Current concepts in the management of non-cirrhotic non-malignant portal vein thrombosis

Table 1 Risk factors for non-cirrhotic non-malignant portal vein thrombosis, %

Risk factor	Prevalence	Investigations
Systemic
Myeloproliferative neoplasm	21-32	JAK2 V617F mutation testing
		CALR mutation testing if platelets > 200 × 109/L and spleen ≥ 16 cm
		Consider bone marrow biopsy
Acquired thrombophilia
Antiphospholipid syndrome	6	Lupus anticoagulant, anti-cardiolipin and anti-b2 glycoprotein-I antibodies (2 positive samples 12 wk apart)
Paroxysmal nocturnal haemoglobinuria	0.30	Flow cytometry (CD55 and CD59 deficient cells)
Inherited thrombophilia
Prothrombin G20210A gene mutation	6-7	Prothrombin G20210A mutation testing
Factor V Leiden	3-7	Factor V Leiden mutation testing
Protein C deficiency	5-6	Protein C levels1
Protein S deficiency	3-5	Protein S levels1
Antithrombin deficiency	1-4	Antithrombin levels1
Hormonal (recent pregnancy/oral contraceptive)	16	Medical history
Other systemic disease e.g., connective tissue disease, sarcoidosis, vasculitis, acute CMV infection	3	Variable
Obesity		Medical history
Local
Abdominal trauma/surgery	14	Medical history/cross-sectional imaging
Inflammatory abdominal conditions e.g., pancreatitis, biliary infection, appendicitis, inflammatory bowel disease	11	Variable
No cause identified	35-42

¹Interpret with caution in liver impairment.

Risk factors for non-cirrhotic non-malignant portal vein thrombosis[1,19]. CMV: Cytomegalovirus; CALR: Calreticulin.

Table 2 Recommended standardized nomenclature for portal vein thrombosis description

Feature	Definition
Time course
Recent	Portal vein thrombus presumed to be present for < 6 months
Chronic	Portal vein thrombus present or persistent for > 6 months
Percentage occlusion of main portal vein
Completely occlusive	No persistent lumen
Partially occlusive	Clot obstructing > 50% of original vessel lumen
Minimally occlusive	Clot obstructing < 50% of original vessel lumen
Cavernous transformation	Gross porto-portal collaterals without original portal vein seen
Response to treatment or interval change
Progressive	Thrombus increases in size or progresses to more complete occlusion
Stable	No appreciable change in size or occlusion
Regressive	Thrombus decreases in size or degree of occlusion

Recommended standardized nomenclature for portal vein thrombosis description[26].

Table 3 Comparison of commonly used anticoagulants

Considerations	Anticoagulant
	Low molecular weight heparin	Vitamin K antagonist	Apixaban	Dabigatran	Edoxaban	Rivaroxaban
Standard dose	Parenteral. Weight-based dosing	Dosed according to INR. Usual target 2-3	10 mg daily for 7 d then 5 mg twice daily	150 mg twice daily after 5 d parenteral anticoagulant	60 mg once daily after 5 d parenteral anticoagulant	15 mg twice daily for 21 d then 20 mg once daily
Age	-	-	-	75-79 years reduce dose to 110-150 mg twice daily. ≥ 80 years reduce dose to 110 mg twice daily	-	-
Weight	Weight-based dosing	-	-	-	< 61 kg reduce dose to 30 mg once daily	-
Renal impairment	Use with caution if CrCl < 30 mL/min. Avoid enoxaparin if CrCl < 15 mL/min	-	Avoid if CrCl < 15 mL/min. Use with caution if CrCl 15-29 mL/min	Avoid if CrCl < 30 mL/min. Consider dose reduction to 110-150 mg twice daily if CrCl 30-50 mL/min	Avoid if CrCl < 15 mL/min. Reduce dose to 30 mg once daily if CrCl 15-50 mL/min	Avoid if CrCl < 15 mL/min. Consider dose reduction to 15 mg daily if CrCl 15-49 mL/min
Pregnancy	Safe	Avoid (especially 1st/3rd trimester)	Avoid	Avoid	Avoid	Avoid
Breastfeeding	Safe	Safe	Avoid	Avoid	Avoid	Avoid
Reversal agent	Protamine sulphate (partially effective)	Vitamin K, prothrombin complex concentrate	Andexanet alfa	Idarucizumab	None	Andexanet alfa
Other		Multiple drug and food interactions	DOAC contraindicated in anti-phospholipid syndrome

Comparison of commonly used anticoagulants[84]. DOAC: Direct oral anticoagulants.