Laser Doppler imaging and capillary microscopy in ischemic ulcers

The local distribution of laser Doppler flu (mainly thermoregulatory perfus ion) and capillary density (nutritive circulation) within 25 ischemic leg u lcers and their adjacent skin were investigated. For this purpose the techn ique of laser Doppler imaging and capillary microscopy were applied. In eac h ulcer a non granulation tissue area (NGTA), a granulation tissue area (GT A) and in adjacent skin a skin area (SA) were defined. In these areas the a verage laser Doppler area flux (arbitrary units, AU) and the number of capi llaries/mm(2) were determined for each patient. The mean +/- S.D. of laser Doppler area fluxes were: NGTA 1.30 +/- 1.93, GTA 2.13 +/- 1.53 and SA 1.21 +/- 0.77 AU, respectively. The differences between GTA and NGTA or SA was statistically significant (p<0.001, each) The mean +/- S.D. of capillary de nsities were as follows: NGTA: 0.56 +/- 2.06, GTA 6.76 +/- 8.39 and SA 16.8 0 +/- 7.38 capillaries/mm(2), respectively. The following differences were statistically significant: NGTA versus GTA (p < 0.01) and SA versus NGTA or GTA (p < 0.001, each). In conclusion following characteristics of the thre e areas can be described: In NGTA low laser Doppler area flux is combined w ith very low capillary density (ulcer area without healing). In GTA the hig hest laser Doppler area flux of all three areas and an intermediate capilla ry density (wound healing) is found. In SA an intermediate laser Doppler ar ea flux is associated with the highest capillary density of all three areas with the healing process nearly completed and no granulation tissue. (C) 1 999 Elsevier Science Ireland Ltd. All rights reserved.