Abstract
Aim
Negative-pressure wound therapy (NPWT) is often propagated as treatment option for fracture-related infection (FRI). After surgical debridement and repeated NPWT dressing changes, the wounds are often closed by free flaps. Sometimes even healing by secondary intention seems an alternative. Recently, concerns have been raised on the long-term use of NPWT as it could be related to bacterial overgrowth and possible re-infection. The purpose of this study was to conduct a retrospective evaluation of the influence of long-term NPWT on tissue culture results and outcome in FRI patients
Method
Between January 1st, 2015 and December 31st, 2018, a total of 852 patients were treated with NPWT for different indications on the Department of Trauma Surgery. Inclusion criteria for this study were patients with a closed fracture, stabilized with osteosynthetic fixation and complicated with a confirmed FRI according to the FRI consensus definition. Patients were included when they received at least three NPWT dressing changes in the operating room. Exclusion criteria were patients younger than 18 years, or the absence of cultures results from dressing changes.
Results
During the study period 23 patients met the inclusion criteria. According to the tripartite classification of Willenegger and Roth, one patient had an early, 14 a delayed and 8 patients a late onset FRI. Overall, 139 NPWT dressing applications were performed, with an average amount of six per patient. In 14 patients (61%) and 57 dressing changes (41%), at least 2 tissue cultures showed the same pathogen or at least one, in case of highly virulent organisms (e.g. S. aureus) during a single dressing exchange. Coagulase-negative staphylococci were present in 33% of the cases, followed by Enterococcus spp. (21%), S. aureus (16%), non-fermentative gram negative bacilli (14%) and Enterobacteriaceae (7%). Furthermore, 17 exchanges showed polymicrobial growth. Five patients had repeatedly significant growth of the same pathogen despite adequate antimicrobial therapy, within this group one patient was immunocompromised.
Conclusions
In a large amount of patients (61%), a significant number of positive culture results could be acquired, even in the presence of adequate local and systemic antimicrobial therapy. The clinical relevance of these results remains unclear. This said, it seems important to limit the duration of NPWT as prolonged treatment could increase bacterial overgrowth and possible (re-)infection. Therefore, a rapid definitive soft tissue coverage should be encouraged. Future larger prospective clinical trials are required.
