CASE 16034 Published on 11.10.2018

Contrast enhanced Ultrasound (CEUS) of a post-trans-jugular liver biopsy hepatic artery pseudoaneuyrsm in a transplant liver.

Section

Abdominal imaging

Case Type

Clinical Cases

Authors

Leenknegt B, Zebari S, Rufai O, Kibriya N, Sidhu PS.

Department of Radiology, King's College Hospital, Denmark Hill, London, United Kingdom. Email: benjamin.leenknegt@ugent.be
Patient

34 years, female

Categories
Area of Interest Liver ; Imaging Technique Catheter arteriography, Ultrasound, Ultrasound-Colour Doppler, CT
Clinical History
A 34-year old woman with a transplant liver 3 years previously for Wilson’s disease was referred for an ultrasound (US) examination of the liver, for monitoring of abnormal liver function tests and work-up for re-transplantation. The patient had undergone a trans-jugular liver biopsy 10 days before, with no complications recorded.
Imaging Findings
A B-mode US (Fig. 1) demonstrated an intrahepatic anechoic area, close to the portal vein. A colour Doppler US (Fig. 2) depicted turbulent flow within the anechoic area with the “ying-yang” appearance of a pseudoaneurysm. Contrast-enhanced ultrasound (CEUS) (Fig. 3-4) demonstrated the feeding hepatic artery branch. The pseudoaneurysm drained into the adjacent hepatic vein. A biphasic contrast-enhanced CT (Fig. 5) shows a 4.1 x 2.2 cm bi-lobulated intrahepatic lesion. The CEUS features were confirmed, and a pseudoaneurysm arising from the liver biopsy likely. Angiography was performed to proceed to coil embolization (Fig. 6). The pseudoaneurysm, arising from the right hepatic artery, was not embolized; because of a risk of ischaemia due to the proximal position of the pseudoaneurysm, the tortuosity of the feeding artery and the prominent drainage into the hepatic vein. In addition, re-transplantation was scheduled, and occurred 10 days following the detection of the pseudoaneurysm.
Discussion
Hepatic artery pseudoaneurysm (HAP) is a rare vascular complication of liver transplantation [1-5], with a reported incidence between 0.27–3 % [2, 3, 5]. HAP is classified according to location as intrahepatic or extrahepatic, with a different pathogenesis [2, 4, 6]. Intrahepatic HAP is most commonly related to an interventional procedures such as liver biopsy, percutaneous trans-hepatic cholangiography or trans-hepatic biliary drainage [4, 6] and is often an incidental finding on surveillance US [2, 3]. Extra-hepatic pseudo-aneurysm are most frequently secondary to an infectious aetiology. This can be systemic haematogenous spread or local sepsis following a biliary leak, breakdown of the Roux-en-Y hepatico-jejunostomy or a small bowel perforation [2, 4, 6]. Rupture of HAP - with consequent haemobilia or intraperitoneal hemorrhage - has a high mortality rate [2, 5, 7]. B-mode US and colour Doppler US are the first-line imaging modality to evaluate vascular complications in the post-transplant liver [1, 2, 4]. On US the HAP appears as a pulsatile anechoic area of varying size close to the hepatic artery, often abutting the vessel [1, 2, 8]. Colour Doppler US depicts the typical “ying-yang” pattern. Spectral Doppler US can show a turbulent, bidirectional or - in rare cases - slow monophasic flow [1, 2, 8, 9]. Contrast-enhanced ultrasound has been used to assess vascular complications following liver transplantation [8, 10-12]. CEUS can depict a HAP as a circular area of contrast perfusion in the hepatic arterial phase [8, 13]. Angiography is the reference standard for diagnosis and treatment planning of vascular complications post-liver transplant [2, 7]. It should be performed in cases of suspected HAP with negative imaging findings [2]. In case of rupture, coil embolization can be used emergently to achieve hemostasis in hemodynamically unstable patients [7]. Using super-selective embolization techniques, graft ischemia resulting from hepatic artery occlusion sometimes can be avoided. In cases of a ruptured HAP involving the anastomosis or main hepatic artery, occlusion of the inflow – which renders the graft ischaemic – can be used as a temporary measure pending emergency re- transplantation. If no bleeding is present, a decision regarding intervention depends on the likely outcome of acute ischemia, the status of the graft and feasibility of revascularization or re-transplantation [2]. In selected cases (i.e. a narrow neck of the HAP), stent graft placement with balloon angioplasty can be a therapeutic option [14].

Written informed patient consent for publication has been obtained.
Differential Diagnosis List
Angiography confirmed the diagnosis of pseudoaneurysm of the hepatic artery.
Simple hepatic cyst
Hepatic abcess
Final Diagnosis
Angiography confirmed the diagnosis of pseudoaneurysm of the hepatic artery.
Case information
URL: https://eurorad.org/case/16034
DOI: 10.1594/EURORAD/CASE.16034
ISSN: 1563-4086
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