Super mini-percutaneous nephrolithotomy by ultrasound-guided for upper urinary tract stones

Abstract

Objective To evaluate the safety and efficacy of super mini-percutaneous nephrolithotomy (SMP) by ultrasound-guided for upper urinary tract stones. Methods The SMP procedure was done using a 7F mini-nephroscope with 3.3 F working channel and a 12 or 14 F nephrostomy sheath that possessed suction-evacuation function.The sheath was connected a specimen container then onto a negative pressure aspirator.Lithotripsy was performed using holmium: YAG laser and/or pneumatic lithotripter.From May 2015 to June 2016, 80 patients with upper tract stones underwent the SMP by ultrasound guidance. The ages of patients were 11 months 81 years.The stone ranged in size from 0.8~3.5 cm , mean(1.7±0.6)cm.Among the 80 patients, single pelvis stones in 28 cases, pelvic-low pole in 26 cases and upper ureter stones in 16 cases, pelvic-upper ureter in 3 cases, renal calculi with diverticulum in 5 cases and double renal pelvis and double ureter in 2 cases were found. Results All patients had a single stage of calculi, single channel in 79 cases, and double channel in one case. Thirty-three cases with F12 channel, 47 cases with F14 channel were found. Mean operative time was 6~70 min, mean(28.5±15.4)min .The stone free rate after 1 day was 95%(4/80). The stone-free rate at 1 month was 97.5%. The hemoglobin drop was 0~35 g/L, mean(12.8±9.5)g/L. Fever occurred in 2 cases.No one needed blood transfusion. None of the patients had nephrostomy tube and 76 patients had neither Double-J stent nor Foley catheter placed.The average hospital stay was 1~4 days, mean (2.20±0.75) days. Conclusions SMP with a suction-evacuation system is a safe and efficacious procedure for upper urinary tract stones smaller than 2.5 cm.It may be particularly suitable for children, patients with lower pole stones, and residual stones after previous surgical interventions. Key words: Urinary Calculi; Nephrostomy, Percutaneous