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When should we involve interventional radiology in the management of acute pulmonary embolism?

Pulmonary embolism (PE) is a common disease associated with high morbidity and mortality. Currently, guidelines recommend systemic thrombolysis in patients with haemodynamic instability (high-risk PE) or patients with intermediate–high-risk PE with haemodynamic deterioration. Nevertheless, more than half of high-risk PE patients do not receive systemic thrombolysis due to a perceived increased risk of bleeding. In these cases, percutaneous catheter-directed therapy (CDT) or surgical embolectomy should be considered. CDT has emerged and appears to be an effective alternative in treating PE, with a hypothetical lower risk of bleeding than systemic thrombolysis, acting directly in the thrombus…

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Articles of Interest

The PE Pipeline: Evidence Trickles in for Catheter-Based Therapies

The jury’s still out on which treatment is best for patients with intermediate-risk pulmonary embolism (PE), particularly whether catheter-directed thrombolysis (CDT) and mechanical thrombectomy have an impact on hard outcomes above and beyond anticoagulation alone.

Acute pulmonary embolism: endovascular therapy

Percutaneous catheter-directed methods to remove pulmonary thrombi include mechanical fragmentation, thrombus aspiration, and targeted thrombolytic drug delivery. CDT is the targeted delivery of a thrombolytic drug using a multi-sidehole infusion catheter. The side holes of the catheter are embedded within the thrombus, maximizing the surface area of thrombus in contact with the thrombolytic agent. As a result of the targeted intrathrombus delivery, a much lower dose is required to achieve clot lysis with CDT vs. ST.

Advanced Endovascular Interventions With Ultrasound-Accelerated Thrombolysis in Intermediate-Risk Pulmonary Embolism

An overview of management of intermediate-risk patients with ultrasound-accelerated thrombolysis and key considerations in treating those in the “gray zone.”

Advanced Therapies for Acute Pulmonary Embolism: A Focus on Catheter-Based Therapies and Future Directions

Patients with acute pulmonary embolism (PE) present on a spectrum of clinical severity with a subset at risk for significant morbidity and mortality. Individuals without contraindications should be treated with systemic anticoagulation therapy; however, advanced therapies including systemic fibrinolysis, catheter-based approaches, surgical embolectomy, and mechanical circulatory support may be considered in the setting of hemodynamic instability or deterioration. Catheter-based therapies, categorized into lytic and non-lytic based approaches, have recently broadened treatment options, and may be of benefit to patients who are in intermediate- or high-risk categories.

Catheter-directed thrombolysis compared with systemic thrombolysis and anticoagulation in patients with intermediate- or high-risk pulmonary embolism: systematic review and network meta-analysis

With moderate certainty of evidence, the risk of death and major bleeding complications was lower with CDT than with systemic thrombolysis. Compared with anticoagulation, CDT was associated with a probable lower risk of death and a similar risk of intracerebral hemorrhage, with moderate certainty of evidence. Although these findings are largely based on observational data, CDT may be considered as a first-line therapy in patients with intermediate- or high-risk PE.

Catheter-Directed Thrombolysis in Submassive Pulmonary Embolism: Safety and Efficacy

The role of systemic thrombolysis for the treatment of sPE is controversial. No benefit with systemic thrombolysis has been observed in patients with PE who were normotensive. However, in the last decade, there has been increasing evidence showing the efficacy of catheter-directed thrombolysis (CDT) in treating sPE. As compared to systemic thrombolysis, CDT is associated with lower incidence of death and major bleeding (18.13% vs 8.43%). Major studies have showed benefit through either decreased RV dilation or reduced pulmonary artery pressures, with ultimate improvement in RV function.

Catheter-Directed Thrombolysis of Pulmonary Embolism

Catheter-directed thrombolysis (CDT) is an alternative revascularization procedure to systemic thrombolysis, transcatheter embolectomy, or surgical embolectomy for massive and submassive PE with hemodynamic instability and a high risk of morbidity and mortality with the standard care.

