Changes after arterial reconstruction in the forefoot local vasoconstrictor response to increased venous transmural pressure.

Local blood flow regulation on the forefoot was studied by the 133Xe wash-out technique in twenty-seven patients before and after arterial reconstruction for occlusive arterial disease. In thirteen limbs with severe symptoms the local vasoconstrictor response to increased venous pressure was absent preoperatively, as blood flow in the foot increased in median by 47% when the foot was lowered 40 cm below the heart. Three months postoperatively the vasoconstrictor response had returned as blood flow decreased 28% during lowering. Fourteen limbs with milder symptoms had a vasoconstrictor response before operation. In nine limbs of this group treated with aortoiliac reconstruction the vasoconstrictor response was absent at the early postoperative examination, but the response returned till the late examination. It is concluded that the local vasoconstrictor response is normalized after arterial reconstruction. Disturbances may, however, occur in the postoperative period, possibly due to operative stress.