Angiologic surveillance of infrainguinal arterial reconstructions

This review article describes the natural course of infrainguinal bypasses, duplex ultrasound flow characteristics of stenosed vein bypasses, and the clinical relevance of duplex surveillance of infrainguinal vein bypasses. A mong multiple factors bypass patency rates and limb salvage rates are influ enced by the surgical technics of revascularisation, graft material, locali sation of the distal anastomosis, distal run-off time interval between dete ction of bypass stenosis and revision. Preliminary duplex ultrasound criter ia of a bypass dysfunction are a distal flow velocity < 45 cm/s, a bypass f low < 25 ml/min, a reduction of the inner diameter < 3 mm. The intrastenoti c mean systolic peak velocity and the peak velocity ratio (PVR) are suitabl e for the grading of bypass stenoses. A vein bypass stenosis > 70% shows an intrastenotic mean peak velocity of 250 cm/s and a PVR > 3.3, a severe ste nosis shows a mean peak velocity of 360 cm/s and a PVR > 7.2.