A liver aneurysm is an abnormal, balloon-like widening in one of the blood vessels that supply or drain the liver, most commonly the hepatic artery. These are uncommon but potentially life-threatening because they can rupture with little warning, causing massive internal bleeding. The term covers several distinct conditions depending on which vessel is involved and whether the full vessel wall has weakened or only partially torn, and the causes, risks, and treatments vary considerably between them.
What Counts as a Liver Aneurysm
The liver has a dual blood supply: oxygenated blood arrives through the hepatic artery, while nutrient-rich blood flows in through the portal vein. An aneurysm can form in either system, but hepatic artery aneurysms get the most clinical attention because they carry a higher risk of rupture and catastrophic hemorrhage. Portal vein aneurysms exist too, but they behave very differently and are usually managed without surgery.
Among hepatic artery aneurysms, doctors distinguish between true aneurysms and pseudoaneurysms. A true aneurysm involves a bulge in all three layers of the artery wall, typically from gradual weakening over time. A pseudoaneurysm, by contrast, forms when the arterial wall is breached and blood pools in a contained pocket held together by surrounding tissue rather than by the vessel wall itself. This distinction matters because pseudoaneurysms tend to be more fragile and more likely to rupture. Roughly 80% of hepatic artery aneurysms sit outside the liver itself, along the extrahepatic portion of the vessel, and most of those arise spontaneously from conditions like immunosuppression or biliary tract infection. Intrahepatic pseudoaneurysms are more often caused by medical procedures such as liver transplantation or gallbladder removal, though they still carry a serious risk of severe bleeding.1PubMed Central. Hepatic Artery Aneurysms as a Rare but Important Cause of Abdominal Pain; a Case Series – Section: Discussion
Why They Form
The underlying cause depends heavily on whether you’re dealing with a true aneurysm or a pseudoaneurysm. True hepatic artery aneurysms most often develop from atherosclerosis, the same buildup of fatty deposits and hardening that causes problems in coronary and leg arteries. Other recognized causes include vasculitis, connective tissue disorders, and infections.2PubMed. Common hepatic artery true aneurysm: Case report and review of the literature Degenerative or structural changes in the vessel wall weaken it over time until a section begins to balloon outward.3PubMed Central. Hepatic Artery Aneurysms as a Rare but Important Cause of Abdominal Pain; a Case Series – Section: Discussion
Pseudoaneurysms, on the other hand, are mainly iatrogenic, meaning they result from medical interventions. Surgical procedures can cause mechanical injury to the vessel, and factors like pancreatic enzyme leakage, bile spillage, or abscess formation can digest the arterial wall. Most pseudoaneurysms follow hepatobiliary or pancreatic surgery, though they occasionally appear after gastric procedures as well.4PubMed Central. Common hepatic artery pseudoaneurysm: A rare complication following total gastrectomy: A case report – Section: Discussion
A few less common causes deserve mention. Polyarteritis nodosa, a type of vasculitis that targets small and medium-sized arteries, can cause aneurysms throughout the body. The liver is frequently involved in the disease, though actual rupture of a hepatic aneurysm in polyarteritis nodosa is uncommon.5PubMed. Polyarteritis nodosa presenting with hemobilia and intestinal hemorrhage Mycotic (infected) hepatic artery aneurysms are another rare variant, sometimes linked to bacterial endocarditis. In one reported case, a young patient with injection-drug-associated staphylococcal endocarditis developed a mycotic hepatic artery aneurysm that was successfully treated with antibiotics and valve replacement.6PubMed Central. Hepatic artery mycotic aneurysm associated with staphylococcal endocarditis with successful treatment: case report with review of the literature
Symptoms and Warning Signs
Many hepatic artery aneurysms produce no symptoms at all. They are increasingly discovered incidentally when a patient undergoes imaging for an unrelated reason, such as trauma evaluation or cancer surveillance. The growing use of CT scans for these purposes has pushed up the detection rate of otherwise silent aneurysms.7PubMed Central. Management of hepatic artery aneurysm: A case series
When symptoms do appear, abdominal pain is the most common complaint, often vague and centered in the upper abdomen. A classic but uncommon presentation is the Quincke triad: epigastric pain, obstructive jaundice (yellowing of the skin from bile-duct blockage), and gastrointestinal bleeding. One case report described a 70-year-old woman who arrived at the emergency department with all three features and was found to have multiple hepatic artery pseudoaneurysms with a clotted connection to the biliary system.8PubMed Central. Quincke Triad and Hepatic Artery Pseudoaneurysm Presenting to the Emergency Department: A Case Report Bleeding into the bile ducts, called hemobilia, is a telltale sign that should prompt investigation for a hepatic artery aneurysm.
Rupture is the most feared complication. It can present as sudden severe abdominal pain, a drop in blood pressure, and loss of consciousness. In one reported case, a 66-year-old woman arrived at the emergency department after abdominal pain and syncope. Emergency surgery revealed a ruptured hepatic artery aneurysm, and her recovery required removal of the gallbladder, spleen, and part of the liver due to ischemic damage before she could be discharged to rehabilitation.9PubMed Central. Ruptured Hepatic Artery Aneurysm The cascade of organ damage in that case illustrates how broadly a single ruptured hepatic aneurysm can affect surrounding structures.
