Earlier Fontan Candidacy Determination: A Focus on Anatomic and Physiologic Variables

Timing and patient selection for Fontan palliation in single-ventricle congenital heart disease remain subjects of debate. An early Fontan procedure can limit long-term morbidity after total cavopulmonary connection, yet patient-specific anatomic and physiologic variables may limit candidacy. Weight thresholds are often applied to anticipate physiologic tolerance and acceptable achievable conduit size. The purpose of this study was to evaluate outcomes within a single, high-volume center by using anatomic and physiologic variables rather than a weight threshold for Fontan candidacy.

A retrospective cohort study was conducted on patients undergoing extracardiac conduit Fontan palliation between 1998 and 2021. After multidisciplinary determination of Fontan candidacy, patients were stratified by weight at surgery: <12 kg (n = 30) and ≥12 kg (n = 175). Pre- and post-Fontan hemodynamics, conduit size, and postoperative outcomes were compared.

Preoperative hemodynamics were comparable between the groups. Postoperatively, patients weighing <12 kg had higher pulmonary vascular resistance (2.59 WU vs 1.78 WU; P = .005), yet 30-day outcomes, including Fontan failure, length of stay, and mortality, were comparable. At a median follow-up of 7.5 years, there were no significant differences in survival, need for heart transplantation, or major complications. Smaller conduits in patients ≥12 kg were associated with increased protein-losing enteropathy (P = .046).

Fontan palliation can be safely performed in select patients weighing <12 kg, a finding supporting a strategy based on anatomic and physiologic variables over a strict weight threshold. Despite comparable clinical outcomes, higher pulmonary vascular resistance in smaller patients warrants longitudinal follow-up. Achievement of a satisfactory conduit size remains an important consideration and determinant of outcomes independent of weight.