Portal vein thrombosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farima Kahe M.D. [2]

Portal vein thrombosis is the formation of thrombus in the portal venous system of liver. Portal vein thrombosis was first discovered by Balfour and Stewart in 1868. Portal vein thrombosis may be classified according to the extension into 4 groups. It is thought that portal vein thrombosis is caused by Virchow’s triad which includes reduced portal blood flow, hypercoagulable state, vascular endothelial injury. Portal vein thrombosis may be caused by inherited prothrombotic disorders and acquired thrombophilic disorders. Portal vein thrombosis must be differentiated from other diseases that cause abdominal pain, diarrhea, nausea and vomiting. The prevalence of portal vein thrombosis is approximately 5000-10,000 per 100,000 in overall cases of portal hypertension in developed counties and 40,000 per 100,000 in developing countries. Common risk factors in the development of portal vein thrombosis include cirrhosis, pancreatitis, duodenal ulcer, cholecystitis, Crohn’s disease, ulcerative colitis and cholecystectomy, diverticulitis and appendicitis. If left untreated, patients with portal vein thrombosis may progress to develop portal cavernoma, gastric or esophageal varices/bleeding, hepatic encephalopathy, splenomegaly, portal biliopathy or cholangiopathy. Common symptoms of portal vein thrombosis include abdominal pain or distention, diarrhea, nausea and vomiting, and anorexia. Less common symptoms of portal vein thrombosis include weight loss, fever, ascites, jaundice, and bloody stools. Common physical examination findings of portal vein thrombosis include abdominal pain or distention, splenomegaly and signs of ascites. Laboratory findings is usually normal among patients with portal vein thrombosis. In patients with cirrhosis, laboratory findings may demonstrate an elevated bilirubin, low platelet count, prolonged international normalized ratio (INR), or renal insufficiency. Ultrasonography is the gold standard test for the diagnosis of portal vein thrombosis. The following result of ultrasonography is confirmatory of portal vein thrombosis is portal cavernoma (multiple tortuous small vessels replacing the portal vein) and absence or reduced flow in portal vein. Medical therapy for portal vein thrombosis include anticoagulation to maintain INR between 2 to 3. The goal of anticoagulation is to prevent extension of the clot and to allow for recanalization so that intestinal infarction and portal hypertension do not develop. Surgery is not the first-line treatment option for patients with portal vein thrombosis. Surgery is usually reserved for patients with either failed medical therapy, liver failure, and cirrhosis.

Portal vein thrombosis was first discovered by Balfour and Stewart in 1868. In 1868, G201210A mutations were first implicated in the pathogenesis of portal vein thrombosis. In 1945, Allan Whipple, an american surgeon, reported treatment of the portal hypertension with shunts. He eventually tried shunts between different mesenteric veins. Finally, he found portocaval shunt as the best choice. In 1980’s, researchers have observed that endoscopic sclerotherapy is more efficient than surgical shunting in preventing recurrent variceal bleeding.

Portal vein thrombosis may be classified according to the extension into 4 groups including confined to the portal vein beyond the confluence of the splenic vein, extended to the superior mesenteric vein, but with patent mesenteric vessels, extended to the whole splanchnic venous system, but with large collaterals, and extended to the whole splanchnic venous system with only fine collaterals. Based on the duration of symptoms, portal vein thrombosis may be classified as either acute or chronic.

It is thought that vein thrombosis is caused by Virchow’s triad which includes reduced portal blood flow, hypercoagulable state, vascular endothelial injury. There are two mechanisms that contribute to loss of portal vein blood flow to liver, arterial rescue and venous rescue. It is a rapid process and takes a few days to start and 3-5 weeks to complete after portal vein obstruction. Collateral vessel joins to form cavernoma which connects the proximal and distal part of thrombosed portal vein. Finally, the portal vein becomes fibrosed, thin cord. All these events leads to low systemic vascular resistance and high cardiac output. These are the characteristic findings of hyper-kinetic circulation.

Portal vein thrombosis may be caused by inherited prothrombotic disorders and acquired thrombophilic disorders. Less common causes of portal vein thrombosis include acquired conditions such as cirrhosis and hepatocellular carcinoma and procedures such as abdominal surgery or surgical injury of the portal vein axis and splenectomy.

