Stone Disease

Abstract

INTRODUCTION AND OBJECTIVE: RIRS is useful in the management of small renal calculi (<2cm), however in developing countries PCNL provides alternative which is economical and provides stone clearance in single stage. Miniaturized PCNL are associated with lesser complications compared to standard PCNL. But concerns in the miniaturized PCNL remains about stone clearance. To address this concern, the current miniPCNL that is Super-mini PCNL (SMP) was designed for effective stone clearance with fragments removal by irrigation/suction and fragment extraction by smaller stone removal forceps and with added advantage to prevent excessive intrarenal pressure and improved visualization. There is lacunae of data comparing the results of this Super mini PCNL procedure with standard PCNL. In the present study, the primary objective is to compare the efficacy (stone-free rate) between SMP and standard PCNL. The secondary objectives are to compare the safety (blood loss, complications), operative time, length of hospital stay and post-operative pain score and analgesic requirement. METHODS: 150 patients presenting with renal calculi < 2 cm were randomized to a standard or a Super-mini PCNL group between September 2018 and April 2019. Randomization was based on centralized computer-generated numbers. In SMP, sheath is of 14-Fr size with internal working channel of 12.5 Fr and an oblique channel to which suction was attached. This oblique part consists of a pressure vent through which pressure can be adjusted by either partially or completely occluding the pressure vent with the surgeon's thumb. Irrigation into pelvi-calyceal system is through a 6 Fr ureteric catheter (with multiple holes at the proximal 5 cm) placed in the ureter. With active suction, the dust and tiny stone fragments would pass through the oblique channel into the collecting bottle of suction. The larger fragments were extracted using a 3Fr grasper. In standard PCNL, 24-28 Fr amplatz sheath and 20.8 / 26 Fr nephroscope were used to manage the calculus. Variables studied were stone free rates, operating time, intraoperative and postoperative complications (according to the ClavieneDindo classification system), postoperative pain score, analgesic requirement and hospital stay. Statistical analysis was performed using a t-test for continuous variables with normal distribution and a ManneWhitney U-test for variables without normal distribution. For categorical variables, the chi-squared test or Fisher's exact test was applied. A P value <0.05 was considered to indicate statistical significance. RESULTS: Comparison of intra-operative and postoperative variables in the two study groups. CONCLUSIONS: Super-mini PCNL offers equal stone clearance rate compared to standard PCNL, however it is more safe when compared to standard PCNL in-terms of complications. Even though SMP has more operative time compared to standard PCNL, it has significantly less intra-operative and post-operative bleeding with less post-operative pain score and thereby less hospital stay and lesser Clavien Dindo complications. Source of Funding: nil