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1、,脑动静脉畸形,执教教师:XXX,CEREBRALARTERIOVENOUS MALFORMATIONS,AVM: a TLA for the CNS,Incidence,0.52% at autopsySlight male preponderance (1.09 to 1.94)Congenital lesions (although rarely familial),Embryology,First half of third week of gestationepiblastic cells migrate to form mesodermmesodermal cells differ
2、entiate to arterial and venous vessels on the surface of the embryonic nervous system,Embryology,First half of third week of gestationepiblastic cells migrate to form mesodermmesodermal cells differentaite to arterial and venous vessels on the surface of the embryonic nervous systemSeventh gestation
3、al weekvessels sprout branches & penetrate developing brainreach the gray-white interface, either loop back to pial surface or traverse entire neural tube, thus epicerebral & transcerebral circneventually connect arterial and venous systems by around the twelfth week,Pathology & Pathophysiology,abse
4、nce of normal capillary system,Pathology & Pathophysiology,absence of normal capillary systemusual function displaced,Pathology & Pathophysiology,absence of normal capillary systemusual function displacedasymptomatic at birth,Pathology & Pathophysiology,absence of normal capillary systemusual functi
5、on displacedasymptomatic at birthvessels change with timemay develop aneurysms,parenchymal changes within and around the lesion,Pathology & Pathophysiology,absence of normal capillary systemusual function displacedasymptomatic at birthvessels change with timemay develop aneurysms,parenchymal changes
6、 within and around the lesionsite frequency is proportional to brain volume,Pathology & Pathophysiology,absence of normal capillary systemusual function displacedasymptomatic at birthvessels change with timemay develop aneurysms,Clinical presentation,95% have symptoms by age of 70 years,Clinical pre
7、sentation,95% have symptoms by age of 70 yearspeak presentation second to fourth decade,Clinical presentation,95% have symptoms by age of 70 yearspeak presentation second to fourth decadehigh output failure, neonate, vein of Galenhydrocephalus, first decadeheadache, hemorrhage, seizures, 2nd & 3rd,C
8、linical presentation,factors contributing to symptomsvessel walls, flow and pressures,Clinical presentation,factors contributing to symptomsvessel walls, flow and pressuresenlargement and encroachment,Clinical presentation,factors contributing to symptomsvessel walls, flow and pressuresenlargement a
9、nd encroachmentdural sinuses,Clinical presentation,factors contributing to symptomsvessel walls, flow and pressuresenlargement and encroachmentdural sinusesischaemia,Clinical presentation,factors contributing to symptomsvessel walls, flow and pressuresenlargement and encroachmentdural sinusesischaem
10、iacardiac output,Clinical presentation,Hemorrhage,AVMrupture not a function of size,Aneurysmrupture related to aneurysm size,Hemorrhage,AVMrupture not a function of sizeno marked increase with exercise, pregnancy, trauma,Aneurysmrupture related to aneurysm sizeincrease with trauma exercise, end preg
11、nancy,Hemorrhage,AVMrupture not a function of sizeno marked increase with exercise, pregnancy, traumaarteriovenous, therefore less severe,Aneurysmrupture related to aneurysm sizeincrease with trauma exercise, end pregnancyarterial, therefore more severe,Hemorrhage,AVMrupture not a function of sizeno
12、 marked increase with exercise, pregnancy, traumaarteriovenous, therefore less severemortality 6 to 13.6%,Aneurysmrupture related to aneurysm sizeincrease with trauma exercise, end pregnancyarterial, therefore more severemortality 30-50%,Hemorrhage,AVMrupture not a function of sizeno marked increase
13、 with exercise, pregnancy, traumaarteriovenous, therefore less severemortality 6 to 13.6%lower rebleed mortality rate (1%),Aneurysmrupture related to aneurysm sizeincrease with trauma exercise, end pregnancyarterial, therefore more severemortality 30-50%higher rebleed mortality rate (13%),Hemorrhage
14、,AVMrupture not a function of sizeno marked increase with exercise, pregnancy, traumaarteriovenous, therefore less severemortality 6 to 13.6%lower rebleed mortality rate (1%)vasospasm rare,Aneurysmrupture related to aneurysm sizeincrease with trauma exercise, end pregnancyarterial, therefore more se
15、veremortality 30-50%higher rebleed mortality rate (13%)vasospasm common,Hemorrhage - AVM,Nonetheless, risk of major, incapacitating, or fatal hemorrhage in untreated lesion is 40 to 50%,Hemorrhage - AVM,Nonetheless, risk of major, incapacitating, or fatal hemorrhage in untreated lesion is 40 to 50%Y
16、early risk of initial hemorrhage 3%Rebleed in first subsequent year 6-18%, reducing to 3% again thereafterPediatric prognosis worse than adult,Spetzler & Martin Grading System,Criteria,Score,Size of Nidus,Small (6cm),3,Eloquence of Adjacent Brain,No,0,Yes,1,Deep Vascular Component,No,0,Yes,1,Treatme
17、nt Options,Surgical Resection,Treatment Options,Surgical ResectionEndovascular Embolisation,Treatment Options,Surgical ResectionEndovascular EmbolisationStereotatic Radiosurgery,Treatment Options,Surgical ResectionEndovascular EmbolisationStereotatic RadiosurgeryMultimodal Therapy,Treatment Options,
18、Surgical ResectionEndovascular EmbolisationStereotatic RadiosurgeryMultimodal TherapyConservative Management,Normal Perfusion Pressure Breakthrough Theory,R.F. Spetzler et al,Normal perfusion pressure breakthrough theory,Loss of autoregulation and carbon dioxide reactivity in presence of large arter
19、iovenous malformation.,Normal perfusion pressure breakthrough theory,Loss of autoregulation and carbon dioxide reactivity in presence of large arteriovenous malformation.Normal hemispheric vessels are chronically maximally dilated to attempt to divert flow from the AVM,Normal perfusion pressure brea
20、kthrough theory,Loss of autoregulation and carbon dioxide reactivity in presence of large arteriovenous malformation.Normal hemispheric vessels are chronically maximally dilated to attempt to divert flow from the AVMObliteration of the AVM diverts all flow to these maximally dilated vessels which ha
21、ve lost their normal control mechanisms,Normal perfusion pressure breakthrough theory,Loss of autoregulation and carbon dioxide reactivity in presence of large arteriovenous malformation.Normal hemispheric vessels are chronically maximally dilated to attempt to divert flow from the AVMObliteration o
22、f the AVM diverts all flow to these maximally dilated vessels which have lost their normal control mechanismsResults in loss of protection of the capillary bed, with edema and hemorrhage,Arterial inflow,Mathematical Models,Arterial inflowNidus,Mathematical Models,Arterial inflowNidusVenous Outflow,Mathematical Models,Anaesthesia Technique,谢谢观看,请指导,