Treatment

• Evaluate and treat concomitant pulmonary embolism and stabilize the patient as needed.

• Assess bleeding risk on anticoagulation for VTE.

• Initiate anticoagulation therapy based on the extent and etiology of DVT

  • Expectant management: serial venous ultrasound without anticoagulation

  • Primary treatment: anticoagulation for 3–6 months in patients not being managed expectantly

  • Secondary prevention (of recurrent DVT): extended anticoagulation after completion of primary treatment; should be individualized (e.g., patients with chronic risk factors)

• Treat the underlying cause, if feasible.

Primary treatment is the duration of anticoagulation required to treat an acute DVT and involves an initial transient period of parenteral anticoagulation (bridging anticoagulation) followed by long-term (typically 3–6 months) oral anticoagulation.

• Bridging anticoagulation for VKAs: parenteral anticoagulation overlaps with oral anticoagulation until therapeutic INR is maintained.

• Parenteral lead-in therapy for dabigatran and edoxaban: These DOACs are started after completion of lead-in parenteral therapy without overlapping.

• Low molecular weight heparin (LMWH) (e.g., enoxaparin) : preferred in pregnant women and patients with normal renal function, liver disease, or active cancer

• Fondaparinux (factor Xa inhibitor) : preferred in patients with a history of heparin-induced thrombocytopenia

• Unfractionated heparin (UFH) bolus plus infusion : preferred in patients with renal failure, inadequate subcutaneous absorption (i.e., morbid obesity), and those at a high risk of bleeding

LMWH can be administered subcutaneously, guarantees a more rapid onset of action, and has a longer duration of effect than unfractionated heparin. Monitoring aPTT is not necessary.

Fondaparinux has a more rapid onset of action than UFH and does not require laboratory monitoring. The choice between fondaparinux and LMWH depends on cost and availability.

Treatment with heparin (especially UFH) can cause heparin-induced thrombocytopenia. For early detection, perform regular CBCs.

All patients with DVT who cannot be managed expectantly and have no contraindications to anticoagulation.

Direct oral anticoagulants (DOACs): first-line therapy in nonpregnant patients (preferred over VKAs)

• Regular monitoring of coagulation parameters is not required.

• Associated with a lower risk of major bleeding

• Options (any of the following)

  • Direct factor Xa inhibitors: rivaroxaban, apixaban, or edoxaban

  • Direct thrombin inhibitors: dabigatran

• Vitamin K antagonists (VKAs): warfarin

  • Bridging anticoagulation required

    • Initiate simultaneously with initial parenteral anticoagulation

    • Continue parenteral anticoagulation with warfarin for at least 5 days and until therapeutic INR has been maintained for 48 hours

  • Second-line therapy in nonpregnant patients

  • Requires dose adjustment to maintain a target INR of 2–3

• LMWH: preferred in pregnant women and in patients with active cancer , e.g., enoxaparin

it takes 5–7 days for warfarin to attain its full anticoagulant effect

Initial parenteral anticoagulation (with LMWH, fondaparinux, or UFH) should be initiated at the same time as warfarin and before dabigatran and edoxaban. Initial parenteral anticoagulation is not required for patients receiving rivaroxaban or apixaban.

The decision to extend anticoagulation indefinitely after primary treatment is typically made after balancing the risk of recurrent DVT (e.g., for patients with chronic risk factors) with the bleeding risk on anticoagulation for VTE.

• Options

  • First episode of DVT: Continue the same anticoagulant used for long-term anticoagulation (e.g., warfarin, or DOACs).

  • Recurrent DVT while appropriately anticoagulated

    • On an oral anticoagulant: Switch to LMWH (e.g., enoxaparin).

    • On LMWH: Increase LMWH dose

• Monitoring: Reassess bleeding risk periodically (e.g., annually).

Extended anticoagulation is usually not required in patients with a provoked DVT due to a transient or reversible risk factor (e.g., surgery, intravascular catheter).

These interventions are not routinely indicated.

• Catheter-directed thrombolysis (CDT)

  • Indications

    • Limb-threatening ischemia (phlegmasia cerulea dolens)

    • Consider in acute (< 14 days) iliofemoral DVT in patients with low risk of bleeding and life expectancy ≥ 1 year

  • Agents: streptokinase, urokinase, rtPA

• Thrombectomy

  • Indications: same as for CDT; consider as an alternative to CDT in patients with absolute contraindications to thrombolysis [51]

• Inferior vena cava filter (Greenfield filter)

  • Indications

    • DVT with a high risk of PE (e.g., proximal DVT) in patients with contraindications for anticoagulation, absolute contraindications to thrombolysis, and contraindications to thrombectomy (e.g., patients with active bleeding, recent major surgery, recent intracranial hemorrhage)

    • Consider in anticoagulated patients with severe PE to prevent subsequent PE.

• Encourage early ambulation; minimize bedrest.

• Graduated compression stockings

  • Consider only for symptomatic relief (i.e., reduction of edema and pain)

  • No longer routinely recommended to prevent postthrombotic syndrome.

• Analgesics for pain relief: avoid NSAIDs if the patient is receiving anticoagulation or thrombolytics.

• Delay any elective surgery for at least 3 months after initiation of anticoagulation therapy.