Study Limitations
The nature of the data currently available in the published literature carries its own inherent limitations. Patients with multiple defects and the Swiss-cheese septum undergoing different types of surgical procedures, and transcatheter/hybrid closure are small in number, with incomplete follow-up. This makes it difficult to draw long-term conclusions at this stage. The numbers of patients reported with the different anatomical sub-sets, including the Swiss-cheese variety, were not large enough for analysis to be convincing, although the results are consistent with the clinical practice. Thus far, furthermore, patients have not been randomized between surgical, and interventional or hybrid closure, thus meaning that comparisons between the groups may be biased. Experienced hands, with highly specialized backup, must be available for safety. Whereas the long-term safety and efficacy of surgery are well documented, the long-term results of device closure are unknown. Future prospectively designed multicentric studies with larger sample sizes will be needed to substantiate our inferences made on the basis of from the published literature.