Faculty Bibliography

Dural arteriovenous fistulas (DAVFs) are rare pathological entities presenting with a diverse clinical course, ranging from benign to life-threatening. Digital subtraction angiography remains the gold standard in the diagnosis of clinically suspected DAVFs. This article reviews the ethiopathogenesis, natural history, classification systems, clinical and angiographic features, and the current treatment strategies for these complex lesions. The management of DAVFs may include conservative treatment, endovascular intervention, microsurgery, and stereotactic radiosurgery. A multidisciplinary approach involving a neurosurgeon, interventional neuroradiologist, and neurologist is required before considering any type of treatment modality. The indication for the best therapeutic alternative must be individualized for each patient.

BACKGROUND: This prospective, single-center study assesses progression-free survival (PFS) and overall survival (OS) in patients with recurrent glioblastoma multiforme (GBM) treated with a single dose of superselective intra-arterial cerebral infusion (SIACI) of bevacizumab (BV) after blood-brain barrier disruption (BBBD). Patients were initially enrolled in our phase I study, for which the primary end point was to determine the safety and maximum tolerated dose of SIACI BV. METHODS: Fourteen patients with recurrent GBM were recruited between August 2009 and November 2010 after failing the standard treatment with radiation therapy and temozolomide. None of these patients were previously treated with BV. After receiving a single dose of IA BV (2 to 15 mg/kg), standard IV BV chemotherapy was continued in 12 of 14 patients (86%). The recently updated Response Assessment in Neuro-Oncology Working Group (RANO) criteria were used to evaluate PFS, and the Kaplan-Meier estimator was used to evaluate PFS and OS. RESULTS: Using RANO criteria, the median PFS in these patients was 10 months. The median OS estimation for this cohort was 8.8 months. The OS was less than the PFS because 4 patients died without progressing. Toxicity attributed to the IA BV treatment was present in 2 patients (wound dehiscence and rash). Another patient suffered from seizures 1 week after the SIACI procedure; however, this patient had epilepsy before and seizure type/frequency were similar before and after therapy. CONCLUSIONS: Our study shows that for patients naive to BV, a single dose of SIACI BV after BBBD followed by IV BV offers an encouraging outcome in terms of PFS when compared with previous trials using IV BV with and without concomitant irinotecan (CPT-11). Larger phase II trials are warranted to determine whether repeated IA BV alone is superior to IV BV for recurrent GBM.

We present neuroimages for a patient in a locked-in state with reversed flow in the anterior spinal artery as a result of bilateral distal vertebral artery occlusion. Following vertebral artery stenting, there is markedly improved flow in the posterior circulation and significant neurological recovery.

Glioblastoma multiforme constitutes the most common primary brain tumor and carries a grim prognosis for patients treated with conventional therapy including surgery, radiation therapy, and chemotherapy. There has been a recent revival of selective intra-arterial delivery of targeted agents for the treatment of glioblastoma multiforme. Because these agents are less toxic and their delivery leads to a higher tumor-drug concentration, this combination may provide a better outcome in patients with high-grade glioma. This article discusses early experiences in patients who received superselective intra-arterial cerebral infusion of bevacizumab, cetuximab, and temozolamide after blood-brain barrier disruption with mannitol.

In this article, a detailed description of the normal arterial supply and venous drainage of the spinal cord is provided, and the role of catheter angiography and MR angiography in depicting the vascular anatomy of the spinal cord is discussed.

BACKGROUND AND PURPOSE: SIACI of bevacizumab has emerged as a promising novel therapy in the treatment of recurrent GB. This study assessed the potential of (1)H-MRS as an adjunctive technique in detecting metabolic changes reflective of antiproliferative effects of targeted infusion of bevacizumab in the treatment of GB. MATERIALS AND METHODS: Eighteen patients enrolled in a phase I/II study of SIACI of bevacizumab for treatment of recurrent GB were included. Concurrent MR imaging and (1)H-MRS scans were performed before and after treatment. Five distinct morphologic ROIs were evaluated for structural and metabolic changes on MR imaging and (1)H-MRS, which included enhancing, nonenhancing T2 hyperintense signal abnormality, and multiple control regions. Pre- and post-SIACI of bevacizumab peak areas for NAA, tCho, tCr, as well as tCho/tCr and tCho/NAA ratios, were derived for all 5 ROIs and compared using the Wilcoxon signed-rank test. RESULTS: A significant median decrease of 25.99% (range -55.76 to 123.94; P = .006) in tCho/NAA was found post-SIACI of bevacizumab relative to pretreatment values in regions of enhancing disease. A trend-level significant median decrease of 6.45% (range -23.71 to 37.67; P = .06) was noted in tCho/NAA posttreatment in regions of nonenhancing T2-hyperintense signal abnormality. CONCLUSIONS: The results of this (1)H-MRS analysis suggest that GB treatment with SIACI of bevacizumab may be associated with a direct antiproliferative effect, as demonstrated by significant reductions of tCho/NAA after the intervention.

BACKGROUND AND PURPOSE: Intraprocedural aneurysmal rupture is a feared complication of coil embolization of intracranial aneurysms and is associated with high rates of morbidity and mortality. We report the incidence, endovascular management, and clinical outcome of patients with IAR, with emphasis on the role of the balloon-assisted technique. MATERIALS AND METHODS: We conducted a retrospective analysis of all intracranial aneurysms treated by coil embolization between September 2001 and June 2011. All patients with IAR were studied. Comparison of immediate clinical outcomes was performed by using univariate analysis (Fisher exact test). RESULTS: Of 652 intracranial aneurysms treated with coil embolization, an IAR occurred in 22 (3.4%). Rupture occurred during placement of coils in 18 cases, microcatheters in 2 cases, and a guidewire in 1 case, and during induction of anesthesia in 1 case. Before treatment, 15 of 22 (68%) patients were in good clinical condition (WFNS grade I). There were fewer patients with worsening of the WFNS grade following an IAR when the balloon-assisted technique was used (7.7%) compared with when it was not (55.5%) (P = .023). Death occurred in 2 (9.1%) patients. CONCLUSIONS: IAR is a potentially serious complication of coil embolization. If IAR occurs, balloon-assistance is helpful in obtaining rapid hemostasis resulting in better short-term outcomes.

Neurofibromatosis type 2 (NF2) is an autosomal dominant syndrome with a prevalence of approximately 1 in 30,000. NF 2 is characterized by bilateral vestibular schwannomas, as well as meningiomas, ependymomas and gliomas. Currently, surgical resection and radiotherapy represent the mainstay of treatment, although new studies suggest a role for certain chemotherapeutic agents. Intravenous administration of Bevacizumab (Avastin, Genetech Pharmaceuticals) has been shown to be active in the treatment of vestibular schwannomas. The IV route of administration, however, carries a risk of known systemic side-effects such as bowel perforation, wound dehiscence and pulmonary embolism. In addition, the percentage of drug that reaches the tumor site may be restricted by the blood tumor barrier. This report describes the super-selective intra-arterial infusion of Bevacizumab following blood brain barrier disruption for the treatment of vestibular schwannomas in three patients with Neurofibromatosis type 2. It represents the first time such a technique has been performed for this disease. Additionally, this method of drug delivery may have important implications in the treatment of patients with vestibular schwannomas associated with Neurofibromatosis type 2.