Faculty Bibliography

Stereotactic radiosurgery is widely used to treat cerebral arteriovenous malformations (AVMs), with the goal of complete angiographic obliteration. A number of case series have challenged the assumption that absence of residual AVM on follow-up angiograms is consistent with elimination of the risk of hemorrhage. The authors describe 3 cases in which patients who had angiographic evidence of AVM occlusion presented with late hemorrhage in the area of their prior lesions. They compare the radiographic, angiographic, and histological features of these patients with those previously described in the literature. Delayed hemorrhage from the tissue of occluded AVMs has been reported as early as 4 and as late as 11 years after initial stereotactic radiosurgery. In all cases for which data are available, hemorrhage occurred in the area of persistent imaging findings despite negative findings on conventional angiography. The hemorrhagic lesions that were resected demonstrated a number of distinct histological findings. While rare, delayed hemorrhage from the tissue of occluded AVMs may occur from a number of distinct, angiographically occult postirradiation changes. The hemorrhages in the authors' 3 cases were symptomatic and localized. The correlation of histological and imaging findings in delayed hemorrhage from occluded AVMs is an area requiring further investigation.

BACKGROUND: Epithelioid hemangioendothelioma (EHE) is a rare sarcoma of vascular origin, which is clinically and histologically intermediate between benign hemangioma and angiosarcoma. It is most commonly found in the liver, lung, and bone, however, 46 intracranial cases have been reported in the literature, of which this is the fifth reported suprasellar tumor. CASE DESCRIPTION: A 45-year-old woman developed progressive lethargy, somnolence, and memory decline over the course of 6 months. On computed tomography (CT), she was found to have a large hypothalamic mass and underwent subtotal resection via a bifrontal craniotomy. CONCLUSIONS: While primary intracranial EHE is an uncommon presentation of a rare tumor, the suprasellar region does not seem to be an unusual location when it does occur. Prognosis is generally good, and may be better for primary intracranial disease than that for EHE originating elsewhere. Surgery is the first line of therapy, with variable benefit from adjuvant chemotherapy or radiation when total resection is not possible. Chemotherapeutic approaches in current use are directed at preventing endothelial proliferation.

BACKGROUND: In this article, we report on the technique of placing fat in between a sellar or parasellar neoplasm and the optic chiasm to possibly protect the optic chiasm from sequelae of radiation. METHODS: A review was performed on three patients, each of whom had planned subtotal resection with fat placed near their optic chiasm to facilitate future radiosurgery. RESULTS: Follow-up on our three patients varied from 6 months to 3 years post-stereotactic radiosurgery. The fat remained stable and in place. The tumors either remained stable or reduced in size. No infections, postoperative marker dependent neurological complications or unusual symptoms were encountered. CONCLUSIONS: Placement of fat between a parasellar neoplasm and the optic chiasm appears to be a safe approach to help define the tumor chiasm space, helping to facilitate radiosurgery. Future experience is warranted to determine the efficacy of this technique.

BACKGROUND AND PURPOSE: Although there is generally thought to be a 2% to 4% per annum rupture risk for brain arteriovenous malformations (bAVMs), there is no way to estimate risk for an individual patient. METHODS: In this retrospective study, patients were eligible who had nidiform bAVMs and underwent detailed pretreatment diagnostic cerebral angiography at our medical center from 1996 to 2006. All patients had superselective microcatheter angiography, and films were reviewed for the purpose of this project. Patient demographics, clinical presentation, and angioarchitectural characteristics were analyzed. A univariate analysis was performed, and angioarchitectural features with potential physiological significance that showed at least a trend toward significance were added to a multivariate logistic regression model. RESULTS: One hundred twenty-two bAVMs met criteria for study entry. bAVMs with single venous drainage anatomy were more likely to present with hemorrhage. In addition, patients with multiple draining veins and a venous stenosis reverted to a risk similar to those with 1 draining vein, whereas those with multiple draining veins and without stenosis had diminished association with hemorrhage presentation. Those bAVMs with associated aneurysms were more likely to present with hemorrhage. These findings were robust in both univariate and multivariate models. CONCLUSIONS: The results of this article lead to the first physiological, internally consistent model of individual bAVM hemorrhage risk, where 1 draining vein, venous stenosis, and associated aneurysms increase risk.

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: The incidence of concomitant carotid artery stenosis and unruptured intracranial aneurysms (UIAs) has been reported at between 0.5% and 5%. In these patients, treatment strategies must balance the risk of ischemic stroke with the risk of aneurysmal rupture. Several studies have addressed the natural course of UIAs in the setting of carotid revascularization; however, the final recommendations are not uniform. The purpose of this study was to review our institutional experience with concomitant UIAs and carotid artery stenosis. METHODS: We performed a retrospective review of all patients with carotid artery stenosis who underwent carotid artery endarterectomy (CEA) or carotid artery stenting (CAS) at our institution between 2003 and 2010. Only patients with preoperative imaging demonstrating intracranial circulation were included. Charts were reviewed for patients' demographic and clinical data, duration of follow-up, and aneurysm size and location. Patients were stratified into 2 groups: carotid artery stenosis with unruptured intracranial aneurysm (CS/UIA) and carotid artery stenosis without intracranial aneurysm (CS). RESULTS: Three hundred five patients met the inclusion criteria and had a total of 316 carotid procedures (CAS or CEA) performed. Eleven patients were found to have UIAs (3.61%) prior to carotid revascularization. Male and female prevalence was 2.59% and 5.26% (P = 0.22), respectively. Patients' demographics did not differ significantly between the 2 groups. The average aneurysm size was 3.25 +/- 2.13 mm, and the most common location was the cavernous segment of the internal carotid artery. No patient in the study had aneurysm rupture, and the mean follow-up time was 26.5 months for the CS/UIA group. CONCLUSIONS: Concomitant carotid artery stenosis and UIAs is a rare entity. Carotid revascularization does not appear to increase the risk of rupture for small aneurysms (<10 mm) in the midterm. Although not statistically significant, there was a higher incidence of aneurysms found in females in our patient population.

