Catheter-Based Thrombectomy for Clot-In-Transit and Massive Pulmonary Embolism In A Young Patient with Rheumatoid Arthritis: Inflammation as A Hidden Catalyst for Catastrophic Thromboembolism.

Introduction: Pulmonary embolism (PE) is a life-threatening condition with well-defined management strategies; however, the presence of a clot-in-transit (CIT)-a mobile thrombus within the right heart-introduces a uniquely high-risk scenario associated with a significantly elevated mortality rate. While several therapeutic approaches are available-including anticoagulation, systemic thrombolysis, surgical embolectomy, and catheter-directed therapies-there is no established consensus on a superior treatment modality. Catheter-based mechanical thrombectomy has emerged as a promising, minimally invasive alternative that mitigates the bleeding risks of systemic thrombolysis and the invasiveness of surgery. Case description: A 37-year-old male with untreated rheumatoid arthritis presented to the emergency department with dyspnea and chest pain, ultimately found to have massive bilateral PE with CIT. This was successfully treated with percutaneous thrombectomy using the INARI FlowTriever device (Inari Medical, USA). Discussion: This case is accompanied by uncommon post-thrombectomy imaging that vividly demonstrates the thrombus burden in the majority of bilateral pulmonary vessels, providing valuable visual insight into the disease process and intervention efficacy. Rheumatoid arthritis is an independent risk factor for PE, deep vein thrombosis, and venous thromboembolism, highlighting the importance of treatment. Conclusion: This report contributes to the limited literature on atypical CIT presentations, highlights the need for standardized treatment algorithms, and demonstrates the success of catheter-directed mechanical thrombectomy in these scenarios. LEARNING POINTS: Rheumatoid arthritis is a risk factor for pulmonary embolism, deep vein thrombosis, and venous thromboembolism.Catheter-directed mechanical thrombectomy for massive pulmonary embolism with clot-in-transit is a promising, minimally invasive alternative to systemic thrombolysis.