Novel lateral tunnel Fontan operation in children promotes continued pathway growth into adulthood.

Objective: Most Fontan operation techniques currently used in children are limited by a blood flow pathway with no growth potential. The external pericardial lateral tunnel Fontan is a novel technique using the patient's pedicled pericardium and atrial wall in situ to create a Fontan pathway. We hypothesize that viable, autologous tissue will allow growth potential of the pathway and adapt to increasing physiologic demands of somatic growth.

Methods: We performed a single-center retrospective review of serial echocardiographic measurements of the inferior vena cava junction and mid tunnel in patients with an external pericardial lateral tunnel Fontan. Linear mixed model and Pearson correlation tests were used for analysis of changes in pathway size with time and body surface area.

Results: A total of 1592 echocardiographic studies from 172 patients up to 23 years after the procedure were identified. Significant enlargement of the pathway at the inferior vena cava junction and mid tunnel was observed over time ( < .0001,  < .0001, respectively). There is a strong positive correlation between increasing size of the inferior vena cava junction and increasing body surface area (R = 0.81,  < .0001). There is also a strong positive correlation between increasing size of the mid tunnel with increasing body surface area (r = 0.67,  < .0001).

Conclusions: The external pericardial lateral tunnel Fontan technique creates a Fontan pathway that enlarges into adulthood. The correlation of increasing pathway size with increasing body surface area suggests pathway growth, responding to increasing physiologic demands of somatic growth into adulthood. Further studies are needed to investigate the impact of this novel technique on Fontan physiology and long-term patient outcomes.