Mayrovitz H N, Larsen P B
Miami Heart Research Institute, Miami Beach, Florida 33140.
Microvasc Res. 1994 Jul;48(1):114-23. doi: 10.1006/mvre.1994.1042.
Chronic venous ulceration has an estimated prevalence of from 0.06 to 1.3% with about 57 to 80% of patients with leg ulcers having demonstrable venous disease. The sequence of events whereby chronic venous insufficiency leads to leg skin ulceration is not yet worked out. Venous hypertension may set the stage for subsequent ulcer development via linkages to observed changes in skin microvessel metrics, morphology, rheology, permeability, hemodynamics, and the interstitium. Periulcer measurements show decreased transcutaneous oxygen and elevated carbon dioxide tensions, yet the skin blood perfusion measured with laser Doppler fluxometry (LDF) is reported to be elevated. This elevated perfusion, (Q), could be due to independent changes in blood velocity (U), and volume (V), with different mechanistic implications depending on the mode. Thus, we sought to determine the relative contributions of these two components with the aim of clarifying the mechanism responsible for the reported skin flow changes. Patients studied (n = 16) had unilateral venous ulcers, an ankle/brachial BP index > 0.8, and venous pathology demonstrated by duplex imaging. Ulcer areas ranged from 0.6 to 76.9 cm2 (mean = 13.7 cm2) and were present for 2 to 144 months, mean = 32. With the patient supine, Q (ml/min/100 g), V (%), and U (mm/sec) were measured by LDF (Vasamedics, BPM403A) at two to three sites on periulcer skin and compared with measurements at corresponding sites on the nonulcerated limb at local skin temperatures of 35 and 44. Results confirm an elevation in basal periulcer flow (7.0 vs 1.8 ml/min/100 g, P = 0.001) and show this to be due to elevations in both circulating blood volume (1.24 vs 0.62%, P < 0.001) and velocity (1.23 vs 0.65 mm/sec, P = .004). Maximal Q, V, and U were also higher on the ulcer leg, being for Q, 11.2 vs 6.42 ml/min/100 g, P = 0.03; for V, 1.49 vs 1.13%, P = .002; and for U, 1.76 vs 1.33 mm/sec, P = 0.020. Expressing each leg's basal values as a percentage of its own maximal response shows the ulcerated leg to have higher values for Q, V, and U, with (ulcer leg/control leg) ratios being 2.5, 1.8, and 1.4, respectively. These findings show that the LDF perfusion increase is due to roughly equal increases in microvessel circulating blood volume and velocity.(ABSTRACT TRUNCATED AT 400 WORDS)
慢性静脉溃疡的估计患病率为0.06%至1.3%，约57%至80%的腿部溃疡患者存在可证实的静脉疾病。慢性静脉功能不全导致腿部皮肤溃疡的一系列事件尚未明确。静脉高压可能通过与皮肤微血管指标、形态、流变学、通透性、血流动力学和间质中观察到的变化相关联，为随后的溃疡发展奠定基础。溃疡周围测量显示经皮氧分压降低，二氧化碳分压升高，但据报道用激光多普勒血流仪（LDF）测量的皮肤血流灌注升高。这种升高的灌注量（Q）可能是由于血流速度（U）和血容量（V）的独立变化，其机制含义因模式而异。因此，我们试图确定这两个组成部分的相对贡献，以阐明导致所报道的皮肤血流变化的机制。研究的患者（n = 16）患有单侧静脉溃疡，踝/臂血压指数> 0.8，且经双功成像证实有静脉病变。溃疡面积为0.6至76.9平方厘米（平均 = 13.7平方厘米），存在时间为2至144个月，平均 = 32个月。患者仰卧位时，用LDF（Vasamedics，BPM / 403A）在溃疡周围皮肤的两到三个部位测量Q（毫升/分钟/100克）、V（%）和U（毫米/秒），并与在35和44局部皮肤温度下非溃疡肢体相应部位的测量值进行比较。结果证实溃疡周围基础血流升高（7.0对1.8毫升/分钟/100克，P = 0.001），且这是由于循环血容量（1.24对0.62%，P < 0.001）和血流速度（1.23对0.65毫米/秒，P = 0.004）均升高所致。溃疡腿上的最大Q、V和U也更高，Q为11.2对6.42毫升/分钟/100克，P = 0.03；V为1.49对1.13%，P = 0.002；U为1.76对1.33毫米/秒，P = 0.020。将每条腿的基础值表示为其自身最大反应的百分比，显示溃疡腿的Q、V和U值更高，（溃疡腿/对照腿）比值分别为2.5、1.8和1.4。这些发现表明，LDF灌注增加大致是由于微血管循环血容量和血流速度的同等增加。（摘要截取自400字）
