A Case of Failure of EkoSonicâ„¢ Endovascular System in the Treatment of Submassive Pulmonary Embolism

Tirthani, Ekta; Said, Mina; Thabet, Salem

Submassive pulmonary embolism (SPE) is characterized by the presence of right ventricular (RV) strain as visualized on echocardiogram or CT scan with brain natriuretic peptide (BNP) and/or troponin elevation. The condition accounts for 20-25% of all pulmonary embolism (PE) cases. In cases of SPE, catheter-directed thrombolysis (CDT) is generally considered in the presence of severe hypoxemia, worsening RV dysfunction, patients with increasing tachycardia and elevated troponins, free-floating thrombus in the right atrium or RV, and presence of extensive clot burden. EkoSonic™ Endovascular System (EKOS; Boston Scientific, Marlborough, MA) has been successfully used to treat cases of PE even where systemic thrombolytic therapy has failed. However, in this article, we describe a unique case of the failure of EKOS in treating a 71-year-old African American man who presented to the hospital with progressively worsening chest pain, shortness of breath, and fatigue. He was suspected to have SPE; however, a CT pulmonary angiogram could not be performed to estimate the clot burden due to an acute kidney injury. He was diagnosed with coronavirus disease 2019 (COVID-19) pneumonia during the hospitalization and had a delayed EKOS procedure with minimal improvement in oxygenation and clot burden. He subsequently underwent half-dose systemic thrombolytic therapy with complete resolution of his symptoms. Given our success with half-dose systemic therapy, we propose that it may be considered as a “rescue therapy” in cases where EKOS fails to deliver results.