CASE 14147 Published on 20.11.2016

Unruptured pseudoaneurysm of the cystic artery complicating acute calculous cholecystitis

Section

Abdominal imaging

Case Type

Clinical Cases

Authors

Arthur DAVID, Frédéric DOUANE, Franck LEAUTE, Eric FRAMPAS

Service de Radiologie Centrale
Centre Hospitalier Universitaire de Nantes
1, place Alexis Ricordeau
44093 Nantes
FRANCE
Patient

66 years, male

Categories
Area of Interest Abdomen ; Imaging Technique CT
Clinical History
A 66-year-old man was admitted to the emergency department with a 48-h history of upper abdominal pain. On physical examination, he was haemodynamically stable, febrile (38.5°C) and had tenderness in the right upper abdominal quadrant.
Imaging Findings
Abdominal computed tomography (CT) confirmed the diagnosis of acute calculous cholecystitis, showing a distended gallbladder with a thick wall and a calcified gallstone at the neck (Figure 1). Unenhanced images also revealed a nodular lesion, 10 mm in diameter, nearby the gallbladder (Figure 2a), enhanced in the same manner as the aorta on contrast-enhanced CT at a portal phase (Figure 2b). This lesion was arising from a branch of the right hepatic artery, suggesting the diagnosis of pseudoaneurysm of the cystic artery (Figure 2c). It was not possible to visualize this pseudoaneurysm by abdominal ultrasonography (US) because of interference from bowel gas. Antibiotherapy was initiated. Because the patient underwent cholecystectomy, transcatheter embolization was not necessary.
Discussion
Pseudoaneurysm of the cystic artery (PCA) is a rare condition, with less than 40 reported cases in the recent English literature [1]. Most of the reported cases of PCA were diagnosed after rupture, with a few exceptions [1-4]. We present here what we believe to be the fourth case of unruptured PCA. PCA is mostly associated with cholecystitis [1], and the mechanism of formation is thought to be the erosion of arterial wall by the inflammatory process [5]. Clinical presentation of PCA includes symptoms of classic gallbladder pathology, potentially associated with symptoms of an upper gastrointestinal bleeding when a rupture has occurred. The Quincke's triad of right upper quadrant pain, jaundice and gastrointestinal bleeding is therefore very suggestive of this condition [1, 6]. The diagnosis of PCA is usually made by US with colour Doppler imaging and/or contrast-enhanced CT. US can show a nodular anechoic lesion with a characteristic "ying-yang" pulsatile flow. However, detection of small aneurysms by US can be limited by patient obesity, bowel gas or acoustic shadowing due to calculi [1, 2]. Abdominal CT shows a nodular lesion with a strong enhancement. 3D CT angiography may reveal the continuity of the pseudoaneurysm with the cystic artery [2]. Definite diagnosis of PCA is possible with CT, without requiring conventional angiography [6], especially when transcatheter embolization is not considered. The definitive treatment of PCA complicating cholecystitis is ligation of the cystic artery during cholecystectomy [2]. Open cholecystectomy, instead of laparoscopic, seems to be a safer option, because of the high risk of rupture [2]. In unstable patients with active bleeding, transcatheter arterial embolization is recommended in order to stabilise the patient before surgery [4].
Although cholecystitis is a very common condition, cases associated with PCA remains extremely rare. CT and/or US are the most effective methods to confirm the diagnosis, and radiologists should be aware of this potentially life-threatening condition.
Differential Diagnosis List
Unruptured pseudoaneurysm of the cystic artery complicating acute calculous cholecystitis
Inflammatory lymphatic node
Extravesicular gallstone
Final Diagnosis
Unruptured pseudoaneurysm of the cystic artery complicating acute calculous cholecystitis
Case information
URL: https://www.eurorad.org/case/14147
DOI: 10.1594/EURORAD/CASE.14147
ISSN: 1563-4086
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