Catheter‐directed therapies for the treatment of high risk (massive) and intermediate risk (submassive) acute pulmonary embolism

Catheter‐directed treatments (catheter‐directed thrombolysis and catheter embolectomy) are minimally invasive reperfusion treatments for high‐ and intermediate‐risk APE. Catheter‐directed treatments can be used either as the primary treatment or as salvage treatment after failure of systemic thrombolysis. Catheter‐directed thrombolysis administers 10% to 20% of the systemic thrombolysis dose directly into the thrombus in the lungs, potentially reducing the risks of haemorrhagic side effects. Catheter embolectomy mechanically removes the thrombus without the need for thrombolysis, and may be useful for people with contraindications for thrombolysis.

Current Status of Interventional Therapies in Acute Pulmonary Embolism

To mitigate bleeding risk, the use of catheter-directed interventions is rising. Currently, catheter-directed interventions can be separated into two broader categories: catheter-directed thrombolysis (CDL) and catheter-based embolectomy (CBE).

Interventional therapy of acute pulmonary embolism: where are we and where are we heading towards?

Acute pulmonary embolism has traditionally been managed with systemic thrombolysis and anticoagulation. Even though anticoagulation is still the first line of treatment for pulmonary embolism, catheter-based treatments are quickly emerging to meet an unmet clinical need. Risk of bleeding outweighs the advantages of systemic thrombolysis in many instances. Catheter-directed thrombolysis may have a lower risk of bleeding despite similar efficacy, but the data remains scarce. Catheter-directed embolectomy may be appropriate for patients with absolute contraindications to thrombolytic therapy, or those who require rapid thrombus removal. In the future, catheter-directed pulmonary embolism reperfusion therapy may be preferable for both high and intermediate-high risk PE treatment.

Potential risk during catheter-directed thrombolytic therapy for pulmonary embolism and how to avoid it

Congenital heart defects are rare but can complicate certain procedures and interventionalists need to be aware of this possibility. Catheter position more caudal than the pulmonary artery silhouettes should alert the operator to the incorrect placement in the pulmonary veins through an ASD. Catheters placed unintentionally through an ASD may erroneously appear to be correctly positioned on anteroposterior (AP) fluoroscopy. In addition, thrombolytic therapy will not reach the target and may, in fact, cause serious consequences.

Rapid treatment for high-risk pulmonary embolism

A high-risk pulmonary embolism can be fatal if not treated promptly. Our radiology specialists use advanced dual-energy CT to rapidly diagnose the presence, location and extent of the clot most accurately in the lungs and offer two minimally invasive procedures to treat the condition.

Rationale for catheter directed therapy in pulmonary embolism

The safety profile for CDT in PE has been favorable. The PERFECT registry evaluated 100 patients with differing types of CDT and found no major procedural related complications, major hemorrhage or hemorrhagic strokes. There were 13 minor bleeding events of which 6 were access site related

Rethinking Thrombus Removal With the Indigo System: Introducing Lightning Intelligent Aspiration

The Indigo Aspiration System provides a treatment option that is now cleared by the FDA to treat PE. The sustained aspiration from the Penumbra ENGINE provides constant uninterrupted full-vacuum aspiration throughout the procedure, addressing the constraints of syringe-based large-bore embolectomy, which include vacuum dropoff from the syringe filling with fluid.

Society of Interventional Radiology Position Statement on Catheter-Directed Therapy for Acute Pulmonary Embolism

Despite some limitations of available evidence, CDT is currently considered an acceptable treatment option (as are systemic thrombolysis and surgical embolectomy) for highly selected patients with massive PE.

Resources

Indigo System Lightning

Penumbra’s Indigo® Aspiration System, launched in 2014, is designed to remove clot from arteries and veins in the peripheral vasculature, and for the treatment of pulmonary embolism.