Cheatle T R, Chittenden S J, Coleridge Smith P D, Scurr J H
Department of Surgery, University College and Middlesex School of Medicine, Middlesex Hospital, London, England.
Angiology. 1991 Feb;42(2):114-22. doi: 10.1177/000331979104200205.
Plugging of skin capillaries by activated white blood cells is one of the proposed mechanisms by which skin damage may be initiated in chronic venous insufficiency. The aim of this study was to determine whether a microcirculatory deficit was induced in the skin by raising the venous pressure proximally for thirty minutes. Seventeen subjects with no evidence of venous or arterial disease had laser Doppler velocimetry performed in the goiter region of the leg; 8 different subjects had the measurement done on the dorsum of the hand. Peak hyperemic response following three minutes of ischemia was measured before and after a thirty-minute period of sustained venous hypertension applied by a proximal tourniquet inflated to 80 mm Hg. A decrease in the peak flow: baseline flow ratio (median ratio 2.25 before, 1.70 after, p less than 0.02) and an increase in the time taken to reach maximal hyperemia (median time ten seconds before, twenty seconds after, p less than 0.01) were observed after the period of venous hypertension in the lower limb. The second parameter, but not the first, was significantly affected in the upper limb. The authors conclude that a microvascular deficit in the skin is demonstrable after a short period of venous hypertension. This is consistent with the white-cell-trapping theory, but other possible explanations are discussed.
活化白细胞堵塞皮肤毛细血管是慢性静脉功能不全引发皮肤损伤的一种推测机制。本研究的目的是确定通过近端抬高静脉压力30分钟是否会在皮肤中诱发微循环缺陷。17名无静脉或动脉疾病证据的受试者在小腿甲状腺肿区域进行了激光多普勒测速；8名不同的受试者在手背部进行了测量。在近端止血带充气至80毫米汞柱施加30分钟持续静脉高压之前和之后，测量缺血三分钟后的峰值充血反应。下肢静脉高压期后观察到峰值血流：基线血流比值降低（中位数比值之前为2.25，之后为1.70，p小于0.02）以及达到最大充血所需时间增加（中位数时间之前为10秒，之后为20秒，p小于0.01）。上肢的第二个参数而非第一个参数受到显著影响。作者得出结论，短时间静脉高压后皮肤中的微血管缺陷是可证实的。这与白细胞捕获理论一致，但也讨论了其他可能的解释。
