STONE-FREE RATE AND PREDICTORS OF SUCCESS AFTER RETROGRADE INTRARENAL SURGERY FOR RENAL STONES

Abstract

Background: Retrograde intrarenal surgery is widely used for the minimally invasive management of renal stones. Objective: To determine the stone-free rate following retrograde Intrarenal surgery and identify predictors of successful stone clearance. Methodology: This prospective observational study was conducted at Hayatabad medical complex Peshawar from June 2024 to June 2025 and included 155 adult patients with renal stones undergoing retrograde intrarenal surgery. Demographic characteristics, comorbidities, stone size, burden, number, location, density, operative time, laser time, perioperative complications, hospital stay, and secondary interventions were recorded. Results: The mean age of the patients was 46.8 ± 12.7 years, and 96 (61.9%) were male. The mean stone size was 15.2 ± 4.8 mm, mean stone burden was 182.6 ± 71.5 mm², and mean stone density was 1046 ± 286 HU. Stone-free status was achieved in 132 (85.2%) patients, while 23 (14.8%) had residual fragments. The mean hospital stay was 1.6 ± 0.8 days. Postoperative fever occurred in 10 (6.5%) patients, urinary tract infection in 8 (5.2%), readmission in 5 (3.2%), and major Clavien–Dindo grade III or higher complications in 3 (1.9%). Compared with patients with residual stones, stone-free patients had smaller stones (14.3 ± 4.2 vs. 20.4 ± 4.8 mm), lower stone burden (169.2 ± 64.7 vs. 259.4 ± 58.6 mm²), lower stone density (998 ± 251 vs. 1322 ± 273 HU), and shorter operative time (68.7 ± 16.2 vs. 93.8 ± 17.5 minutes); all p-values were <0.001. Conclusion: It is concluded that retrograde intrarenal surgery provides a high stone-free rate with low major morbidity. Smaller stone size, lower density, single-stone disease, and shorter operative time were associated with successful clearance, whereas lower-pole location reduced procedural success.