BACKGROUND: Giant intracranial artery aneurysms (GIAAs) are often not amenable to neurosurgical clipping or endovascular coiling. Extracranial-intracranial (EC-IC) bypass, a procedure that has been essentially abandoned for the treatment of intracranial ischemic disease, followed by parent vessel occlusion, is often successful in treating these aneurysms. Vascular surgeons should be familiar with this operation, especially in centers with neurosurgical capability. METHODS: A retrospective review of patients treated from 1990 to 2010 at New York University Medical Center was performed. Office and hospital records of all patients identified were reviewed with attention to the age and sex of the patient, presenting symptoms, preoperative testing, procedure performed, type of bypass conduit, graft patency, intraoperative and postoperative complications, length of follow-up, and overall outcome. EC-IC bypass was performed using a graft of great saphenous vein (GSV) or radial artery (RA). The vascular surgeon harvested the vascular conduit, tunneled the graft, and performed the extracranial anastomosis, and the intracranial anastomosis was performed by the neurosurgeon. RESULTS: A total of 36 patients (14 men, 22 women) underwent 37 EC-IC bypasses with 34 GSV and three RA grafts. The median age was 57 years (interquartile range, 49-66 years), and the median follow-up was 53 months (interquartile range, 29-77 months). Aneurysm location was the internal carotid artery in 30 patients, the basilar artery in three, and the middle cerebral artery in four. All 37 aneurysms were excluded from the cerebral circulation, with 33 grafts remaining patent at follow-up, as determined by serial cerebral or magnetic resonance angiogram. At follow-up, 33 of 34 of the GSV grafts (88%) and three of three (100%) of the RA grafts were patent. There were two deaths (5.6%), despite patent grafts. Postoperative graft occlusion led to homonymous hemianopsia in one patient and temporary hemiparesis in another (5.6%). Graft occlusions were asymptomatic in two patients. CONCLUSIONS: EC-IC bypass is a safe and effective treatment for GIAAs, with acceptable rates of morbidity (5.6%), mortality (5.6%), and graft patency (89.2%). We suggest that the technique described in this report should be routinely used for treatment of GIAAs in centers where neurosurgery and vascular surgery services are available and should be considered a standard procedure in the armamentarium of the vascular surgeon.

BACKGROUND: : Stereotactic radiosurgery is an effective treatment modality for small arteriovenous malformations (AVMs) of the brain. For larger AVMs, the treatment dose is often lowered to reduce potential complications, but this decreases the likelihood of cure. One strategy is to divide large AVMs into smaller anatomic volumes and treat each volume separately. OBJECTIVE: : To prospectively assess the long-term efficacy and complications associated with staged-volume radiosurgical treatment of large, symptomatic AVMs. METHODS: : Eighteen patients with AVMs larger than 15 mL underwent prospective staged-volume radiosurgery over a 13-year period. The median AVM volume was 22.9 mL (range, 15.7-50 mL). Separate anatomic volumes were irradiated at 3- to 9-month intervals (median volume, 10.9 mL; range, 5.3-13.4 mL; median marginal dose, 15 Gy; range, 15-17 Gy). The AVM was divided into 2 volumes in 10 patients, 3 volumes in 5 patients, and 4 volumes in 3 patients. Seven patients underwent retreatment for residual disease. RESULTS: : Actuarial rates of complete angiographic occlusion were 29% and 89% at 5 and 10 years. Five patients (27.8%) had a hemorrhage after radiosurgery. Kaplan-Meier analysis of cumulative hemorrhage rates after treatment were 12%, 18%, 31%, and 31% at 2, 3, 5, and 10 years, respectively. One patient died after a hemorrhage (5.6%). CONCLUSION: : Staged-volume radiosurgery for AVMs larger than 15 mL is a viable treatment strategy. The long-term occlusion rate is high, whereas the radiation-related complication rate is low. Hemorrhage during the lag period remains the greatest source of morbidity and mortality. ABBREVIATION:: AVM, arteriovenous malformation.

Mysophobia is a variant of obsessive-compulsive disorder (OCD) characterized by intense fear of germs, dirt or contamination accompanied by behaviors to decrease contamination and exposure. While brain tumors, traumatic brain injury (TBI) and strokes have been demonstrated in patients with OCD and implicate abnormal function in the left frontotemporal regions, our review found no cases of mysophobia associated with structural lesions. Meningiomas are one of the most common forms of brain tumors and are more frequently diagnosed in women. We describe a woman with a three-year history of severe mysophobia found to have a large, left sphenoid wing meningioma. Following complete surgical resection and improvement in the mass effect on the frontal and temporal lobes, her mysophobia resolved completely and has remained in complete remission for almost 3 years