Abstracts

**Background:** Sterile water has been shown to provide better visual clarity compared to normal saline in transurethral resection of the prostate and percutaneous nephrolithotomy, but its use had not been explored during ureteroscopic lithotripsy (URSL) despite low systemic fluid absorption. This study aimed to compare visual clarity and post-operative outcomes between sterile water and normal saline as irrigant fluids during URSL.

**Methods:** A total of 107 adults aged 18–70 years with ureteric stones were randomized into two groups: Arm A (sterile water, n=53) and Arm B (normal saline, n=54). All patients underwent ureteroscopic laser lithotripsy. Intra-operatively, fluid samples were collected from the ureter for turbidity measurement, and the quality of vision was rated by the surgeon using a 5-point Likert scale. On completion of ureteroscopy, the grade of ureteric injury was recorded. Longitudinal data analysis was performed using generalized estimation equations for turbidity and Likert values. A p-value <0.05 was considered statistically significant.

**Key Results:** Baseline characteristics including age, stone size, and stone location were similar between the two groups. The overall mean Likert score was significantly higher in Arm A (water), indicating better visual clarity (p=0.001). Mean turbidity was significantly lower in Arm A, correlating with a clearer visual field (p=0.01). The rate of mild-grade ureteric injury was lower with water (34%) compared to saline (62%). The additional intervention rate for stone clearance was 5% in Arm A (water) versus 9% in Arm B (saline).

**Clinical Implications:** Sterile water provides superior visual clarity compared to normal saline during URSL, which translates into fewer ureteric injuries and a lower need for re-intervention. These results support the use of sterile water as the irrigant of choice for ureteroscopic lithotripsy, potentially improving surgical safety and efficiency.