 Objective: To evaluate the efficacy of RIRS in patients with lower pole renal stones of <2.5cm.  Methodology: This Descriptive Case Series was conducted at Urology Department, Galway University Hospital, Galway, Republic of Ireland from 1st January 2018 to 31st December 2018. Total 75 patients with lower pole renal calculi of <2.5 cm in size were included. RIRS was done after completion of all investigations. All patients were given prophylactic antibiotics. Stone free rate 4 month post-operatively was assessed. The stone free rate at the end of 4th month was the endpoint of this study. The collected information was analysed by using SPSS 23. Frequencies and percentages were calculated for qualitative data like efficacy and gender. Mean and SD were calculated for quantitative data like age. Stratification was used for gender, age and stone size to investigate modifiers effects. In post stratification Chi- Square test was used at p value < 0.05 (significant).  Results: Total 75 patients with renal calculi were enrolled. Among these patients, 45(60%) were males, while 30(40%) were females. Age range in this study was from 18 to 65 years with mean age of 42.11±13.55 years. Mean size of the stone was 1.22±0.15. Most of the patients 52(69.33%) had the size of stone <1.25 cm, while 23(30.67%) patients had the size of stone >1.25 cm. Overall success rate with RIRS was 88.0% in patients with lower pole renal calculi.  Conclusion: The technique (RIRS) are safe and effective for stones, with best success rate, low morbidity and proper duration of operation.

Keywords : Retrograde Intra Renal Surgery (RIRS), Lower Pole Renal Calculi.