To compare the potential healing prognosis of the different routine noninvasive techniques implemented in the International Working Group Diabetic Foot Guidelines with the novel use of hyperspectral imaging (HSI) in patients with diabetic foot ulcers.
Twenty-one patients with active diabetic foot ulcers participated in this 1-year prospective study in a specialized diabetic foot unit between December 2018 and January 2020. HSI was performed at baseline to quantify tissue oxygenation and should be presented on an anatomical map by analyzing the following parameters: (1) oxygen saturation of the hemoglobin (StO) (%), (2) tissue hemoglobin index, (3) the near-infrared perfusion index and (4) finally, tissue water index. In addition, transcutaneous oxygen pressure (TcpO), systolic toe and ankle pressures, ankle brachial index (ABI) and toe brachial index (TBI) values were calculated for the ulcerated limb. Primary outcome measure was wound healing, defined as complete epithelization without any drainage confirmed for at least 10 days after closure was first documented at 24 weeks.
During the follow-up period 14 patients (66.66 %) healed and 7 patients did not heal (33.3%) by 24 weeks. TcpO optimal cut-off point as determined by a balance of sensitivity and specificity of 28.5 mmHg that yielded a sensitivity of 91% and a specificity of 100%, and area under the curve (AUC) of 0.989 (p = 0.005; 95% CI 0.945-1). Followed by the StO optimal cut-off point as determined by a balance of sensitivity and specificity of 48.5 mmHg that yielded a sensitivity of 93% and a specificity of 0.71%, and AUC of 0.932 (p = 0.013; 95% CI 0.787-1). The logistic regression analyses showed that TcpO was the only variable associated with wound healing at 24 weeks (p < 0.001, 95% CI 0.046-0.642).
HSI was shown to be effective in the prognosis of diabetic foot ulcer healing compared to other noninvasive test; only TcpO values resulted in better diagnosis potential in wound healing.

Copyright © 2021. Published by Elsevier Inc.

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