Cardiac arrest due to tamponade during secondary-stage endovascular stent implantation in a patient with DeBakey type I dissection: a case report and literature review.

Background: Hemorrhagic cardiac tamponade is a rare but potentially fatal complication of endovascular aortic intervention, mostly caused by aortic rupture or cardiac perforation; cases without arterial/cardiac injury are extremely uncommon. Protamine anaphylactic reaction is a common perioperative adverse event, and its synergistic effect with cardiac tamponade on hemodynamic instability is often overlooked in clinical practice. Case presentation: We report a 63-year-old man with 10 years of poorly controlled hypertension and a 2-year history of stroke who was diagnosed with DeBakey type I aortic dissection. The patient underwent hemi-arch replacement combined with Bentall operation as the first-stage surgery, and the second-stage descending aorta stent implantation (femoral artery retrograde implantation, chimney stent placement in the innominate artery, and carotid-carotid cross-over bypass) was performed on the 20th postoperative day in line with clinical consensus. During the second-stage surgery, protamine anaphylaxis occurred first, followed by progressive hemodynamic instability; the patient then suffered cardiac arrest due to acute cardiac tamponade. Transesophageal echocardiography (TEE) confirmed a large amount of pericardial effusion with right heart chamber collapse, and subxiphoid surgical pericardial window and drainage were immediately performed, with 300 mL of bloody fluid aspirated. Anticoagulant/antiplatelet therapy was timely adjusted after drainage, and the patient was discharged without neurological complications 2 weeks later. Serial perioperative biological and physiological data were comprehensively monitored and recorded during the whole process. Conclusion: Cardiac tamponade can be readily reversed with timely recognition and intervention, and TEE is the gold standard for its rapid perioperative diagnosis. For patients undergoing staged TEVAR for DeBakey type I aortic dissection with a history of cardiac surgery, long procedural duration, and systemic anticoagulation, tamponade should be highly vigilant even without obvious aortic/cardiac injury. The protamine reaction can synergize with tamponade to aggravate hemodynamic disorder and mask its early manifestations, requiring enhanced multi-modal monitoring. Timely subxiphoid surgical pericardial window drainage is an effective intervention for tamponade-induced cardiac arrest, and individualized adjustment of anticoagulation therapy is crucial for avoiding rebleeding.