Analysis of the hemodynamic characteristics of brain arteriovenous malformations using electrical models: baseline settings, surgical extirpation, endovascular embolization, and surgical bypass.

OBJECTIVE: The goal of this report is to analyze the hemodynamic characteristics of low- and high-flow arteriovenous malformations (AVM) using computerized electrical models.
METHODS: Two electrical models of brain AVMs were created. These models consist of electrical resistors that simulate AVM vessels. In both models, a low-flow AVM and a high-flow AVM, the flow of electrons simulates the flow of blood.
RESULTS: Using the models, it was possible to analyze the pressure and flow patterns in the nidus of the small, low-flow AVM and in the nidus of the large, high-flow AVM. Baseline hemodynamic "physiological" conditions of the two AVMs were studied. With the models, it was also possible to assess the AVM hemodynamic changes (in the feeding arteries, in the various parts of the nidus, and in the draining veins) after surgery, after embolization, and after surgical bypass of the malformation. The role of autoregulation in the three treatment modalities was also assessed.
CONCLUSION: These electrical models seem to be useful in simulating and studying the behavior of flow and pressure in the different parts of the AVM nidus (arterial, arteriolar, arteriolar-venular, venular, venous) before and after treatment. The models can also be used to devise and simulate new treatment strategies that might lead to improved treatment of these highly complex vascular malformations of the brain.