Effective biofilm removal and changes in bacterial biofilm building capacity after wound debridement with low-frequency ultrasound as part of wound bed preparation before skin grafting

摘要

The aim of the study was to evaluate the efficacy of ultrasonic-assisted wound debridement (UAW) used for wound bed preparation of chronic wounds prior to skin grafting. Initially, 140 patients were enrolled into study. Group 1 patients (n=53) with critically colonized wounds underwent a single UAW procedure before skin grafting. Group 2 patients (n=87) with colonized wounds received two UAW sessions, skin grafting followed by the second UAW treatment. Initial wound classification in colonized and critically colonized wounds did not correlate with results from microbiological analysis of wound swab samples. Hence, comparison of efficacy of one or two debridement sessions was conducted solely for a similar group of patients, that is, patients with colonized wounds of group 1 (n=40) and group 2 (n=47). In wounds of group 1 patients, a single debridement session resulted in reduction of bacteria from >104 to 4 CFU/mL. However, bacteria remaining at wound site showed minor differences in biofilm slime production, with skin graft failure being observed in 25% cases. In wounds of group 2 patients, two debridement sessions significantly reduced bacterial presence up to 2 CFU/mL. Bacteria remaining at wound site showed low capacity for biofilm slime production and high accumulation of biomass; a complete graft healing was observed in all patients. We suggest two to three debridement sessions with UAW to be most effective in wound bed preparation before skin grafting of chronic wounds. UAW showed to be effective in cleaning the wound bed, destroying the extracellular substances in biofilms, and influencing biofilm slime building capacity of bacteria left at wound site.