Xianli Lv, Chuhan Jiang, Youxiang Li and Zhongxue Wu
Use of the Onyx liquid embolic system has become an option for treating dural arteriovenous fistulas (DAVFs) because of its advantageous nonadhesive and cohesive properties. However, the complication rates associated with the use of this system have not been reported. The authors present their initial experience of the risks related to transarterial embolization using this system.
Between February 2005 and February 2007, 31 patients with DAVFs were treated at Beijing Tiantan Hospital. Transarterial embolization using Onyx-18 was performed as a preoperative adjunct or as definitive therapy. The demographic characteristics, angiographic features, clinical presentation, treatment, and outcome of the patients were reviewed. Clinical follow-up status was supplemented by telephone interviews to determine Glasgow Outcome Scale scores.
In 19 patients (61.3%) there was complete angiographic evidence of elimination of the shunts and resolution of the symptoms. The remaining 12 patients were treated successfully but did not attain complete embolization and had residual shunting. Adverse events occurred in 5 of 31 patients, with 3 DAVFs located at the tentorium, 1 at the inferior petrosal sinus, and 1 at the cavernous sinus. Complications included trigeminocardiac reflex in 2 patients (6.5%), hemifacial hypesthesia in 3 patients (9.7%), hemifacial palsy in 2 patients (6.5%), jaw pain in 1 patient (3.2%), posterior fossa infarction in 1 patient (3.2%), and microcatheter gluing in 1 patient (3.2%). At the last follow-up examination, all patients had returned to an independent clinical status.
Although a complete resolution of symptoms can be achieved with transarterial embolization using the Onyx liquid embolic system, the potential for serious complications exists with this procedure, necessitating the participation of a skilled neurointerventionalist.
Xianli Lv, Youxiang Li, Xinjian Yang, Chuhan Jiang and Zhongxue Wu
The purpose of this study was to report the potential proneness of a fetal-type posterior cerebral artery (PCA) to develop vascular insufficiency in parent vessel occlusion of distal PCA aneurysms.
Between January 2005 and January 2011, 19 patients (9 females and 10 males) with 20 distal PCA aneurysms (16 dissecting and 4 saccular) were treated with endovascular parent vessel occlusion. The ages of the patients ranged from 5 to 71 years, with a mean age of 40.2 years. Of the 20 aneurysms, 4 were ruptured and 16 were unruptured. One of the unruptured aneurysms was additional to another ruptured aneurysm, and 15 were incidentally discovered. Five aneurysms were smaller than 10 mm, and the other 15 were 10 mm or larger.
All aneurysms were successfully treated with simultaneous coil occlusion of the aneurysm and the parent PCA. One patient had hemianopia at the initial presentation, and 2 patients had new persistent hemianopia due to insufficient leptomeningeal collateral circulation; in 16 patients with an intact visual field, no hemianopia developed because there was sufficient leptomeningeal collateral circulation. A fetal-type PCA was involved in all 3 patients with hemianopia, which was initially presented or caused by parent vessel occlusion. However, in the patients without hemianopia, an adult-type PCA was involved in all cases.
Endovascular treatment via coil occlusion of the aneurysm as well as the parent artery can be used to cure distal PCA aneurysms. A fetal-type PCA could be an important predictive factor for vascular insufficiency in parent vessel occlusion treatment.
Xiaochuan Huo, Yuhua Jiang, Xianli Lv, Hongchao Yang, Yang Zhao and Youxiang Li
A combination of embolization and radiosurgery is used as a common strategy for the treatment of large and complex cerebral arteriovenous malformations (AVMs). This study presents the experiences of partially embolized cerebral AVMs followed by Gamma Knife surgery (GKS) and assesses predictive factors for AVM obliteration and hemorrhage.
The interventional neuroradiology database that was reviewed included 404 patients who underwent AVM embolization. Using this database, the authors retrospectively analyzed all partially embolized AVM cases followed by GKS for a residual nidus. Except for cases of complete AVM obliteration, the authors excluded all patients with radiological follow-up of less than 2 years. Logistic regression analysis was used to analyze the predictive factors related to AVM obliteration and hemorrhage following GKS. Kaplan-Meier analysis was used to evaluate the obliteration with a cutoff AVM nidus volume of 3 cm3 and 10 cm3.
One hundred sixty-two patients qualified for the study. The median patient age was 26 years and 48.8% were female. Hemorrhage presented as the most common symptom (48.1%). The median preembolization volume of an AVM was 14.3 cm3. The median volume and margin dose for GKS were 10.92 cm3 and 16.0 Gy, respectively. The median radiological and clinical follow-up intervals were 47 and 79 months, respectively. The annual hemorrhage rate was 1.71% and total obliteration rate was 56.8%. Noneloquent area (p = 0.004), superficial location (p < 0.001), decreased volume (p < 0.001), lower Spetzler-Martin grade (p < 0.001), lower Virginia Radiosurgery AVM Scale (RAS; p < 0.001), lower Pollock-Flickinger score (p < 0.001), lower modified Pollock-Flickinger score (p < 0.001), increased maximum dose (p < 0.001), and increased margin dose (p < 0.001) were found to be statistically significant in predicting the probability of AVM obliteration in the univariate analysis. In the multivariate analysis, only volume (p = 0.016) was found to be an independent prognostic factor for AVM obliteration. The log-rank (Mantel-Cox) test of the Kaplan-Meier analysis (chi-square = 54.402, p < 0.001) showed a significantly decreased obliteration rate of different cutoff AVM volume groups of less than 3 cm3, 3–10 cm3, and more than 10 cm3. No independent prognostic factor was found for AVM hemorrhage in multivariate analysis.
Partially embolized AVMs are amenable to successful treatment with GKS. The volume of the nidus significantly influences the outcome of radiosurgical treatment. The Virginia RAS and Pollock-Flickinger score were found to be reliable scoring systems for selection of patient candidates and prediction of partially embolized AVM closure and complications for GKS.