Interventional Radiology Treatment for Pulmonary Embolism
For patients requiring interventional radiology (IR) treatment for pulmonary embolism, catheter-directed thrombolysis should be considered as first-line therapy for intermediate-risk PE, while surgical embolectomy or catheter-directed treatment should be considered for high-risk PE patients who deteriorate hemodynamically. 1
Risk Stratification and Treatment Selection
High-Risk PE (Massive PE with Shock/Hypotension)
- First-line treatment: Systemic thrombolysis (50 mg bolus of alteplase) 2
- Alternative options when systemic thrombolysis fails or is contraindicated:
Intermediate-Risk PE (Normotensive with RV Dysfunction)
- Preferred option: Catheter-directed thrombolysis (CDT)
- Associated with lower in-hospital mortality compared to systemic thrombolysis (OR 0.55) 3
- Delivers lower total dose of thrombolytic (typically 20-24 mg alteplase, approximately one-fourth of systemic dose) 1
- Reduces right heart strain and lowers pulmonary artery pressures more quickly than anticoagulation alone 4
Catheter-Directed Interventions
Catheter-Directed Thrombolysis (CDT)
- Technique: Direct delivery of thrombolytic agent into pulmonary arteries via multi-sidehole infusion catheter 1
- Advantages:
- Similar or improved effectiveness compared to systemic thrombolysis
- Lower bleeding risk than systemic thrombolysis
- Early RV recovery comparable to standard-dose systemic thrombolysis 1
- FDA-cleared device: EKOSonic endovascular system (ultrasound-assisted thrombolysis) 1
Catheter-Based Embolectomy
- FDA-cleared device: FlowTriever embolectomy device 1
- Indications:
- Patients with contraindications to thrombolysis
- Failed thrombolytic therapy
- Severe hemodynamic compromise requiring rapid thrombus removal
Other Catheter-Based Techniques
- Manual aspiration thrombectomy: Using large sheath or guide catheter for thrombus extraction 1
- Rheolytic thrombectomy: Using AngioJet catheter (not recommended as initial treatment due to safety concerns) 1
- Percutaneous mechanical thrombectomy: Various devices for thrombus fragmentation and removal 1
Anticoagulation Management During IR Procedures
- Preferred agent: Unfractionated heparin (UFH) during the acute phase when mechanical thrombectomy is planned 2
- Initial IV bolus: 80 U/kg
- Continuous infusion: 18 U/kg/h
- Target aPTT: 1.5-2.5 times control
Procedural Considerations
- Clinical success rate: Approximately 87% (stabilization of hemodynamic parameters, resolution of hypoxia, and survival to discharge) 1
- Potential complications (reported in ~2% of interventions):
- Death from worsening RV failure
- Distal embolization
- Pulmonary artery perforation with lung hemorrhage
- Systemic bleeding
- Pericardial tamponade
- Heart block or bradycardia
- Hemolysis
- Contrast-induced nephropathy
- Puncture-related complications 1
Post-Procedural Care
- Anticoagulation: Continue therapeutic anticoagulation after procedure
- Follow-up: Routine clinical evaluation at 3-6 months after acute PE (Class I recommendation) 1
- Monitoring: Assess for signs of chronic thromboembolic pulmonary hypertension (CTEPH)
- Integrated care model: Recommended to ensure optimal transition from hospital to ambulatory care (Class I recommendation) 1
Special Considerations
- Multidisciplinary approach: Set-up of multidisciplinary teams (Pulmonary Embolism Response Team) for management of high-risk and selected cases of intermediate-risk PE is recommended (Class IIa) 1
- Pregnancy: Thrombolysis or surgical embolectomy should be considered for pregnant women with high-risk PE (Class IIa) 1
- Cancer patients: Higher bleeding risk with thrombolysis; individualized approach needed
The evidence supporting catheter-directed interventions is less robust than for systemic thrombolysis, but these techniques offer promising options for patients with contraindications to systemic thrombolysis or those at high risk of bleeding complications.