Indirect bypass using autologous tissue is effective in Moyamoya disease, especially among pediatric patients. This study aimed to evaluate the effectiveness of indirect bypass using DuraGen (absorbable artificial dura mater composed of collagen matrix), as a substitute for autologous tissue in a rat model of chronic cerebral hypoperfusion. Male Wistar rats were subjected to bilateral internal carotid artery occlusion and divided into three groups: a control group without bypass surgery, a group wherein indirect bypass was performed using the temporalis muscle (encephalo-myo-synangiosis [EMS] group), and a group wherein DuraGen was used (Dura group). The ratio of the number of vascular endothelial cells, detected by antibodies to CD31 and glucose transporter type 1 (Glut-1), on the operative side to that on the non-operative side was measured and compared between the three groups. The ratio of CD31-positive cells was 1.50 ± 0.13 and 1.92 ± 0.29 in the EMS and Dura groups, respectively, and that of Glut-1-positive cells was 1.32 ± 0.10 and 1.53 ± 0.18 in the EMS and Dura groups, respectively. No significant difference was observed in the ratio of vascular endothelial cells on the bypass side between the EMS and Dura groups. Indirect bypass with DuraGen resulted in an increased ratio of vascular endothelial cells, equivalent to that of an indirect bypass with the temporalis muscle in a rat model. Thus, in an actual indirect bypass for patients with Moyamoya disease, the use of DuraGen may produce the same angiogenesis as using autologous tissue.