Endovascular therapies for pulmonary embolism

Figures

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  Figure 1. Risk stratification in PE. Patients with PE are classified according to haemodynamic consequences, biomarker levels and imaging findings. High-risk patients have acute haemodynamic failure, including cardiac arrest and cardiogenic shock. Patients with paradoxical bradycardia, ventricular tachycardia and relative hypotension (systolic blood pressure <90 mmHg) are included in this group. Normotensive patients with elevated cardiac biomarkers (troponin and natriuretic peptides) or CT/ultrasound evidence of right ventricular strain (dilation, interventricular septum bulging or right ventricular systolic dysfunction) are assigned to the intermediate-risk group. The low-risk group comprises patients without haemodynamic instability, with normal levels of RV strain biomarkers and low prognostic index scores (simplified pulmonary embolism severity index, sPESI).

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  Figure 2. Multihole infusion catheter (AngioDynamics, Inc.). Multihole infusion catheter with side holes for delivery of fibrinolytics within the thrombus using a simple wire that occludes the tip of the catheter in order to deliver the fluid through the side holes.

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  Figure 3. Ekos system. The Ekos system consists of a multihole infusion catheter, an ultrasonic core and a control unit (Ekos Corp.).

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  Figure 4. AngioVac catheter (AngioDynamics) removes thrombi by pumping and filtering the patient's blood and then reinfusing it via a reperfusion circuit. This large-bore device is designed to be inserted via the femoral vein and used for removal by aspiration of large thrombi from the pulmonary arteries. The funnel-shaped balloon on its distal tip is used to occlude the vein in which it is placed.

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  Figure 5. Penumbra INDIGO system (Penumbra Inc.): Penumbra's Indigo CAT 8 system is a flexible 8 F aspiration catheter connected to a continuous vacuum system. The catheter's lumen contains a wire with an olive-shaped distal tip that enhances clot fragmentation and recovery.

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  Figure 6. The FlowTriever device (Inari Medical) has 3 nitinol mesh disks that deploy into the thrombus and draw it into the catheter by manual aspiration.

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  Figure 7. ASPIREX (Straub). Catheter with a worm screw beneath a side opening at its distal end. Thrombectomy is achieved by rotating the screw which draws the thrombus into the catheter.

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  Figure 8. AngioJet rheolytic thrombectomy (Boston Scientific). Pressure-pulsed delivery of saline at the catheter's distal tip fragments the thrombus and creates a Venturi effect that aspirates and removes the fragments via a second lumen.