OBJECTIVETo analyze factors influencing the choice of atrial septal occluder (ASO) for transcatheter closure of patients with secundum atrial septal defect (ASD).

METHODSA total of 1114 ASD patients [388 males, aged from 2 to 75 years, mean age (26.3 +/- 17.0) years] were enrolled. Patients were divided to adult (> 14 years, mean 34.4 years, n = 779) and child (< or = 14 years, mean 7.3 years, n = 335) groups. ASD size in different ultrasound cross-sections was determined by transthoracic echocardiography (TTE). ASO size was chosen on the basis of the maximum diameter of the defect (MD). Defect-shapes and rim lengths of ASD, the difference choice of ASO in the two groups were compared.

RESULTSMD of the defects ranged from 5 to 40 mm [mean (19.7 +/- 7.8) mm]. ASD was successfully occluded in 1085 out of 1114 patients (97.4%). Occluder size ranged from 6 to 46 mm [mean (25.8 +/- 8.9) mm] and the difference between occluder size and MD ranged from 2 to 10 mm [mean (6.1 +/- 3.4) mm, ASO/MD ratio 1.3:1]. Though the diameter of the defect was similar between the 2 groups, the size of occluder was significantly larger in adult group than that in child group (ASO/MD ratio 1.1 - 1.6:1 vs. 1.2 - 1.8:1, P < 0.05). MD was significantly correlated with ASO in both groups (r = 0.911 and r = 0.944 in adults and child groups, respectively, all P < 0.01). The size and increment of the occluder used in patients with deficient anterior rims was significantly bigger than patients with sufficient anterior rims (P < 0.01).

CONCLUSIONThe maximum diameter of the defect was the major determinant for selecting occluder size and choice of occluder size was also influenced by patient age, defect-shape and defect rim for transcatheter closure of secundum ASD.