How Liver Aneurysms Are Found
CT angiography is the most widely used first-line tool. It is readily available, noninvasive, and can map both the aneurysm itself and the surrounding blood vessels, which is critical for planning any intervention. CT can also reveal potential underlying causes like regional infection or tumor involvement. Despite these advantages, catheter-based digital subtraction angiography (DSA) remains the gold standard for definitive diagnosis because it offers the highest resolution of the arterial anatomy.10Vascular Specialist International. Endovascular Management of Hepatic Artery Pseudoaneurysms: A Case Series – Section: DISCUSSION In practice, many patients get a CT scan first that raises the suspicion, and DSA is then performed if intervention is planned.
Ultrasound, including Doppler techniques, can sometimes identify a hepatic artery aneurysm during routine abdominal imaging, particularly if the aneurysm is large. Magnetic resonance angiography is another option, especially for patients who cannot receive iodinated contrast dye. But neither carries the same diagnostic confidence as CT angiography or DSA for smaller or more complex lesions.
Treatment Options
Treatment depends on the aneurysm’s size, location, whether it has ruptured, and the patient’s overall health. The broad choice is between endovascular (catheter-based) procedures and open surgery.
Endovascular approaches have become increasingly favored because they are less invasive. Three main techniques exist: packing embolization (filling the aneurysm sac with coils or other material to promote clotting), isolation embolization (blocking blood flow into and out of the aneurysm), and stent deployment (placing a covered stent across the aneurysm to exclude it from the circulation while preserving flow through the artery).11PubMed Central. Hepatic artery aneurysms: Endovascular therapeutic techniques In one case, a large 43-mm common hepatic artery aneurysm was repaired using overlapping self-expanding covered stent grafts, with preserved arterial flow to the liver and no recurrence at three years of follow-up.12Journal of Vascular Surgery Cases, Innovations and Techniques. Endovascular repair of a common hepatic artery aneurysm using overlapping self-expanding covered stent grafts
Open surgical repair remains necessary for some patients, particularly when the aneurysm is very large, when endovascular access is not feasible, or when rupture demands immediate control of bleeding. Open approaches include resecting the aneurysm and reconnecting the arteries. In one striking example, a giant 14.9-cm hepatic artery aneurysm was successfully removed through open surgery, with the distal common hepatic artery sewn directly to the gastroduodenal artery.13PubMed Central. Open surgical repair of giant hepatic artery aneurysm The choice between endovascular and open repair depends on aneurysm anatomy, the adequacy of nearby collateral blood vessels, and the patient’s surgical risk profile.
Why the Liver Can Survive Arterial Interruption
One of the more counterintuitive aspects of treating hepatic artery aneurysms is that the liver can often tolerate having its main arterial supply blocked, at least temporarily. This is possible because the portal vein, not the hepatic artery, is the dominant blood vessel feeding the liver. During an acute interruption of hepatic artery flow, the portal vein maintains about 70% of total blood inflow to the liver and roughly half of its oxygen supply. Over time, the body develops new arterial pathways to compensate.14Hong Kong Medical Journal. Technical considerations for ligation of ruptured hepatic artery aneurysm: is arterial reconstruction necessary? – Section: Discussion
That said, this safety margin is not universal. When embolization is used to stop bleeding and the patient lacks adequate collateral arterial pathways, the risk of liver damage goes up dramatically. One study found that hepatic complications were eight times more likely when no collateral arteries were present, and deaths occurred only in patients without collaterals.15PubMed. The fatal risk in hepatic artery embolization for hemostasis after pancreatic and hepatic surgery: importance of collateral arterial pathways This is why surgeons and interventional radiologists carefully evaluate the collateral circulation before deciding whether simply blocking the artery is safe or whether flow needs to be reconstructed.
Long-Term Outlook After Treatment
For patients who undergo planned (non-emergency) repair, the prognosis is generally favorable. A surgical series following patients after operative repair of hepatic artery aneurysms reported overall survival of 86% at five years, with graft patency also at 86% at five years. Only one patient in that series required reintervention due to a blocked vein graft.16PubMed. Operative management of hepatic artery aneurysms Outcomes after emergency repair for rupture are considerably worse, as the patient starts the operation already hemodynamically compromised and organ damage may have already begun.
Long-term follow-up imaging is standard after both endovascular and open repairs. The concern is recurrence, graft failure, or new aneurysm formation at a different site. Patients with an underlying systemic cause, such as vasculitis or a connective tissue disorder, need especially close surveillance because their risk of developing aneurysms elsewhere remains elevated.
