Pulsed Doppler and Real-Time “Duplex” Imaging of Dacron Arterial Grafts

Abstract

Ultrasonic imaging was performed in 50 10 mm woven dacron arterial grafts. Patients were scanned either using a “duplex” echo-Doppler scanner or a multichannel pulsed Doppler scanner, or by both methods. The “duplex scanner” had the advantage of maneuverability of the scanning head, but accurate waveform sampling was better with the pulsed Doppler scanner. The development of fibrous pseudointima was detected in long dacron grafts by inference from pulse-echo and pulsed-Doppler imaging, but was not visualized by real-time B-mode scanning alone. The pseudointima developed in the distal ends of 75 percent of the iliopopliteal grafts, and was related to time since implantation. The average thickness of pseudointima was 0.8 mm, and the maximum stenosis seen was 34 percent.