Pulmonary Embolus Thrombectomy
Acute pulmonary embolism (PE) can present in a variety of ways, from an incidental asymptomatic pick up on imaging, to a huge saddle embolus presenting an imminent threat to life.
Risk stratification of acute PE can help guide treatment and takes into considering haemodynamic status, imaging and biochemical markers of right heart strain and comorbidities.
Treatment options broadly vary between systemic and locoregional options:
- Systemic anticoagulation can be provided, on an outpatient basis, in stable patients while systemic thrombolysis will require close monitoring in an HDU/ITU setting.
- Locoregional therapies include catheter-directed thrombolysis (CDT) and thrombectomy. CDT delivers a smaller dose of lytic agent directly to the pulmonary vascular bed and requires HDU/ITU support. Thrombectomy provides a valuable treatment option in patients in whom anticoagulation is strictly contraindicated. Thrombectomy may be required as a rescue therapy in an unstable patient and can provide immediate relief of right heart strain.
Operator Considerations
Indications: Intermediate-high or high-risk PE and/or contraindication to anticoagulation or thrombolysis.
Planning: Clinical risk stratification. CTPA to determine clot distribution. Review prior imaging (US or CT), if available, to determine whether groin access is feasible. Rule out ipsilateral iliofemoral DVT.
Preparation: Thrombectomy catheters can vary in size reaching up to 24 Fr and there is a risk of cardiac injury in traversing the right heart. Full anticoagulation is required when using the large bore aspiration catheters.
Duration: 45-90 minutes.
Position: Supine.
Access: Common femoral vein. The smaller thrombectomy catheters may permit the use of the right internal jugular vein but this increases procedural difficulty due to the additional bend the catheter must take traversing the right heart
Technique: Percutaneous access, traverse the right heart with catheter and guidewire, perform pulmonary angiograms. Cross target thrombus with the wire, position the thrombectomy catheter against the thrombus and aspirate. Repeat until improvement in haemodynamic status or diminishing yield.
Complications: Cardiac injury, pulmonary artery injury, bleeding from access site. Due to the underlying haemodynamic instability of this group of patients, acute deterioration to the point of arrest should be anticipated and prepared for.
Post-procedure instructions: 2-4 hours flat (as tolerated) bed rest depending on the size of groin access sheath and use of closure device.