Intermediate-risk superficial vein thrombosis
An isolated superficial vein thrombosis is at an intermediate risk of extension to a proximal DVT or PE if it is located more than 3 cm from the deep venous system and is longer than 5 cm.
Anticoagulant therapy can be used for patients with an isolated superficial vein thrombosis that is at an intermediate risk of extension; however, there is debate about the most appropriate dose of anticoagulant. Depending on clinician and patient preference, suitable regimens areStevens, 2021Thrombosis Canada, 2021:
1dalteparin (CrCl 30 mL/min or more) 5000 units to 10 000 units subcutaneously, once daily for 45 days1 dalteparin dalteparin dalteparin
OR
1enoxaparin enoxaparin enoxaparin enoxaparin
CrCl 30 mL/min or more: 40 mg to 80 mg subcutaneously, once daily for 45 days2
CrCl less than 30 mL/min: 20 mg subcutaneously, once daily for 45 days
OR
1fondaparinux (CrCl more than 50 mL/min) 2.5 mg subcutaneously, once daily for 45 days fondaparinux fondaparinux fondaparinux
OR
1rivaroxaban 10 mg orally (CrCl 30 mL/min or more), once daily for 45 days3Beyer-Westendorf, 2017. rivaroxaban rivaroxaban rivaroxaban
If dalteparin or rivaroxaban are required for a patient with a CrCl of less than 30 mL/min, seek advice from a specialist. If fondaparinux is required for a patient with a CrCl of less than 50 mL/min, seek advice from a specialist. Fondaparinux should be used with caution in patients aged 75 years or older, or in those who weigh less than 50 kg, as the clinical trials showed an increased bleeding risk in these groups.