LAUSR

INTRODUCTION & OBJECTIVES percutaneous nephrolithotomy (PNL) is the standard treatment of renal stone more than 2 cm. ultra-mini-percutaneous nephrolithotomy had emerged in the last decade as a new technique in treating renal stones less than 2 cm. in this study we compare between outcomes of (UMP) in modified flank free supine (FFSP), and prone position. MATERIALS & METHODS A prospective randomized study was conducted between January 2016 and April 2020, including 122 patients, divided into two matched groups. Group A included 61 patients who underwent UMP in FFSP, and group B included 61 patients who underwent UMP in a prone position. All patients had a single renal pelvic stone 1-2 cm. Patients with a single kidney, renal anomalies, BMI≥40, history of ipsilateral renal surgery, and age less than 18 years were excluded. In both groups, the dilatation was done up to 13 f; a holmium laser was used through a 9f ureteroscope for fragmentation. Nephrostomy tube and ureteric stent were used only when indicated. RESULTS 122 patients who divided into two groups. The mean age was 40.09±13.63 and 39.67±13.80 years in both groups, respectively. The operative time was 63.64±9.22 and 78.48±9.55 minutes in groups A &B, respectively (P=0.0001). The fluoroscopy time was 3.47±0.56 and 4.45±0.39 minutes in groups A &B, respectively (P=0.0001).no significant difference between both groups regarding operative and post-operative complications. Shift to miniPNL was needed in one patient in group A and four patients in group B due to impaired vision. The hospital stay was 25.36±4.23 and 26.13±4.76 hours in both groups, respectively. The initial stone-free rate was 95.1% and 91.8% in both groups, respectively. CONCLUSIONS ultra-mini-percutaneous nephrolithotomy in modified supine position shows comparable results to the prone position regarding stone-free rate, hospital stay, and perioperative complication, with significantly shorter operative and fluoroscopy time.