The Sensitivity, Specificity And Reliability Of Arterial Doppler Ultrasonography In The Diagnosis Of Critical Ischaemia Of The Lower Limbs Compared To Arteriography

Introduction. Arteriography is still considered to be the gold standard in the diagnosis of critical ischaemia. Nevertheless, it can cause locoregional arterial damage, as well as allergic reactions and nephrotoxicity, and it does not evaluate the lesions haemodynamically. Arterial Doppler ultrasonography (ADU) has proved to be valid and reliable in the lower limbs and supra-aortic trunks but, because it is an examiner-dependent technique, individual and laboratory validation of findings is required. Aim. To analyse and validate ADU as a diagnostic test in patients with critical ischaemia, as compared to arteriography. Patients and methods. A cross-sectional random design, with ADU applied blind and independently with respect to arteriography conducted in a sample of 60 patients with critical lower limb ischemia undergoing their preoperative study. Reliability is determined by means of the percentage of overall agreement and the kappa index. Validity is determined by the sensitivity, specificity, predictive positive value (PPV) and diagnostic likelihood ratio (DLR). Results. Mean examination time per limb: 39 min. Good or very good kappa indexes in all sectors, except in the fibular artery (moderate). Highly sensitive in proximal territories. Specificity above 90%, except in the fibular artery (88%). PPV always above 90%. High DLR values. Conclusions. In the light of the results obtained in our laboratory, ADU can be considered to be a diagnostic test that is very useful as an alternative to arteriography, since its reliability is good or very good and its validity, in terms of sensitivity, specificity, PPV and DLR, is very high. Yet, in the distal sector, with special attention to the fibular artery, another imaging test must always be carried out before setting an indication for surgery.