Thermographic imaging in diabetic patients with critical limb ischemia undergoing endovascular revascularisation

Abstract

Introduction: The success of endovascular intervention for lower limb arterial occlusive disease is usually based on radiological evidence and physiological testing. However current tools to assess peripheral arterial disease (PAD) have significant limitations particularly in patients with diabetes and critical limb ischaemia (CLI). Method: Forty patients undergoing endovascular treatment of stenotic or occlusive lower limb arterial disease were recruited and underwent physiological testing (ankle brachial pressure index, toe pressure index, pulsatility index, spectral waveforms) as well as infrared thermography of both lower limbs at pre-intervention (pre) and at two separate time points after intervention (post 1 within 48 hours and post 2 at 6-8 weeks). The pre and post results of both the thermographic images as well as the physiological data were compared. Results: Thermography could be performed in all subjects, while standard physiological tools could not and were only found useful in a small proportion of patients. In the treated limbs there was a significant increase in temperature readings in the metatarsal aspect of the foot (p-value of 0.0001 between pre and post 1, p-value of 0.056 between pre and post two), heels (p-value 0.009 between pre and post one, p-value of 0.045 at pre and post two) and shins (p-value 0.008 at pre and post one, p-value of 0.006 between pre and post two) after revascularisation, while no change was seen in the untreated limb, indicating thermography usefulness in assessing the success of endovascular intervention. Standard physiological tools were only found useful in 10 out of the 40 treated limbs. Conclusion: The results of this study indicate that thermography has significant potential in assessing the success of endovascular revascularisation in patients with CLI compared to standard physiological testing.