Monitoring the microcirculation to evaluate dressing performance in patients with venous leg ulcers

Abstract

To compare the effect on the microcirculation in venous leg ulcers (VLUs) of two treatment regimens that promote a moist wound environment versus paraffin gauze. The hypothesis is that moist wound dressings are more likely to stimulate the microcirculation and therefore angiogenesis. Patients with non-healing VLUs were randomised to receive either a foam dressing (Suprasorb P), a collagen dressing (Suprasorb C) plus the foam dressing, or paraffin gauze (control). All patients wore short-stretch high compression bandages. Parameters used to measure the effects of the treatments on the microcirculation were: TcPO2 measurements, video laser Doppler measurements and the number of capillaries in the wound bed. The progression towards healing was measured by the reduction in ulcer area and formation of granulation tissue. The treatment period was four weeks. Significant increases in TcPO2 values were reported between baseline and week 4 for patients receiving the foam dressing only or the collagen plus foam dressing combination (p<0.008 versus p<0.003 respectively). There was also a significant increase in the number of capillaries for the collagen plus foam treatment only (p<0.002). This pilot study suggests that a moist wound environment stimulates perfusion of blood and oxygen to the wound tissue, thereby promoting angiogenesis. The collagen and foam dressing combination demonstrated superior results to the control and the foam dressing only. Monitoring the microcirculation may help to assess the effect of dressings on VLU healing, although more research is needed. This pilot study was supported by a limited grant from Lohmann & Rauscher GmbH, Germany.