In Vitro Quantification of the Radiopacity of Onyx during Embolization / 신경중재치료의학

PURPOSE: Onyx has been successfully applied in the treatment of various neurovascular lesions. However, some experience is required to get accustomed to its unpredictable fluoroscopic visibility during injection. This in vitro study aimed to evaluate the characteristics of radiopacity change in a simulated embolization procedure. MATERIALS AND METHODS: Using a bench-top Onyx injection experiment simulating a typical brain arteriovenous malformation embolization, nine cycles of casting modes (continuous injection) and plugging modes (injection with intermittent pauses) were performed. Radiodensity of Onyx droplets collected from the microcatheter tip and the distal head portion of the microcatheter were measured as time lapsed. Distribution of droplet radiodensity (radiodensity) and distribution of radiographic grade (grade) were analyzed and compared by repeated measurements. RESULTS: Within-group analysis revealed no significant radiodensity change with time (P>0.05). The radiodensity was significantly higher in the casting mode than in the plugging mode (P<0.01). The lateral radiograph of the microcatheter showed higher radiopacity (P<0.01) and better evenness (P<0.01) in the casting mode than in the plugging mode. A significant difference in microcatheter attenuation (both radiographic grade mean and SD; P<0.01) was noted between the two modes. Radiodensity had a significant influence on the radiopacity and radiopacity evenness of the microcatheter. CONCLUSION: The radiopacity of the Onyx can vary significantly over time because of early precipitation of tantalum powder. Radiopacity decreased significantly during plugging modes, characterized by pauses between injections.

The clinical features and treatment strategy of brain arteriovenous malformations associated with arterial an-eurysms / 中国神经精神疾病杂志

Objective To investigate the clinical features and treatment strategy of brain arteriovenous malforma-tions(AVM) associated with arterial aneurysms. Methods The clinical manifestation, imaging data, treatment and out-come of the patients with AVM were retrospectively analyzed in 38(10.4%) of these 364 patients. Results Hemorrhage was the most common clinical manifestation (60.5%). The hemorrhage risk was higher in AVM associated with arterial an-eurysms than in single AVM(χ2=5.956,P<0.05). The most common type of associated aneurysms was feeding artery an-eurysm (69.4%). Hemorrhage more frequently occurred within the aneurysm.(χ2=8.869,P<0.05). The bleeding lesions and 43 associated aneurysms of the 37 patients were treated effectively by endovascular treatment and/or craniotomy. Thirty-four patients had excellent or good outcomes, six patients had complications, 3 patients had neurological deficits. Postoperative digital subtraction angiography (DSA) examination showed the complete disappearance of arteriovenous malformation and aneurysm in sixteen cases. Conclusions The AVM associated with aneurysms is common in patients with AVM. AVM associated with aneurysms has a higher risk of hemorrhage than single AVM. The aneurysm within AVM has a higher rate of hemorrhage. The treatment priority should be given to the bleeding lesions and aneurysms.

Angioarchitecture and clinical presentation of brain arteriovenous malformations / Angioarquitetura e apresentação clínica de malformações arteriovenosas encefálicas

The purpose of this study was to correlate the angioarchitecture of brain arteriovenous malformations (AVM) with their clinical presentation. A total of 170 patients with AVM 78 males and 92 females, were studied. Univariate and multivariate analyses were conducted in order to test the associations between morphological features and clinical presentation. The most frequent clinical presentations at diagnosis were hemorrhage in 89 (52 percent) patients, headache in 79 (46 percent), focal neurological deficit in 54 (32 percent), and seizure in 52 (31 percent). According to the Spetzler-Martin classification, grade I was found in 15 patients, II in 49, III in 55, IV in 41, and grade V in 10 patients. AVM with small nidus size, single feeding artery and single draining vein were associated with hemorrhage. Hemorrhage was positively associated with Spetzler-Martin grade I and negatively with grade V. The association between seizure and large nidus size was positive, however negative with small nidus size.

O objetivo deste estudo foi correlacionar a angioarquitetura de malformações arteriovenosas encefálicas (MAV) com sua apresentação clínica. Foram estudados 170 pacientes portadores de MAV, sendo 78 do sexo feminino e 92 do masculino. Análises univariada e multivariada foram efetuadas para testar associações entre características morfológicas e quadro clínico. As principais formas de apresentação clínica no momento do diagnóstico incluíram hemorragia em 89 (52 por cento) pacientes, cefaléia em 79 (46 por cento), déficit focal em 54 (32 por cento) e convulsão em 52 (31 por cento). De acordo com a classificação de Spetzler e Martin, 15 pacientes tinham MAV grau I, 49 grau II, 55 grau III, 41 grau IV, e 10 grau V. MAV com nidus de tamanho pequeno, aferência e eferência únicas foram associados à hemorragia. Hemorragia foi positivamente associada com grau I e negativamente com grau V. A associação entre convulsão e nidus de tamanho grande foi positiva, porém negativa com nidus de tamanho pequeno.

Sinus Pericranii in an Infant: MR Imaging and Angiographic Findings

Sinus pericranii is a rare vascular anomaly involving abnormal communication between the intracranial and extracranial venous circulations. Although the condition can be diagnosed clinically, imaging is required to distinguish it from other entities and to identify the connection between the extracranial and intracranial dural venous sinus. We report the characteristic MR imaging and angiographic findings of a case of sinus pericranii.

Endovascular treatment of brain arteriovenous malformations in Siriraj Hospital.

Objective: To present our experience on endovascular embolization by using N-butyl cyanoacrylate and to demonstrate that this is an effective method in the treatment of brain arteriovenous malformations. Malerials and Methods: From 1992 to 1998, 92 patients with brain arteriovenous malformations who having had endovascular embolization as primary treatment was retrospectively reviewed. Results: 8 patients (8.7%) had completely cure by embolization alone wthout neurological complication. 17 patients (18.5%) were cured after combined treatment, 9 with surgical removal and the other 8 with radiosurgery. The neurological complications occurred in 17 patients (18.5%) with 3 deaths and vegetative stage. Conclusion: The endovascular embolization can cure the arteriovenous malformations that smaller than 3 cm, no matter what its location, and it is effective to reduce the nidus volume of the larger lisions, making them suitable for surgical resection or radiosurgery as to achieve te goal of complete eradication of the malformations.