Hepatic Artery Stenosis Following Liver Transplantation: Significance of the Tardus Parvus Waveform and the Role of Microbubble Contrast Media in the Detection of a Focal Stenosis

• Published in: Clinical radiology Vol. 57; no. 9; pp. 789 - 799
• Main Authors: Sidhu, P.S, Ellis, S.M, Karani, J.B, Ryan, S.M
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.09.2002; Elsevier
• Subjects: Adolescent; Adult; Arterial Occlusive Diseases - diagnostic imaging; Biological and medical sciences; Contrast Media; Female; Hepatic Artery - diagnostic imaging; Humans; Liver Transplantation - diagnostic imaging; Liver transplantation, hepatic arteries, stenosis or obstruction, hepatic arteries, transluminal angioplasty; Liver, biliary tract, pancreas, portal circulation, spleen; Male; Medical sciences; Middle Aged; Polysaccharides; Postoperative Complications - diagnostic imaging; Prospective Studies; Radiography; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Surgery of the digestive system; Ultrasonography, Doppler, Color; ultrasound (US), contrast media; ultrasound (US), Doppler studies; Liver transplantation, hepatic arteries, stenosis or obstruction, hepatic arteries, transluminal angioplasty; ultrasound (US), contrast media; ultrasound (US), Doppler studies; Sonography; Hepatic artery; Human; Liver; Stenosis; Cardiovascular disease; Transplantation; Duplex ultrasonography; Homotransplantation; Arterial disease; Vascular disease; Treatment; Surgery; Medical imagery; Complication; Contrast media
• ISSN: 0009-9260; 1365-229X
• DOI: 10.1053/crad.2002.0969

PURPOSE: To evaluate the role of microbubble ultrasound contrast media in detecting stenosis of the post-liver transplant extrahepatic hepatic artery (HA) in the presence of the tardus parvus spectral Doppler waveform of the intrahepatic HA. MATERIALS AND METHODS: All post-liver transplant patients with a prolonged systolic acceleration time (SAT>0.08s) and/or a reduced resistant index (RI<0.50) of the HA (the tardus parvus waveform) on colour Doppler ultrasound (CDUS), were assessed with microbubble contrast medium for a focal arterial stenosis. Following microbubble contrast-enhanced CDUS, patients underwent arteriography or follow-up CDUS. RESULTS: A total of 2038 examinations were performed in 529 liver transplant recipients; 16 (3.02%) tardus parvus waveforms were identified. The median SAT of the intrahepatic HA was 0.18s (range 0.11–0.38s) and the RI 0.47 (range 0.22–0.58). No extrahepatic elevated peak systolic velocity (PSV), defined as above 1.00m/s, was detected on the baseline examinations. Following the administration of microbubble contrast, medium, PSV in the extrahepatic HA was elevated in 14 of 16 patients, (median=2.15m/s, range=1.44–3.10m/s); flow was not identified in two patients. Arteriography was performed in 10 patients and confirmed stenosis in eight (median grade of stenosis 93%, range 60–99%) and occlusion in two. The measured median PSV at contrast-enhanced CDUS in the stenosis group was 2.03m/sec (range 1.44–2.71m/sec). Repeat CDUS in six patients not undergoing arteriography showed resolution in four; one underwent re-transplantation before arteriography and one patient maintains a tardus parvus waveform. In transplant recipients undergoing arteriography during the study period (n=55), no hepatic artery stenosis without a tardus parvus waveform was seen. CONCLUSION: The tardus parvus waveform pattern is an excellent screening test for the presence of post-liver transplantation hepatic artery stenosis. There is only a limited role for microbubble ultrasound contrast agent in the presence of a tardus parvus waveform. It could be used following equivocal colour Doppler ultrasound, but arteriography will still be necessary. Sidhu, P. S. et al. (2002). Clinical Radiology57, 789–799.