Portal vein thrombosis must be differentiated from other diseases that cause abdominal pain, diarrhea, nausea and vomiting, such as chronic pancreatitis, Pancreatic carcinoma, Dumping syndrome, Acute appendicitis, acute diverticulitis, Infective colitis, viral hepatitis, Liver abscess, Mesenteric ischemia, Acute ischemic colitis.

The incidence of portal vein thrombosis in cirrhotic patients is unknown. The prevalence of portal vein thrombosis is approximately 5000-10,000 per 100,000 in overall cases of portal hypertension in developed counties and 40,000 per 100,000 in developing countries. The overall mortality rate of portal vein thrombosis is less than 10% except for patients with malignancy or cirrhosis. Patients of all age groups may develop portal vein thrombosis. There is no racial predilection to portal vein thrombosis. Portal vein thrombosis affects men and women equally.

Common risk factors in the development of portal vein thrombosis include cirrhosis, pancreatitis, duodenal ulcer, cholecystitis, Crohn’s disease, ulcerative colitis and cholecystectomy, diverticulitis and appendicitis. Less common risk factors in the development of portal vein thrombosis include oral contraceptives, pregnancy or puerperium, and hyperhomocysteinemia.

There is insufficient evidence to recommend routine screening for portal vein thrombosis.

If left untreated, patients with portal vein thrombosis may progress to develop portal cavernoma, gastric or esophageal varices/bleeding, hepatic encephalopathy, splenomegaly, portal biliopathy or cholangiopathy. Depending on the extent of the model for end-stage liver disease score at the time of diagnosis, the prognosis may vary. However, the prognosis is generally regarded as good.

Ultrasonography is the gold standard test for the diagnosis of portal vein thrombosis. The following result of ultrasonography is confirmatory of portal vein thrombosis is portal cavernoma (multiple tortuous small vessels replacing the portal vein) and absence or reduced flow in portal vein.

Common symptoms of portal vein thrombosis include abdominal pain or distention, diarrhea, nausea and vomiting, and anorexia. Less common symptoms of portal vein thrombosis include weight loss, fever, ascites, jaundice, and bloody stools.

Patients with portal vein thrombosis usually appear ill. Common physical examination findings of portal vein thrombosis include abdominal pain or distention, splenomegaly and signs of ascites.

Laboratory findings is usually normal among patients with portal vein thrombosis. In patients with cirrhosis, laboratory findings may demonstrate an elevated bilirubin, low platelet count, prolonged international normalized ratio (INR), or renal insufficiency.

There are no ECG findings associated with portal vein thrombosis.

There are no x-ray findings associated with portal vein thrombosis.

Findings on an ultrasound diagnostic of portal vein thrombosis include echogenic material obstructing lumen of vessel, complete or partial absence of flow in portal vein, and collateral circuits by-passing the obstructed vessel.

Abdominal CT scan is used for the diagnosis of portal vein thrombosis. Findings on CT scan suggestive of hyperattenuating material in the portal vein lumen, nonenhanced intraluminal-filling defect, Lack of luminal enhancement, increased hepatic enhancement in the arterial phase and decreased hepatic enhancement in the portal phase.

Abdominal MRI is used for the diagnosis of portal vein thrombosis. Findings of MRI diagnostic for portal vein thrombosis include filling defect that partially or completely occludes the vessel lumen in the portal venous phase, clot appears iso-intense on T-1 weighted images, and usually has a more intense signal on T-2 images, and the presence of varices.

Contrast enhanced ultrasonography (CEUS) is helpful in the diagnosis of portal vein thrombosis. Findings on CEUS suggestive of portal vein thrombosis include pulsatile flow in a portal vein thrombus, absence of enhancement of the portal vein thrombus in the arterial phase.

There are no other diagnostic studies associated with portal vein thrombosis.

Medical therapy for portal vein thrombosis include anticoagulation to maintain INR between 2 to 3. The goal of anticoagulation is to prevent extension of the clot and to allow for recanalization so that intestinal infarction and portal hypertension do not develop.

Surgery is not the first-line treatment option for patients with portal vein thrombosis. Surgery is usually reserved for patients with either medical failed therapy, liver failure, and cirrhosis.

There are no established measures for the primary prevention of portal vein thrombosis.

There are no established measures for the secondary prevention of portal vein thrombosis.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farima Kahe M.D. [2]

Portal vein thrombosis was first discovered by Balfour and Stewart in 1868. In 1868, G201210A mutations were first implicated in the pathogenesis of portal vein thrombosis. In 1945, Allan Whipple, an american surgeon, first described the treatment of the portal hypertension with shunts. He eventually tried shunts between different mesenteric veins. Finally, he found portocaval shunt as the best choice. In 1980’s, researchers have observed that endoscopic sclerotherapy is more efficient than surgical shunting in preventing recurrent variceal bleeding.

