Imaging Pearls ❯ Vascular ❯ Portal Vein
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- “Portal vein aneurysm (PVA) is a rare vascular abnormality, representing 3% of all venous aneurysms in the human body, and is not well understood. It can be congenital or acquired, located mainly at the level of confluence, main trunk, branches and bifurcation. A PVA as an abnormality of the portal venous system was first reported in 1956 by Barzilai and Kleckner. A review from 2015 entitled “Portal vein aneurysm: What to know” considered fewer than 200 cases.”
.Portal vein aneurysm-etiology, multimodal imaging and current management.
Kurtcehajic A, Zerem E, Alibegovic E, et al.
World J Clin Cases. 2023 Feb 6;11(4):725-737. - “A portal vein aneurysm (PVA) is the abnormal focal saccular or fusiform dilatation of the portal venous system, and it is defined as a PV diameter exceeding 19 mm in cirrhotic patients and 15 mm in a normal liver. It is a rare vascular abnormality, representing 3% of all venous aneurysms in the human body, and is not well understood. Douglass et al studied 92 autopsies and reported that the diameter of the PV was between 0.64 mm and 12.1 mm in patients without cirrhosis and those without portal hypertension. In 1976, Doust et al conducted a vascular study of 53 patients to assess the size of the PV and underlying liver status through abdominal ultrasound, and they detected that the maximum calibre of the PV was 19 mm in cirrhotic patients and 15 mm in patients with normal livers. Hence, a portal vein diameter of > 20 mm is universally regarded as the threshold for diagnosis of a PVA.”
Portal vein aneurysm-etiology, multimodal imaging and current management.
Kurtcehajic A, Zerem E, Alibegovic E, et al.
World J Clin Cases. 2023 Feb 6;11(4):725-737. - “ In terms of aetiology, the frequency of congenital PVAs was 29 (46.7%), and it was 17 (27.4%) for acquired PVAs. In 16 (25.8%) patients, the aetiology of the PVAs was unclear. Regarding the location of PVAs, 27.41% were at the level of the splenomesenteric confluence; 19.35% were at the main trunk; 17.74% were at branches; 6.45% were at the PV bifurcation; 6.45% were at the SV; and 4.83% were at the SMV; 14.51% were classified as intrahepatic PVAs.”
Portal vein aneurysm-etiology, multimodal imaging, and current management.
Kurtcehajic A, Zerem E, Alibegovic E, et al.
World J Clin Cases. 2023 Feb 6;11(4):725-737. - “Contrast-enhanced CT with angiography shows the filling of PVA. On a CT and magnetic resonance imaging (MRI) scan, a PVA will appear as a well-defined contrast-enhanced focal saccular anomaly or fusiform dilatation of the portal venous system during the portal venous phase.”
Portal vein aneurysm-etiology, multimodal imaging, and current management.
Kurtcehajic A, Zerem E, Alibegovic E, et al.
World J Clin Cases. 2023 Feb 6;11(4):725-737. - “PVA can be congenital or acquired, located mainly at the level of confluence, main trunk, branches and bifurcation. Up to 30% of patients can be asymptomatic, and non-specific abdominal pain should be investigated to exclude other pathological causes, such as cholecystitis or peptic ulcer disease, etc. Thrombosis complications occur in approximately 19%-23% of patients, and biliopathy occurs in approximately 4%-6% of patients. Other complications can also arise from compression due to a PVA, including thrombosis of the ICV and intestinal obstruction. Diagnosis of a PVA is based on spectral and colour Doppler sonography, and CT and MRI. EUS and IDU have also been used as a diagnostic tool. If a PVA is asymptomatic, it does not require any active treatment, and monitoring (a policy of “wait and see”) should be adopted. ”
Portal vein aneurysm-etiology, multimodal imaging, and current management.
Kurtcehajic A, Zerem E, Alibegovic E, et al.
World J Clin Cases. 2023 Feb 6;11(4):725-737.
- “In particular, the significance of these aneurysms must be appreciated in the emergency setting, as portal vein aneurysms can rarely present with symptoms of abdominal pain and other complications (such as thrombosis, portal hypertension, rupture, embolism, and compression of the duodenum and inferior vena cava) making surgical repair necessary.”
Portal Vein Aneurysms: Imaging Manifestations and Clinical Significance
Dalal PS, Raman SP, Horton KM, Fishman EK
Emerg Radiol 2013 May 23 (Epub ahead of print) - “ Although portal vein aneurysms (PVAs) are the most common of the visceral venous aneurysms (>95%), they are quite rare and account for only 3% of all venous aneurysms.”
Portal Vein Aneurysms: Imaging Manifestations and Clinical Significance
Dalal PS, Raman SP, Horton KM, Fishman EK
Emerg Radiol 2013 May 23 (Epub ahead of print) - “A portal vein aneurysm is defined as a focal dilatation of the portal venous system, a dilatation which present with a number of different shapes/morphologies (i.e. saccular, fusiform, bilobular). Studies suggest that a fusiform shape may be the most common, followed by saccular and bilobular aneurysms.”
