Using dynamic vascular optical spectroscopy to evaluate peripheral arterial disease (PAD) in patients who undergo a vascular intervention

Peripheral artery disease (PAD) affects approximately 12 million people in the US. The disease is caused by an accumulation of plaque in arteries, which leads to stenosis and reduction in blood flow. In advanced cases, surgery or endovascular interventions are required to re-establish blood flow to the extremities. In over 40% of these cases a second intervention is required within 12 months. Therefore, accurate monitoring the blood flow in the feet of these patients is crucial. In this study, dynamic vascular optical spectroscopy was used to assess perfusion in 4 different angiosomes of 25 patients who underwent a surgical intervention. Imaging was performed just before the intervention, 4 hours later and 1 month later. Each optical spectroscopy session consisted in inflating a thigh pressure cuff to 60 mmHg, maintaining the pressure for 60 seconds and releasing it, then repeating the procedure while inflating the cuff to 100 mmHg. Totalhemoglobin [THb] time traces for each angiosome were calculated. We found a strong correlation between the dynamic shapes of the THb-signals obtained before the intervention, 3 hours after the intervention and 1 month later and the longterm outcome of the procedure.