Acute Decompensation in a Post-operative Fontan Patient: What Happened?
- In Fontan patients , CT scans performed to evaluate for thrombus may have significant artifact and must be interpreted in the context of flow dynamics.
- Patients who undergo delayed primary Fontan operation are high risk and must be treated with a high suspicion for morbidity and complications when deviating from the expected course.
- A procoagulant state exists in Fontan patients, especially in the first 6 months after the operation.
An 11-year-old male with dextrocardia, congenitally corrected transposition of the great arteries, subpulmonary stenosis, and a large inlet ventricular septal defect with a straddling tricuspid valve underwent primary non-fenestrated Fontan palliation due to exercise intolerance and cyanosis. He is on atenolol for a history of atrial tachycardia. His pre-Fontan cardiac catheterization demonstrated the following hemodynamics: indexed pulmonary vascular resistance (PVRi) 1.1 Wood.units.m2, cardiac index 2.9 L/min/m2, Qp:Qs ratio 0.6, aortic oxygen saturation 83%, left ventricle end-diastolic pressure 10 mmHg, and right ventricle end-diastolic pressure 11 mmHg. Upon weaning of bypass after his surgery, the central venous pressure measured 15 mmHg and the patient was extubated. A right internal jugular central line was removed 3 days later. His post-operative course was complicated by one episode of atrial tachycardia that resolved with initiation of his home dose of atenolol. He was started on 81 mg of acetylsalicylic acid daily. Between the fifth and eighth post-operative day, he required escalation of respiratory support and pain medications due to increased work of breathing and chest pain.
On the eighth post-operative day, the patient decompensated and required transfer to the intensive care unit (ICU). In the ICU, he arrested, and was intubated and cannulated for veno-arterial extracorporeal membrane oxygenation (ECMO) via the right internal jugular vein and carotid artery. Once stabilized on ECMO, a chest computed tomography (CT) scan was obtained (Figure 1). Notably, factor 8 was 185 (high) and von Willebrand factor antigen was >400 (high) immediately after ECMO cannulation.
What was the most likely cause of this patient's decompensation?