Hyperaemic colour duplex scanning for the detection of aortoiliac stenoses. A comparative study with intra-arterial pressure measurement

Objectives: Intra-arterial pressure measurement is considered the "gold standard" for the haemodynamic evaluation of aortoiliac lesions. When compared to pressure measurement duplex scanning fails to detect some of the haemodynamically significant lesions. To improve the assessment of the haemodynamic significance of these lesions by duplex scanning, the flow-related duplex parameters Delta PSV and EDV at rest and after exercise were compared with intra-arterial pressure gradients before and during increased blood flow. Patients and Methods: Forty-Jive aortoiliac segments with art isolated stenosis were studied prospectively. Doppler samples were taken at the site of the stenosis both at rest and after exercise on a bicycle ergometer, followed by intra-arterial pressure measurement at rest and during pharmacologically induced increased blood flow. Results: At rest a Delta PSV (Delta PSVr) of 1.6 m/s showed a sensitivity and specificity of 85% and 88%, respectively After exercise a Delta PSV (Delta PSVe) of 1.6 m/s showed a sensitivity of 100% at the cost of only a slight reduction in specificity when compared to Delta PSVr. The end diastolic velocity at rest (EDVr) had only limited clinical value. The EDV after exercise (EDVe) provided important information if the velocity tons 0.5 mis or lower or if the velocity was 1.6 mis or greater. Conclusion: The Delta PSV and rite EDV after exercise can be of value in the assessment of the haemodynamic significance of aortoiliac stenoses.