Vascular complications after adult living donor liver transplantation: Evaluation with ultrasonography

Abstract

Living donor liver transplantation (LDLT) has been widely used to treat end-stage liver disease with improvement in surgical technology and the application of new immunosuppressants. Vascular complications after liver transplantation remain a major threat to the survival of recipients. LDLT recipients are more likely to develop vascular complications because of their complex vascular reconstruction and the slender vessels. Early diagnosis and treatment are critical for the survival of graft and recipients. As a non-invasive, cost-effective and non-radioactive method with bedside availability, conventional gray-scale and Doppler ultrasonography play important roles in identifying vascular complications in the early postoperative period and during the follow-up. Recently, with the detailed vascular tracing and perfusion visualization, contrast-enhanced ultrasound (CEUS) has significantly improved the diagnosis of postoperative vascular complications. This review focuses on the role of conventional gray-scale ultrasound, Doppler ultrasound and CEUS for early diagnosis of vascular complications after adult LDLT.

Keywords: Contrast-enhanced ultrasound; Doppler ultrasound; Living donor liver transplantation; Ultrasonography; Vascular complications.

Figure 1

Hepatic artery thrombosis in a 51-year-old woman who underwent right-lobe living donor liver transplantation. A: Color Doppler ultrasound reveals no hepatic artery flow at the hilus hepatis (arrow head points to the portal vein flow); B: Contrast-enhanced ultrasound shows no enhancement in the hepatic artery neighboring portal vein (arrow head points to the portal vein). PV: Portal vein.

Figure 2

Portal vein stenosis in a 40-year-old woman who underwent right-lobe living donor liver transplantation. A:Gray-scale ultrasound detected a stenotic region in the portal vein (arrow); B:Color Doppler ultrasound showed disturbance of the blood flow at the stenotic site (arrow); C: Spectrum Doppler ultrasound showed that the blood flow velocity at the stenotic was 128 cm/s; D: Spectrum Doppler ultrasound showed that the blood flow velocity at a pre-stenotic segment of the portal vein was 19.8 cm/s. The ratio between stenotic and pre-stenotic flow was significantly greater than 4:1.

Figure 3

Bridging vein occlusion in a 43-year-old woman who underwent right-lobe living donor liver transplantation sparing the middle hepatic vein. A:Gray-scale ultrasound showed the bridging vein (arrow); B: Contrast-enhanced ultrasound showed no enhancement in the bridging vein (arrows); C:Color Doppler ultrasound revealed the opening of collateral circulation of intrahepatic veins (arrow).