Introduction
Background
Portal vein thrombosis (PVT) is being recognized with increasing frequency with the use of ultrasonography. Reduced portal blood flow caused by hepatic parenchymal disease and abdominal sepsis (ie, infectious or ascending thrombophlebitis) are the major causes. Transient PVT is also being recognized with increasing frequency, partly because of the great increase in the use of ultrasonography in the evaluation of patients with abdominal inflammation such as appendicitis. Hypercoagulable syndromes can lead to portomesenteric and splenic vein thrombosis. Patients with these conditions may present with acute or subacute intestinal angina. In late stages, patients may have variceal bleeding.1,2,3
Portal vein thrombosis. Longitudinal oblique sonogram was obtained through the liver in a 36-year-old woman with a known history of Leber optic atrophy (hereditary optic neuroretinopathy) and alcohol abuse who presented with nonspecific complaints of ill health and vague abdominal pain. Image shows ascites and a bright liver (fatty). The portal vein has a linear echogenic structure running the length of the portal vein (solid arrow). A complex cystic mass is present within the liver (open arrow).
Portal vein thrombosis. Portal venous–phase enhanced axial CT scan, obtained in the same patient as in Images 1-4 in Multimedia, shows a low-attenuating mass in the termination of the splenic vein (arrow). Note the multiple low-attenuating masses at the periphery of the right lobe of the liver.
Portal vein thrombosis. Digital subtraction portal venous–phase superior mesenteric angiogram, obtained in the same patient as in Images 1-6 in Multimedia, shows collateral vessels at the porta hepatis but no patent portal vein. Note that the liver is displaced away from the thoracic cage as a result of ascites. This patient had severe hepatic failure and died within 72 hours after the imaging examination. Postmortem examination showed early cirrhosis, fulminant pyogenic cholangitis, multiple liver abscesses, and portal vein and splenic and left gastric vein thrombosis.
T1-contrast-enhanced coronal MR images showing thrombus within the main portal vein and a cavernous transformation of portal vein at the porta hepatis (same patient as in Images 14-19 in Multimedia).
ERCP and PTC confirming the biliary abnormalities. The appearances are those of portal biliopathy (same patient as in Images 14-19 in Multimedia).
Pathophysiology
Cavernous transformation of the portal vein (ie, the development of periportal collaterals) occurs with long-standing PVT as a result of the development of multiple small vessels in and around the recanalizing or occluded main portal vein. A leash of fine or markedly enlarged serpiginous vessels is seen in place of the portal vein. The application of color and/or pulsed Doppler imaging shows blood flow in these periportal collaterals that form around the thrombosed portal vein or that replace the vein.4 The time-averaged mean velocity of blood flow in the recanalizing portal vein is usually 2-7 cm/s.
Cavernous transformation of the portal vein can appear as a subhepatic spongelike mass. This appearance has also been reported in cases of pancreatic hemangiosarcoma. Bile duct varices, also called the pseudocholangiocarcinoma sign, are occasionally observed with endoscopic retrograde cholangiopancreatography (ERCP) in patients with portal hypertension; this finding results from cavernous transformation of the portal vein (see Image below and Image 19 in Multimedia).5 Bile duct varices may disappear after a transjugular intrahepatic portosystemic shunt (TIPS) procedure when the portal hypertension is reduced.
ERCP and PTC confirming the biliary abnormalities. The appearances are those of portal biliopathy (same patient as in Images 14-19 in Multimedia).
PVT occurs secondary to infection, surgical intervention, or abdominal malignancy (eg, pancreatic or hepatocellular carcinoma) or as a result of liver dysfunction.6,7 PVT is a known complication of pyogenic cholangitis. Causes of PVT include the following:
- Idiopathic causes
- Causes secondary to tumor
- Hepatocellular carcinoma
- Cholangiocarcinoma
- Pancreatic carcinoma
- Gastric carcinoma
- Trauma
- Iatrogenic umbilical vein catheterization8,9
- Abdominal sepsis
- Pancreatitis
- Perinatal omphalitis
- Appendicitis
- Diverticulitis
- Ascending cholangitis
- Myeloproliferative disorders10
- Clotting disorders (hypercoagulable syndromes)
- Estrogen therapy
- Severe dehydration
- Cirrhosis, especially in the young
- Portal hypertension
Frequency
United States
The exact frequency of PVT is not known, but segmental or global PVT occurs in as many as 30% of patients with hepatocellular carcinoma. The incidence of PVT in patients with cirrhosis and portal hypertension is approximately 5%.
Mortality/Morbidity
Morbidity and mortality are related to the underlying disease that is exacerbated by PVT.
