Posterior fossa brain arteriovenous malformations

BackgroundPosterior fossa brain arteriovenous malformations (PFbAVM) are relatively rare brain disorders but have a high risk of hemorrhage. Endovascular embolization to reduce the lesion size before treatment may improve the outcome of PFbAVM. The purposes of this study were to identify risk factors associated with hemorrhage in PFbAVM and to assess clinical outcomes in patients receiving initial endovascular embolization.Material and methodsFrom 1999 to 2013 a total of 63 patients with PFbAVMs were treated (31 males and 32 females, 14.1 % of all AVM cases). A retrospective examination of patient demographics, clinical presentation, angiographic features, treatment modalities, complications and outcomes was carried out. The re-hemorrhage rate, obliteration rate and modified Rankin scale (MRS) were used as measures of outcome.ResultsOf the 63 PFbAVM patients 54 (85.7 %) exhibited hemorrhage and 15 had confirmed aneurysms. The cerebellar location (P = 0.007) and deep venous drainage (P = 0.012) were independent predictors of hemorrhage in multivariate analyses. The mean estimated devascularization was 46.9 % (range 10–100 %) in the 20 patients (31.7 %) treated by endovascular embolization. The 16 patients with residual niduses were further treated by radiosurgery, microsurgery or embolization. Complete obliteration was attained in 12 patients (67 %) while 2 (5.7 %) were left with persisting neurological deficits and 1 had a re-hemorrhage 3 years later (annual rate of 4.6 %). Favorable outcome (MRS ≤ 2) was obtained in the 20 patients receiving initial endovascular embolization (P = 0.039 versus preoperative MRS).ConclusionCerebellar location and deep venous drainage are predictors of hemorrhage in PFbAVM. Adjuvant endovascular embolization is useful and safe for PFbAVM prior to microsurgery or radiosurgery.

背景 后颅窝脑动静脉畸形（PFbAVM）是相对罕见的脑部疾病，但出血风险较高。在治疗前进行血管内栓塞以减小病变大小可能会改善PFbAVM的治疗效果。本研究的目的是确定与PFbAVM出血相关的危险因素，并评估接受初始血管内栓塞治疗的患者的临床结果。 材料与方法 1999年至2013年，共治疗了63例PFbAVM患者（31例男性，32例女性，占所有AVM病例的14.1%）。对患者的人口统计学资料、临床表现、血管造影特征、治疗方式、并发症及结果进行了回顾性检查。以再出血率、闭塞率和改良Rankin量表（MRS）作为结果衡量指标。 结果 63例PFbAVM患者中，54例（85.7%）出现出血，15例确诊有动脉瘤。在多变量分析中，小脑部位（P = 0.007）和深静脉引流（P = 0.012）是出血的独立预测因素。在接受血管内栓塞治疗的20例患者（31.7%）中，平均估计的血运减少率为46.9%（范围10 - 100%）。16例有残留病灶的患者进一步接受了放射外科治疗、显微外科手术或栓塞治疗。12例患者（67%）实现完全闭塞，2例（5.7%）遗留持续性神经功能缺损，1例在3年后再次出血（年出血率为4.6%）。在接受初始血管内栓塞治疗的20例患者中获得了良好的结果（MRS≤2）（与术前MRS相比，P = 0.039）。 结论 小脑部位和深静脉引流是PFbAVM出血的预测因素。在显微外科手术或放射外科手术之前，辅助性血管内栓塞对PFbAVM是有用且安全的。