AVM出血的病死率比动脉瘤破裂出血及其他非AVM破裂的脑内出血的病死率低。[26]Perret G, Nishioka H. An analysis of 545 cases of cranio-cerebral arteriovenous malformations and fistulae reported to the Cooperative Study. J Neurosurg. 1966;25:467-490.http://www.ncbi.nlm.nih.gov/pubmed/5925721?tool=bestpractice.com[53]Choi JH, Mast H, Sciacca RR, et al. Clinical outcome after first and recurrent hemorrhage in patients with untreated brain arteriovenous malformation. Stroke. 2006;37:1243-1247.http://stroke.ahajournals.org/content/37/5/1243.fullhttp://www.ncbi.nlm.nih.gov/pubmed/16614321?tool=bestpractice.com文献报道AVM破裂出血病死率可达18%。[1]Brown RD Jr., Wiebers DO, Torner JC, et al. Frequency of intracranial hemorrhage as a presenting symptom and subtype analysis: a population-based study of intracranial vascular malformations in Olmsted County, Minnesota. J Neurosurg. 1996;85:29-32.http://www.ncbi.nlm.nih.gov/pubmed/8683279?tool=bestpractice.com[2]Al-Shahi R, Warlow C. A systematic review of the frequency and prognosis of arteriovenous malformations of the brain in adults. Brain. 2001;124:1900-1926.https://academic.oup.com/brain/article/124/10/1900/333474/A-systematic-review-of-the-frequency-and-prognosishttp://www.ncbi.nlm.nih.gov/pubmed/11571210?tool=bestpractice.com
出血的风险
考虑目前对于AVM破裂出血的危险因素尚无统一的认识,且各危险因素间有复杂的相关性,AVM保守治疗的风险很难预测。一般认为年出血率为2%-4%。出血后5年内出血风险增加,且出血后1年再出血风险最高,有报道概率>30%。[16]Hernesniemi JA, Dashti R, Juvela S, et al. Natural history of brain arteriovenous malformations: a long-term follow-up study of risk of hemorrhage in 238 patients. Neurosurgery. 2008;63:823-829.http://www.ncbi.nlm.nih.gov/pubmed/19005371?tool=bestpractice.com[17]Mast H, Young WL, Koennecke HC, et al. Risk of spontaneous haemorrhage after diagnosis of cerebral arteriovenous malformation. Lancet. 1997;350:1065-1068.http://www.ncbi.nlm.nih.gov/pubmed/10213548?tool=bestpractice.com然而,目前对未出血的患者出血的风险有所高估,其年出血率可能<1%。[18]Stapf C, Mast H, Sciacca RR, et al. Predictors of hemorrhage in patients with untreated brain arteriovenous malformation. Neurology. 2006;66:1350-1355.http://www.ncbi.nlm.nih.gov/pubmed/16682666?tool=bestpractice.com在这些患者中,治疗的风险可能大于破裂的风险。[19]Wedderburn CJ, van Beijnum J, Bhattacharya JJ, et al. Outcome after interventional or conservative management of unruptured brain arteriovenous malformation: a prospective, population-based cohort study. Lancet Neurol. 2008;7:223-230.http://www.ncbi.nlm.nih.gov/pubmed/18243054?tool=bestpractice.com为证明干预治疗组患者5年功能预后较保守治疗组患者差,研究者设计了ARUBA试验(未破裂脑动静脉畸形的随机对照试验)。The ARUBA trial