During thrombectomy, with femoral vein access, how is pulmonary (lung) access achieved?

From the Guidelines

During a thrombectomy procedure that accesses the femoral vein to reach the lungs, interventionalists navigate through the venous system to the pulmonary arteries, advancing a catheter through the inferior vena cava into the right atrium, then through the right ventricle, and finally into the pulmonary arteries where the clot is located, as described in the 2020 European Heart Journal guidelines 1. This approach allows for targeted treatment of pulmonary emboli while minimizing systemic effects of thrombolytic medications. The procedure, known as catheter-directed thrombolysis or mechanical thrombectomy, may use specialized catheters with various mechanisms to break up and remove the clot, such as aspiration, fragmentation, or rheolytic devices. Some key points to consider in this procedure include:

• The use of anticoagulation therapy during and after the procedure to prevent further clot formation, with options including heparin or direct thrombin inhibitors like bivalirudin, as suggested in the 2011 Circulation study 1.
• The potential for temporary transvenous pacemaker insertion during rheolytic thrombectomy, as noted in the 2011 Circulation study 1.
• The importance of careful patient selection and consideration of the risks and benefits of the procedure, including the potential for major complications such as death from worsening RV failure, distal embolization, or pulmonary artery perforation, as discussed in the 2014 European Heart Journal guidelines 1. Overall, the goal of the procedure is to remove the obstructing thrombi from the main pulmonary arteries, facilitate right ventricular recovery, and improve symptoms and survival, as outlined in the 2014 European Heart Journal guidelines 1.

From the Research

Accessing the Lungs During Thrombectomy

• The procedure of thrombectomy for acute pulmonary embolism involves accessing the lungs through the femoral vein, which is a common approach for catheter-based interventions 2, 3.
• The catheter is guided through the femoral vein to the pulmonary artery, where the thrombus is located, using imaging techniques such as fluoroscopy or echocardiography 4, 5.
• Once the catheter is in place, various techniques can be used to remove the thrombus, including mechanical thrombectomy, catheter-directed thrombolysis, or a combination of both 3, 6.
• The choice of technique depends on the size and location of the thrombus, as well as the patient's overall condition and medical history 2, 4.

Mechanical Thrombectomy Techniques

• Mechanical thrombectomy techniques, such as the FlowTriever system, can be used to remove thrombi from the pulmonary artery and right atrium 5.
• These techniques involve using a catheter-based device to fragment and extract the thrombus, which can help to restore blood flow to the lungs and improve patient outcomes 4, 5.
• Mechanical thrombectomy can be performed under echocardiography guidance, which allows for real-time visualization of the procedure and can help to reduce the risk of complications 5.

Catheter-Directed Thrombolysis

• Catheter-directed thrombolysis involves delivering a thrombolytic agent directly to the thrombus through a catheter, which can help to dissolve the clot and restore blood flow to the lungs 6.
• This technique can be used in combination with mechanical thrombectomy or as a standalone treatment, depending on the patient's condition and the size and location of the thrombus 3, 6.
• Catheter-directed thrombolysis has been shown to be effective in reducing pulmonary artery pressure and improving patient outcomes in patients with submassive pulmonary embolism 6.