• In 1868, Balfour and Stewart described portal vein thrombosis for the first time.^[1]
• In 1868, G201210A mutations were first implicated in the pathogenesis of portal vein thrombosis.^[1]
• In 1319, Mondino de Liuzzi (Mundinus), an Italian surgeon, published the textbook named “Anhotomia” and described the anatomy of liver vascular system for the first time. The book was the most reliable textbook of anatomy for about 200 years and been partially modified by Avicenna (1000 years ago).
• In 1543, Andreas van Wesel (Andrea Vesalio in Latin), Flemish anatomist, described portal system accurately for the first time in his textbook called “De humani corporis fabrica”.^[2]
• In 1650, Francis Glisson, a British physician, demonstrated the portal circulation for the first time, using goat as a study model.^[3]
• In 1761, Giovani Battista Morgagni, an Italian anatomist, described the characteristics of cirrhotic liver in his precious textbook named “De sedibus and causis morborum per anatomen indagatis“.^[4]
• In 1819, Renè Laennec, a French physician, coined the term cirrhosis in his textbook, from antique Greek words of “Skirros” (hard, fibrotic) and “Kirrhos” (yellowish). He also mentioned his new invention “stethoscope” in the textbook.^[2]

• In 1877, Nicholas Eck, a German physician, did the first portocaval shunt to treat the liver congestion in dogs.^[5]
• In 1945, Allan Whipple, an american surgeon,first described the treatment of the portal hypertension with shunts. He eventually tried shunts between different mesenteric veins. Finally, he found portocaval shunt as the best choice.

• In 1985, David Westaby, a British gastroenterologist, postulated that variceal sclerosing therapy is an better option than pharmacotherapy in the treatment of portal hypertension.^[6]
• In 1980s, researchers have observed that endoscopic sclerotherapy is more efficient than surgical shunting in preventing recurrent variceal bleeding.^[7]

• In 1967, Thomas Earl Starzl, an american physician, mentioned that liver transplantation is an effective way to treat both portal vein thrombosis and the underlying hepatic disease.^[8]

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farima Kahe M.D. [2]

Portal vein thrombosis may be classified according to its extension into 4 groups including: Confined to the portal vein beyond the confluence of the splenic vein, extended to the superior mesenteric vein with patent mesenteric vessels, extended to the whole splanchnic venous system with large collaterals, and extended to the whole splanchnic venous system with only fine collaterals. Portal vein thrombosis may be classified based on the duration of symptoms as either acute or chronic.

Portal vein thrombosis may be classified according to the extension into 4 groups:^[1][2]

• Confined to the portal vein beyond the confluence of the splenic vein
• Extended to the superior mesenteric vein, but with patent mesenteric vessels
• Extended to the whole splanchnic venous system, but with large collaterals
• Extended to the whole splanchnic venous system with only fine collaterals

Based on the onset of symptoms, portal vein thrombosis may be classified as either acute or chronic:^[3]

• Acute portal vein thrombosis: Defined as duration of symptoms <60 days and absence of portal carvernoma and portal hypertension
• Chronic portal vein thrombosis: Defined as duration of symptoms >60 days and/or presence of portal carvernoma and portal hypertension

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farima Kahe M.D. [2]

It seems portal vein thrombosis is caused by Virchow’s triad which includes: Reduced portal blood flow, hypercoagulable state, and vascular endothelial injury. There are two mechanisms that contribute in loss of portal vein blood flow to liver, arterial rescue and venous rescue. It is a rapid process and takes a few days to start and 3-5 weeks to complete after portal vein obstruction. Collateral vessel joins to form cavernoma which connects the proximal and distal part of thrombosed portal vein. Finally, the portal vein becomes a fibrosed and thin cord. All these events leads to low systemic vascular resistance and high. These are the characterstic findings of hyperkinetic circulation.

• Portal vein is formed by the union of the splenic vein and superior mesenteric vein and divides into a right and a left branch before entering the liver.

• The portal vein drains blood into the liver, not from the liver, the blood entering the liver from the portal vein, after being cleaned by the liver, flows into the inferior vena cava via the hepatic veins.
• The inferior mesenteric vein usually does not directly connect to the hepatic portal vein; it drains into the splenic vein.

