Effects of topical negative pressure therapy on perfusion and microcirculation of human skin.

BACKGROUND: Topical negative pressure wound therapy (TNPWT) is one of the most frequently used techniques in wound treatment. But some of the underlying mechanisms still remain unclear. One possible explanation is an improved microcirculation by TNPWT. OBJECTIVE: This study investigated the influence of TNPWT on microcirculation on intact skin in real-time. METHODS: In healthy individuals, we performed a combined tissue - laser/photo - spectrometry technique to monitor changes of 4 different microcirculation parameters in real-time: The local blood flow, the capillary-venous oxygen saturation, the blood flow velocity and the relative amount of hemoglobin. We compared these parameters using two different protocols: a continuously (VAC ON 60/OFF 60) and discontinuously (VAC ON 30/OFF 60/ON 5) application. RESULTS: Our results demonstrate a significant increase of all four measured parameters during the active TNPWT and the pressure free period. The comparison of two different protocols shows an advantage of the examined parameters using a discontinuous TNPWT application. CONCLUSIONS: Our study demonstrated the changes of the microvascular tissue perfusion in intact human skin under the conditions of negative pressure and may thereby offer a broader understanding of mechanisms underlying the TNPWT.