Visualization of Wound Healing Progression With Near Infrared Spectroscopy: A Retrospective Study

The aim of this retrospective study is to determine if near infrared spectroscopy (NIRS) can be used to evaluate wounds and adjacent soft tissues to identify patterns involved in tissue oxygenation and wound healing as well as predict which wounds may or may not heal.

In this study, 25 patients with either diabetic foot ulcers or venous leg ulcers were examined retrospectively to determine if NIRS could be used to predict which wounds may or may not close. All patients had either diabetic or venous ulcers and were being actively treated in the clinic. Regardless of the treatment rendered, all wounds were tracked with NIRS at regular intervals. Retrospectively, the de-identified images were reviewed to determine any patterns that might exist. Wound bed and periwound oxygenation patterns were observed and classified, including correlation with both the clinical appearance and the NIRS images. Images of wounds that closed and those that did not were compared.

Four distinct patterns of tissue oxygenation that appeared to have some value for predicting which wounds would heal, and which would not, were identified among the 25 patients. A mechanism has also been proposed to try to explain the patterns of healing observed; Hyperperfusion, Imbibition, Neovascularization, and Trailing (HINT) describes various aspects of these patterns.

As with any imaging technology, both qualitative and quantitative data are used to determine what is happening clinically. This study represents an early attempt to understand the role of NIRS and percent oxygenated hemoglobin in the wound healing process. It also lays the groundwork for identifying patterns associated with wound closure.