A hand-held ultrasound machine vs. conventional ultrasound machine in the bedside assessment of post-liver transplant patients

Abstract

The purpose was to assess the diagnostic accuracy of a hand-held Doppler ultrasound (US) machine for the bedside detection of liver and vascular abnormalities after liver transplantation in the intensive care unit. The IRB approved this study, and written informed consent was obtained from all patients or the patient's legal representative. Any liver transplant recipient at our institution who needed a bedside Doppler US examination in the intensive care unit was eligible. Patients underwent routine grey-scale, colour, and spectral Doppler US examinations of the liver with a conventional machine, which was taken as the reference method, and with a hand-held machine on the same day. Examinations followed one another and were performed in a blinded fashion by two radiologists. Over a 4-month period, 24 consecutive patients (16 men, median age 54 years old; 16 cadaveric and 8 living related right liver transplantations) underwent 43 examinations with both conventional and hand-held machines. Image quality and overall satisfaction scores of grey-scale were lower with the hand-held than with the conventional machine. The hand-held was similar to the conventional machine for assessing the patency of portal veins, hepatic veins and the IVC in all patients but one. The hand-held machine failed to detect signals in the right branch of the hepatic artery and in the hilum in two and one cases, respectively. There was no abnormal hepatic arterial flow with the conventional machine in any of the patients, and the results were the same with the hand-held machine. Total examination time was significantly longer with the hand-held machine. The hand-held US machine had a high diagnostic accuracy for both parenchymal and vascular analyses compared with a conventional US machine in the bedside assessment of post-liver transplant patients.