Pulmonary embolism with thrombus in transit across a patent foramen ovale.

Thromboembolism-in-transit, specifically impending paradoxical embolism (IPDE), is a rare and life-threatening condition with limited reported cases. We present a case of a 51-year-old male with obstructive sleep apnea, initially diagnosed with deep vein thrombosis and pulmonary embolism. Further evaluation revealed a saddle pulmonary embolus extending into the right atrium, straddling a patent foramen ovale (PFO), confirmed by transesophageal echocardiogram. Despite a critical left anterior descending coronary artery stenosis, surgical thrombectomy, PFO closure, and coronary artery bypass grafting were successfully performed. Thromboembolism-in-transit poses diagnostic challenges, and there is a lack of consensus on the optimal treatment strategy. Surgical interventions, including embolectomy and PFO closure, have shown promise, while thrombolytic therapy remains controversial. This case underscores the importance of tailored management in the absence of standardized guidelines, emphasizing the need for further research to establish evidence-based protocols for this uncommon but potentially fatal condition.