Topical negative pressure wound therapy enhances the local tissue perfusion - A pilot study

Topical negative pressure wound therapy (TNPWT) is a regularly used method in modern wound treatment with a growing and diverse potential for clinical use. So far positive effects on microcirculation have been observed and examined, although precise statements on the underlying mechanism appear unsatisfying.

The aim of our study was to extend the understanding of the effect of TNPWT on tissue perfusion and determine the time frame and the extent to which the tissue perfusion changes due to TNPWT.

TNPWT was applied to the anterior thighs of 40 healthy individuals for 30 min, respectively. Before and up to 90 min after the application, measurements of the amount of regional haemoglobin (rHb), capillary venous oxygen saturation (sO2), blood flow (flow) and velocity were conducted with spectrophotometry (combining white light spectrometry and laser Doppler spectroscopy) within two different depths/skin layers. A superficial measuring probe for depths up to 3 mm and a deep measuring probe for up to 7 mm were used.

All parameters show significant changes after the intervention compared to baseline measurements. The greater effect was seen superficially. The superficially measured rHb, sO2 and flow showed a significant increase and stayed above the baseline at the end of the protocol. Whereas deeply measured, the rHb initially showed a decrease. The flow and sO2 showed a significant increase up to 60 min after the intervention.

The application of TNPWT on healthy tissue shows an increase in capillary-venous oxygen saturation and haemoglobin concentration of at least 90 min after intervention. A possible use in clinical practice for preconditioning to enhance wound healing for high-risk patients to develop wound healing disorder, requires further studies to investigate the actual duration of the effect.