Monteplase (Genetical Recombination)

An 8‐year‐old Leonberger receiving immunosuppressive treatment with clinical signs of acute dyspnea, cyanosis, and difficulty standing was referred to our institution (Day 1). Treatment including oxygen, clopidogrel, and low‐molecular‐weight heparin was initiated for suspected pulmonary thrombosis. However, exertional dyspnea persisted until Day 10, and increased tricuspid regurgitation velocity, pulmonary vascular resistance, and McConnell's signs also were observed. Thus, beraprost sodium was administered PO on Day 11 to treat suspected pulmonary hypertension. On Day 13, contrast‐enhanced computed tomography identified extensive contrast defects in the pulmonary arteries, and IV monteplase was administered on Days 14 and 18, with marked improvement in respiratory status and exertional dyspnea on Day 20. Right ventricular function and McConnell signs also improved, and tricuspid regurgitation velocity and pulmonary vascular resistance decreased. On Day 250, echocardiography indicated further improvement in pulmonary hypertension pathophysiology. The patient was still progressing well with antithrombotic and pulmonary vasodilator treatment 400 days later.

Acute massive pulmonary thromboembolism (PE) has a high mortality rate of 18%-65%. Along with anticoagulation and thrombolytic therapy, treatment may require a catheter-based thrombectomy or surgical thrombectomy. We report a case of pulmonary thromboembolism treated with a Stent Retriever (Trevo® NXT ProVue Retriever, Stryker, Kalamazoo, MI, USA), which is commonly used to treat stroke. An 81-year-old woman complained of back pain and was transported to our hospital after she became unconscious. Cardiopulmonary resuscitation was initiated before her arrival at the hospital; she returned to spontaneous circulation after arrival. After undergoing computed tomography (CT) scanning, she went into cardiac arrest again, and we established veno-arterial extracorporeal membrane oxygenation and performed catheter thrombectomy using a stent retriever. The left basilar pulmonary artery and the right middle pulmonary artery trunk were retrieved after the stent's deployment, and bilateral pulmonary arteries were confirmed to be reopened. A residual thrombus was present, and Monteplase was administered. A contrast-enhanced CT scan taken on day 15 following admission revealed that the thrombus had disappeared, and echocardiography revealed improved right ventricular dysfunction. The patient was transferred to another hospital on day 64 for rehabilitation. We report the first case of pulmonary artery thrombosis that was successfully recanalized by endovascular treatment with a stent retriever. The stent retriever may be useful as an endovascular treatment device for PE because it is easier to achieve recanalization using this method compared to conventional treatment methods.