Our animal experiments supplied precise information on hemodynamic characteristics in vessels with high flow velocities and of vessels connected in parallel to AV fistulas. Comparable investigations did not exist until now. It was shown that blood flow rates in cervical AV fistulas increase to about ten times the normal values. This increase is limited only by the cardiac output volume, by the diameters of fistula vessels, by the cross-sectional plane of the shunt and by systemic blood pressure. The stream resistance in the fistula feeding vessel drops with minimal resistance indices reaching 0.28. The flow rates and vascular resistances in experimental cervical AV fistulas were the same as in human AVMs.