Faculty Bibliography

BACKGROUND:: Despite increasing acceptance of endovascular coiling for treating intracranial aneurysms, incomplete occlusion remains a limitation. Attempts to reduce recanalization have prompted creation of polyglycolic/polylactic acid coated (Matrix) coils shown to improve neointima formation; however, previous publications demonstrate conflicting results regarding their efficacy. Few studies account for factors influencing recurrence and only four studies include bare platinum (BP) control groups. Objective: To compare initial, short, and mid-term occlusion as well as retreatment rates using Matrix versus BP coils. METHODS:: Retrospective review of patients undergoing coiling of cerebral aneurysms from 2001-2005 was performed. Analysis included a multivariate logistic regression model designed to detect a 35% absolute difference in initial occlusion between coil treatment groups with 80% power. RESULTS:: Complete initial occlusion was achieved in 64% of BP (n=45) and 63% of Matrix (n=56) cases (p=1.0). Follow-up occlusion rates in the short-term and mid-term were 52% and 60% for BP and 42% and 67% for Matrix cases (p=.24;p=.38), respectively. After adjusting for size, morphology, volumetric packing density, location, rupture, and balloon remodeling, no difference in initial and subsequent occlusion or retreatment rates for BP versus Matrix coils was appreciated. CONCLUSION:: After controlling for factors influencing recanalization, the present investigation failed to show a significant difference between coil groups

Intra-arterial (IA) chemotherapy for malignant gliomas including glioblastoma multiforme was initiated decades ago, with many preclinical and clinical studies having been performed since then. Although novel endovascular devices and techniques such as microcatheter or balloon assistance have been introduced into clinical practice, the question remains whether IA therapy is safe and superior to other drug delivery modalities such as intravenous (IV) or oral treatment regimens. This review focuses on IA delivery and surveys the available literature to assess the advantages and disadvantages of IA chemotherapy for treatment of malignant gliomas. In addition, we introduce our hypothesis of using IA delivery to selectively target cancer stem cells residing in the perivascular stem cell niche.

BACKGROUND:: Arteriovenous malformations (AVM) with associated aneurysms (AA) increase hemorrhagic risk in adults. Associated aneurysms are thought to develop over time, and the incidence in children is therefore thought to be minimal but thus far has not been studied. OBJECT:: To define the incidence and morbidity of AA in children, and to assess the results of our treatment strategy. METHODS:: Patients less than 18 years of age with pial AVM were reviewed from 2000 to 2009. Demographics, presentation, hemorrhage, associated aneurysms, treatment method, and outcome were analyzed. RESULTS:: Of 144 patients with AVM, 30 were less than 18 years. AA was identified in 5/30 (16.7%) children and 33/114 (28.9%) adults. (p=0.25) Mean age at presentation was 11.67 years (range 6mo-17yrs), and mean follow up was 28.8 months (range 1 - 75 months). Hemorrhage at presentation was 80% with AA and 72% with AVM alone. Emergent therapy was required in 60% of patients with AA and 40% with AVM alone (p=0.63). Time to treatment was 4.3 days with AA and 27.3 days without (p=0.42). There was no difference in outcome between patients with AA and AVM alone. CONCLUSION:: The incidence of pediatric AA was higher in our series than projected in the current literature. Time to treatment was shorter in children with AA compared with AVM alone, although there was no difference in clinical outcome. While hemorrhage rates were similar, emergent therapy was required more frequently in patients with AA. Our findings support the need for early diagnosis and treatment of associated aneurysms in children

The current role of CT perfusion (CTP) imaging in the diagnosis and treatment of vasospasm in the setting of aneurysmal subarachnoid hemorrhage is discussed in this article, with specific attention directed towards defining the terminology of vasospasm and delayed cerebral ischemia. A commonly used CTP technique in clinical practice is described. A review of the literature regarding the usefulness of CTP for the diagnosis of vasospasm and its role in guiding treatment are discussed. Recent research advances in the utilization of CTP and associated ongoing challenges are also presented.

SUMMARY: During the past few decades, there have been significant advances in the understanding of spinal vascular lesions, mainly because of the evolution of imaging technology and selective spinal angiography techniques. In this article, we discuss the classification, pathophysiology, and clinical manifestations of spinal vascular lesions other than DAVFs and provide a review of the endovascular approach to treat these lesions

