Impact of infection severity on clinical outcomes in critical limb ischemia with tissue loss after endovascular treatment

Critical limb ischemia with infected wounds is known to have a poor prognosis and evaluation of infection severity using the Wound, Ischemia, and foot Infection classification system has been recommended. However, little is known about how infection severity influences the clinical outcomes of critical limb ischemia in patients with tissue loss. We investigated the impact of infection severity on the clinical outcomes in critical limb ischemia with tissue loss after endovascular treatment. In April 2007–August 2014, we enrolled 263 patients (328 limbs) who received endovascular treatment for critical limb ischemia with tissue loss. In the limbs examined, 369 individual wounds existed. We evaluated wound infection using the Infectious Disease Society of America (IDSA) classification. We also investigated wound healing rates at 12 months and limb salvage and major amputation-free survival rates at 2 years after endovascular treatment. Wound healing rates at 12 months for class 0, 1, 2, and 3 were 89, 81, 58, and 33%, respectively (log rank P < 0.001). Limb salvage and major amputation-free survival rates at 2 years were lower in patients with lower vs. higher IDSA classes (classes 0–3: limb salvage rate: 97, 90, 61, and 0%, respectively; P < 0.001; major amputation-free survival: 67, 61, 38, and 0%, respectively; P < 0.001). In Rutherford category 5, only wound healing rates at 12 months and limb salvage and major amputation-free survival rates at 2 years were stratified according to wound infection severity (wound healing rates: 87% in classes 0 and 1 and 65% in classes 2 and 3; P < 0.001; limb salvage rates: 93% in classes 0 and 1 and 69% in classes 0 and 2; P < 0.0001; major amputation-free survival rates: 61% in classes 0 and 1 and 46% in classes 2 and 3; P < 0.001). Wound infection severity affects clinical outcomes of critical limb ischemia with tissue loss, especially in critical limb ischemia with systemic inflammatory response syndrome. In Rutherford category 5, only clinical outcomes of critical limb ischemia were well-stratified according to infection severity. Wound infection affects clinical outcomes of patients with critical limb ischemia with tissue loss.