The Effect of Positive Postdebridement Cultures on Local Muscle Flap Reconstruction of the Lower Extremity

BACKGROUND: Local muscle flaps are a reconstructive option for wound coverage in the distal lower extremity, particularly in high-risk patients who are poor candidates for free tissue transfer. At our institution, chronic and infected wounds are managed with serial debridement before definitive reconstruction. There is a paucity of data on optimal timing for reconstruction in this patient population. This study investigates the relationship of positive postdebridement cultures (PDC) and wound closure rates at 90 days. METHODS: A retrospective review of patients undergoing local muscle flap coverage of chronic distal lower extremity wounds between 2006 and 2012 was performed. All patients were managed with serial debridement until negative PDC were obtained. In some cases, PDC remained positive or exhibit delayed culture growth in the day(s) following closure. Data recorded include demographics, flap type/location, culture data, and wound closure at 90-day follow-up. RESULTS: Of 76 patients, 60 met inclusion criteria with minimum 90-day follow-up. Despite 100% flap survival, 17 patients (28.3%) had failure of wound closure at 90 days and 22 patients (36%) had positive PDC. Multivariate analysis identified positive PDC (odds ratio, 29.6; 95% CI, 3.6–246.4; P = 0.002) and smoking (odds ratio, 8.9; 95% CI, 1.4–57.6; P = 0.02) as independent predictors of nonclosure at 90 days. CONCLUSIONS: In this series of local muscle flap coverage of distal lower extremity wounds, positive PDC were a strong independent predictor of failure of wound closure at 90 days. This study demonstrates the importance of serial debridement to negative cultures before definitive coverage in this patient population.