OBJECTIVE Numerous surgical approaches regarding aortic arch advancement for neonatal arch hypoplasia have been described. These repairs can be classified into two categories: those that incorporate a patch and those that do not. The decision between repairs remains largely experiential, rather than empirical, because of the limited number of reported outcomes. We report early outcomes from neonates undergoing modified aortic arch advancement with an anterior patch and our experience using computational fluid dynamic modeling to better understand the hemodynamic consequences associated with this repair. METHODS A retrospective review of neonates undergoing aortic arch advancement with anterior patch in 2014 at a single institution was performed. Anatomical, perioperative, and follow-up data were collected. Three-dimensional cardiac magnetic resonance images were used to generate computational fluid dynamic models of the modified anterior patch and direct end-to-side repairs. Cardiac waveform inputs were simulated and hemodynamic analyzed. RESULTS Ten neonates underwent modified aortic arch advancement. No hemodynamically significant gradients were observed at a median follow-up of 0.77 (0.30-1.2) years. Asymmetrical flow was observed in the end-to-side repair, whereas more concentric laminar flow was observed throughout the modified model. Spatial variations in velocities immediately distal to the anastomosis were greater in the end-to-side model (0.35 vs 0.17 m/s, P < 0.001). Time-averaged variations in wall shear stress during systole were greater in the end-to-side model at the same location (3.44 vs 1.98 dynes/cm, P < 0.001). CONCLUSIONS Early outcomes after the use of an anterior patch for neonatal hypoplastic aortic arch repair show favorable hemodynamic outcomes.