Closure of foramen ovale triggered by injury to tunnel surfaces of septum primum and secundum.

Introduction: We investigated the feasibility to proactively stimulate subsequent closure of a patent foramen ovale (PFO) by injuring (mechanical trauma or radiofrequency [RF] energy) the opposing surfaces of the septum primum (SP) and septum secundum (SS).

Methods: 1. Mechanical Injury: The interatrial septum of patients who underwent multiple left atrial (LA) ablations over 6 years, where a PFO was used for LA access, were examined. Patients whose PFO was absent during a later procedure were identified. Eleven patients with LA accessed via a PFO also underwent subsequent LA procedures. 2. Ablation: Ten patients undergoing ablation for drug-resistant atrial fibrillation (AF), who also had a PFO, were studied. RF delivery was extended along the upper SP. Transthoracic echocardiogram (TTE) bubble study was repeated after 3 months.

Results: 1. Mechanical Injury: Seven were male with a mean age of 58.3 ± 9.99. LA size was 42.73 ± 3.52 mm. The mean left ventricular ejection fraction (EF) was 62 ± 7.4%. During the repeat procedure, in 4 patients, the PFO could not be visualized and the fossa ovalis (FO) was punctured. The fourth patient had three procedures. During the second procedure the PFO was accessed, but with difficulty. During the third procedure, it was no longer present. All four patients had subsequent TTE showing no PFO. 2. Ablation: Seven were male with a mean age of 61.1 ± 9.8 years. The mean EF and LA diameters were 55 ± 5% and 4.4 ± 0.8 cm respectively. The mean RF time was 5.4 ± 2.2 min. At 3 months, 9 patients out of 10 showed no interatrial communication.

Conclusion: Injury of tunnel surfaces of the SP and SS by mechanical trauma or ablation can fuse the foramen ovale.