The Society for Vascular Surgery Wound, Ischemia, and foot Infection (WIfI) classification system predicts wound healing but not major amputation in patients with diabetic foot ulcers treated in a multidisciplinary setting

Abstract

Objective: The Society for Vascular Surgery Wound, Ischemia, and foot Infection (WIfI) threatened limb classification has been shown to correlate well with risk of major amputation and time to wound healing in heterogeneous diabetic and nondiabetic populations. Major amputation continues to plague the most severe stage 4 WIfI patients, with 1-year amputation rates of 20% to 64%. Our aim was to determine the association between WIfI stage and wound healing and major amputation among patients with diabetic foot ulcers (DFUs) treated in a multidisciplinary setting.

Methods: All patients presenting to our multidisciplinary DFU clinic from July 2012 to December 2015 were enrolled in a prospective database. Wound healing and major amputation were compared for patients stratified by WIfI classification.

Results: There were 217 DFU patients with 439 wounds (mean age, 58.3 ± 0.8 years; 58% male, 63% black) enrolled, including 28% WIfI stage 1, 11% stage 2, 33% stage 3, and 28% stage 4. Peripheral arterial disease and dialysis were more common in patients with advanced (stage 3 or 4) wounds (P ≤ .05). Demographics of the patients, socioeconomic status, and comorbidities were otherwise similar between groups. There was a significant increase in the number of active wounds per limb at presentation with increasing WIfI stage (stage 1, 1.1 ± 0.1; stage 4, 1.4 ± 0.1; P = .03). Mean wound area (stage 1, 2.6 ± 0.6 cm²; stage 4, 15.3 ± 2.8 cm²) and depth (stage 1, 0.2 ± 0.0 cm; stage 4, 0.8 ± 0.1 cm) also increased progressively with increasing wound stage (P < .001). Minor amputations (stage 1, 18%; stage 4, 56%) and revascularizations (stage 1, 6%; stage 4, 55%) were more common with increasing WIfI stage (P < .001). On Kaplan-Meier analysis, WIfI classification was predictive of wound healing (P < .001) but not of major amputation (P = .99). For stage 4 wounds, the mean wound healing time was 190 ± 17 days, and risk of major amputation at 1 year was 5.7% ± 3.2%.

Conclusions: Among patients with DFU, the WIfI classification system correlated well with wound healing but was not associated with risk of major amputation at 1 year. Although further prospective research is warranted, our results suggest that use of a multidisciplinary approach for DFUs may augment healing time and reduce amputation risk compared with previously published historical controls of standard wound care among patients with advanced stage 4 disease.