To evaluate the diagnostic value of bedside contrast-enhanced ultrasound (CEUS) for early hepatic artery thrombosis (HAT) after liver transplantation (LT).

585 recipients undergoing LT in the Third Affiliated Hospital of Sun Yat-sen University from March 2016 to March 2020 were enrolled in this prospective study. Among them, 516 patients were male and 69 female, aged from 0.5 to 78.0 years, with a median age of 48.1 years. The informed consents of all recipients and/or their guardians were obtained and the local ethical committee approval was received. Bedside color Doppler ultrasound (CDUS) and CEUS were performed on the 1st, 2nd and 3rd days after LT. For the recipients who stayed in ICU at postoperative 4 d, ultrasound examinations were more frequently performed according to clinical requirements. Digital subtraction angiography (DSA) or CT angiography (CTA) was the gold standard for the diagnosis of HAT. The diagnostic value was evaluated by the ROC curve.

Among 585 recipients of LT, CDUS showed no intra- and extra-hepatic arteries in 21 cases, CEUS found no contrast perfusion in the intra- and extra-hepatic arteries of 12 recipients. The diagnosis of HAT was confirmed by DSA. In the remaining 9 cases, CEUS revealed contrast perfusion in the hepatic arteries, avoiding DSA. CDUS could display extrahepatic arteries and unilateral intrahepatic arteries in 11 recipients. Among 11 cases, CEUS could display intrahepatic arteries in 4 cases, whereas CEUS failed to clearly display unilateral intrahepatic arteries in the remaining 7 cases. Ultrasound during subsequent follow-up could display these intrahepatic arteries. CTA, ultrasound and clinical follow-up confirmed that neither bedside CDUS nor CEUS missed the diagnosis of HAT. The sensitivity, specificity, Youden's index, positive predictive value and negative predictive value of CDUS in diagnosing HAT were 1.00, 0.98, 0.98, 0.57, 1.00, and 1.00, 1.00, 1.00, 1.00, 1.00 for CEUS, respectively. The area under the ROC curve (AUC) of bedside CDUS and CEUS was respectively 0.992 and 1.000, and the difference was statistically significant (Z=3.021, P=0.003).

Bedside CEUS can correct the false positive diagnosis of CDUS, improve the diagnostic accuracy of early HAT after LT, and avoid DSA and alternative invasive examinations.