The Role of Hepatic Arterial Doppler Ultrasound after Liver Transplantation: an ‘Audit Cycle’ Evaluation

Abstract

AIMS: To compare the diagnostic performance of hepatic arterial (HA) Doppler ultrasound post-liver transplantation for hepatic artery thrombosis and stenosis in our unit with the literature. To evaluate the role of the technique in clinical practice.MATERIALS AND METHODS: In a two-phase ‘audit cycle’ study, adult OLT patients had Doppler studies comprising detection of HA flow and measurements of peak systolic velocity, resistive index and systolic acceleration time. In phase I, patients had Doppler examinations ‘routinely’ and for any hepatic biochemical abnormality. In phase II, Doppler ultrasound was performed early post-OLT and later only if a senior transplant clinician suspected graft ischaemia. In addition to HA measurements the waveform was visually assessed. Clinical outcome was the ‘gold standard’.RESULTS: Phase 1: 38 patients, 40 OLT operations, 125 Doppler studies; 14 arteriograms. Phase 2: 35 patients, 42 OLT operations, two HA angioplasties, one HA revision, one non-occlusive thrombus, 140 studies; 17 arteriograms. Results; Phase 1 [Phase 2]: sensitivity 80% [100%]; specificity 71% [81%]; PPV 28% [56%]; NPV 96% [100%]; incidence of HA abnormality 12.5% [19.5%]; likelihood ratio of negative result 0.28 [0]; of positive result 2.8 [5.3].CONCLUSION: Previously reported results are reproducible. Normal HA waveform should also be a criterion of normality. The technique is very sensitive but relatively non-specific. Predictive values improve with discriminate use.MacEneaney, P. M. (2000). Clinical Radiology55, 517–524.