动静脉畸形（ppt）课件

Arteriovenous Arteriovenous malformation of malformation of the brainthe brain Diagnosis and treatment DevelopmentDevelopment 3rd week of pregnancy primitive vessels do not develop into normal vasculature formation of an arteriovenous shunt SymptomsSymptoms HemorrhageHemorrhage history of sudden headache age usually 25 35 years hemorrhage less severe than SAH no vasospasm risk 2 3 % per year SeizuresSeizures often focal, but may generalize often better after operation Neurological deficitNeurological deficit due to ischaemia of surrounding brain develops with increasing age especially in large AVMs DiagnosisDiagnosis history and neurological examination CT-scan MRI and MRA angiography EvaluationEvaluation size draining veins (deep) arterial feeders localization in brain associated aneurysms define bleeding source TreatmentTreatment conservative closing of feeder arteries excision endovascular radiotherapy Conservative Conservative treatmenttreatment control of epilepsy control of hypertension life-style advice Closing feeder Closing feeder arteriesarteries reduction in blood flow short lived effect collaterals will develop no risk reduction! ExcisionExcision size localisation number of feeders venous drainage 75% can be excised only 100% effective treatment! depends on EndovascularEndovascular balloon occlusion occlusion of the nidus identify bleeding source only indicated if 100% elimination may be combined with surgical treatment RadiotherapyRadiotherapy causes hyperplasia of intima secondary thrombosis for deep-seated AVMs 3 cm occlusion rate 80% effect after two years life-long follow-up necessary? Operative techniqueOperative technique BP 100 mm Hg moderate cooling start on the arterial side! observe natural shape of AVM occlusion of veins as last step keep BP low post op. keep patient sedated 24 48 hours ProblemsProblems oedema seizures perfusion pressure breakthrough re-b