To start, the Fontan procedure serves as the definitive final stage for single-ventricle palliation. However, achieving Fontan procedure candidacy is not always a guaranteed outcome for every child. Therefore, a 10-year report recently analyzed why some patients experience attrition following their stage 2 surgery. Initially, researchers included 427 patients who underwent superior cavopulmonary anastomosis at a single institution. Notably, 93% of these patients successfully reached the Fontan stage or received a referral for it. In contrast, 31 patients became non-candidates due to various clinical complications.

Barriers to Fontan Procedure Candidacy

Specifically, cardiac reasons accounted for 26 of these non-candidacy cases. For example, univentricular dysfunction and severe atrioventricular valve regurgitation were the primary limiting factors. In addition, respiratory conditions prevented progression in three patients, while miscellaneous reasons affected two others. Furthermore, outcomes differed significantly based on the underlying reason for attrition. Specifically, patients with respiratory or miscellaneous issues remained alive without further surgical palliation during the study. Conversely, cardiac non-candidates faced much poorer prognoses. In fact, 55% of them eventually required a heart transplant or were added to the waitlist.

Clinical Implications for Management

As a result, cardiac health remains the most critical factor for maintaining Fontan procedure candidacy. Moreover, predicting this candidacy before the second stage of surgery remains a significant challenge for clinicians. Similarly, researchers found that a higher incidence of moderate or severe valve regurgitation before stage 2 was a major risk factor. Consequently, early and rigorous echocardiographic screening is essential for identifying patients at risk of attrition. Ultimately, these findings highlight the complex physiological demands required to complete the single-ventricle surgical pathway.

Frequently Asked Questions

What are the primary reasons for Fontan attrition?

Cardiac issues, specifically univentricular dysfunction and significant atrioventricular valve regurgitation, are the leading causes. Respiratory concerns and miscellaneous health conditions contribute to a smaller percentage of cases.

Can patients survive without completing the Fontan stage?

Yes, many patients disqualified for non-cardiac reasons remain alive without further surgical palliation. However, those with cardiac-related non-candidacy often have a higher risk of heart failure and may require a heart transplant.

What markers predict a failure to reach Fontan candidacy?

Moderate or severe atrioventricular valve regurgitation prior to the superior cavopulmonary anastomosis is a significant predictor of attrition. Early detection of these markers through echocardiography is vital for long-term planning.

Disclaimer: This content is for informational and educational purposes only. It does not constitute medical advice or a substitute for professional healthcare. Refer to the latest local and national guidelines for clinical practice.

References

1. Adamson ME et al. A 10-year single-centre report on Fontan attrition and non-Fontan candidacy. Cardiol Young. 2026 Mar 25. doi: 10.1017/S1047951126111354. PMID: 41878897.


2. Rychik J, et al. The Fontan circulation: a review. J Am Coll Cardiol. 2022;79(13):1234-1245.


3. Khairy P, et al. Fontan survivors: the next generation. Circulation. 2014;130(10):1001-1005.