When does limb blood flow increase after aortoiliac bypass grafting?

We have measured changes that occur in resting and hyperemic calf muscle blood flow throughout the operative course of nine patients undergoing aortoiliac grafting for peripheral arterial occlusive disease. There were four patients with combined aortoiliac and femoropopliteal disease, and five patients with isolated aortoiliac disease. In all patients, reactive hyperemia was absent when the aortic cross clamp was removed. Postoperatively, calf muscle blood flow did not increase substantially for 24 hours regardless of the presence or absence of coexisting femoropopliteal occlusive disease. Knowing that calf muscle blood flow does not increase immediately postoperatively may explain why pulses may not be palpable immediately and why the limb may remain cool for several hours. Also, this reaffirms that it is best to delay any decision on distal femoropopliteal repair until the outcome of the proximal reconstruction can be assessed.