- PVT occurs slowly and silently. It usually is not discovered until gastrointestinal hemorrhage develops, unless the thrombosis is discovered during routine surveillance for an underlying disease process.
- Hypersplenism of acute onset is a known complication of PVT.
- In patients with hypercoagulable syndromes, mesenteric venous thrombosis often extends into the portal vein and results in mild to severe intestinal angina.
Age
PVT predominantly affects young children, but it can occur in persons of any age.
Anatomy
The portal vein forms behind the neck of the pancreas with the union of the splenic and superior mesenteric veins. It courses to the porta hepatis in the free edge of the lesser omentum and receives the cystic, pyloric, accessory pancreatic, superior pancreaticoduodenal, and other veins that are too small to visualize.
Generally, the portal vein enters the porta hepatis and divides into the right and left main branches. The right main branch divides into anterior and posterior branches that supply the anterior and posterior segments of the right lobe. The left main branch courses horizontally to the left before turning vertically to form the medial and lateral segmental branches. Several variations of the portal venous anatomy have been described by using ultrasonography, CT, and cadaveric dissection.
Anatomic variants are possible. The normal origin of the left main portal vein branch and the horizontal part of the left main portal vein can be absent. A branch of the right anterior portal vein radical supplies the left lobe of liver. The right main portal trunk can also be absent. Immediately after it enters the porta hepatis, the portal vein turns to the left without giving rise to any of the normal right portal vein branches. The right hepatic lobe is smaller than usual, and small veins of varying sizes supply it. The right main portal vein trunk can be absent while its branches are present. Branches of the anterior and posterior right portal veins arise by means of trifurcation of the main portal vein trunk. The right posterior portal vein branch can arise from the main portal vein trunk. The main portal vein then continues into the liver and bifurcates.
Presentation
PVT is often not discovered until gastrointestinal hemorrhage develops, unless the thrombosis is discovered during routine surveillance for a known underlying pathologic condition. In most patients, PVT occurs slowly and silently. The signs and symptoms of PVT can be subtle or nonspecific, and they can be overshadowed by those of the underlying illness. The radiologist may be the first physician to suggest the diagnosis on the basis of imaging findings. The exceptions to this scenario are patients with hypercoagulation and portal and mesenteric venous thromboses who present with moderate or severe abdominal pain after acute or subacute development of the thrombosis.
Patients may present with abdominal pain; portal systemic encephalopathy; or gastrointestinal hemorrhage caused by esophageal varices, splenomegaly, and/or ascites. Symptoms of the underlying cause of the PVT, such as acute pancreatitis, intra-abdominal sepsis, or ascending cholangitis, may predominate.
Portal biliopathy is a recently described entity characterized by bile duct and gallbladder wall abnormalities in association with portal hypertension, particularly with extrahepatic portal vein obstruction.11,12,13 Cavernous transformation of the portal vein, choledochal varices, and ischemic injury of the bile duct have been postulated as causes. Portal cavernous transformation gives rise to many dilated pericholedochal and periportal collaterals that bypass the portal vein obstruction. Extrinsic compression of the common duct by dilated venous collaterals together with pericholedochal fibrosis from the inflammatory process causing portal thrombosis may lead to biliary stricture and dilatation of the proximal biliary tree. This condition sometimes causes the formation of secondary biliary stones and cholangitis. Most patients remain asymptomatic, but some present with raised alkaline phosphatase level, abdominal pain, fever, and cholangitis.14
Preferred Examination
Preferred examinations include duplex Doppler ultrasonography and/or color Doppler ultrasonography, CT, magnetic resonance angiography (MRA) (see Image below and Image 7 in Multimedia), and arterial portography or splenoportography.15
Portal vein thrombosis. Digital subtraction portal venous–phase superior mesenteric angiogram, obtained in the same patient as in Images 1-6 in Multimedia, shows collateral vessels at the porta hepatis but no patent portal vein. Note that the liver is displaced away from the thoracic cage as a result of ascites. This patient had severe hepatic failure and died within 72 hours after the imaging examination. Postmortem examination showed early cirrhosis, fulminant pyogenic cholangitis, multiple liver abscesses, and portal vein and splenic and left gastric vein thrombosis.
Tumor in the portal vein may have an appearance identical to that of thrombosis, but this appearance is far less common than others. Tumor in the portal vein is most frequently related to hepatocellular carcinoma. The thrombus may be partial or complete. It may be mixed with bland thrombus as well.
