Surgical debridement alone does not adequately reduce planktonic bioburden in chronic lower extremity wounds

Objective: It is commonly believed that sharp surgical debridement provides adequate bacteria control for local wound beds, despite limited supporting scientific evidence. We undertook a prospective study to evaluate the reduction in planktonic bacteria pre- and post-operative debridement in critically colonised wounds. Method: Twelve patients, corresponding to 14 wounds, underwent debridement with either hydrodebridement or sharp steel debridement with pulse irrigation. Wound quantitative tissue cultures were taken pre- and post-debridement. There was no significant difference in wound aetiology or surface area between the two groups. Results: The bacterial counts before debridement were 1x107 colony-forming units per gram (CFU/g) in the hydrodebridement group vs 1.4x107 CFU/g in the sharp debridement group; and 2.5x106 CFU/g (hydrodebridement) vs 7.5x105 CFU/g (sharp) after debridement (p=0.41). The total bacteria reduction was 7.5x106 CFU/g after hydrodebridement vs 1.3x107 CFU/g after sharp steel debridement (p=0.37). The mean percentage of bacteria killed from baseline was 75% by hydrodebridement and 93% killed by sharp debridement (p<0.05). Conclusion: Extensive operative debridement using either modality does not provide adequate immediate reduction in wound planktonic bioburden. However, all wounds appeared clinically appropriate for closure after debridement and postoperative antibacterial therapy. Postoperative antibacterial therapy may be imperative in cases of critically colonised wounds to achieve good outcomes.