Case Report: Pulmonary reperfusion injury with bilateral bronchial cast thrombosis after VA-ECMO-bridged catheter-based reperfusion for cardiac arrest caused by high-risk pulmonary embolism.

Abstract

High-risk pulmonary embolism (PE) can lead to acute right ventricular failure, obstructive shock, and cardiac arrest. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) provides bridging life support, buying time for imaging confirmation and reperfusion. However, reperfusion injury, pulmonary hemorrhage, and airway thrombotic obstruction may follow pulmonary artery reperfusion. Severe airway obstruction caused by bronchial cast thrombi is rare and challenging. We report a woman in her 60s awaiting surgery for a left femoral neck fracture who developed preoperative cardiac arrest due to high-risk PE. After VA-ECMO bridging and staged catheter-based pulmonary reperfusion, the patient developed reperfusion injury and bilateral bronchial cast thrombosis, managed by repeated bronchoscopy with cryoextraction. Electrical impedance tomography (EIT) monitored ventilation and perfusion. The patient was weaned from VA-ECMO and invasive ventilation but remained in a persistent vegetative state due to hypoxic-ischemic encephalopathy. This case suggests that in cardiac arrest caused by high-risk PE, VA-ECMO can buy time for diagnosis and reperfusion; however, reperfusion injury after recanalization can cause severe hemorrhage, with blood coagulating within the airways into bronchial cast thrombi and life-threatening obstruction. Bronchoscopy with cryoextraction effectively clears tenacious airway cast thrombi. EIT assists ventilation/perfusion monitoring during complex VA-ECMO support. Even when cardiopulmonary function recovers, hypoxic-ischemic brain injury may determine long-term prognosis.