OBJECT: The authors assessed the safety and maximum tolerated dose of superselective intraarterial cerebral infusion (SIACI) of bevacizumab after osmotic disruption of the blood-brain barrier (BBB) with mannitol in patients with recurrent malignant glioma. METHODS: A total of 30 patients with recurrent malignant glioma were included in the current study. RESULTS: The authors report no dose-limiting toxicity from a single dose of SIACI of bevacizumab up to 15 mg/kg after osmotic BBB disruption with mannitol. Two groups of patients were studied; those without prior bevacizumab exposure (naive patients; Group I) and those who had received previous intravenous bevacizumab (exposed patients; Group II). Radiographic changes demonstrated on MR imaging were assessed at 1 month postprocedure. In Group I patients, MR imaging at 1 month showed a median reduction in the area of tumor enhancement of 34.7%, a median reduction in the volume of tumor enhancement of 46.9%, a median MR perfusion (MRP) reduction of 32.14%, and a T2-weighted/FLAIR signal decrease in 9 (47.4%) of 19 patients. In Group II patients, MR imaging at 1 month showed a median reduction in the area of tumor enhancement of 15.2%, a median volume reduction of 8.3%, a median MRP reduction of 25.5%, and a T2-weighted FLAIR decrease in 0 (0%) of 11 patients. CONCLUSIONS: The authors conclude that SIACI of mannitol followed by bevacizumab (up to 15 mg/kg) for recurrent malignant glioma is safe and well tolerated. Magnetic resonance imaging shows that SIACI treatment with bevacizumab can lead to reduction in tumor area, volume, perfusion, and T2-weighted/FLAIR signal

Spinal dural arteriovenous fistulas (SDAVFs) represent the most frequent spinal arteriovenous malformation and have an ominous natural history if left untreated. In the present review, we describe the spinal vascular anatomy, pathophysiology and clinical manifestations of SDAVFs, and the current role of endovascular embolization in this type of lesion.

OBJECTIVE: To review notable aneurysm cases that required complex decision making from a single institution and to examine available literature when relevant to highlight evidence-based paradigms for treatment of complex aneurysms. METHODS: Case illustrations were used to highlight topics in complex aneurysm treatments. Reviews of the literature were conducted to evaluate the evidence for available treatment models. RESULTS: Current modalities for treating complex aneurysms involve endovascular and microsurgical tools. CONCLUSIONS: Innovations in both arms of the cerebrovascular field will continue to advance the field and provide novel approaches to these complex lesions.

BACKGROUND: The International Study of Intracranial Aneurysms found that for patients with no previous history of subarachnoid hemorrhage, small (< 7 mm) anterior circulation and posterior circulation aneurysms had a 0% and 2.5% risk of subarachnoid hemorrhage over 5 years, respectively. OBJECTIVE: To determine whether cerebral aneurysms shrink with rupture. METHODS: The clinical databases of 7 sites were screened for patients with imaging of cerebral aneurysms before and after rupture. Inclusion criteria included documented subarachnoid hemorrhage by imaging or lumbar puncture and intracranial imaging before and after cerebral aneurysm rupture. The patients were evaluated for aneurysm maximal height, maximal width, neck diameter, and other measurement parameters. Only a change of >/= 2 mm was considered a true change. RESULTS: Data on 13 patients who met inclusion criteria were collected. The median age was 60, and 11 of the 13 patients (84.6%) were female. Only 5 patients had posterior circulation aneurysms. None of the aneurysms had a significant decrease in size. One aneurysm decreased by 1.8 mm in maximum size after rupture (7.7%). Six aneurysms had an increase in maximum size of at least 2 mm after rupture (46.2%) with a mean increase of 3.5 mm (+/- 0.5 mm). CONCLUSION: Unruptured aneurysms do not shrink when they rupture. The large percentage of ruptured small aneurysms in previous studies were likely small before they ruptured

Purpose: To assess in vivo performance of new eCLIPs (ENDOVASCULAR CLIP SYSTEM) device for treatment of rabbit bifurcation and sidewall aneurysms. The device was evaluated for flow diversion and coil assist. Performance was evaluated during acute implant and 30 days follow up. Materials and Methods: 8 animals with 10 surgical aneurysms were treated with eCLIPs, 6 bifurcation and 4 sidewall. Three devices were evaluated: High density (HD) bifurcation, Low density (LD) bifurcation, Sidewall. Two bifurcation aneurysms treated with HD device; following implantation, 1 device crossed for coiling; the other aneurysm treated with eCLIPs alone. Four bifurcation aneurysms treated with LD device - following implantation, 1 device crossed for coiling; 2 aneurysms treated with 1 eCLIPs alone and another with 2 'overlapping' eCLIPs devices. Two sidewall aneurysms treated with eCLIPs and coiling; 2 sidewall aneurysms treated with eCLIPs alone. Results: eCLIPs was intuitive with ease of delivery and positioning across the necks of both bifurcation and sidewall aneurysms. Post implantation angiograms showed flow reduction. When chosen, eCLIPs was crossed for coiling, demonstrating stability and containment of the coils within the aneurysm. As a flow diverter, the device provided flow effect at the aneurysm neck and stasis. 30 day follow up angiographic results and histopathological healing response is pending. Conclusion: eCLIPs is an evolved endoluminal treatment device with unique ability to treat aneurysms arising at sidewall and bifurcation locations; it predominantly affects the neck of the aneurysm for closure, respecting adjacent perforators and side branches