Howard A Riina

CUNY Graduate Center, New York City, New York, United States

Are you Howard A Riina?

Claim your profile

Publications (79)144.76 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: 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.
    Neurosurgical FOCUS 09/2014; 37(3):E19. · 2.49 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: 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.
    AJNR. American journal of neuroradiology. 08/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cerebral aneurysms (CAs) and abdominal aortic aneurysms (AAAs) are both degenerative vascular pathologies that manifest as an abnormal dilation of the arterial wall. They arise with different morphologies in different types of blood vessels under different haemodynamic conditions. Although these aneurysms are treated as very different and separate pathologies, we sought to examine common pathways in the haemodynamic pathogenesis to further elucidate mechanisms of formation.
    Journal of Neurointerventional Surgery 07/2014; 6 Suppl 1:A45. · 2.50 Impact Factor
  • Source
    AANS/CNS JOINT CEREBROVASCULAR SECTION NEWSLETTER. 06/2014;
  • Matthew B Potts, Howard A Riina
    World Neurosurgery 06/2014; · 1.77 Impact Factor
  • Omar Tanweer, Taylor A Wilson, Howard A Riina
    World Neurosurgery 01/2014; · 1.77 Impact Factor
  • Phillip Cezayirli, Omar Tanweer, Howard A. Riina
    World Neurosurgery 01/2014; · 1.77 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: 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.
    Central European neurosurgery 01/2014; · 0.72 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: 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. The National Inpatient Sample (NIS) database was queried for patients with ICAD who underwent angioplasty or ICS from 2005 to 2010. 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). 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.
    Clinical neurology and neurosurgery 11/2013; · 1.30 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: 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.
    Journal of Clinical Neuroscience 10/2013; · 1.25 Impact Factor
  • Matthew B Potts, Howard A Riina
    World Neurosurgery 10/2013; · 1.77 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: 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.
    American Journal of Neuroradiology 08/2013; · 3.17 Impact Factor
  • Source
    Daniel Zumofen, Howard A Riina
    World Neurosurgery 08/2013; · 1.77 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Treatment of non-saccular vertebrobasilar aneurysms remains highly challenging despite significant recent advances in endovascular techniques. Establishing the natural history of this heterogeneous disease, as best as currently available data allows, is crucial to help guide counseling and management. A review of the literature was conducted to identify publications describing the presentation and natural history of vertebrobasilar dolichoectasia and non-saccular aneurysms. Nine studies of 440 patients met the analysis inclusion criteria. The majority of patients presented with ischemia, mass effect, or incidentally; hemorrhage was uncommon and overlapped with the population of vertebrobasilar dissection. Overall mortality was ∼40% after 7 years of follow-up, with 43% of these deaths resulting from non-neurologic causes. Neurologic course was dominated by ischemic stroke rather than hemorrhage. Mass effect prognosis was especially poor, with 40% mortality after ∼4 years. Incidentally discovered lesions which remain morphologically stable have a favorable long term course. Initial clinical presentation is a strong predictor of subsequent disease course. Although overall prognosis is poor, nearly half of all deaths resulted from non-neurologic causes, underscoring the importance of comprehensive medical management. Aneurysms characterized by expansion, established mass effect, or hemorrhage have a poor natural history, and may be considered for invasive treatment, which is increasingly endovascular in nature. Lesions presenting with ischemia or incidentally are likely best addressed with aggressive neurologic and overall medical management.
    Journal of Neurointerventional Surgery 07/2013; · 2.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: 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.
    Clinical neurology and neurosurgery 12/2012; · 1.30 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: OBJECTIVES: To evaluate the efficacy of combining an endonasal endoscopic skull base approach and repair with a transcranial orbitozygomatic approach for Spheno-orbital meningiomas (SOMs). METHODS: Three patients with recurrent SOMs were underwent combined orbitozygomatic and endonasal endoscopic surgery. In two patients both procedures were done in one operation and in one patient the endonasal surgery was done 2.5 months after the craniotomy. Extent of resection, complications, morbidity and mortality were evaluated. RESULTS: GTR was achieved in one patient and near total resection in the other two with tumor left in the cavernous sinus and parapharyngeal space. Two patients suffered cranial neuropathy from the transcranial surgery and the other developed a pseudomeningocele. There were no complications from the endonasal surgery. Patients having combined single setting cranionasal surgery were discharged on day 6 and 8 whereas the patient having only the endonasal component on a later date was discharged on day 2. CONCLUSION: A combined cranionasal approach involving transcranial orbitozygomatic and endonasal endoscopic approaches is an effective two-stage surgery for resecting SOMs invading into the sinuses and paranasal compartments. The ability to perform a multilayer closure involving a vascularized nasoseptal flap additionally decreases the risk of post-operative CSF leak.
