Fact-sheet: Portal and/or mesenteric vein thrombosis
Updated on 10/07/2017 at 6:32 AM
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Definition
Obstruction of the portal vein and/or superior mesenteric vein related to the formation of a partial or complete endoluminal thrombus, which may extend downstream to the intrahepatic portal branches or upstream to the splanchnic vessels (splenic vein, superior mesenteric vein), of thrombotic or tumoral origin.
Clinical features
Symptom severity depends on the extent of thrombosis within the portal system and the speed of onset of thrombosis:
- Asymptomatic
- Nonspecific abdominal pain
- Diarrhea
- Nausea, vomiting
- Peritoneal signs (guarding)
- Infectious syndrome in cases of pylephlebitis (fever, chills)
Laboratory findings
- Elevated CRP
- Neutrophilic leukocytosis
- Late lactic acidosis
Ultrasound
- Detection of intravascular thrombus (hypoechoic then hyperechoic) with widening of the portal vein caliber - Absence of flow recorded on pulsed Doppler with turbulence upstream of the thrombosis - Absence of filling on color Doppler Indirect signs: CHRONIC THROMBOSIS - Portal cavernoma: peri-choledochal and peri-cholecystic collateral venous network visible at the hepatic hilum - Portal hypertension: dilatation of the portal trunk, loss of respiratory variation, splenomegaly, dilatation of the gastric vein, splenorenal shunts
CT
Spontaneous intravascular hyperdensity in cases of recent thrombus (less than 10 days), which subsequently becomes isodense then hypodense.
After contrast injection at the portal phase:
- Intravascular hypodense filling defect located in the portal vein and/or superior mesenteric vein
- Extension of the thrombosis +++, increased caliber of the thrombosed vessel
- Hepatic perfusion abnormalities corresponding to the obstructed portal territory, hypervascularization of the obstructed territory during the arterial phase (reactive perfusion) subsequently appearing isodense during the portal phase
- Look for signs of mesenteric venous ischemia
Management
Prolonged anticoagulation for at least 6 months in the absence of a prothrombotic disorder, and lifelong otherwise