Postocclusive Reactive Hyperemia During Vascular Reconstruction
The purpose of this basic investigation was to clarify the postocclusive reactive hyperemia during vascular reconstruction using laser Doppler flowmetry (LDF). For the fundamental experiment, thirty-nine limbs with arteriosclerosis obliterans (ASO) in Stage II according to Fontaine's classification and 33 limbs without arterial or venous disease were chosen. In the supine position, a thigh cuff was applied to the lower thigh of a subject. Systolic Doppler thigh pressure was obtained and thigh/arm pressure index (TPI) was calculated. A LDF probe was then fixed to the bottom of the first toe and cutaneous blood flow was measured continuously before, during, and after femoral artery occlusion by the thigh cuff. The occlusion time was 3 and 6 minutes. For the clinical study, thirty-three lower limbs with arterial occlusive disease were selected. During the vascular surgery, the LDF probe was attached to the bottom of the first toe and cutaneous blood flow was monitored continuously before, during, and after the vascular clamping. In the fundamental experiment, after the release of the occlusion, the maximum blood flow of the reactive hyperemia (peak flow) appeared. The period between the release of the occlusion and the peak flow was called the peak time. When the occlusion time was longer, the reactive hyperemia appeared later and was bigger. When TPI decreased, the peak time lengthened and the peak flow after a 6-minute occlusion decreased. In the clinical study, the more severe the degree of the preoperative limb ischemia was, the longer was the peak time. The longer the intraoperative clamping time, the longer the peak time. In conclusion, postocclusive reactive hyperemia during vascular surgery was influenced by the degree of the preoperative limb ischemia and the length of the vascular clamping time.