Electrical models in the analysis of hemodynamic characteristics of arteriovenous malformations. Part 1: baseline measurements.

SUMMARY: This paper describes the creation of two electric arteriovenous malformation (AVM) models where electric resistors simulate AVM vessels. The flow of electrons simulates the flow of blood. Using the models, it was possible to analyze the pressure and flow patterns in the nidus of a small, low-flow AVM and in the nidus of a large, high-flow AVM. "Normal" hemodynamic "physiologic" conditions of the two AVMs were studied, including the autoregulation of normal brain surrounding the AVMs. It is the first time that the hemodynamics within the different parts of the nidus (arterious, arteriolar, venular, venous) can be determined. The models will be utilized to assess AVM hemodynamic changes when different parameters (systemic blood pressure, embolization of arterial feeders, embolization of nidus, embolization of draining veins, surgical by-pass of the AVM) are changed. This will be the subject of part 2 of this paper.