What are the signs and symptoms of a portal venous thrombus?

Signs and Symptoms of Portal Venous Thrombosis

Portal venous thrombosis (PVT) typically presents with abdominal pain, nausea, vomiting, anorexia, and hepatomegaly in acute cases, while chronic PVT may be asymptomatic due to collateral formation or present with signs of portal hypertension including splenomegaly and esophageal varices. 1

Acute Portal Vein Thrombosis Presentation

Acute PVT is characterized by symptoms present for 8 weeks or less without portal cavernoma formation. Common clinical manifestations include:

• Abdominal pain (most common symptom) 1
• Mid-abdominal colicky pain 1
• Abdominal distention 1
• Nausea and vomiting 1
• Anorexia 1
• Diarrhea 1
• Hepatomegaly 1
• Ascites 1
• Fever 1

Warning Signs of Complications

• Rebound tenderness, guarding, and fever may indicate progression to bowel infarction 1
• Intestinal infarction occurs in 30-45% of patients with mesenteric vein thrombosis at diagnosis 1
• Up to 19% of intestinal infarctions can be fatal 1

Chronic Portal Vein Thrombosis Presentation

Chronic PVT is defined by symptoms present for more than 8 weeks with evidence of portal cavernoma (collateral formation around portal vein). Presentation may include:

• Often asymptomatic due to formation of collateral veins 1, 2
• Abdominal pain (may be postprandial) 1
• Nausea and vomiting 1
• Anorexia 1
• Lower-extremity edema 1
• Splenomegaly 1, 2
• Weight loss 1
• Abdominal distension 1

Signs of Portal Hypertension

• Splenomegaly 1, 2
• Esophageal varices 1, 2
• Complications from bleeding varices 1
• Portal cavernoma on imaging (cavernous transformation showing network of collaterals) 1, 2

Diagnostic Findings

Imaging Findings

• Absence of blood flow or presence of thrombus in splanchnic veins 1
• Portal cavernoma indicates chronic thrombosis 1, 2
• Doppler ultrasonography shows:
  • Absence of flow in portal vein 1, 2
  • Flow velocity <30 cm/s (normal is approximately 30 cm/s) 2
  • Dilated left and short gastric veins 2
  • Portosystemic collaterals 2
  • Reversal of portal flow direction 2

Laboratory Abnormalities

• Often non-specific 3
• Consider testing for:
  • JAK2V617F mutation (detected in 20-40% of PVT patients without overt myeloproliferative disorders) 1
  • Paroxysmal nocturnal hemoglobinuria (PNH) 1
  • Thrombophilia workup 1, 4

Risk Factors in Cancer Patients

PVT is particularly concerning in cancer patients, as it is an independent predictor of decreased survival, especially in hepatocellular carcinoma where it occurs in 20-30% of patients at diagnosis 1. Risk factors specific to cancer patients include:

• Recent abdominal surgery (e.g., splenectomy) 1
• Abdominal mass 1
• Pancreatitis 1
• Myeloproliferative disorders 1
• Cirrhosis 1
• Paroxysmal nocturnal hemoglobinuria 1
• JAK2V617F mutation 1
• Exogenous estrogen use 1

Clinical Pitfalls and Caveats

1. PVT may be an incidental finding on imaging with no symptoms 1, 2
2. Chronic PVT is often missed due to asymptomatic presentation from collateral formation 1, 2
3. Mesenteric vein involvement significantly increases mortality risk 1
4. Thrombosis in multiple segments has significantly decreased 10-year survival compared to isolated segment thrombosis (48% vs. 68%) 1
5. Early diagnosis is crucial to prevent complications like variceal bleeding and intestinal ischemia 3
6. Consider PVT in young patients with unexplained abdominal pain, especially with risk factors for thrombophilia 4

Early recognition of these signs and symptoms is critical for timely intervention to prevent serious complications including intestinal infarction and variceal bleeding.