Abstract
Background
Lower extremity free tissue transfer (LE FTT) expands limb salvage options for patients
with chronic wounds. Infected wounds require serial debridement to optimize the wound
bed before reconstruction, but the role of qualitative microbiological cultures in
guiding surgical wound closure timing remains unclear. This study evaluates the impact
of final preoperative culture results on postoperative outcomes, including flap success,
infection rates, and limb salvage.
Methods
A retrospective review of 344 patients undergoing LE FTT at a single institution was
conducted. All patients underwent serial debridement, with final cultures obtained
from the final debridement prior to flap reconstruction. Patients were stratified
into positive and negative final culture groups. Subgroup analyses assessed the impact
of polymicrobial colonization and comorbidity burden (Charlson Comorbidity Index [CCI]
>6) on outcomes. Primary outcome was flap infection, defined as any documented clinical
concern for infection, including cellulitis, purulent drainage, abscess formation,
or initiation of targeted antibiotic therapy.
Results
Polymicrobial final cultures were associated with increased infection (p = 0.003) and flap complications (p = 0.041). Among patients with CCI >6, positive final culture was associated with
significantly higher infection rates (p = 0.032), but not among those with CCI ≤6. In the total cohort, comparing positive
final culture to negative final culture, flap outcomes were similar between groups.
Conclusion
Final culture positivity alone does not predict poor outcomes, but polymicrobial cultures
and host factors may increase flap infection risk. A risk-stratified approach should
guide surgical decision-making, with additional debridement and/or wound bed optimization
considered for polymicrobial wounds and polymorbid patients (CCI >6).
Keywords lower extremity reconstruction - free tissue transfer - qualitative wound - culture
