Contrast-enhanced ultrasound in liver transplant: first results and potential for complications in the postoperative period.
OBJECTIVE
This study compared the efficacy of contrast-enhanced ultrasound (CEUS) using a second generation contrast medium versus CT or MRA in the assessment of vascular and biliary complications in postoperative follow-up of liver transplantation.


METHODS
The study group consisted of 36 consecutive liver transplant recipients who underwent post-transplantation CEUS examination after developing ascites and/or unclear liver function tests. Real time CEUS was performed after a bolus injection of SonoVue (1.6-2.4 ml, Bracco, Imaging Germany) followed by 10 ml of saline solution. Using contrast harmonic imaging (CHI) technique (Logiq 9, GE) with a 2.5-4-MHz transducer, a low mechanical index was chosen to avoid early destruction of the microbubbles (MI 0.1-0.2). In order to confirm the results, the patients underwent contrast-enhanced MRI or CT.


RESULTS
Complications were identified in 16 of 36 patients (44.4%). Five transplants (14%) had hepatic artery thrombosis (n=2) or significant stenosis (n=3). Six transplants (16%) developed portal vein stenosis (n=4) or portal vein thrombosis (n=2). MRI or CT confirmed the findings of the CEUS in all 11 cases. Biliary stricture at the anastomotic site was detected in 5 patients. MR-CP confirmed the findings of all strictures.


CONCLUSIONS
Due to advances in contrast-enhanced US, vascular and biliary complications in the postoperative period following liver transplantation can be reliably diagnosed non-invasively on the intensive care unit. CEUS shows vascular as well as biliary complications in the postoperative patient with a high degree of accuracy.
Clevert
D-A
DA
Department of Clinical Radiology, University Hospitals - Grosshadern, Ludwig-Maximilians-University, Munich, Germany. Dirk.Clevert@med.uni-muenchen.de
Stickel
M
M
Minaifar
N
N
Löhe
F
F
Graeb
C
C
Jauch
K W
KW
Reiser
M
M
D001659:Biliary Tract / Q000098:blood supply / Q000000981:diagnostic imaging; D003287:Contrast Media; D005260:Female; D006801:Humans; D008099:Liver / Q000098:blood supply / Q000000981:diagnostic imaging; D016031:Liver Transplantation / Q000009:adverse effects* / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography
D003287:Contrast Media