Acute pulmonary embolism (PE) covers a wide clinical spectrum, from small subsegmental clots to massive embolism with hemodynamic collapse. Risk stratification — based on hemodynamic status, right ventricular strain, and cardiac biomarkers — guides whether a patient is managed with anticoagulation alone or with an escalation strategy. Catheter-directed therapy has become an important option for the intermediate-high and high-risk groups.
The rationale for a catheter-directed approach
Systemic thrombolysis restores pulmonary perfusion quickly but carries a meaningful risk of major bleeding, including intracranial hemorrhage. Catheter-directed thrombolysis (CDT) delivers a much smaller total dose of fibrinolytic directly into the thrombus, aiming to relieve right ventricular strain while limiting systemic exposure. For patients in whom any lysis is contraindicated, mechanical thrombectomy provides a drug-free alternative.
Techniques
- Standard catheter-directed thrombolysis. A multi-side-hole infusion catheter is positioned across the thrombus and a low-dose fibrinolytic is infused over several hours.
- Pharmacomechanical thrombolysis. Mechanical disruption or aspiration is combined with local drug delivery to accelerate clot resolution and shorten infusion time.
- Mechanical thrombectomy. Large-bore aspiration or rotational systems remove thrombus without any lytic agent, suited to patients with bleeding contraindications.
Patient selection
The strongest candidates are patients with intermediate-high-risk PE showing right ventricular dysfunction and clinical deterioration despite anticoagulation, and selected high-risk patients as part of a multidisciplinary decision. A Pulmonary Embolism Response Team model helps align interventional, critical-care, and cardiology input on the best strategy for each patient.
Outcomes and considerations
Reported series describe improvement in right ventricular to left ventricular ratio and pulmonary pressures after catheter-directed therapy, with lower fibrinolytic doses than systemic regimens. As with any intervention, outcomes depend on timely recognition, appropriate case selection, and operator experience. Follow-up assessment for persistent symptoms and chronic thromboembolic disease remains part of comprehensive care.
INVAMED technologies in this space
INVAMED's venous and thrombectomy portfolio includes the Inca thrombolysis catheter with embolic protection and the Mantis rotational thrombectomy and aspiration platforms. Related patient-facing background is available in the pulmonary embolism condition guide.
Device availability and approved indications vary by country. This content is prepared for healthcare professionals and does not replace clinical judgment or the instructions for use.