therapy leading to the adjunctive use of endoluminal devices, to review the published literature on stent-supported coil embolization of cerebral aneurysms, and to describe our experience with this technique in a limited subgroup of problematic complex aneurysms over a medium-term follow-up period. METHODS: Between January 2003 and June 2004, 28 individuals among 157 patients with cerebral aneurysms we evaluated were identified as harboring aneurysms with exceptionally broad necks. Out of these 28 patients, 16 were treated with a combination of stents and detachable coils, preserving the parent artery. Recorded data included patient demographics, the clinical presentation, aneurysm location and characteristics, procedural details, and clinical and angiographic outcome. RESULTS: Over an 18-month period, 16 patients with large cerebral aneurysms additionally characterized by neck sizes between 7 and 14 mm were treated, using combined coil embolization of the aneurysm with stent reconstruction of the aneurysm neck. Thirteen out of the 16 aneurysms were occluded at angiographic reevaluation between 11 and 24 months (mean angiographic follow-up, 17.5 mo). There were no treatment-related deaths or clinically evident neurological complications. Thirteen patients experienced excellent clinical outcomes, with good outcomes in two patients and a poor visual outcome in one patient (mean clinical follow-up, 29 mo). A single technical complication occurred, involving transient nonocclusive stent-associated thrombus, which was treated uneventfully with abciximab. CONCLUSION: Stent-supported coil embolization of large, complex-neck cerebral aneurysms seems to provide superior medium-term anatomic reconstruction of the parent artery compared with historic series of aneurysms treated exclusively with endosaccular coils. In the near future, increasingly sophisticated endoluminal devices offering higher coverage of the neck defect will likely enable more definitive endovascular treatment of complex cerebral aneurysms and further expand our ability to manipulate the vascular biology of the parent artery