Antegrade Ureteral Stenting in Pediatric Patients: Introducing a Novel Ureteral Morphological Classification and a New Perspective on Functional Success.

Background/Objectives: The objective of the current research is to assess the benefits that come with antegrade ureteral stenting coupled with imaging techniques in children and also provide a new classification based on the ureter's morphological elements. Methods: Between 2011 and 2024, 107 antegrade stent placement procedures performed in 71 pediatric patients aged 0-12 years who could not undergo retrograde double-J stent placement were retrospectively analyzed. According to the morphologic structure of the ureter, four categories were classified as normal, straight/slightly angled, S-shaped, and spiral-shaped. Functional success was evaluated by comparing the results of ultrasonography and Tc-99m MAG3 scintigraphy before and after the procedure. Results: Technical success rate was 99.1% and functional success rate was 84.1%. Intra-procedural complication rate was 5.6% and post-procedural complication rate was 39.3%. According to morphologic classification, the functional success rate was lowest in spiral-shaped ureters with 79.5%, but this difference was not statistically significant (p = 0.775). There was no significant correlation between stent diameter, balloon dilatation, and degree of hydronephrosis and functional success. Conclusions: Antegrade ureteral stent placement is a safe method with high technical success and acceptable complication rates in pediatric patients. The developed ureteral morphologic classification may guide clinical practice.