    World Neurosurgery 10/2012; · 1.77 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND AND PURPOSE:DCI is a serious complication following aneurysmal SAH and remains a leading cause of morbidity and mortality. Our aim was to evaluate CTP in aneurysmal SAH by using outcome measures of DCI.MATERIALS AND METHODS:This was a retrospective study of consecutive patients with SAH enrolled in a prospective institutional review board-approved clinical accuracy trial. Qualitative CTP deficits were determined by 2 neuroradiologists blinded to clinical and imaging data. Quantitative CTP was performed by using a standardized protocol with region-of-interest placement sampling of the cortex. Primary outcome measures were permanent neurologic deficits and infarction. The secondary outcome measure was DCI, defined as clinical deterioration. CTP test characteristics (95% CI) were determined for each outcome measure. Statistical significance was calculated by using the Fisher exact and Student t tests. ROC curves were generated to determine accuracy and threshold analysis.RESULTS:Ninety-six patients were included. Permanent neurologic deficits developed in 33% (32/96). CTP deficits were seen in 78% (25/32) of those who developed permanent neurologic deficits and 34% (22/64) of those without (P < .0001). CTP deficits had 78% (61%-89%) sensitivity, 66% (53%-76%) specificity, and 53% (39%-67%) positive and 86% (73%-93%) negative predictive values. Infarction occurred in 18% (17/96). CTP deficits were seen in 88% (15/17) of those who developed infarction and 41% (32/79) of those without (P = .0004). CTP deficits had an 88% (66%-97%) sensitivity, 59% (48%-70%) specificity, and 32% (20%-46%) positive and 96% (86%-99%) negative predictive values. DCI was diagnosed in 50% (48/96). CTP deficits were seen in 81% (39/48) of patients with DCI and in 17% (8/48) of those without (P < .0001). CTP deficits had 81% (68%-90%) sensitivity, 83% (70%-91%) specificity, and 83% (70%-91%) positive and 82% (69%-90%) negative predictive values. Quantitative CTP revealed significantly reduced CBF and prolonged MTT for DCI, permanent neurologic deficits, and infarction. ROC analysis showed that CBF and MTT had the highest accuracy.CONCLUSIONS:CTP may add prognostic information regarding DCI and poor outcomes in aneurysmal SAH.
    American Journal of Neuroradiology 08/2012; · 3.17 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: The balloon-assisted coil embolization (BACE) technique represents an effective tool for the treatment of complex wide-necked intracranial aneurysms; however, its safety is a matter of debate. This study presents the authors' institutional experience regarding the safety of the BACE technique. METHODS: 428 consecutive patients with 491 intracranial aneurysms (274 acutely ruptured and 217 unruptured) treated with conventional coil embolization (CCE) or with BACE were retrospectively reviewed. All procedure-related adverse events were reported, regardless of clinical outcome. Thromboembolic events, intraprocedural aneurysm ruptures, device-related complications, morbidity and mortality were compared between the CCE and BACE groups. RESULTS: The total rate of procedural and periprocedural adverse events was 9.6% (47/491 embolizations). Thromboembolic events, intraprocedural aneurysmal rupture and device-related complications occurred in 2.4%, 3.9% and 3.3% of procedures, respectively. The risk of thromboembolic events and device-related problems was similar between the CCE and BACE groups. A trend towards a higher risk of intraprocedural aneurysm rupture was observed in the BACE group (not statistically significant). The total cumulative morbidity and mortality for both groups was 2.6% (11/428 patients) and there was no statistically significant difference in the morbidity, mortality and cumulative morbidity and mortality rates between the two groups. CONCLUSION: In this series of patients with acutely ruptured and unruptured aneurysms, the BACE technique allowed treatment of aneurysms with unfavorable anatomic characteristics without increasing the incidence of procedural complications.
    Journal of Neurointerventional Surgery 06/2012; · 2.50 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: 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.
    Interventional Neuroradiology 06/2012; 18(2):127-32. · 0.77 Impact Factor
  • Child s Nervous System 05/2012; 28(8):1273-7. · 1.24 Impact Factor

Publication Stats

596 Citations
144.76 Total Impact Points

Institutions

  • 2012–2014
    • CUNY Graduate Center
      New York City, New York, United States
  • 2011–2012
    • NYU Langone Medical Center
      New York City, New York, United States
  • 2003–2012
    • Weill Cornell Medical College
      • • Department of Neurology and Neuroscience
      • • Department of Neurological Surgery
      • • Division of Neurobiology
      • • Department of Radiology
      New York City, NY, United States
    • New York Presbyterian Hospital
      • • Department of Neurological Surgery
      • • Department of Anesthesiology
      • • Department of Radiology
      • • Department of Neurology and Neuroscience
      New York City, New York, United States
  • 2003–2008
    • Cornell University
      • • Department of Public Health
      • • Department of Radiology
      Ithaca, NY, United States