CT Case 058

These CT images are taken with contrast in the portal venous phase. There is acute thrombosis of the portal vein and superior mesenteric vein.

On CT, acute thrombus is differentiated from chronic thrombosis by the presence of a dilated vein with surrounding fat stranding due to reactive inflammation as we see in this case.

Another distinguishing feature is the presence of venous collaterals which will only be seen in cases of chronic thrombus.

This patient also has a small non-occlusive (not filling the entire lumen) thrombus in the infrarenal IVC.

The digital subtraction venography image shows the same thrombi, seen as irregular filling defects in the portal and superior mesenteric vein and no contrast opacification of the proximal SMV.

Reminder of the anatomy of the venous system

Portal vein thrombosis is a life-threatening condition. Patients often present with non-specific abdominal pain or if extensive with ischaemic bowel.

The cause can be categorised depending on which branch of Virchow’s triad has been disrupted

Reduced flow /portal hypertension

• Cirrhosis
• Hepatobiliary malignancies (HCC, pancreatic, cholangiocarcinoma)

Hypercoagulable states;

• Inherited thrombophilia
• Malignancy
• Dehydration
• Oral contraceptive pill
• Pregnancy
• Trauma

Endothelial disturbance

• Local infection or inflammation;  eg pancreatitis, cholangitis

This case demonstrates portal vein and SMV thrombosis which resulted in mesenteric venous congestion and eventually ischemia of the small bowel.

The goals in treating portal vein thrombosis are to re-establish portal vein flow, prevent secondary infection which results from bowel ischaemia and to identify and treat any underlying precipitant.

This patient was managed initially with IV heparinisation and prophylactic IV antibiotics.

Unfortunately, despite treatment her condition deteriorated. Due to extension of the thrombus management was escalated to include catheter directed thrombolysis, multiple attempts of IR guided thrombectomy, and eventually systemic thrombolysis.

Unfortunately, this patient developed bowel ischaemia with resultant septic shock and passed away seven days after her presentation to hospital.

• Hartung MP. Abdominal CT: Phases. LITFL
• Hartung MP. Abdominal CT: Liver. LITFL
• Hartung MP. Abdominal CT: abdominal veins. LITFL
• Simonetto DA, Singal AK, Garcia-Tsao G, Caldwell SH, Ahn J, Kamath PS. ACG Clinical Guideline: Disorders of the Hepatic and Mesenteric Circulation. Am J Gastroenterol. 2020 Jan;115(1):18-40.