Obliteration Index (OI) – a simple, non-invasive bed-side tool for semiquantitative assessment of peripheral vascular disease

Abstract

Background: Peripheral artery disease (PAD) represents a major complication in chronic kidney disease (CKD) patients, but its early diagnosis is still problematic. Traditionally, ankle-arm blood pressure index (API) determined by means of a simple hand-held unidimensional Doppler device has been used for noninvasive diagnosis of PAD, with a cutoff value of 0.9.

However, in CKD patients, vascular disease includes not only atherosclerosis but also arteriosclerosis with high calcification score. There, the API method often fails.

Development of the method: Based on complex examination of Doppler signals recorded at 4 main arteries of both lower extremities (a. femoralis, a. poplitea, a. dorsalis pedis, a. tibialis posterior) and their semiquantitative assessment, we introduced the Obliteration Index (OI) as a novel and simple tool allowing semiquantitative assessment of PAD in CKD patients: the signal from each artery is assessed in a 6-grade scale, with each grade represented by 5 points.