The Mechanism Research Of Dural Arteriovenous Fistula Induced By Intracranial Vein High-pressure In Rabbits

Objective The rabbit model of intracranial vein high-pressure was established by different ways of anastomosis CCA-PFV + ligation the contralateral EJV ,then to observe the dural arteriovenous which was newly formed, And find the ideal animal model of dural arteriovenous fistula.use this model , research dura mater and brain vessel growth factor, and to explore the mechanism of dural arteriovenous fistula formation.Methods【The first part】50 male Japanese white rabbits, weighing 2.0-2.5KG,,was randomly divided into control group (group A) and four vein high-pressure groups:end to end anastomosis group (group B),end to end anastomosis + ligation of the contralateral EJV group(group C),end-to-side anastomosis group(group D),end-to-side anastomosis + ligation of the contralateral EJV group (group E);n=10.Vein high-pressure model was made by anastomosis the right CCA-PFV, and the arterial pressure of the CCA, the venous pressure of the PFV and the venous pressure of the PFV after anastomosis was measured. 7,14,90 days after surgery, each group selected two rabbits were inked perfusion and dural vascular near the superior sagittal sinus weret observed; 90 days after surgery, 4 of each groups were did head and neck DSA, and observed whether new dural arteriovenous fistula were formated..Analysis using statistical software SPSS16.0.【The second part】50 male Japanese white rabbits, weighing 2.0-2.5KG, were randomly divided into control group, intracranial vein high-perssure group (one week, two weeks, three weeks group, 90 days group); end to end anastomosis of CCA-PFV +ligation of the contralateral EJV fabrication of intracranial vein high-perssure model; immunohistochemical determinate of HIF-1α, VEGF expression(n=6); Western blotting determinate of HIF-1α, VEGF levels(n=4).Results【The first part】After operation ,the vein high-perssure groups were observed right ear congestion, edema, ptosis, right eye congestion, prominent conjunctival edema, unsteady gait, anorexia, blindness, etc. surface vein pressure was immediately increased at vein high-perssure groups, there were not significantly different between BC groups and DE groups(P>0.05,RDE>RBC). group A of dura mater microvessel count 12±2/mm2, 7,14day after opteration of vein high-perssure group blood counts were slightly increased (respectively, 13±4,15±2/mm2), no significant differences between the two groups (P> 0.05); 90 days blood counts were significantly increased (up to 39±4/mm2), and thickening of vascular diameter, vascular links increased, and even arteries directly into thickening veins can be seen. After operation of 90 days , vein high-perssure groups were DSA imaged, cycle time is extended to 35s, and DAVF, eye AVF, ear AVF formation can be seen oe; which DAVF success rate was43.75%.【The second part】Occipital cortex, arachnoid blood vessels and dural around the superior sagittal sinus of One week, two weeks, three weeks groups can be visible VEGF expression was sustained, and the arachnoid blood vessel lumen been expansion; the control group, 90 days group with VEGF negative or weakly positive, 90 days group increased dural blood vessel, vessels lumen were irregular. Arachnoid blood vessels of One week, two weeks, three weeks groups were visible sustained HIF-1αexpression ,in the control group, 90 days group were negative. HIF-1αprotein expression of occipital lobe brain and dura were: one week group> two weeks group>three weeks group >90 days group> control group. VEGF protein expression in dura mater was: two weeks group> oneweek group> three weeks group >90 days group> control group.Conclusion This experiment used two ways of anastomosis which are end to end and end to side anastomosis, anastomosis CCA-PFV + ligation of the contralateral EJV, rabbit model of intracranial high-pressure, successfully induced the formation of DAVF, the model has good stability, repeatability, can be used as animal models of dural arteriovenous fistula research, end to end anastomosis is more suitable for experimental study. The key of DAVF formation is the formation of intracranial vein high-pressure,And it can cause cerebral perfusion pressure deficiency and dura "congenital arteriovenous direct access"opening. Cerebral ischemia caused by lack of cerebral perfusion pressure play a key role in the process from intracranial vein high-pressure to the HIF-1α, VEGF high expression. HIF-1α, VEGF can promote dural abnormality angiogenesis.