Catheter-directed therapy to treat intermediate- and high-risk pulmonary embolism: Personal experience and review of the literature

Pulmonary embolism (PE) is the third leading cause of cardiovascular death in the western world. Prompt recognition, risk stratification, and individualized treatment are crucial to improve outcomes in patients with PE. Anticoagulation alone is a sufficient therapeutic option in low-risk patients, whereas primary reperfusion with systemic thrombolysis (ST) is usually chosen in high-risk patients. The choice of treatment in intermediate-risk patients is complex and depends on the clinical presentation. Catheter-directed therapy (CDTh) includes all therapies delivered via a catheter placed in the branches of the pulmonary arteries directly into the thrombus. Because ST bears a high risk of major bleeding and numerous patients have contraindications to ST, CDTh is an alternative to ST in intermediate- and high-risk PE patients. CDTh includes local thrombolysis using low-dose alteplase, ultrasound-assisted thrombolysis, and mechanical fragmentation and aspiration of the thrombi, as well as their combinations. In this review article, we have summarized devices and technical details for CDTh, discussed the efficacy and safety of CDTh in comparison to ST in previous clinical trials, and outlined future research directions regarding CDTh, both based on the literature and our personal experience from the local PE Response Team of the Center for the Management of Pulmonary Embolism (CELZAT) in Warsaw.