Faculty Bibliography

Endovascular embolization is typically reserved as an adjuvant therapy in the management of cerebral arteriovenous malformations (AVMs), either for preoperative devascularization or preradiosurgical volume reduction. Curative embolization plays a limited role in AVM treatment but several studies have shown that it is possible, especially with later-generation liquid embolic agents. Given the complexity of AVM anatomy and the recent controversies over the role of any intervention in AVM management, it is critical that the cerebrovascular community better define the indications of each treatment modality to provide quality AVM management. In this review, the authors evaluate the role of curative AVM embolization. Important considerations in the feasibility of curative AVM embolization include whether it can be performed reliably and safely, and whether it is a durable cure. Studies over the past 20 years have begun to define the anatomical factors that are amenable to complete endovascular occlusion, including size, feeding artery anatomy, AVM morphology, and endovascular accessibility. More recent studies have shown that highly selected patients with AVMs can be treated with curative intent, leading to occlusion rates as high as 100% of such prospectively identified lesions with minimal morbidity. Advances in endovascular technology and techniques that support the efficacy and safety of curative embolization are discussed, as is the importance of superselective diagnostic angiography. Finally, the durability of curative embolization is analyzed. Overall, while still unproven, endovascular embolization has the potential to be a safe, effective, and durable curative treatment for select AVMs, broadening the armamentarium with which one can treat this disease.

BACKGROUND AND PURPOSE: Recent techniques of endoluminal reconstruction with flow-diverting stents have not been incorporated into treatment algorithms for cavernous carotid aneurysms. This study examines the authors' institutional experience and a systematic review of the literature for outcomes and complications using the Pipeline Embolization Device in unruptured cavernous carotid aneurysms. MATERIALS AND METHODS: A retrospective search for cavernous carotid aneurysms from a prospectively collected data base of aneurysms treated with the Pipeline Embolization Device at our institution was performed. Baseline demographic, clinical, and laboratory values; intrainterventional data; and data at all follow-up visits were collected. A systematic review of the literature for complication data was performed with inquiries sent when clarification of data was needed. RESULTS: Forty-three cavernous carotid aneurysms were included in the study. Our mean radiographic follow-up was 2.05 years. On last follow-up, 88.4% of the aneurysms treated had complete or near-complete occlusion. Aneurysm complete or near-complete occlusion rates at 6 months, 12 months, and 36 months were 81.4%, 89.7%, and 100%, respectively. Of patients with neuro-ophthalmologic deficits on presentation, 84.2% had improvement in their visual symptoms. Overall, we had a 0% mortality rate and a 2.3% major neurologic complication rate. Our systematic review of the literature yielded 227 cavernous carotid aneurysms treated with the Pipeline Embolization Device with mortality and morbidity rates of 0.4% and 3.1%, respectively. CONCLUSIONS: Endoluminal reconstruction with flow diversion for large unruptured cavernous carotid aneurysms can yield high efficacy with low complications. Further long-term data will be helpful in assessing the durability of the cure; however, we advocate a revisiting of current management paradigms for cavernous carotid aneurysms.

Aim: Embolization of cerebral and spinal neoplasms is performed for highly vascular tumors including hemangioblastomas, paragangliomas, juvenile nasopharyngeal angiofibromas, hemangiopericytomas, schwannomas, meningiomas, and selected metastases. While diagnostic angiography may contribute to clarify the tumoral arterial supply, superselective infusion of embolics may effectively obliterate the tumoral vascular bed. At present, determinants of safe and effective presurgical embolization remain under debate. Methods: We investigate and illustrate the endovascular technique, ideal timing, and effectiveness of presurgical embolization of cerebral and spinal tumors performed at the NYU Langone Medical Center. Results: Detailed diagnostic angiography is key to identify the arterial supply to the tumor, to consistently recognize dangerous external carotid-to-internal carotid anastomoses, and to detect the highly variable arterial supply to cranial nerves and neuronal structures. Meticulous technique is essential for performing safe and effective tumor embolization that causes tumor necrosis and facilitates subsequent resection by limiting intraoperative blood loss. Although general anesthesia precludes the use of provocative testing, it does improve patient comfort and enhances the accuracy of angiography by limiting motion artifact. Additionally, electrophysiology may provide an additional degree of safely when general anesthesia is used. Embolization may be best performed within a week prior to the scheduled surgery to allow for effective tumor necrosis while avoiding neovascularization. Embolic agents include a range of liquids, particulates, or coils. Selecting the most advantageous agent is performed in light of the desired degree of tumor penetration, the presence or possibility of a dangerous anastomosis, and the ability to navigate the microcatheter in a safe position for superselective infusion of embolics. Although the most effective embolization is obtained with small particles that penetrate the tumoral bed at the capillary level, these agents are also the most dangerous to use by putting cranial nerves and normal structures such as the retina and myelon at risk. Conclusion: In depth knowledge of anatomy, meticulous technique, and the proper choice of the embolic material determine the safety and effectiveness of preoperative tumor embolization that may contribute to surgical success.

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.

INTRODUCTION: Angioplasty and intracranial stenting (ICS) are both endovascular revascularization procedures that have emerged as treatment options for intracranial atherosclerotic disease (ICAD). Some believe angioplasty alone is better, while others believe stenting is better. This study examines recent trends in utilization and outcomes of angioplasty alone and ICS in the United States using a population-based cohort. METHODS: The National Inpatient Sample (NIS) database was queried for patients with ICAD who underwent angioplasty or ICS from 2005 to 2010. RESULTS: There were 1115 patients (angioplasty: n=495, ICS: n=620) with ICAD who underwent endovascular revascularization. Over time, the number of endovascular revascularization procedures increased. The percentage of symptomatic patients (p=0.015) as well as in the number of comorbidities of patients treated (p<0.001) also increased. Combined post-procedure stroke and death rates were 16% and 28.9% for angioplasty and ICS, respectively (p<0.001). A larger percentage of angioplasty patients presented symptomatically compared to those who underwent ICS (p<0.001). CONCLUSION: Angioplasty appears to be associated with higher rates of peri-procedural complications; however, that may represent patient selection bias. Further studies are needed to identify patients who would benefit from revascularization and to clarify the roles of angioplasty and ICS.