Diagnostic Approach for Portal Vein Thrombosis

Initial Diagnostic Workup

Doppler ultrasound should be used as the first-line investigation for diagnosing portal vein thrombosis, looking specifically for absence of flow within the portal vein, hyperechoic thrombus in the portal lumen, and flow reversal within the portal system, which is 100% specific for clinically significant portal hypertension 1, 2
Contrast-enhanced CT scan should be performed to confirm the diagnosis, assess extension of thrombus to mesenteric veins and arches, identify presence of local factors, and evaluate for signs of bowel congestion and ischemia 1

Recent thrombus can be identified by clinical presentation with abdominal pain and/or systemic inflammatory response syndrome, spontaneous hyperdense clot in portal vein lumen on non-enhanced CT, and absence of portal cavernoma 1
Assessment should determine whether thrombosis is partial or complete, which vessels are involved, and signs of intestinal ischemia, such as persistent severe abdominal pain despite anticoagulation, organ failure, massive ascites, or rectal bleeding 1, 3

Liver stiffness measurement by transient elastography with a cut-off of >20-25 kPa can help diagnose clinically significant portal hypertension in patients with compensated advanced chronic liver disease 2
Combined parameters such as LSPS score (liver stiffness × spleen size/platelet count) can improve diagnostic accuracy, with a score >2.06 having 90% specificity 2

Follow-up CT scan should be performed at 6-12 months to assess recanalization of the portal venous system 1
Doppler ultrasound should be performed early and then every 6 months to detect thrombosis or TIPS dysfunction in patients with Budd-Chiari syndrome or chronic portal vein thrombosis 4, 5
Screening for gastroesophageal varices is recommended in unrecanalised patients 1