What management strategies should be considered besides heparin (anticoagulant) infusion for a patient with a pulmonary embolism (PE) and a nonocclusive thrombus within the right common iliac artery extending to the infrarenal inferior vena cava (IVC)?

Management of PE with Nonocclusive Thrombus in Right Common Iliac Artery Extending to Infrarenal IVC

For a patient with pulmonary embolism (PE) and nonocclusive thrombus extending from the right common iliac artery to the infrarenal IVC, an IVC filter placement is strongly recommended in addition to heparin infusion to prevent further potentially fatal pulmonary emboli. 1

Immediate Management Steps

1. Continue Unfractionated Heparin (UFH) infusion

   • Maintain UFH infusion with target aPTT of 1.5-2.5 times control
   • UFH is preferred over LMWH in this scenario due to extensive clot burden and potential need for rapid reversal if intervention becomes necessary 1
   • Initial dosing: 80 units/kg bolus followed by 18 units/kg/hour infusion 1

2. Urgent IVC filter placement

   • Indicated due to extensive thrombus in the IVC and iliac artery that could lead to further PE 2, 1
   • Retrievable filter preferred over permanent filter 2
   • Filter should be placed in the infrarenal portion of the IVC unless thrombus extends to renal veins 2, 3
   • Filter retrieval should be planned once anticoagulation is therapeutic and clot burden has decreased 2

3. Urgent Pulmonary Embolism Response Team (PERT) consultation

   • Multidisciplinary team including cardiology, vascular surgery, interventional radiology, and hematology should evaluate the patient 1
   • This complex case with both PE and iliocaval thrombosis requires specialized expertise

Additional Workup

1. Hemodynamic assessment

   • Continuous monitoring of vital signs and oxygen saturation
   • Consider ICU admission if any signs of hemodynamic instability 1

2. Echocardiography

   • To evaluate right ventricular function and strain 1
   • Helps risk stratify patient (massive vs. submassive vs. low-risk PE)

3. Thrombophilia workup

   • Complete blood count with platelet monitoring
   • Coagulation profile and D-dimer levels
   • Consider testing for Factor V Leiden, Prothrombin gene mutation, Protein C, Protein S, and Antithrombin III levels 1
   • Antiphospholipid antibodies and homocysteine levels

4. Cancer screening

   • Unprovoked extensive thrombosis should prompt age-appropriate cancer screening
   • Consider CT chest/abdomen/pelvis if not already performed 1
   • Tumor markers if clinically indicated

Interventional Considerations

1. Catheter-directed therapies

   • Consider if patient has:
     • Massive PE with hemodynamic instability
     • Submassive PE with evidence of right heart strain and extensive clot burden 2
   • Options include:
     • Catheter-directed thrombolysis (if no contraindications to thrombolysis)
     • Rheolytic thrombectomy
     • Suction or rotational thrombectomy 2

2. Surgical embolectomy

   • Consider for massive PE with contraindications to thrombolysis or failed thrombolysis 2

Long-term Management

1. Transition to oral anticoagulation

   • After at least 5 days of heparin therapy and when clinically stable
   • Direct Oral Anticoagulants (DOACs) preferred over vitamin K antagonists for most patients 1
   • Specific DOAC options:
     • Apixaban: 10 mg BID for 7 days, then 5 mg BID
     • Rivaroxaban: 15 mg BID for 21 days, then 20 mg daily 1

2. Duration of anticoagulation

   • Extended anticoagulation (>3 months) recommended due to extensive clot burden and involvement of both pulmonary and systemic circulation 1
   • Reassessment at 3-6 months to evaluate for:
     • Resolution of thrombi
     • Development of chronic thromboembolic pulmonary hypertension
     • Need for continued anticoagulation 1

Common Pitfalls to Avoid

• Delaying IVC filter placement in patients with iliocaval thrombosis and PE 1
• Inadequate thrombophilia workup in patients with extensive, unprovoked thrombosis 1
• Premature discontinuation of anticoagulation in patients with extensive clot burden 1
• Failure to retrieve retrievable IVC filters once anticoagulation is therapeutic and risk of PE has decreased 2
• Not considering suprarenal filter placement if thrombus extends to or above renal veins 3

Follow-up Plan

• Follow-up imaging at 3-6 months to assess for resolution of thrombi
• Evaluation for chronic thromboembolic pulmonary hypertension
• Regular reassessment of the risk-benefit ratio of continued anticoagulation 1
• Plan for IVC filter retrieval if retrievable filter was placed 2