Re-accessing previously implanted stents in children with complex congenital heart disease presents significant technical challenges, particularly when severe angulation or tortuosity makes true lumen entry nearly impossible and the guidewire instead passes through a stent strut. In this retrospective case series, we describe the Cell-to-Lumen Wire Switch Technique as a novel and effective solution to this problem. The study included 14 pediatric patients (median age: 12 months) who had previously undergone stent implantation in either the right ventricular outflow tract (RVOT) or a vertically oriented ductus arteriosus. The technique involved advancing an initial guidewire through a stent cell to guide catheter positioning, followed by the insertion of a second wire through the true stent lumen to achieve coaxial alignment. In four cases with severe angulation or vertical ductal orientation, a modified approach was used, employing support wires placed either from the right ventricle across the aortic valve or from the carotid artery into the descending aorta to facilitate catheter positioning. All patients successfully underwent re-access using this technique without acute or delayed complications. Balloon dilatation was performed in eight patients, re-stenting in three, while three required no further intervention. The Cell-to-Lumen Wire Switch Technique proved to be a safe, reproducible, and hardware-sparing method that may offer particular advantages in small children where anatomical constraints make conventional dual-wire or buddy wire strategies impractical. This technique expands the interventional toolkit for complex re-access scenarios in pediatric patients.