Abstract
We measured the flow velocity (FV) of the middle cerebral artery (MCA) using the transcranial Doppler sonography and the diameter of the MCA (R) from the angiography and calculated the blood flow (BF) by FV×πR2 in 7 normal persons and 15 AVM patients. FV and BF of the common carotid artery (CCA) were also measured using the QFM-2000XA. FV and BF of MCA increased proportional to the size of the nidus of the AVMs, but BF showed a steeper increase than FV, because of the dilatation of the feeding artery of MCA especially in large AVMs. BF of CCA showed more increase than FV in large AVMs but no or little increase in medium and small AVMs; and the increase of FV and BF of CCA was much less than that of FV and BF of MCA in AVM patients. From the steep increase of BF in large AVMs, normal perfusion pressure breakthrough occurs because of hemodynamic stress as a result of the sudden increase of blood flow of the distal cerebral arteries after excision of the AVM.
