Two unusual complications after surgical interruption of an accessory pathway.

In a patient with the Wolff-Parkinson-White syndrome, Ebstein's anomaly of the tricuspid valve, a right atrial Chiari net and a patent foramen ovale two unusual complications developed after surgical epicardial dissection combined with cryoablation of the anomalous pathway. The first complication was that ablation of the right atrial wall led to changes in interatrial pressure gradients and the development of a right to left shunt necessitating surgical closure of the atrial septal defect. The second complication was the development of a thrombotic mass in the Chiari net simulating on intracavity tumour, which also had to be removed surgically.