Pathophysiology
1) thrombosis of portal vein, causing mechanical obstruction 2) obstruction causes flow backup and increased pressure in distal portal vein and splenic vein (with splenomegaly) 3) collateral vascular channels open between portal vein and systemic system (varices develop in porta hepatis, umbilical, rectal, esophagus, and jejunum)
Signs and Symptoms
1) splenomegaly 2) ascites initially occurs but usually resolves 3) portal hypertension and hypertensive gastropathy 4) GI hemorrhage (usually late sequelae) 5) abdominal pain (most common presenting symptom) 6) jaundice
Characteristic Test Findings
Laboratory – 1) increased serum bilirubin Radiology – 2) echogenic thrombi and hepatofugal flow on Doppler ultrasound
Histology/Gross Pathology
1) thrombosis eventually forms into collagenous plug, with new channels formed in it (process takes weeks to months) 2) found in 15% of patients undergoing liver transplantation
Associated Conditions
1) most common cause in children is sepsis, particularly umbilical sepsis 2) cirrhosis 3) splenectomy 4) neoplasm 5) hypercoagulable states 6) pregnancy 7) sickle cell 8) polycythemia vera 9) inflammatory diseases (Behcet’s, inflammatory disease)
Treatment
1) sclerotherapy and/or banding of varices to initially control bleeding 2) mesocaval or splenorenal shunts
Tips for USMLE
transjugular intrahepatic portosystemic shunt (TIPS) procedure is not effective in portal vein thrombosis
Leave a Reply