Ultrasound-guided Mini-percutaneous Nephrolithotomy For The Management Of Small-size Renal Calculi In Mild-hydronephrosis

Objective: To evaluate the efficacy and safety of management of small-size renalcalculi and upper ureteral calculi which diameter of1～2cm in mild-hydronephrosisby mini-percutaneous nephrolithotomy (MPCNL) under ultrasound guidance.Patients and methods: Between March2012and September2013, there were90patients with1～2cm renal calculi and upper ureteral calculi in mild-hydronephrosiswere applied to this procedure. All MPCNL were made by the urologist under B-typeultrasound guidance in the prone position. The data were analyzed for the success rate,the operation time, the intraoperative complications，the postoperative complicationsand the stone clearance.Results: The percutaneous renal access was successfully established under B-typeultrasound guidance in all patients. Immediate phase I lithotripsy was performed in87cases and delayed phase II lithotripsy in3cases. The puncture time ranged from5minutes to15minutes, average time was7minutes and the operation time rangedfrom10minutes to80minutes, average time was40minutes. Stones were cleared in80out of90cases (88.9%) during one MPCNL, completely removed in72cases and8cases had clinically insignificant residual fragment. And the residual fragment wasfound in10cases who received second MPCNL, adjuvant extracorporeal shock wavelithotripsy(ESWL) and medical expulsive therapy(MET). The total clinicallysignificant complications were20%, included infection and fever(3cases of bodytemperature <38.5℃and2cases of body temperature≥38.5℃), postoperativehemorrhage and hemoglobin decreased significantly in3cases, mild pain in7cases and moderately severe pain needed significantly analgesic treatment in3cases. Othersevere complications as urinary fistula, hemopneumothorax, organ damage and othercomplications did not occur during hospitalization.Conclusion: The management of1～2cm renal calculi and upper ureteral calculi inmild-hydronephrosis using MPCNL under B-type ultrasound guidance appears to beefficacy and safety, with higher success rate and stone clearance rate, whilecomplications are acceptable. Ultrasound-guided Mini-percutaneous nephrolithotomyis one of the important methods of treating such stones.