Portal Vein Aneurysms: Imaging Manifestations and Clinical Significance
Dalal PS, Raman SP, Horton KM, Fishman EK
Emerg Radiol 2013 May 23 (Epub ahead of print) - “Aneurysms of the intrahepatic portal vein branches tend to be smaller than extrahepatic aneurysms, possibly due to the restrictive effects of the liver parenchyma on intrahepatic aneurysm growth . Accordingly, extrahepatic portal venous dilatation is considered to be “aneurysmal” after exceeding 2 cm in diameter, while intrahepatic portal vein branches are considered to be “aneurysmal” when they exceed 0.7 cm in diameter in patients without relevant risk factors and 0.85 cm in diameter in cirrhotic patients.”
Portal Vein Aneurysms: Imaging Manifestations and Clinical Significance
Dalal PS, Raman SP, Horton KM, Fishman EK
Emerg Radiol 2013 May 23 (Epub ahead of print)
- Portal Vein: Pathologies
- Portal vein aneurysm
- Portal vein thrombosis
- Portal venous gas
- Portosystemic collateral pathways
- Congenital anomalies of the portal vein - “Portal vein aneurysm is an uncommon finding. Two major causes, congenital and acquired, have been proposed. Strong support is given to the theory that they are acquired because a significant number of portal vein aneurysms are detected in patients with underlying hepatocellular disease and portal hypertension. The congenital cause is supported by the fact that some of the portal vein aneurysms are found in children and young adults who have no evidence of liver disease or portal hypertension.”
Extrahepatic Portal Vein Aneurysms
Blasbalg R et al.
AJR March 2000 vol 174 - “Although aneurysms of the portal venous system may be present in patients with liver disease, an overwhelming majority of patients do not have portal hypertension or chronic liver disease. Therefore, portal hypertension could be contributory but is not essential to the development of portal venous system aneurysms.”
Congenital and Acquired Anomalies of the Portal Venous System
Gallego C et al.
RadioGraphics 2002; 22:141-159 - “Reasons to favor a congenital origin are the in utero diagnosis of a portal vein aneurysm , evidence of portal venous system aneurysms in patients with histologically proved normal livers , and the frequent stability of the aneurysms at follow-up . Incomplete regression of the distal right vitelline vein leading to a diverticu- lum that would ultimately develop into an aneu- rysm in the proximal superior mesenteric vein could explain aneurysms in that location.”
Congenital and Acquired Anomalies of the Portal Venous System
Gallego C et al.
RadioGraphics 2002; 22:141-159 - “The most common locations are the splenomesenteric venous confluence, main portal vein, and intrahepatic portal vein branches at bifurcation sites; the rarest locations are the splenic, mesenteric, and umbilical veins.”
Congenital and Acquired Anomalies of the Portal Venous System
Gallego C et al.
RadioGraphics 2002; 22:141-159 - “Most portal venous system aneurysms are asymptomatic and do not demonstrate a significant increase in size once discovered, although some manifest with nonspecific abdominal pain as a major symptom.”
Congenital and Acquired Anomalies of the Portal Venous System
Gallego C et al.
RadioGraphics 2002; 22:141-159 - “Complications of portal venous system aneurysms are abdominal pain; thrombosis; portal hypertension (due to flow alterations or compression of the main portal vein); rupture; thrombosis and distal embolism; compression of the common bile duct causing jaundice, cholestasis, and cholelithiasis; and com- pression of the duodenum.”
Congenital and Acquired Anomalies of the Portal Venous System
Gallego C et al.
RadioGraphics 2002; 22:141-159
"Portal system venous aneurysms were present with abdominal pain in 44.7% of the patients, gastrointestinal bleeding in 7.3%, and are asymptomatic in 38.2%. Portal hypertension is reported in 30.8% and liver cirrhosis in 28.3%. Thrombosis occurred in 13.6% and rupture in 2.2% of the patients. Adjacent organ compression is reported in 2.2% (organs compressed: common bile duct, duodenum, inferior vena cava)"
Visceral Venous Aneurysms: Clinical Presentation, Natural History and Their Management: A Systematic Review
Styroeras GS et al.
European J of Vasc and Endovasc Surg Volume 38 No 4 Pages 498-5055 Oct 2009"The most frequent location of visceral venous aneurysms is the portal venous system. They are often associated with cirrhosis and portal hypertension."
Visceral Venous Aneurysms: Clinical Presentation, Natural History and Their Management: A Systematic Review
Styroeras GS et al.
European J of Vasc and Endovasc Surg Volume 38 No 4 Pages 498-5055 Oct 2009- "The most frequent location of visceral venous aneurysms is the portal venous system. They are often associated with cirrhosis and portal hypertension. They may be asymptomatic or present with abdominal pain and other symptoms. Watchful waiting is an appropriate treatment, except when complications occur. Most common complications are aneurysm thrombosis and rupture. Other visceral venous aneurysms are extremely rare."