False Positive Tardus-Parvus Waveforms After Liver Transplantation: A Case of Wide Discrepancy Between Donor and Recipient Hepatic Arteries Mimicking Anastomotic Stenosis

Background. Parvus-tardus waveforms of the hepatic artery after liver transplantation usually indicate an arterial complication and severe impairment of hepatic arterial perfusion with a sensitivity of 91% and a specificity of 99.1%. Thus, it has been emphasized that detection of such waveforms should prompt emergency angiography. Materials and Methods. Arterial reconstruction during a liver transplantation was successfully accomplished by an end-to-end anastomosis, performing a flute-spout widening of the anastomosis with a 7/0 prolene running suture between a small recipient proper hepatic artery and the donor common hepatic artery. Results. On day 7 posttransplantation color Doppler ultrasonography revealed a parvus-tardus waveform pattern in the hepatic arterial flow. Computed tomographic (CT) angiography showed only a caliber discrepancy between the donor and recipient stumps, excluding an arterial stenosis or thrombosis. Since normal liver function persisted, the patient underwent routine follow-up. After 15 months the patient was alive and well; hepatic artery spectral waveforms were unchanged and liver functions were consistent with a mild hepatitis C virus (HCV) recurrence. Conclusions. This is a report of false positive tardus-parvus waveforms, due to a discrepancy between the donor and recipient arteries despite a wide anastomosis. Knowledge of technical reconstruction details may be helpful for correct interpretation of color Doppler findings. CT angiography should be considered before more invasive examinations.