Outcomes of Early and Late Muscle Flap Salvage of Complicated Lower Extremity Vascular Grafts

<b><i>Introduction:</i></b> Muscle flaps are commonly used to protect high-risk vascular grafts in the lower extremities. This study aimed to identify differences between early and late salvage procedures. <b><i>Methods:</i></b> Patients undergoing lower extremity vascular reconstruction with muscle flap coverage at a tertiary medical center from 2017 to 2023 were identified. Data included demographics, procedure details, and complications. The study compared early (placed at index or ≤7 d after vascular surgical procedure) versus delayed (>7 d) flap inset. Primary outcomes included rates of infection, hematoma, seroma, necrosis, wound dehiscence, flap failure, and patency of the vascular repair. Secondary outcomes included culture results from the surgical site. <b><i>Results:</i></b> Eighty-one patients met inclusion criteria. Early flaps were inset in 53% of cases, and 47% were delayed. Sartorius flaps were most common (53%), followed by gracilis flaps (37%). The indication for flap coverage significantly varied between immediate and delayed flaps (p = 0.004), with immediate more commonly placed for tissue coverage (37%) and delayed inset to address infection (68%). Flap survival (86.1% vs. 76.3%, p = 0.261) and graft patency (74.4% vs. 68.4%, p = 0.55) were similar between groups. Rates of infection, seroma, hematoma, and wound dehiscence did not differ significantly. Regression analysis did not find associated factors with complication incidence. <i>Enterobacter</i> infections were more common in the delayed group (15.8% vs. 2.3%, p = 0.031). <b><i>Conclusion:</i></b> This study showed no difference in outcomes between immediate and delayed muscle flaps placed over vascular grafts. Delayed procedures show a greater prevalence of certain bacteria in delayed flaps.