• Portal vein branches into many generations of vessels that open into hepatic sinusoids. Blood is recollected into the hepatic vein and enters the inferior vena cava.

The tributaries of the hepatic portal vein include:

• Left gastric vein and right gastric vein
• Superior mesenteric vein
• Splenic vein

• It is thought that vein thrombosis is caused by Virchow’s triad which includes:^[1]
  • Reduced portal blood flow
  • Hypercoagulable state
  • Vascular endothelial injury

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Shown below is a table depicting the elements of Virchow’s triad and their modern counterparts.

Virchow’s[2]	Modern	Notes
Phenomena of interrupted blood-flow	“Stasis” or “venous stasis“[3]	The first category, alterations in normal blood flow, refers to several situations. These include turbulence, stasis, mitral stenosis, and varicose veins. The equivalence of Virchow’s version and the modern version has been disputed.[4]
Phenomena associated with irritation of the vessel and its vicinity	“Endothelial injury” or “vessel wall injury”	The second category, injuries and/or trauma to endothelium includes damage to the veins arising from shear stress or hypertension.
Phenomena of blood–coagulation	“Hypercoagulability”	The last category, alterations in the constitution of blood,[5] has numerous possible risk factors such as hyperviscosity, deficiency of antithrombin III, nephrotic syndrome, changes after severe trauma or burn, disseminated cancer, late pregnancy, and delivery, race, age, whether the patient is a smoker or obese. All of these risk factors lead to hypercoagulability.

• There are two mechanisms that contribute in loss of portal vein blood flow to liver:^[6]
  • Arterial rescue:
    • Arterial rescue is the phenomenon that occurs after portal vein clamping during liver surgery.^[7]
    • It is a vascular reflex present in organs with both arterial and venous supply.
    • It has a role in preserving liver function in the acute stages of portal vein thrombosis.
  • Venous rescue:
    • Venous rescue is the phenomenon of neovascularization by forming collateral vessels.
    • It helps to bypass the obstruction.
    • It is a rapid process and takes a few days to start and 3-5 weeks to complete after portal vein obstruction.^[8]
    • Collateral vessel joins to form cavernoma which connects the proximal and distal part of thrombosed portal vein.
    • Finally, the portal vein becomes a fibrosed and thin cord.^[9]
• All these events leads to low systemic vascular resistance and high cardiac output. These are the characterstic findings of hyperkinetic circulation.^[10]

• The development of portal vein thrombosis is the result of G201210A mutations.

• Conditions associated with portal vein thrombosis include:^[1][11][12]
  • Cirrhosis
  • Hepatocellular carcinoma
  • Portal cavernoma
  • Gastric or esophageal varices/bleeding
  • Hepatic encephalopathy
  • Portal biliopathy or cholangiopathy
  • Peritonitis
  • Hypoxia or pulmonary artery hypertension
  • Portal hypertensive gastropathy

• There is no finding on gross pathology of portal vein thrombosis.

• There is no finding on microscopic histopathological analysis.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farima Kahe M.D. [2]

Portal vein thrombosis may be caused by inherited prothrombotic disorders and acquired thrombophilic disorders. Less common causes of portal vein thrombosis include acquired conditions such as cirrhosis and hepatocellular carcinoma and procedures such as abdominal surgery or surgical injury of the portal vein axis and splenectomy.

• Life-threatening causes of portal vein thrombosis include: hepatocellular carcinoma, and Philadelphia-chromosome negative chronic myeloproliferative disorders (polycythemia vera, essential thrombocythemia, idiopathic myelofibrosis, and unclassifiable myeloproliferative disorders).

Portal vein thrombosis may be caused by:^{[1][2][3][4][5][6][7][8][9][10][11]}

• Inherited prothrombotic disorders
  • Factor V Leiden mutation
  • Factor II gene mutation
  • Protein C deficiency
  • Protein S deficiency
  • Antithrombin III deficiency
• Acquired thrombophilic disorders
  • Primary myeloproliferative disorders
  • Paroxysmal nocturnal hemoglobinuria
  • Antiphospholipid syndrome
  • Increased factor VIII levels
  • Thrombin activatable fibrinolysis inhibitor gene (TAFI)