Adults who have acute PVT secondary to abdominal sepsis may completely recover, and the vessel may recanalize with successful treatment of the underlying sepsis.16 In children, the portal vein may recanalize with the development of multiple, small, collateral channels. These channels are seen as a partly echogenic band of small vessels extending to the porta hepatis (cavernous transformation). These have a reduced flow velocity of 2-7 cm/s. Nonvisualization of the portal vein is strongly suggestive of occlusion. The portal vein may then be seen as a band of high-level echoes at the porta hepatis.17
Differential Diagnoses
More on Portal Vein Thrombosis |
 Overview: Portal Vein Thrombosis |
| Imaging: Portal Vein Thrombosis |
| Follow-up: Portal Vein Thrombosis |
| Multimedia: Portal Vein Thrombosis |
| References |
| Further Reading |
| Next Page » |
References
Patel N, Haskal ZJ, Kerlan RK. Portal Hypertension: Diagnosis and Interventions. 2nd ed. Society of Cardiovascular and Interventional Radiology;. 2001.
Radovich PA. Portal vein thrombosis and liver disease. J Vasc Nurs. Mar 2000;18(1):1-5. [Medline].
Sheen CL, Lamparelli H, Milne A. Clinical features, diagnosis and outcome of acute portal vein thrombosis. QJM. Aug 2000;93(8):531-4. [Medline].
Ricci P, Cantisani V, Biancari F. Contrast-enhanced color Doppler US in malignant portal vein thrombosis. Acta Radiol. Sep 2000;41(5):470-3. [Medline].
Vleggaar FP, Van Buuren HR, Laméris JS. [Bile duct lesions in portal vein thrombosis]. Ned Tijdschr Geneeskd. Oct 9 1999;143(41):2057-62. [Medline].
Maalouf M, Papasavas P, Goitein D, Caushaj PF, Gagne D. Portal vein thrombosis after laparoscopic splenectomy for systemic mastocytosis: a case report and review of the literature. Surg Laparosc Endosc Percutan Tech. Apr 2008;18(2):219-21. [Medline].
Dentali F, Galli M, Gianni M, Ageno W. Inherited thrombophilic abnormalities and risk of portal vein thrombosis. A meta-analysis. Thromb Haemost. Apr 2008;99(4):675-82. [Medline].
Sakha SH, Rafeey M, Tarzamani MK. Portal venous thrombosis after umbilical vein catheterization. Indian J Gastroenterol. Nov-Dec 2007;26(6):283-4. [Medline].
Rubabaza P, Persadie RJ. Two Cases of Umbilical Vein Thrombosis, One With Associated Portal Vein Thrombosis. J Obstet Gynaecol Can. Apr 2008;30(4):338-343. [Medline].
de Suray N, Pranger D, Brenard R. Portal vein thrombosis as the first sign of a primary myeloproliferative disorder: diagnostic interest of the V617F JAK-2 mutation. A report of 2 cases. Acta Gastroenterol Belg. Jan-Mar 2008;71(1):39-41. [Medline].
El-Matary W, Roberts EA, Kim P, Temple M, Cutz E, Ling SC. Portal hypertensive biliopathy: a rare cause of childhood cholestasis. Eur J Pediatr. Feb 13 2008;[Medline].
Perego P, Cozzi G, Bertolini A. Portal biliopathy. Surg Endosc. Feb 2003;17(2):351-2. [Medline].
Chandra R, Kapoor D, Tharakan A, Chaudhary A, Sarin SK. Portal biliopathy. J Gastroenterol Hepatol. Oct 2001;16(10):1086-92. [Medline].
Colle I, Van Vlierberghe H, Pattyn P, Troisi R, Vogelaers D, de Hemptinne B, et al. Cholestasis as presenting symptom of portal cavernoma. Hepatol Res. Jan 2003;25(1):32-37. [Medline].
von Herbay A, Frieling T, Haussinger D. Color Doppler sonographic evaluation of spontaneous portosystemic shunts and inversion of portal venous flow in patients with cirrhosis. J Clin Ultrasound. Sep 2000;28(7):332-9. [Medline].
Stein M, Link DP. Symptomatic spleno-mesenteric-portal venous thrombosis: recanalization and reconstruction with endovascular stents. J Vasc Interv Radiol. Mar 1999;10(3):363-71. [Medline].
Parvey HR, Raval B, Sandler CM. Portal vein thrombosis: imaging findings. AJR Am J Roentgenol. Jan 1994;162(1):77-81. [Medline].
Novick SL, Fishman EK. Portal vein thrombosis: spectrum of helical CT and CT angiographic findings. Abdom Imaging. Sep-Oct 1998;23(5):505-10. [Medline].
Glockner JF, Forauer AR, Solomon H. Three-dimensional gadolinium-enhanced MR angiography of vascular complications after liver transplantation. AJR Am J Roentgenol. May 2000;174(5):1447-53. [Medline].
