Clinical effect of wound depth in critical limb ischemia with tissue loss after endovascular treatment

Objective: Wound severity is assessed mainly by the Rutherford classification for critical limb ischemia (CLI) with tissue loss. The Rutherford classification is based on the extent of tissue loss; however, its classification criteria are ambiguous and do not include information regarding wound depth. We investigated the effects of wound depth on clinical outcomes in CLI with tissue loss after endovascular treatment (EVT). Methods: Between April 2007 and August 2013, we enrolled 210 consecutive patients (247 limbs) who received EVT for CLI with tissue loss. In the limbs examined, 271 individual wounds existed. We evaluated wound depth using the University of Texas grade (grade 1: superficial wound not involving the tendon, capsule, or bone, n = 97; grade 2: wound penetrating the tendon or capsule, n = 124; and grade 3: wound penetrating the bone or joint, n = 50). We also investigated the wound healing rate at 12 months and limb salvage and major amputation-free survival rates 3 years after EVT. Results: The wound healing rates at 12 months in Texas 1, 2, and 3 were 88%, 48%, and 24%, respectively (log-rank P <.001). The limb salvage and major amputation-free survival rates at 3 years were lower in deep wounds than in shallow wounds (limb salvage rates: 98%, 82%, and 67%, respectively; P <.001; major amputation-free survival rates: 78%, 52%, and 42%, respectively; P <.001). In only minor tissue loss, the wound healing rates at 12 months and the limb salvage and major amputation-free survival rates at 3 years were stratified according to wound depth (wound healing rates: 92% in Texas 1 and 51% in Texas 2 or 3; P <.001; limb salvage rates: 99% in Texas 1 and 86% in Texas 2 or 3; P = .001; major amputation-free survival rates: 79% in Texas 1 and 57% in Texas 2 or 3; P =. 001). In only major tissue loss, deep wounds also caused poor outcomes compared with shallow wounds (wound healing rates: 70% in Texas 1 and 36% in Texas 2 or 3; P = .019; limb salvage rates: 94% in Texas 1 and 73% in Texas 2 or 3; P = .050; major amputation-free survival rates: 75% in Texas 1 and 45% in Texas 2 or 3; P = .039). Conclusions: Wound depth is an important indicator of wound status and affects the clinical outcomes of CLI with tissue loss.