Less common causes of portal vein thrombosis include:^{[12][13][3][14][15]}

• Acquired conditions:
  • Cirrhosis
  • Hepatocellular carcinoma
  • Behçet’s syndrome
  • Recent pregnancy or oral contraceptive use
  • Abdominal inflammatory lesions including infection, pancreatitis, and inflammatory bowel disease
  • Trauma
  • Philadelphia-chromosome negative chronic myeloproliferative disorders (polycythemia vera, essential thrombocythemia, idiopathic myelofibrosis, and unclassifiable myeloproliferative disorders)
• Procedures:
  • Abdominal surgery or surgical injury of the portal vein axis
  • Endoscopic sclerotherapy
  • Transjugular intrahepatic portosystemic shunt
  • Splenectomy
  • Hepatic resection
  • Pancreatic islet cell transplantation

Cardiovascular	No underlying causes
Chemical/Poisoning	No underlying causes
Dental	No underlying causes
Dermatologic	No underlying causes
Drug Side Effect	Oral contraceptive use
Ear Nose Throat	No underlying causes
Endocrine	No underlying causes
Environmental	No underlying causes
Gastroenterologic	Cirrhosis, hepatocellular carcinoma, hepatic resection
Genetic	No underlying causes
Hematologic	Factor V Leiden mutation, factor II gene mutation, protein C deficiency, protein S deficiency, antithrombin III deficiency, primary myeloproliferative disorders, paroxysmal nocturnal hemoglobinemia, antiphospholipid syndrome, increased factor VIII levels, thrombin activatable fibrinolysis inhibitor gene (TAFI), Philadelphia-chromosome negative chronic myeloproliferative disorders (polycythemia vera, essential thrombocythemia, idiopathic myelofibrosis, unclassifiable myeloproliferative disorders)
Iatrogenic	Abdominal surgery or surgical injury of the portal vein axis, transjugular intrahepatic portosystemic shunt, abdominal inflammatory lesions including infection, pancreatitis, and inflammatory bowel disease, trauma, procedures, endoscopic sclerotherapy, splenectomy, pancreatic islet cell transplantation
Infectious Disease	No underlying causes
Musculoskeletal/Orthopedic	No underlying causes
Neurologic	No underlying causes
Nutritional/Metabolic	No underlying causes
Obstetric/Gynecologic	Recent pregnancy
Oncologic	No underlying causes
Ophthalmologic	No underlying causes
Overdose/Toxicity	No underlying causes
Psychiatric	No underlying causes
Pulmonary	No underlying causes
Renal/Electrolyte	No underlying causes
Rheumatology/Immunology/Allergy	No underlying causes
Sexual	No underlying causes
Trauma	No underlying causes
Urologic	No underlying causes
Miscellaneous	No underlying causes

List the causes of the disease in alphabetical order.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farima Kahe M.D. [2]

• Portal vein thrombosis must be differentiated from other diseases that cause abdominal pain, diarrhea, and nausea and vomiting, such as: Chronic pancreatitis, Pancreatic carcinoma, Dumping syndrome, Acute appendicitis, acute diverticulitis, Infective colitis, viral hepatitis, Liver abscess, Mesenteric ischemia, and Acute ischemic colitis.

• Portal vein thrombosis must be differentiated from other diseases that cause abdominal pain, diarrhea, and nausea and vomiting, such as: Chronic pancreatitis, Pancreatic carcinoma, Dumping syndrome, Acute appendicitis, acute diverticulitis, Infective colitis, viral hepatitis, Liver abscess, Mesenteric ischemia, and Acute ischemic colitis.

