The effect of the geometry of the vessel and the number of anastomoses on the blood flow was studied. Four different shapes of the vessel were constructed by using a 6-cm-long double vein graft model with three anastomoses: (1) an alpha loop, (2) an omega loop, (3) a sigmoid curve, and (4) straight. Blood flow was measured by an ultrasound Doppler flowmeter. The result showed no alternation in blood flow across different geometry and through three patent microanastomoses. However, six out of seven vein grafts were thrombosed at 24 hr postoperative due to vascular kinks. This model demonstrates potential sites of kinking at the dissection end of the femoral artery, the microanastomoses, the side branches of the vein graft, and the adventitial adhesions. This model is recommended to microvascular trainees for the study of kinking and the management of redundant pedicles and vein grafting.