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

The effect of incisional negative pressure wound therapy on the improvement of postoperative cosmetic suture wounds and scar hyperplasia

This study aimed to explore the effects of early incisional negative pressure wound therapy (INPWT) on cosmetic suture wounds and postoperative scar hyperplasia. We retrospectively evaluated 120 patients who underwent abdominoperineal resection at the Changhai Hospital between February 2018 and October 2021 and divided them into two groups according to their treatment: the INPWT group (n = 60) and the control group (n = 60). The quality of post-surgical wound healing in the two groups was evaluated. The Patient Scar Assessment Scale (PSAS), the Vancouver Scar Scale (VSS), and the visual analogue scale (VAS) were used to evaluate the surgical incision scar at 1-year follow-up. At this follow-up visit, 115 patients underwent reexamination; five patients were lost to follow-up, including two patients in the INPWT group and three patients in the control group. The INPWT group showed better wound healing than the control group (P < .05). The proportion of patients who received INPWT was significantly higher in the non-surgical site infection (SSI) group than in the SSI group (P < .05). The PSAS, VSS and VAS scores were significantly improved in the INPWT group compared with those in the control group (P < .05). Our results show that INPWT improved the quality of cosmetic suture wounds and reduced the degree of postoperative scar hyperplasia.

Camera-based assessment of cutaneous perfusion strength in a clinical setting

Objective. After skin flap transplants, perfusion strength monitoring is essential for the early detection of tissue perfusion disorders and thus to ensure the survival of skin flaps. Camera-based photoplethysmography (cbPPG) is a non-contact measurement method, using video cameras and ambient light, which provides spatially resolved information about tissue perfusion. It has not been researched yet whether the measurement depth of cbPPG, which is limited by the penetration depth of ambient light, is sufficient to reach pulsatile vessels and thus to measure the perfusion strength in regions that are relevant for skin flap transplants.Approach. We applied constant negative pressure (compared to ambient pressure) to the anterior thighs of 40 healthy subjects. Seven measurements (two before and five up to 90 minutes after the intervention) were acquired using an RGB video camera and photospectrometry simultaneously. We investigated the performance of different algorithmic approaches for perfusion strength assessment, including the signal-to-noise ratio (SNR), its logarithmic components logS and logN, amplitude maps, and the amplitude height of alternating and direct signal components.Main results. We found strong correlations of up tor=0.694 (p<0.001) between photospectrometric measurements and all cbPPG parameters except SNR when using the green color channel. The transfer of cbPPG signals to POS, CHROM, and O3C did not lead to systematic improvements. However, for direct signal components, the transformation to O3C led to correlations of up tor=0.744 (p<0.001) with photospectrometric measurements.Significance. Our results indicate that a camera-based perfusion strength assessment in tissue with deep-seated pulsatile vessels is possible.