B46-21 Spontaneous Hemothorax Following Mechanical Thrombectomy for Pulmonary Embolism: A Case Report

Abstract Spontaneous hemothorax is a rare complication after mechanical thrombectomy for pulmonary embolism (PE). While thrombectomy is increasingly used for high- and intermediate-risk PE, the risk of major bleeding is typically associated with vascular access rather than intrathoracic hemorrhage. Reports of massive hemothorax in this setting are rare, particularly with volumes exceeding 2 liters. We present a case of spontaneous hemothorax following thrombectomy requiring emergent intervention. An 82-year-old male with no significant past medical history presented after a near-syncopal episode. He was found at an outside hospital to have bilateral segmental pulmonary emboli with right heart strain on Computed Tomography (CT) pulmonary angiography, elevated troponin (831 nanograms per liter), Brain Natriuretic Peptide (BNP) (240 picograms per milliliter), and a right lower extremity deep venous thrombosis (DVT). He was started on a heparin infusion and transferred to our facility for interventional management. On arrival, he was stable on room air. He complained of mild shortness of breath on the exam. The following day, he underwent mechanical thrombectomy. Several hours later, a rapid response was called for hypotension, chest pain, decreased responsiveness and diaphoresis. Heart Rate was 50 beats per minute, Blood Pressure 79/50 mmHg, Pulse-oximetry 100% on non-rebreather. CTA of the chest, abdomen, and pelvis demonstrated a large left pleural effusion not present on prior imaging, raising concern for hemothorax. He was transferred to the Intensive Care Unit (ICU). An emergent chest tube drained 1900 mL of dark blood in 30 minutes, confirming massive hemothorax. While thrombectomy has shown favorable outcomes for intermediate-risk PE, reported complications are primarily vascular access injuries, pulmonary hemorrhage, or hemoptysis. Hemothorax is rarely documented in the literature. The mechanism in this case may have involved injury to small pulmonary vessels or anticoagulation-related exacerbation of minor bleeding, though no direct procedural vascular injury was identified. This case highlights the importance of maintaining suspicion for hemothorax in patients with unexplained hypotension and respiratory distress after thrombectomy. Massive spontaneous hemothorax is a rare complication of thrombectomy for PE. Prompt recognition and management are essential, as delayed intervention may result in significant morbidity or mortality. References: Tu T, et al. FLASH registry: real-world outcomes with mechanical thrombectomy for PE. JACC Cardiovasc Interv. 2022. Sista AK, et al. Complications of percutaneous mechanical thrombectomy for PE. Chest. 2020. Dudzinski DM, et al. Massive pulmonary embolism and bleeding complications of reperfusion therapies. Circulation. 2016. This abstract is funded by: None