Contrast-enhanced duplex scanning of crural arteries by means of continuous infusion of Levovist

Objectives: To estimate the dosage needed for continuous infusion and to investigate whether continuous infusion of the ultrasound contrast-enhancing agent Levovist (SH U 508A) can improve duplex scanning of crural arteries in patients with peripheral arterial obstructive disease (PAOD) eligible for distal bypass graft surgery. Design, patients, and methods: The study design consisted of two parts. Part I investigated the color and spectral Doppler scan enhancement of three different Levovist dosages (200, 300, and 400 mg/mL) in one arterial segment of a patent lumen of a crural artery in seven patients with PAOD. Part 2 investigated the value of the optimum Levovist dosage in the assessment of 10 crural arteries in 10 consecutive patients with PAOD. Angiography was the reference standard. Results: Part 1: Levovist significantly enhanced color and spectral Doppler scan as compared with baseline ultrasound scan, but no differences were found between the Levovist dosages. Thus, the lowest Levovist dosage sufficed for application in part 2, because of its infusion volume and prolonged enhancement time. Part 2: The agreement between contrast-enhanced duplex scanning and angiography was moderate (kappa = 0.50; 95% confidence interval [CI], 0.03-0.97). Five (50%) of 10 crural arteries that could not adequately be visualized with routine duplex scanning could be visualized with contrast-enhanced duplex scanning. Conclusion: Contrast-enhanced duplex scanning by means of continuous infusion of Levovist in patients with PAOD improves the ultrasound scan investigation of crural arteries in case routine duplex scanning is inconclusive and might reduce the need for angiography.