An In Vivo Optic Imaging Study Of Dural Arteriovenous Fistula On Cerebral Micro-circulation

The dural arteriovenous fistula(DAVF)is a kind of rare intracranial vascular disease.It's a kind of abnormal arteriovenous communicating vascular disease which occurs at dural mater and its accessory--falx cerebri and tentorium cerebelli.DAVE accounts for 10%-15%intracranial vascular malformation and it can occurs at any part of dura mater,but mostly concentrated on transverse sinus,sigmoid sinus,cavernous sinus and tentorium cerebelli.The mild clinical presentation are intracranianl vascular murmur,pulsatile tinnitus,exophthalmos,some severe intracranial hemorrhage may also occur.DAVF is mostly seem in male adult,and 60%of them are among 40 to 60 years old.The pathogenesis are:l)Congenital theory 2)Acquired theory:1.The formation of Cerebral venous sinus thrombosis.2.vicious circle theory.3.The new formation theory.Currently acquired theory is generally accepted,the hyper-perfusion of venous sinus caused by venous sinus thrombosis leads to open of living rational arterio-venous tunnel.Meanwhile,huge amount of biochemical factors promote the proliferation of neovascularization and at last participate in the formation of DAVF.However,there is no a definite generally-accreditated theory.Detecting technique in the past such as DSA,LDF,normal optical microscope and electro-microscope can not real-time detect the parameters of nicrovascular blood-flow.Laser speckle imaging technique can perform the global-blood flow detection of cerebral cortex.Laser speckle technique is of high time resolution and spatial resolution.In this paper,we will use laser speckle blood-flow imaging technique to investigate the microvascular bloodflow changes of cerebral cortex after DAVF and its mechanism.Objective:Utilize the laser speckle blood-flow imaging technique to realtime obeserve the microvascular bloodflow changes of cerebral cortex after DAVF in order to prove the open of collateral circulation.Methods:Using laser speckle blood-flow imaging technique to broadly detect the formation of neovascular and changes of bloodflow on the cerebral cortex at diffrent at dif'f-erent courses of DAVF rat model.Result:In the DAVF rat model,due to the hyperperfusion of vcnous sinus,the bloodflow of superior saggital sinus(SSS)decreases and later on increases to a higher level less than baseline after 2 weeks.The bloodflow of branch-vessels decreases and lateron increases to a higher level than baseline and that of 2-week SSS.Obvious collateral vasculars formation can bee observed on cerebral cortex,and bloodflow speed increases,the vascular morphology can gradually be seen.Conclusion:The hyperperfusion caused by DAVF lead to the decrease of branch-vessels bloodflow of saggital sinus and later on an increase higher than baseline after 2 weeks.The neonatal collateral bloodflow volume increases and the vascular morphology can gradually be seen.