Small Left Atrial Size Complicating Percutaneous Transcatheter Device Closure of Secundum Atrial Septal Defect with Conventional Approach

BACKGROUND AND OBJECTIVES Transcatheter device closure becomes the first option for treating secundum atrial septal defect (ASD), but the conventional method is sometimes unsuccessful even when the defect size indicates the closure to be feasible. To increase the success rate, modified methods have been introduced and used. This study aimed to find predictors for using the modified methods in the device closure of secundum ASDs. SUBJECTS AND METHODS Between October 2010 and December 2012, 92 patients with ASDs underwent the transcatheter device closure. We analyzed the sizes of the defect, the surrounding rims, and the ratios of the left atrium (LA) dimensions to the device size in the patients who underwent the procedure either using the conventional or modified methods. RESULTS Among the 88 successful cases (95.7%), 22 patients (25%) required modified methods (12 using pulmonary vein and 10 using balloon). The modified method group had the larger size of ASDs and smaller posterosuperior rim. The mean ratios of the LA anteroposterior diameter, width, and length to the device size were all significantly smaller in the modified methods group than in the conventional group (1.20 vs. 1.56, 1.32 vs. 1.71, and 1.61 vs. 2.07, respectively). We found that the risk factors for the modified methods were smaller retroaortic rim, larger ASD, and smaller LA dimension/device size. CONCLUSION In addition to larger defects and smaller retroaortic rim, the smaller ratios of the LA dimensions to the device size influenced the need for the application of modified methods in the transcatheter device closure of ASDs.