Cost-effectiveness of identifying aortoiliac and femoropopliteal arterial disease with angiography or duplex scanning.

OBJECTIVES: Cost-effectiveness analysis of three diagnostic imaging strategies for the assessment of aortoiliac and femoropopliteal arteries in patients with peripheral arterial occlusive disease. The strategies were: angiography as the reference strategy, duplex scanning (DS) plus supplementary angiography (S1) and DS plus confirmative angiography (S2). DESIGN, MATERIALS AND METHODS: A decision model was built with sensitivity and specificity data from literature, supplemented with prospective hospital cost data in Euro (euro). The probability of correctly identifying the status of a lesion was taken as the primary outcome. We compared strategies by assessing the extra costs per additional correctly identified case. RESULTS: Assuming no false positive or false negative results, angiography is the most effective strategy if the prevalence of significant obstructive lesions in the aortoiliac and femoropopliteal tract exceeds 70%, or if the sensitivity of duplex scanning is lower than 83%. In case of lower prevalence, strategy S1 becomes equally or even more effective than angiography. At a prevalence of 75%, performing angiography costs euro 8443 per extra correctly identified case compared with strategy S1. CONCLUSIONS: In most situations angiography is more effective than diagnostic strategy S1. However, if society is unwilling to pay more than euro 8443 for knowing a patient's disease status, diagnostic strategy S1 is a cost-effective alternative to angiography, especially at lower prevalence values.

The value of the peak systolic velocity ratio in the assessment of the haemodynamic significance of subcritical iliac artery stenoses.

OBJECTIVES: iliac stenoses with a PSV ratio between 2.0 and 3.0 in patients with symptomatic arterial obstructive disease of the legs might be misinterpreted when compared with intra-arterial pressure measurements (IAPM). The aim of this study was to compare the value of the PSV ratio with IAPM as the reference standard in the assessment of the haemodynamic significance of subcritical iliac artery stenoses (iliac stenosis with PSV ratio between 1.5 and 3.5). DESIGN, PATIENTS AND METHODS: fifty-eight iliac tracts in 53 consecutive patients with symptomatic arterial obstructive disease of the legs with an isolated stenosis with PSV ratio between 1.5 and 3.5 were studied prospectively. The results of those iliac duplex scanning were compared to IAPM. Results a poor agreement was found between IAPM and PSV ratios. For the PSV ratios > or =2.0, 2.5 and 3.0 the sensitivities were 74%, 37% and 16%, respectively. The specificities were 70%, 90% and 95%, the positive predictive values 82%, 88% and 86%, respectively, and the negative predictive values 58%, 43% and 37%, respectively. CONCLUSION: the results of this study show that the PSV ratio parameter is not accurate enough to evaluate the haemodynamic significance of subcritical iliac artery stenoses.