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Background: Data on balloon-assisted techniques (BAT) for transcatheter closure (TCC) of ostium secundum atrial septal defect (ASD-II) is scarce. The objective was to study the outcomes of the balloon-assisted technique (BAT) for transcatheter closure (TCC) of ostium secundum atrial septal defect. A single-centre retrospective study of patients with ostium secundum ASD who underwent balloon-assisted TCC. Results: This study included 36 patients. Thirty-three out of 36 patients with ASD-II and complex morphological features underwent successful BAT TCC. Our cohort of patients had a high prevalence of inadequate/floppy Aortic (90%), Posterior (40%) and Superior/Right upper pulmonary vein (25%) rims. Procedural success was defined as stable device position on post-procedure echocardiogram at 24-48 hours with no residual shunt. BAT was successful in 33 out of 36 patients (91.6%). The mean ASD size with BAT success was 27 mm. BAT was unsuccessful in 3 out of 36 patients. The combined deficiency and floppy nature of the Aortic, Superior, and Posterior rims was the reason for the failure of the Balloon-assisted technique along with the large size of ASD-II. BAT-failed patients were referred for emergent surgical device retrieval and closure of the atrial septal defect. No procedure-related mortality was encountered. Conclusions: Balloon-assisted device closure of ASD had a 90% success rate. BAT is a safe and effective technique in patients with large ASD-II. This technique enables controlled device delivery and alignment when conventional techniques fail.

This paper presents the automated system for minimizing the deviation of the path of passage and the divergence of a secondary radiation source with parameters similar to ones of the main beam of a high-power Ti:Sa laser using mirrors in kinematic mounts on the motorized stages. As an alignment laser, the diode laser with a fiber output was used with radiation characteristics coinciding with the parameters of the main beam (wavelength, beam diameter). The successive approximation algorithm was used to minimize the beam deflection. The positioning accuracy and beam size matching were analyzed on the near-field camera and were equaled to 28.6 µm along the X-axis and 26.4 µm along the Y-axis. Beam size mismatch was equaled to 0.151 mm. The pointing accuracy was analyzed on the far-field sensor and equaled 15.34 µrad along the X axis and 12.03 µrad along the Y axis. The curvature of the wavefront was 0.06 µm.