Disease Clinical manifestations Diagnosis Comments Symptoms Signs Abdominal Pain Fever Rigors and chills Nausea or vomiting Jaundice Constipation Diarrhea Weight loss GI bleeding Hypo- tension Guarding Rebound Tenderness Bowel sounds Lab Findings Imaging Portal vein thrombosis Diffuse ± − + ± − + + ± − − − N Usually normal CT MRI US MRA CEUS Chronic pancreatitis Epigastric − − ± ± − + + − − − − N Increased amylase / lipase Increased stool fat content Pancreatic function test CT scan Calcification Pseudocyst Dilation of main pancreatic duct Predisposes to pancreatic cancer Pancreatic carcinoma Epigastric − − + + − + + − − − − N ↑ Alkaline phosphatase ↑ serum bilirubin ↑ gamma-glutamyl transpeptidase ↑ CA 19-9 MDCT with PET/CT MRI Skin manifestations may include: Bullous pemphigoid Cicatricial pemphigoid Migratory superficial thrombophlebitis (classic Trousseau’s syndrome) Pancreatic panniculitis Dumping syndrome Lower and then diffuse − − + − − + + − + − − Hyperactive Glucose challenge test Hydrogen breath test Upper GI series Gastric emptying study Postgastrectomy Disease Abdominal Pain Fever Rigors and chills Nausea or vomiting Jaundice Constipation Diarrhea Weight loss GI bleeding Hypo- tension Guarding Rebound Tenderness Bowel sounds Lab Findings Imaging Comments Acute appendicitis Starts in epigastrium, migrates to RLQ + Positive in pyogenic appendicitis + − − ± − − Positive in perforated appendicitis + + Hypoactive Leukocytosis Ct scan Ultrasound Positive Rovsing sign Positive Obturator sign Positive Iliopsoas sign Acute diverticulitis LLQ + ± + − + ± − + Positive in perforated diverticulitis + + Hypoactive Leukocytosis CT scan Ultrasound History of constipation Infective colitis Diffuse + − ± − − + − + Positive in fulminant colitis ± ± Hyperactive Stool culture and studies Shiga toxin in bloody diarrhea PCR CT scan Bowel wall thickening Edema Viral hepatitis RUQ + − + + − Positive in Hep A and E + − Positive in fulminant hepatitis Positive in acute + N Abnormal LFTs Viral serology US Hep A and E have fecal-oral route of transmission Hep B and C transmits via blood transfusion and sexual contact. Liver abscess RUQ + + + + − ± + − + + ± Normal or hypoactive CBC Blood cultures Abnormal liver function tests US CT Mesenteric ischemia Periumbilical Positive if bowel becomes gangrenous − + − − + + + Positive if bowel becomes gangrenous Positive if bowel becomes gangrenous − Hyperactive to absent Leukocytosis and lactic acidosis Amylase levels D-dimer CT angiography SMA or SMV thrombosis Also known as abdominal angina that worsens with eating Acute ischemic colitis Diffuse + ± + − − + + + + + + Hyperactive then absent Leukocytosis Abdominal x-ray Distension and pneumatosis CT scan Double halo appearance, thumbprinting Thickening of bowel May lead to shock Pneumonia RUQ/LUQ + + + − − ± − − + − − Normal or hypoactive ABGs Leukocytosis Pancytopenia CXR CT chest Bronchoscopy Shortness of breath Cough

Abbreviations: RUQ= Right upper quadrant of the abdomen, LUQ= Left upper quadrant, LLQ= Left lower quadrant, RLQ= Right lower quadrant, LFT= Liver function test, SIRS= Systemic inflammatory response syndrome, ERCP= Endoscopic retrograde cholangiopancreatography, IV= Intravenous, N= Normal, AMA= Anti mitochondrial antibodies, LDH= Lactate dehydrogenase, GI= Gastrointestinal, CXR= Chest X ray, IgA= Immunoglobulin A, IgG= Immunoglobulin G, IgM= Immunoglobulin M, CT= Computed tomography, PMN= Polymorphonuclear cells, ESR= Erythrocyte sedimentation rate, CRP= C-reactive protein, TS= Transferrin saturation, SF= Serum Ferritin, SMA= Superior mesenteric artery, SMV= Superior mesenteric vein, ECG= Electrocardiogram, MRA= MR angiography, CEUS=Contrast enhanced ultrasound

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farima Kahe M.D. [2]

The incidence of portal vein thrombosis in cirrhosis patients is unknown. The prevalence of portal vein thrombosis is approximately 5000-10,000 per 100,000 in overall cases of portal hypertension in developed counties and 40,000 per 100,000 in developing countries. The overall mortality rate of portal vein thrombosis is less than 10% except for patients with malignancy or cirrhosis. Patients of all age groups may develop portal vein thrombosis. There is no racial predilection to portal vein thrombosis. Portal vein thrombosis affects men and women equally.

• The incidence of portal vein thrombosis in cirrhosis patients is unknown.^[1]

• The prevalence of portal vein thrombosis is approximately 5000-10,000 per 100,000 in overall cases of portal hypertension in developed counties and 40,000 per 100,000 in developing countries.^[1][2]
• The prevalence of portal vein thrombosis is less than 1000 per 100,000 in patients with compensated cirrhosis, but is 8000-25000 per 100,000 in patients who are candidates for liver transplantation.^[3][4][5]

• The overall mortality rate of portal vein thrombosis is less than 10% except for patients with malignancy or cirrhosis.^[1]
• The mortality rate of portal vein thrombosis in patients with malignancy or cirrhosis about 26%.^[6]
• In patients with chronic portal vein thrombosis one-year survival alters from 80% to 95%, and 3-year survival varies from 75% to 90%.^[7]

• Patients of all age groups may develop portal vein thrombosis.^[1]
• The incidence of portal vein thrombosis increases with age and it commonly affects individuals 66-70 years in men and 69-74 years in women.^[2]

• There is no racial predilection to portal vein thrombosis.

