Commentary: Thinking inside and outside of the box with intraextracardiac Fontan.

What is the most optimal way to palliate univentricular physiology? We are reviewing a manuscript by Simsek and colleagues in the Journal of Cardiac Surgery-describing their experience with the intraextracardiac Fontan procedure (IECF). They report encouraging early results in 17 patients who underwent the procedure between 2014 and 2021 and clearly describe their operative technique and variant anatomy they encountered. There are now at least four generations of Fontan procedures, each attempting to palliate while maintaining appropriate hemodynamics as long as possible. IECF provides a good option for cavopulmonary bypass as it avoids pitfalls of prior generations. It may be even more favorable in situations with additional anatomic complexity. We look forward to seeing the long-term outcomes of the IECF.