Objective:

To evaluate the initial causes of contraindication for Fontan completion, the clinical course during follow-up, and outcomes after delayed Fontan completion in patients who initially did not undergo the procedure.

Approach:

• Study Design: Retrospective single-center study reviewing infants with univentricular hearts who underwent BCPS between 1998 and 2022.
• Data Collection: Clinical data were collected from hospital and outpatient records, including demographics, cardiac anatomy, perioperative details, and clinical status.
• Assessment Criteria: Cardiac catheterization assessed pulmonary artery pressure, ventricular function, and significant atrioventricular valve regurgitation.

Key Findings:

• A significant proportion of patients could not undergo Fontan completion due to elevated pulmonary artery pressure, reduced ventricular function, or significant atrioventricular valve regurgitation.
• Some patients were able to achieve Fontan circulation after re-assessment and appropriate medical or interventional therapies.

Interpretation:

Limitations:

• The study is retrospective and conducted at a single center, which may limit generalizability.
• Data availability was restricted, and individual patient consent was waived.

Conclusion: