Super-Mini Percutaneous Nephrolithotomy (SMP) Versus Retrograde Intrarenal Surgery (RIRS) for Symptomatic Lower Pole Renal Calculi of 10-20 mm Size: a Randomized Controlled Trial (IAU-01)

To evaluate the efficacy and safety of SMP and RIRS for the treatment for symptomatic lower pole calculi renal calculi measuring 10-20 mm.Investigators will do a multi-centers international randomized controlled trial(RCT)，and investigators plan to perform this study in 10 hospitals，which are the First Affiliated Hospital of Guangzhou Medical University of China, Department of Urology, Renmin Hospital, Wuhan University of China, Shenzhen People's Hospital of China, The Second Affiliated Hospital of Zhengzhou University of China, The Second Affiliated Hospital of Harbin Medical University of China, Zhujiang Hospital of Southern Medical University of China, Jiangsu Province hospital, The First Affiliated Hospital With Nanjing Medical University of China, Zhejiang provincial people's hospital of china, Dr. Lutfi Kirdar Training and Research Hospital of Turkey and Global Rainbow Healthcare of India respectively.

Investigators plan to beginning their study at August in 2015 and end at July in 2017.One hundred and sixty patients with symptomatic lower pole calculi renal calculi measuring 10-20 mm will be enrolled in this study. By simple random sampling technique, patients will be assigned to two 80-patient groups.All the patients will be diagnosed definitely before operations with non-contrast CT.Patients with positive preoperative urine culture should be treated with suitable antibiotics based on the culture sensitivity result for at least 72h before SMP/RIRS. Patients who have negative urine culture should receive a single dose of broad spectrum antibiotic prophylaxis just prior to the procedure.

Surgical technique

SMP

All the biochemistry tests and preoperative preparations are referenced to the mini-PCNL. Under general anesthesia a 6 French(Fr).Open end ureteral catheter is first inserted in to the relevant ureter. Patient is then turned into prone position and the desired calyx is punctured under fluoroscopic or sonographic guidance. Nephrostomy tract dilation is carried out using fascial dilators up to 12-14 Fr. as indicated. Corresponding size of suction-evacuation sheath was placed. The sheath is connected to the specimen collection bottle and the bottle then onto the aspirator. A rubber cap with a center aperture was placed at the proximal end of the sheath. The negative pressure aspirator was adjusted to a setting of 150-200 mm Hg. The miniature endoscope is inserted into the sheath through the cap. Stone is visualized and lithotripsy is performed using either Holmium-yttrium aluminum garnet(YAG) laser or pneumatic lithotripsy. At the end of procedure fluoroscopic images are obtained to assess stone clearance status. Double J ureteral stent is placed only in the presence of ureteral inflammatory polyp; evidence of ureteropelvic obstruction; presence of significant pyelocalyceal blood clots following lithotripsy; significant residual stones. Indications for nephrostomy tube placement included: significant residual stone fragments which would require a second look procedure; significant pyelocalyceal blood clots or bleeding after lithotripsy (because the nephrostomy tube could tamponade the access tract and drain the urine and clots).