Intraluminal micro-stenting improves urinary tract reconstruction in murine kidney transplant model

BACKGROUND: Urinary tract reconstruction is a key technical barrier in murine kidney transplantation due to the tiny ureteral caliber. Conventional methods are technically demanding with high morbidity. This study assesses a refined intraluminal stenting approach for better surgical stability, fewer complications, and preserved anti-reflux structural anatomy of the ureterovesical junction. We performed 88 orthotopic mouse kidney transplantations using three distinct reconstruction modalities: bladder patch (n = 31), ureter implantation (n = 28), and intraluminal stenting (n = 29). The stenting protocol utilized a micro-polyethylene (PE) stent to achieve end-to-end ureteral alignment. Outcomes included operative efficiency, learning curve trajectories, postoperative survival, and urinary-related morbidity. RESULTS: The stenting cohort achieved a 14-day survival rate of 96.6% (28/29), significantly higher than the bladder patch group (67.7%, 21/31; p = 0.006), while the difference compared with the ureter implantation group (82.1%, 23/28) did not reach statistical significance (p = 0.102). Intraluminal stenting markedly reduced reconstruction time (8'22''±0'41'', p < 0.05 vs. both control groups) and was associated with an accelerated proficiency acquisition curve. The overall urological morbidity in the stenting group was 10.3% (3/29), consisting of 1 case of mild urinary leakage and 2 cases of mild hydronephrosis, which was significantly lower than in the bladder patch (58.1%, 18/31) and ureter implantation (42.9%, 12/28) cohorts (p < 0.05 for morbidity comparison). Notably, this approach effectively precluded severe complications including ischemic necrosis, ureteral dislodgement, and obstruction, with no urinary tract reconstruction-related deaths observed. CONCLUSIONS: This retrospective study shows that the intraluminal stenting technique offers a reliable and highly reproducible approach for urinary tract reconstruction in murine kidney transplantation. This modality significantly minimizes technical complexity and postoperative morbidity, and maintains the intact ureterovesical anatomy that provides the structural foundation for physiological anti-reflux function. It provides an optimized surgical platform for short-term experimental protocols, particularly in acute rejection research.