Implantable Continuous Doppler Monitoring Device for Detection of Hepatic Artery Thrombosis After Liver Transplantation

Abstract

Early hepatic artery thrombosis (eHAT) after liver transplantation occurs in 3% of adults and 8% of children and often results in retransplantation. eHAT is initially asymptomatic and arterial patency is monitored with percutaneous Doppler ultrasound screening (pDUS). The aim of the study is to analyze the diagnostic accuracy of "continuous" Doppler registration (CONDOR) using an implantable miniature Doppler. This prospective observational study was conducted in 102 liver transplant recipients. Hepatic arterial signal is checked by CONDOR at least six times per day for the first 10 days after transplantation with comparison of diagnostic accuracy of CONDOR versus pDUS. Extra investigations were performed after 48 (11%) regular pDUS where arterial patency was questioned: 32 extra pDUS, 14 computed tomography (CT) angiographies, and 2 reoperations. CT scan confirmed eHAT in 4 cases. In 10 cases of pDUS-suspected eHAT, where subsequent CT showed an open artery, the CONDOR signal was clearly pulsatile. In 2 of 4 patients with five eHATs, a weak arterial signal was inadvertently interpreted as an open artery (sensitivity of 60%). The accuracy for detection of eHAT increased from 93% (pDUS) to 99% (CONDOR). Using CONDOR, additional CT angiographies may be prevented in 10% of cases. CONDOR is a useful adjunct to pDUS because it reduces the false-positive rate of pDUS. Further development of the technique and analysis of the signal generated by CONDOR are needed to improve the sensitivity before CONDOR can replace pDUS as a reliable screening method for detection of eHAT.