This study aims to investigate the safety and efficacy of transcatheter exclusion of atrial septal aneurysm (ASA) via transseptal perforation in patients with ASA.

Atrial septal aneurysm (ASA) has been considered a potential cardiac source of embolism, and its prevalence is about 1%. In adult patients with stroke and normal carotid arteries, ASA is an important predictor of recurrent stroke. The most common abnormalities associated are interatrial shunts, that is, a patent foramen ovale (PFO) or an atrial septal defect (ASD). For large ASA with interatrial shunt, it is difficult to cover ASA with conventional devices, which might result in unstability of occluders and related complications . For isolated ASA with high risk, thrombus and emboli have been reported and anticoagulation has been used empirically.

In addition, the left atrial septal pouch can be considered as a special subtype of atrial septal aneurysm, in which thrombus might arise from the cavity of the pouch. Pervious researches have noted that left atrial septal pouch was a site of origin of thrombus formation and a source of embolism, and it was associated with cryptogenic stroke. For patients with ASA, we hypothesizes that transcatheter reconstruction of atrial septum might be achieved with PFO occluder through transseptal perforation. The aim of this study is to investigate the safety and efficacy of transcatheter exclusion of ASA via transseptal perforation.

This study will enroll subjects with ASA (including left atrial septal pouch), and enrollment will be divided into three phases.

Phase 1: large ASA patients with interatrial communication (ASD or PFO). A maximum of 30 patients is reached.

Phase 2: ASA patients with intact septum and high risk of cryptogenic stroke. A maximum of 20 patients is reached.

Phase 3: left atrial septal pouch with high risk of cryptogenic stroke. A maximum of 20 patients is reached.

Inclusion Criteria:

1. In large-ASA patients with PFO (Phase1) (1)The length of ASA >20 mm and bulging >10 mm or a combined total excursion right and left > 15 mm; (2)Presence of a PFO indicated for device closure (Echocardiographic and/or transcranial Doppler evidence of right to left shunt at the atrial level); (3)History of cryptogenic stroke/TIA/migraine without other risks; (4) Failure to cover ASA after trial device-closure of PFO and the unstable device confirmed with push-pull test;
2. In large-ASA patients with secundum ASD (Phase1) (1)The length of ASA >20 mm and bulging >15 mm or a combined total excursion right and left > 15 mm; (2)Secundum ASD with Qp/Qs>1.5 or echocardiographic evidence of right heart enlargement; (3)Failure to cover ASA after trial device-closure of ASD and the unstable device confirmed with push-pull test;
3. Isolated ASA with high risk (Phase2) (1)History of migraine attacks/TIA/cryptogenic stroke without other risks in the last 6 months; (2)Thickening of ASA wall ≥ 5 mm; (3)Spontaneous echo contrast;
4. Left atrial septal pouch (Phase3) (1)History of migraine attacks/TIA/cryptogenic stroke without other risks in the last 6 months; (2)Spontaneous echo contrast in left atrium;

Exclusion Criteria:

1. Acute infection or sepsis;
2. Intra-cardiac thrombus;
3. Carotid, vertebral or basilar artery stenosis > 50% on duplex imaging;
4. Patients unable to grant informed, written consent.