• Portal vein thrombosis affects men and women equally.^[2]

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farima Kahe M.D. [2]

Common risk factors in the development of portal vein thrombosis include cirrhosis, pancreatitis, duodenal ulcer, cholecystitis, Crohn’s disease, ulcerative colitis, cholecystectomy, diverticulitis, and appendicitis. Less common risk factors in the development of portal vein thrombosis include oral contraceptives, pregnancy or puerperium, and hyperhomocysteinemia.

• Common risk factors in the development of portal vein thrombosis include: Hepatic cancer, cirrhosis, pancreatitis, duodenal ulcer, cholecystitis, Crohn’s disease, ulcerative colitis, and cholecystectomy.

• Common risk factors in the development of portal vein thrombosis include:^{[1][2][3][4][5][6]}
  • Cirrhosis
  • Focal inflammatory lesions
  • Neonatal omphalitis, umbilical vein catheterization
  • Diverticulitis
  • Appendicitis
  • Pancreatitis
  • Duodenal ulcer
  • Cholecystitis
  • Tuberculous lymphadenitis
  • Crohn’s disease, ulcerative colitis
  • Cytomegalovirus hepatitis
  • Injury to the portal venous system
  • Splenectomy
  • Colectomy and gastrectomy
  • Cholecystectomy
  • Liver transplantation
  • Abdominal trauma
  • Surgical portosystemic shunting
  • Iatrogenic (fine needle aspiration of abdominal masses etc.)
  • Preserved liver function with precipitating factors (splenectomy, surgical portosystemic shunting, TIPS dysfunction, thrombophilia)
  • Advanced disease in the absence of obvious precipitating factors

• Less common risk factors in the development of portal vein thrombosis include:^[5][7][8]
  • Oral contraceptives
  • Pregnancy or puerperium
  • Hyperhomocysteinemia
  • Malignancy

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farima Kahe M.D. [2]

There is insufficient evidence to recommend routine screening for portal vein thrombosis.

There is insufficient evidence to recommend routine screening for portal vein thrombosis.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farima Kahe M.D. [2]

If left untreated, patients with portal vein thrombosis may progress to develop portal cavernoma, gastric or esophageal varices/bleeding, hepatic encephalopathy, splenomegaly, portal biliopathy, and cholangiopathy. Depending on the extent of the model for end-stage liver disease score at the time of diagnosis, the prognosis may vary. However, the prognosis is generally regarded as good.

• There is usually subclinical prothrombotic state in about in about 72% of idiopathic portal vein thrombosis.
• If left untreated, patients with portal vein thrombosis may progress to develop portal cavernoma, gastric or esophageal varices/bleeding, hepatic encephalopathy, splenomegaly, portal biliopathy, and cholangiopathy.^[1]

• Common complications of portal vein thrombosis include:^{[2][3][4][5][6]}
  • Portal cavernoma
  • Gastric or esophageal varices/bleeding
  • Hepatic encephalopathy
  • Portal biliopathy or cholangiopathy
  • Thrombocytopenia
  • Splenomegaly
  • Ascites
  • Peritonitis
  • Hypoxia
  • Pulmonary artery hypertension
  • Portal hypertensive gastropathy

• The 1 year mortality rate of patients with chronic portal vein thrombosis is approximately 80%-95% and the 3 year mortality rate of patients with chronic portal vein thrombosis is approximately 75%-90%.^[7][8][9]
• Mortality in patients with cancer or cirrhosis in one year is 26% and those without cancer or cirrhosis is 8%.^[3]
• Depending on the extent of the model for end-stage liver disease score at the time of diagnosis, the prognosis may vary. However, the prognosis is generally regarded as good.^[10]
• Morbidity and mortality is associated with following factors:^[7]
  • Increasing age
  • Recurrent thrombosis
  • Portal cholangiopathy
  • Progression of the underlying myeloproliferative disease or its transformation into acute leukemia

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