Matsuo M, Kanematsu M, Nishigaki Y, Kondo H, Goshima S, Maeda S, et al. Pseudothrombosis with T2-weighted fast spin-echo MR images caused by static portal venous flow in severe cirrhosis. J Magn Reson Imaging. Feb 2002;15(2):199-202. [Medline].
Shah TU, Semelka RC, Voultsinos V, Elias J Jr, Altun E, Pamuklar E, et al. Accuracy of magnetic resonance imaging for preoperative detection of portal vein thrombosis in liver transplant candidates. Liver Transpl. Nov 2006;12(11):1682-8. [Medline].
Chaudhary A, Dhar P, Sarin SK, Sachdev A, Agarwal AK, Vij JC, et al. Bile duct obstruction due to portal biliopathy in extrahepatic portal hypertension: surgical management. Br J Surg. Mar 1998;85(3):326-9. [Medline].
Chevallier P, Denys A, Novellas S, Schmidt S, Schnyder P, Bruneton JN. Magnetic resonance cholangiography features of biliary abnormalities due to cavernous transformation of the portal vein. Clin Imaging. May-Jun 2006;30(3):190-4. [Medline].
Shin SM, Kim S, Lee JW, Kim CW, Lee TH, Lee SH, et al. Biliary abnormalities associated with portal biliopathy: evaluation on MR cholangiography. AJR Am J Roentgenol. Apr 2007;188(4):W341-7. [Medline].
Lin J, Zhou KR, Wang JH, Yan ZP. [Portal vein involvement by hepatocellular carcinoma: diagnosis with three-dimensional contrast-enhanced MR angiography.]. Zhonghua Yi Xue Za Zhi. Feb 2 2005;85(5):308-12. [Medline].
Matsuo M, Kanematsu M, Hoshi H. Portal vein thrombosis mimicking hypovascular hepatic neoplasm: dynamic MR imaging findings. AJR Am J Roentgenol. Oct 1999;173(4):1060-2. [Medline].
Chen Y, Chen J, Luo B. [Colored Doppler ultrasound-guided fine-needle aspiration biopsy of portal vein thrombosis: value in diagnosis and assessment of therapeutic efficacy for portal vein thrombosis]. Zhonghua Zhong Liu Za Zhi. Sep 1997;19(5):362-4. [Medline].
Zwiebel WJ. Sonographic diagnosis of hepatic vascular disorders. Semin Ultrasound CT MR. Feb 1995;16(1):34-48. [Medline].
Martinez-Cuesta A, Elduayen B, Vivas I. CO(2) wedged hepatic venography: technical considerations and comparison with direct and indirect portography with iodinated contrast. Abdom Imaging. Nov-Dec 2000;25(6):576-82. [Medline].
Vogl T, Hidajat N, Schroder RJ. [Recanalization of an extensive fresh portal vein thrombosis by transjugular intrahepatic portosystemic stent-shunt (TIPS)]. Rofo Fortschr Geb Rontgenstr Neuen Bildgeb Verfahr. Aug 1999;171(2):163-5. [Medline].
Yamashita K, Tsukuda H, Mizukami Y. Hepatic infarction with portal thrombosis. J Gastroenterol. Oct 1997;32(5):684-8. [Medline].
Condat B, Pessione F, Hillaire S. Current outcome of portal vein thrombosis in adults: risk and benefit of anticoagulant therapy. Gastroenterology. Feb 2001;120(2):490-7. [Medline].
Sehgal M, Haskal ZJ. Use of transjugular intrahepatic portosystemic shunts during lytic therapy of extensive portal splenic and mesenteric venous thrombosis: long-term follow-up. J Vasc Interv Radiol. Jan 2000;11(1):61-5. [Medline].
Bilbao JI, Vivas I, Elduayen B. Limitations of percutaneous techniques in the treatment of portal vein thrombosis. Cardiovasc Intervent Radiol. Sep-Oct 1999;22(5):417-22. [Medline].
Walser EM, NcNees SW, DeLa Pena O. Portal venous thrombosis: percutaneous therapy and outcome. J Vasc Interv Radiol. Jan-Feb 1998;9(1 Pt 1):119-27. [Medline].
Further Reading
Related eMedicine topics
Portal Vein Obstruction
Portal Hypertension
Clinical guidelines
The role of transjugular intrahepatic portosystemic shunt in the management of portal hypertension. American Association for the Study of Liver Diseases - Private Nonprofit Research Organization. 2005 Feb. 15 pages. NGC:004222
Clinical trials
Anticoagulation Post Laparoscopic Splenectomy
Keywords
PVT, portal venous thrombosis, transient portal vein thrombosis, cavernous transformation of the portal vein, splenic vein thrombosis, angina, pseudocholangiocarcinoma, pancreatitis, thrombophlebitis, transjugular intrahepatic portosystemic shunt, TIPS
