【正文】 AVM中的血流動力學(xué)單位，畸形血管團可以是單間隔或多間隔組成。 ?單間隔畸形血管團： 1個 AVM有多支供血動脈，每支供血動脈都供應(yīng)整個畸形血管團。 DSA時每支動脈造影均可顯示整個 AVM，其充盈度相等，引流靜脈也完全相同。 ?多間隔畸形血管團： 1支供血動脈只供應(yīng) AVM的一部分，另一支供血動脈供應(yīng)其另一部分，互相間有或無部分重疊供血。 DSA時各支動脈造影所顯示的AVM大小、部位和形狀不相同，可能部分影像重疊，其中一個供血動脈系統(tǒng)占優(yōu)勢或完全不重疊。 AVM診斷、分級 及發(fā)病與風(fēng)險評估 AVM的診斷 ?反復(fù)自發(fā)出血表現(xiàn)和頑固性癲癇發(fā)作 。 ?頭顱 MRI:局灶性流空血管團影 。 ?腦血管造影 (DSA). 發(fā)病與風(fēng)險因素 (Natural History) ? 發(fā)病年齡 （ Average age at presentation） : 33yrs(1) ? 癥狀表現(xiàn) （ Symptomatic presentation）： Hemorrhage %, seizures %, headaches % (2). Ischemia %. (3). Others: mass effect. ? 出血風(fēng)險因素 （ Risk factors of hemorrhage: ）： increase age, infratentorial amp。 deep location, exclusive deep venous drainage amp。 associated arterial aneurysm. (4) Risk of Hemorrhage of untreated AVM 24% per year. (5) (1) Greenberg. Chapter 28 Vascular Malformations: Handbook of Neurosurgery. 6th ed. Thieme publishers. 2022. (2) Hamilton amp。 Spetzler. The Prospective Applicatiopn of a Grading System for Arteriovenous Malformations. Neurosurgery: Volume 34 (1) January 1994 p 27. (3) Deruty et al. Reflections on the management of cerebral arteriovenous malformations. Surg Neurol 1998。 50: 245256. (4) Staph et al. Predictors of hemorrhage in patients with untreated arteriovenous malformation. Neurology 2022。 66: 13501355 (5) Graf et al. Bleeding from cerebral arteriovenous malformations as part of their natural history. J Neurosug 58: 331337, 1983. 發(fā)病與風(fēng)險因素 (Natural History) Increase hemorrhage risk post diagnosis: Staph et al. Independent risk factors: increase age, initial hemorrhagic presentation, deep brain location amp。 exclusive deep venous drainage.(1) ? Rebleed upto 34% of cases. (1) ? 50% serious risk of neurological morbidity associated with each hemorrhage. (1,2) ? Mortality Rate per bleed – 1%(3), 510%(4) ? (1) Staph et al. Predictors of hemorrhage in patients with untreated arteriovenous malformation. Neurology 2022。 66: 13501355 ? (1) Gerosa et al: Cerbral arteriovenous malformations in children (56 cases). Childs Brain 8: ? (2) Wilkins RH: Natural history of intracranial vascular malformations: A review. Neurosurgery 16: 421430, 1985. ? (3) Ondra et al. The natural history of symptomatic arteriovenous malformations of the brain: 24 yr follow up assessment. J of Neurosurg 1990。 73: 387391 ? (4) Reyns et al. Role of Radiosurgery in the Management of Cerebral Arteriovenous Malformations in the Pediatric Age Group: Data From a 100Patient Series. Neurosurgery 60: 268276, 2022 Cumulative Risk of Bleed in an AVM ?An example of a 13 yr old with a newly detected AVM has a 33% cumulative risk of hemorrhage in the next 20 yrs and a 55% risk in 40yrs (1) ?Risk of bleeding (at least once in xyrs)= 1(annual risk of not bleeding) expected years of remaining life (2) ?(1) Kondziolka amp。 Lundsford: Re: Current Status of Radiosurgery for arteriovenous malformations. Can J Neurol Sci 19:514515, 1992. ?(2) Greenberg. Chapter 28 Vascular Malformations: Handbook of Neurosurgery. 6th ed. Thieme publishers. 2022. 腦 AVM引起顱內(nèi)出血的危險因素 因素 危險增加 危險減低 年齡 ＞ 60歲 出血史 以前有出血 無出血 部位 顳葉、島葉、胼胝體、腦室旁 頂葉、枕葉、額葉 大小 小型 AVM 大型 AVM 靜脈引流 深靜脈引流 淺靜脈引流 血管結(jié)構(gòu)