Measurement of Revascularization Effect Using Near Infrared Spectroscopy in Below the Knee Arteries

Abstract

Background: Current methods evaluating tissue ischemia are based mainly on evaluating blood flow and not tissue perfusion. However, diabetes mainly affects small vessels and blood flow evaluation is insufficient. The aim of the trial was to evaluate the feasibility of NIRS in measuring perfusion changes during chronic total occlusion (CTO) revascularization in below the knee (BTK) arteries.

Methods: A prospective observational study was performed. During the endovascular revascularization procedure, tissue oxygenation changes were measured using three NIRS sensors. Postoperative angiographies and 30 days wound healing was evaluated.

Results: The study enrolled 30 patients with chronic limb threatening ischemia, occluded below the knee arteries, Rutherford 5. Mean age 74.7 $\pm$ 11.2 years, 16 (53%) of the patients had diabetes mellitus, 10 (33%) had end-stage renal disease. A statistically significant NIRS ${\mathrm{rSO}}_2$ increase was observed on sensors near the wound after the revascularization, p = 0.001. Thirty days follow-up visits included 27 patients, because 3 patients had died. Comparing good wound healing group with poor wound healing group intraoperative NIRS ${\mathrm{rSO}}_2$ increase difference was statistically significant, p = 0.017.

Conclusions: The study confirmed tissue perfusion increase could be detected using NIRS during revascularization of below the knee arteries. An intraoperative increase of NIRS ${\mathrm{rSO}}_2$ proved to predict wound healing results.

Keywords: below the knee; blood perfusion; chronic limb-threatening ischemia; chronic total occlusion; near-infrared spectroscopy; wound healing.