What is the approach for accessing the femoral vein for pulmonary thrombectomy?

From the Guidelines

The femoral vein is the preferred access site for pulmonary thrombectomy, allowing for the advancement of thrombectomy catheters through the inferior vena cava, right heart, and into the pulmonary arteries where the thrombus is located. To access the femoral vein, position the patient supine with slight external rotation of the hip. Identify the femoral vein by locating it medial to the femoral artery, approximately 1-2 cm below the inguinal ligament. After sterile preparation and local anesthesia (1-2% lidocaine), use ultrasound guidance to visualize the vein and insert a needle at a 45-degree angle. Once venous blood return is confirmed, insert a guidewire followed by an appropriate-sized sheath, typically a 6F femoral venous sheath as suggested by the American Heart Association 1.

The approach to catheter-based pulmonary thrombectomy involves advancing a 6F angled pigtail catheter into each main pulmonary artery, followed by injection of low-osmolar or isosmolar contrast (30 mL over 2 seconds) 1. Anticoagulation can be achieved with either UFH 70 IU/kg intravenous bolus, with additional heparin as needed to maintain an activated clotting time 250 seconds, or the direct thrombin inhibitor bivalirudin (0.75 mg/kg intravenous bolus, then 1.75 mg/kg/h) 1. The femoral approach is preferred because it provides a relatively straight path to the pulmonary vasculature and accommodates larger devices needed for thrombectomy. Alternative access sites include the internal jugular or subclavian veins, but these are typically reserved for cases where femoral access is contraindicated due to lower extremity deep vein thrombosis, inferior vena cava filters, or anatomical variations.

Key considerations for the procedure include:

• Using a 6F multipurpose guiding catheter to reach the thrombus, which is crossed with a 0.014-inch hydrophilic guidewire 1
• Temporary transvenous pacemaker insertion may be required during rheolytic thrombectomy 1
• Maintaining adequate anticoagulation to prevent further thrombus formation 1

From the Research

Accessing Femoral Vein for Thrombectomy to Lungs

• The femoral vein can be accessed for thrombectomy to remove blood clots that can travel to the lungs and cause a pulmonary embolism 2, 3.
• Thrombectomy can be performed using various techniques, including mechanical thrombectomy with devices such as the ClotTriever catheter 2, 3.
• The ClotTriever system has been shown to be effective in removing subacute and chronic thrombus, and can be used as a valuable option for vascular interventionalists to treat deep vein thrombosis (DVT) 2, 3.
• Other studies have compared the efficacy of percutaneous aspiration thrombectomy (PAT) with anticoagulation therapy alone for the treatment of acute proximal lower extremity DVT, and found that PAT with or without stenting is superior to anticoagulant therapy alone in terms of ensuring venous patency and improving clinical symptoms 4.
• Thrombolytic strategies, including catheter-directed thrombolysis (CDT), have also been shown to be effective in reducing the incidence of post-thrombotic syndrome (PTS) and improving clot lysis, but may increase the risk of bleeding complications 5.
• Open thrombectomy can be considered in patients with a contraindication to thrombolytic agents who can receive anticoagulation, and may be effective in restoring venous patency and preserving venous valve function 6.

Techniques for Thrombectomy

• Mechanical thrombectomy using devices such as the ClotTriever catheter 2, 3
• Percutaneous aspiration thrombectomy (PAT) 4
• Catheter-directed thrombolysis (CDT) 5
• Open thrombectomy 6

Considerations for Thrombectomy

• Patient selection and indications for thrombus removal 4, 6
• Risk of bleeding complications 5
• Effectiveness of different thrombectomy techniques 2, 3, 4, 5
• Importance of anticoagulation therapy in conjunction with thrombectomy 2, 3, 4, 5, 6