FIGURE 7

Effects of stepwise occlusion for medium (A) and large (B) arteriovenous malformations (AVM). The anatomic location of the AVM was shown in Fig. 1. These simulations assumed the presence of vessel dilation from shear stress (+d). The percent occlusion of the AVM was defined by Eq. 16. For the model with autoregulation (+a), the perfusion pressures increased from 33 to 66 mm Hg for the medium AVM (A), and from 21 to 70 mm Hg for the large AVM (B). Before occlusion, the CBF in the near-field tissues compartment (microvessel group represented by compartment 100 [3774] in Table 2) was 33 mL/100g/min for the medium AVM and 21 mL/100g/min for the large AVM. When the percent occlusion was larger than 70% for the medium AVM or larger than 90% for the large AVM, the CBF of the near-field tissue returned to a normal level (approximately 50 mL/100 g/min). The CBF in the model without autoregulation (-a) increased further with a percent occlusion of greater than 70% for the medium AVM and 90% for the large AVM. With complete occlusion, CBF increased to 66 mL/100 g/min for the medium AVM and 71 mL/100 g/min for the large AVM. () near-field tissue pressure (mm Hg) on arterial side (node 37 in Fig. 1); () near-field tissue pressure (mm Hg) on venous side (node 74 in Fig. 1); () near-field tissue CBF (mL/100 g/min) in the model with autoregulation; () near-field tissue CBF (mL/100 g/min) in the model without autoregulation; percent AVM flow: blood flow through the AVM in percentage of initial AVM flow.