*4.3.2 Stage IIIB*

In the final stage, Stage IIIB, the fenestration is closed (**Figures 7b**, **8b**, and **9B** and **C**) by transcatheter methodology [27, 30–35], usually 6–12 months after Fontan Stage, IIIA. In the past, most devices used to occlude ASDs [32–35] were employed for this purpose, but at the present time, Amplatzer septal occluders are the most commonly used devices to accomplish such closures. If there are any other residual shunts, they should also be occluded (**Figure 10**) by device closure.
