What is the treatment for subtotal occlusion of bilateral pulmonary arteries?

Treatment of Subtotal Occlusion of Bilateral Pulmonary Arteries

For patients with subtotal occlusion of bilateral pulmonary arteries, surgical pulmonary embolectomy is the treatment of choice when there is hemodynamic compromise, while catheter-directed interventions are appropriate for patients with contraindications to surgery or thrombolysis. 1

Initial Assessment and Treatment Decision Algorithm

Acute vs. Chronic Occlusion

• Determine if the occlusion is acute (pulmonary embolism) or chronic (chronic thromboembolic pulmonary hypertension - CTEPH) 1
• If symptoms have been present for >3 months despite adequate anticoagulation, consider CTEPH 1
• Acute occlusions typically present with sudden onset dyspnea, hypoxemia, and right heart strain 1

Risk Stratification

• Assess for hemodynamic compromise: hypotension (systolic BP <90 mmHg), shock, or need for inotropic support 1
• Evaluate for right ventricular dysfunction using echocardiography 1, 2
• Check cardiac biomarkers (troponin, BNP) to assess severity 1

Treatment Options Based on Clinical Presentation

For Acute Pulmonary Embolism with Hemodynamic Compromise

1. Surgical Pulmonary Embolectomy

   • First-line treatment for massive bilateral pulmonary artery occlusion with hemodynamic instability 1
   • Procedure involves:
     • Median sternotomy with normothermic cardiopulmonary bypass 1
     • Bilateral pulmonary artery incisions to remove clots down to segmental level 1
     • Avoidance of aortic cross-clamping and cardioplegic arrest 1
   • Perioperative mortality rates as low as 6% with experienced teams 1
   • Long-term outcomes show favorable survival rates and quality of life 1

2. Catheter-Directed Interventions (if surgery contraindicated or unavailable)

   • Options include: 1
     • Thrombus fragmentation with pigtail or balloon catheter
     • Rheolytic thrombectomy with hydrodynamic devices
     • Suction thrombectomy with aspiration catheters
     • Rotational thrombectomy
   • Clinical success rate of approximately 87% 1
   • Consider catheter-directed thrombolysis for patients without contraindications to thrombolytics 1

3. Systemic Thrombolysis

   • Consider in massive PE with shock/hypotension when surgical or catheter interventions are unavailable 1
   • Contraindications include recent surgery, active bleeding, or history of hemorrhagic stroke 1

For Chronic Thromboembolic Disease (CTEPH)

1. Pulmonary Endarterectomy (PEA)

   • Treatment of choice for CTEPH 1
   • Performed in specialized centers by experienced teams 1
   • In-hospital mortality as low as 4.7% 1
   • Three-year survival rate of 89% for operated patients vs. 70% for non-operated patients 1

2. Balloon Pulmonary Angioplasty (BPA)

   • Alternative for patients ineligible for PEA or with residual pulmonary hypertension after PEA 3
   • Requires specialized training (at least 50 procedures under guidance) 3
   • Targeted, incremental balloon dilatation strategy based on vascular lesion type 3

Post-Procedure Management

• Maintain effective anticoagulation therapy post-procedure 3
• Monitor for reperfusion pulmonary edema, especially after BPA 3
• For patients with CTEPH, long-term follow-up at specialized centers is recommended 1

Special Considerations

• Vena cava filter insertion may be considered alongside surgical embolectomy, especially with retrievable filters 1
• Transportable extracorporeal assistance systems can help in critical situations before definitive treatment 1
• Pre-operative thrombolysis increases bleeding risk but is not an absolute contraindication to surgical embolectomy 1

Pitfalls to Avoid

• Delaying treatment in hemodynamically unstable patients 1
• Failing to refer CTEPH patients to specialized centers for evaluation 1
• Attempting complex interventional procedures without adequate training and experience 3
• Overlooking the possibility of chronic disease in patients with persistent symptoms 1