Atrial septal defect percutaneous closure


 * Associate Editor(s)-In-Chief: Priyamvada Singh, M.B.B.S. [mailto:psingh@perfuse.org]; Assistant Editor(s)-In-Chief: Kristin Feeney, B.S. [mailto:kfeeney@perfuse.org]

Overview
The percutaneous device closure are commonly done for ostium secundum type of atrial septal defects and patent foramen ovale. It is still not FDA approved for other types of atrial septal defects like primum, sinus venosus and coronary sinus. With proper patient's selection it has been found to be as successful, safe and effective as surgical closure. Additionally, it was associated with fewer complications and decreased average hospital stay compared to surgical closure.

Mechanisms of benefit
In percutaneous closure of atrial septal defects a self-expandable round disc is placed around the defect that prevents the left-to-right shunting of blood across the lesion. The mechanical prevention of this shunting helps in improvement of circulation in the heart. It has excellent results specially in patients who have not developed irreversible pulmonary artery disease.

Indications
The percutaneous closure of atrial septal defects is currently only indicated for the closure of ostium secundum atrial septal defects and patent foramen ovale (patent formen ovale has inter-atrial communications but it is not a true atrial septal defect). In patients with a secundum defect, there must be a sufficient rim of tissue around the defect for successful percutaneous closure.

Contra-indications
It should not be used in patients with primum, sinus venosus and coronary sinus type of atrial septal defects. Surgical closure of ostium secundum atrial septal defect can be done when a concomitant tricuspid valve repair is considered or when the anatomy of the defect doesn't favor a percutaneous device.

Trials comparing percutaneous versus surgical closure
1) In a multicenter, non-randomized study performed in 29 pediatric cardiology centers, the patients were allotted to either the percutaneous closure or the  surgical closure group depending on their preference. The success rate of the surgery was similar in the percutaneous closure and the surgical closure. However, the complication rates were more in the surgical groups (24%) compared to the percutaneous groups (7.2%). Also, the mean hospital stay was 3 days in  surgical group compared to 1 day in the percutaneous device group. Additionally,  surgical closure required sternotomy and cardiopulmonary bypass. With appropriate patient selection, device closure could be very successful. Also, it is safe and effective compared to other modalities.

2) A study done on 45 subjects (15 with percutaneous closure, 15 with surgical correction and 15 control) to evaluate the left and right atrial function after transcatheter atrial septal defect closure compared with surgically treated ASD, using strain (epsilon) and epsilon rate imaging (SR) techniques, found that in the  surgical corrected groups the peak systolic epsilon and SR values were significantly reduced compared to device and control group. Thus, it could be concluded that percutaneous closure helps in conserving both the atrial regional myocardial properties.

Trials testing the efficacy and safety of device closure
1) In a study done on 236 patients with ostium secundum (ASD), to evaluate the safety and efficacy of transcatheter closure with the amplatzer septal occluder, the device was found to be very efficient. It causes atrial septal defect closure in 84.7% of the treated patient population. During a median follow up of 2.3 years complete closure was documented in 94%, with a residual shunt only in 12 patients. Two of the treated patients were reported to have procedure related complications like retroperitoneal bleeding and air embolism.