Management of rupture of incidental right hepatic artery aneurysm using angio-embolization

Hepatic artery aneurysms (HAAs) constitute a rare subset of vascular anomalies affecting the liver, comprising a mere 0.01–2% of all arterial aneurysms and 20% of visceral aneurysms [1],[2],[3]. Predominantly identified incidentally through imaging modalities, the majority of HAAs remain asymptomatic until rupture, manifesting as abdominal pain, obstructive jaundice, or hemorrhage [1],[3],[4],[5]. Timely diagnosis assumes paramount importance given the elevated mortality rates associated with rupture and ensuing complications [6],[7]. Notably, contemporary advancements have led to a decline in HAA-related mortality owing to the increased detection of incidental cases via imaging modalities [6]. The majority of hepatic artery aneurysms are extrahepatic, indicating their occurrence outside the liver. Additionally, hepatic artery aneurysms are more frequently observed in males [5],[6].

A 64-year-old female patient presented at the emergency department with a history of vomiting and severe upper abdominal pain persisting for two days. Initial blood investigations revealed elevated amylase levels of 1101 µ/L, ALT levels of 387 µ/L, and a total bilirubin level of 74 µmol/L, while hemoglobin and renal function remained within normal parameters. These findings raised suspicion of acute pancreatitis, prompting a erral to the general surgery team for further management. Within six hours of admission, the patient experienced a collapse, with subsequent cardiac monitoring indicating ventricular fibrillation. Resuscitation efforts ensued, resulting in the restoration of spontaneous circulation (ROSC), following the administration of the initial DC shock. The patient was then transferred to the intensive care unit (ICU) for ionotropic support. Serial blood analyses revealed a significant decline in hemoglobin levels from 148 to 93, coupled with acute kidney injury and deteriorating liver function, necessitating an urgent computed tomography (CT) scan.

The emergent dual-phase CT scan unveiled a 1 cm density in the right segmental hepatic artery, suggestive of a hepatic artery aneurysm (Figure 1). Concurrently, the liver exhibited gross abnormalities, including areas of varying density within the parenchyma and a 3 cm sub-capsular fluid collection (Figure 2). Moreover, high-density fluid accumulation in the pelvis indicated peritoneal hemorrhage. These radiological findings, in conjunction with the suspected vascular anomaly, pointed toward an intra-parenchymal hepatic and sub-capsular hematoma secondary to a ruptured right hepatic artery aneurysm. Given the patient’s hemodynamic instability, an urgent erral was made to interventional radiology (IR) for emergency embolization.

Angiography confirmed the presence of a pseudo-aneurysm in the distal segmental branch of the right hepatic artery, subsequently embolized using micro coils (Figure 3). Post-embolization angiography exhibited complete occlusion of the aneurysm and its feeding vessel, while sparing the segmental vessels (Figure 4). After four days in the ICU, the patient was transferred to the ward for continued antibiotic therapy due to escalating inflammatory markers and persistent pyrexia. A follow-up portal venous CT scan revealed unchanged coil positions, along with infarcts in segments 7 and 8 of the right liver lobe, indicative of ongoing pancreatitis. Subsequent imaging over a two-week period demonstrated a reduction in hemoperitoneum, evolving hematoma density, and transformation of hepatic infarcts into an abscess. Adjustments to the antibiotic regimen were made based on sensitivity results and consultations with a microbiologist. The case was reviewed by the Hepato-Pancreato-Biliary (HPB) team at a specialized center, resulting in the addition of antifungal therapy. The patient remained under ward care, receiving antibiotics, intravenous fluids, and analgesics for a suspected liver abscess, presumed to have arisen from liver infarction. Following the establishment of a follow-up plan, the patient was discharged home. It is noteworthy that the infarction likely began early after the bleeding episode, as pre-embolization CT scans displayed ill-defined hypo-attenuated areas within the segments of the right hepatic lobe. These areas were attributed to hypoperfusion secondary to compromised flow in the distal sub-segmental branches of the right hepatic artery. Subsequent imaging showed the evolution and clarification of the infarct over time.

Genuine hepatic artery aneurysms (HAAs) primarily arise from degenerative or dysplastic changes in the extrahepatic vessels, with atherosclerosis being the predominant cause, albeit cases associated with vasculitis have also been documented. Pseudo-HAAs, constituting approximately 20% of all HAAs, may manifest either intrahepatically or extrahepatically. Extrahepatic HAAs, accounting for about 80% of cases, often occur spontaneously and are associated with factors such as immunosuppression, biloma, and biliary tract infection. In contrast, intrahepatic pseudo-aneurysms are frequently iatrogenic, arising from procedures like liver transplantation and cholecystectomy, posing a notable risk of severe hemorrhage [8].

Clinical presentations of HAAs vary and are typically nonspecific, contingent upon the size of the aneurysm. Initially asymptomatic, small HAAs tend to progressively enlarge, heightening the risk of rupture and associated mortality. Symptoms may include right upper quadrant and epigastric pain or biliary tract obstruction. The classic triad of Quinke’s, characterized by obstructive jaundice, abdominal pain, and hemobilia, is observed in approximately 30% of patients [8].

Inflammation related to septic emboli can erode arterial walls, precipitating HAA rupture and hemobilia. Individuals with a common channel for both pancreatic and biliary ducts and no accessory duct drainage are predisposed to acute pancreatitis due to pancreatic duct obstruction by blood clots [8].

Various diagnostic modalities are employed, including abdominal ultrasound, CT scans, CT angiography, magnetic resonance imaging (MRI), endoscopy, and angiography. Among these, angiography emerges as a perred therapeutic approach for splanchnic aneurysms, particularly through embolization. Multi-detector CT angiography exhibits notably high diagnostic accuracy for detecting hepatic artery aneurysms, with both sensitivity and specificity reaching 100% [8].

In conclusion, the rupture of a hepatic artery aneurysm constitutes a genuine surgical emergency necessitating both clinical expertise and surgical acumen. Typically asymptomatic unless actively dissecting, these aneurysms require urgent treatment when symptomatic. Despite not commonly being the primary consideration for right upper quadrant pain, hepatic artery aneurysms should be recognized as a significant underlying cause of symptoms, and prompt repair is imperative upon identification through imaging. This case underscores the critical role of interventional radiology as a safe and reliable alternative to surgical intervention in unstable patients requiring emergency management.