Case Reports Draining Vein Pressure Increases and Hemorrhage in Patients With Arteriovenous Malformation

Background Recent radiological studies have shown that arteriovenous malformations with impaired venous drainage may be susceptible to hemorrhage. To evaluate this hypothesis using a hemodynamic approach, we measured intravascular pressure during surgery in three patients with arteriovenous malformation. Summary of Report In three patients we measured intravascular pressures in the draining venous system and the feeding arteries simultaneously before removal of arteriovenous malformations with marked segmental stenotic or occlusive draining veins and evidence of hemorrhage. The draining vein pressures at prestenotic (or preocclusive) sites in the three patients were 38, 25, and 40 mm Hg, respectively, all significantly above the normal cortical venous pressure, whereas pressure measurements in poststenotic sites and the sagittal sinus pressure in the venous drainage system approached normal values. The feeding artery pressures in the patients were lower than normal cortical artery pressure because of the arteriovenous shunt. Conclusions Intraoperative vascular pressure measurements support the hypothesis that arteriovenous malformations with impaired venous drainage may be associated with a local increase in venous pressure and thus may be susceptible to hemorrhage. (Stroke. 1994;25:504-507.)