Portal Vein Aneurysms
Portal vein aneurysms are a separate entity from hepatic artery aneurysms, though both fall under the umbrella of “liver aneurysm.” A portal vein aneurysm is defined as a portal vein diameter exceeding 1.9 cm in patients with cirrhosis, or 1.5 cm in people with normal livers.17PubMed. Portal vein aneurysm: What to know They represent about 3% of all venous aneurysms in the body and can be either congenital or acquired. Portal hypertension, often from liver cirrhosis, is the main driver of the acquired form.18PubMed Central. Portal vein aneurysm-etiology, multimodal imaging and current management
The management philosophy for portal vein aneurysms is strikingly different from that of hepatic artery aneurysms. A study with 35 years of experience following these patients found that portal vein aneurysms tend to remain structurally stable over time with minimal complications. Abdominal pain, large size, and even blood clots within the aneurysm did not appear to increase risk enough to justify surgery on their own.19PubMed. Feasibility and safety of non-operative management of portal vein aneurysms: a thirty-five year experience Non-operative management with monitoring is therefore the approach for most patients. Surgery is generally reserved for rupture, symptomatic thrombosis, or situations where the aneurysm is clearly progressing. In patients without underlying liver disease, the surgical options include removing or plicating the aneurysm. For patients with portal hypertension, shunt procedures or liver transplantation may be more appropriate.20PubMed. Portal vein aneurysm: What to know
Genetic Conditions and Younger Patients
When a hepatic artery aneurysm turns up in someone young, a genetic connective tissue disorder often deserves consideration. Vascular Ehlers-Danlos syndrome, caused by defects in the metabolism of fibrillar collagen, weakens the walls of blood vessels and hollow organs. Patients with this condition frequently develop spontaneous complications in medium-sized arteries at a young age.21ScienceDirect. Arterial complications of vascular Ehlers-Danlos syndrome Other heritable conditions that increase aneurysm risk include Marfan syndrome, Loeys-Dietz syndrome, and certain forms of fibromuscular dysplasia. In these patients, the hepatic artery aneurysm may be one manifestation of a broader vascular fragility that requires screening of other arterial beds as well.
Hepatic artery aneurysms in children are extremely rare, but they have been reported. In one documented case, a child was found to have aneurysms of both hepatic arteries during evaluation for nonspecific symptoms. Simple ligation of both hepatic arteries was performed, and a year later the child remained symptom-free and developing normally.22PubMed. Hepatic artery aneurysm in a child The success of ligation alone in that case again reflects the liver’s ability to survive on portal venous flow and newly developed collateral arteries.
Pregnancy and Hormonal Factors
Pregnancy is a recognized risk period for certain visceral artery aneurysms, though the evidence for hepatic artery aneurysms specifically is limited and based largely on case reports rather than large studies. The best-documented association is with splenic artery aneurysms: the combination of increased blood volume, hormonal changes to vessel walls, and elevated cardiac output during pregnancy can push a previously stable aneurysm to rupture. When a splenic artery aneurysm ruptures during pregnancy, the consequences for both mother and fetus are dire.23PubMed Central. Rupture of Splenic Artery Aneurysm during Pregnancy: A Report of two Cases The same hemodynamic stresses apply to the hepatic artery, and several case reports describe hepatic artery aneurysm rupture during pregnancy, though the overall event rate is too low to quantify precisely.
For any pregnant patient presenting with sudden severe upper abdominal pain and signs of shock, visceral artery aneurysm rupture belongs on the list of possible diagnoses. The challenge is that this diagnosis competes with more common pregnancy-related emergencies, and a delay in imaging can be fatal. In women with known connective tissue disorders, vascular screening before or during pregnancy is increasingly considered standard care to catch aneurysms before they reach a dangerous size.
When an Aneurysm Is Found Incidentally
The growing availability of cross-sectional imaging means more people are learning they have a hepatic artery aneurysm that was never causing symptoms. This creates a management dilemma: not all aneurysms will rupture, but predicting which ones will is difficult. There is no universally agreed-upon size threshold that triggers automatic repair the way there is for abdominal aortic aneurysms. Many vascular specialists recommend treatment for hepatic artery aneurysms larger than 2 cm, but the decision also hinges on whether the aneurysm is a true aneurysm or a pseudoaneurysm (pseudoaneurysms are treated more aggressively regardless of size), whether it is growing on serial imaging, and whether the patient has risk factors that make rupture more likely, such as ongoing infection or a connective tissue disorder.
For portal vein aneurysms discovered incidentally, as discussed above, the threshold for intervention is much higher. Most are monitored with periodic imaging and left alone unless complications develop. The reassurance that portal vein aneurysms follow an indolent course over decades helps avoid unnecessary surgery in patients who may never develop problems from them.
If you have been told you have a liver aneurysm, the single most important piece of information is which vessel is involved and whether the aneurysm is true or pseudo. Those two facts determine how urgently it needs to be addressed, what treatment options apply, and how closely you need to be followed. For hepatic artery aneurysms, particularly pseudoaneurysms, the bias is toward intervention because the consequences of rupture are so severe and the modern endovascular options carry relatively low procedural risk. For portal vein aneurysms, watchful waiting with imaging is usually all that is needed.