Is a patent foramen ovale (PFO) a contraindication to thrombectomy?

Is a Patent Foramen Ovale a Contraindication to Thrombectomy?

No, a patent foramen ovale (PFO) is not a contraindication to thrombectomy; rather, it is an indication for more aggressive intervention, including catheter-based or surgical thrombectomy, particularly in patients with massive or submassive pulmonary embolism. 1

PFO as a High-Risk Feature, Not a Contraindication

The presence of a PFO in patients with pulmonary embolism significantly increases mortality and morbidity risk, making it a marker for aggressive treatment rather than a reason to withhold intervention:

• PFO increases the relative risk of death by 2.4-fold, ischemic stroke by 5.9-fold, and peripheral arterial embolism by 15-fold in patients with massive PE 1
• Patients with PFO and PE have a 5.2-fold increased risk of complicated hospital course 1
• Silent brain infarction occurs in 33% of PE patients with PFO versus only 2% without PFO 1

Treatment Algorithm for PE with PFO

For Hemodynamically Unstable Patients (Massive PE):

Immediate anticoagulation with unfractionated heparin should be initiated without delay 2

Patients with intracardiac shunt should be considered for aggressive therapeutic options, including catheter-based techniques and surgical embolectomy, particularly if intracardiac thrombus is identified 1

• Surgical thrombectomy may result in the lowest rate of stroke compared to thrombolysis in patients with impending paradoxical embolism 1
• Systemic thrombolytic therapy is recommended for hemodynamically unstable patients, though surgery is preferred when thrombus-in-transit is visualized 2, 3
• Surgical pulmonary embolectomy is the recommended alternative for patients with contraindications to thrombolysis or failed thrombolysis 2, 4

For Hemodynamically Stable Patients (Submassive PE):

Screening for PFO with echocardiogram with agitated saline bubble study for risk stratification may be considered 1

Anticoagulation should be initiated without delay in non-high-risk patients 2

• Low-molecular-weight heparin or fondaparinux is preferred over unfractionated heparin 2
• Thrombolysis may be considered in selected intermediate-risk patients with clinical deterioration 2

Special Consideration: Thrombus-in-Transit

When thrombus is visualized crossing the PFO (thrombus-in-transit), this represents a medical emergency requiring immediate intervention:

• Surgery is associated with fewer complications of recurrent embolic events than thrombolysis and anticoagulation alone 3
• Thrombolysis is linked to the highest mortality, likely explained by the severity of initial presentation 3
• Anticoagulation alone may be acceptable for patients at high surgical risk with small PFO 3

Critical Pitfalls to Avoid

Do not delay thrombectomy or embolectomy based on PFO presence - the PFO actually increases the urgency for intervention due to paradoxical embolization risk 1

Avoid routine thrombolysis without imaging assessment - if thrombus-in-transit is present, surgical approach may be safer than thrombolysis 1, 3

Be cautious during transesophageal echocardiography - Valsalva maneuver during probe manipulation can dislodge thrombus-in-transit and cause paradoxical embolization 5

Screen high-risk patients for PFO - adding bubble study to routine transthoracic echocardiography increases detection of impending paradoxical embolism 1

Post-Thrombectomy Management

Anticoagulation should be continued long-term 2

Consider PFO closure after the acute event - particularly in patients with documented paradoxical embolism and deep vein thrombosis 1

Routine re-evaluation at 3-6 months is recommended 2