Massive pulmonary embolism and thrombus-in-transit via a patent foramen ovale: a case report of successful use of extracorporeal membrane oxygenation to manage post-embolectomy severe right ventricular dysfunction

BACKGROUND: Pulmonary embolism with thrombus-in-transit through a patent foramen ovale is rare. It may present with neurological sequalae and rapid diagnosis is needed to prevent mortality and morbidity. The European Society of Cardiology (ESC) published guidelines in 2019 for diagnosis and management of acute pulmonary embolism which were useful in this case. CASE SUMMARY: A 32-year-old sedentary male presented with sudden onset shortness of breath, syncope, a probable seizure, and chest pain. Investigations showed an acute pulmonary embolism with mobile thrombus in the right atrium and right ventricle and also thrombus-in-transit passing through a patent foramen ovale into the left atrium. He was resuscitated and rapidly transferred to theatre where he underwent surgical thromboembolectomy. There was difficulty in separating him from cardiopulmonary bypass due to right ventricular failure and he was initiated on extracorporeal membrane oxygenator support. He recovered fully and was discharged home after 43 days. DISCUSSION: This case report highlights the presentation of this rare diagnosis and discusses the management of acute pulmonary embolism according to recent ESC guidelines.