Interobserver variation in interpretation of arteriography and management of severe lower leg arterial disease

Objective: arteriography is the reference standard for the assessment of th e lower leg arteries in patients with severe lower limb ischaemia. Inter ob server variation in arteriography interpretation may cause disparities with non-invasive imaging modalities. We determined interobserver variation in lower leg artery assessment with intra-arterial digital subtraction angiogr aphy (IaDSA) and subsequent patient management. Materials: iaDSA studies of patients evaluated for severe claudication (n = 5) or critical ischaemia (n = 43). Methods: arteriograms were independently judged by four observers. The popl iteal and tibial arteries were graded as fully patent, severely diseased, o ccluded ol non-diagnostic The dorsalis pedis, common and deep plantar arter y were graded as directly, indirectly or not filling the pedal arch or non- diagnostic. Agreement on grading arteries was expressed as kappa -values. T reatment plans (conservative, PTA, surgery, amputation, non-diagnostic) pro posed by each observer based on clinical information and iaDSA were compare d. Results: the rate of non-diagnostic judgements ranged from 1% in the poplit eal to 22% in the pedal auter ies. Overall agreement tons good for grading the popliteal arteries (kappa = 0.64), moderate for the tibial (kappa = 0.4 7-0.54) and fair for the pedal arteries (kappa = 0.39). Agreement was good to excellent for grading occlucled or fully patent popliteal and tibial art ery segments, and fair to moderate for grading severe disease. In 57% of ca ses at least 3 observers proposed identical treatment, which indicates fair overall agreement (kappa = 0.33). Conclusion: interobserver agreement on iaDSA is good to determine occluded or fully patent popliteal or tibial arteries, but not for severe disease. T his should be taken into account when other diagnostic modalities nr e comp ared with iaDSA. Evaluation of diagnostic modalities as concordance in trea tment plans is flawed by interindividual variation.