Objective grading of peripheral vascular disease strongly predicts morbidity in microsurgical lower limb salvage.

Background: Chronic lower extremity wounds in diabetic and vasculopathic populations frequently lead to amputation. Microvascular free tissue transfer (FTT) is a limb salvage option, but outcomes in patients with peripheral vascular disease (PVD) are variable. This study aimed to assess the severity of PVD using accepted standardized metrics to predict morbidity and negative outcomes in patients undergoing lower extremity FTT.

Methods: A retrospective review of 97 FTT procedures performed between January 2018 and April 2023 was conducted. PVD severity was assessed using Wound-Ischemia-Foot Infection (WIfI), Global Limb Anatomic Staging System (GLASS), and Medial Arterial Calcification (MAC) scores. Outcomes of interest included flap failure, amputation, mortality, and major morbidities at various time points.

Results: Overall, flap failure occurred within 30 days in 8.2% of cases and amputation within 90 days occurred at a rate of 5.2%. In patients with incomplete pedal arches (i.e. pGLASS scores of P1 or P2), there were increased rates of 90-day mortality (11.1% vs 0; p=0.026) and 30-day flap failure (18.5% vs 3.2%; p=0.026). Severe MAC scores were associated with increased 90-day mortality (p=0.002), 1-year mortality (p=0.003), and major morbidity. WIfI scores were not significantly associated with negative outcomes.

Conclusion: PVD severity can be objectively assessed using pedal GLASS and MAC scores to guide patient selection for lower extremity FTT. In patients with an incomplete pedal arch and extensive vascular calcifications, there is a significantly higher risk of major adverse outcomes, emphasizing the need for careful preoperative assessment and shared decision-making in limb salvage procedures.