SMP vs RIRS for Symptomatic Lower Pole Renal Calculi of 10-20 mm Size: a Randomized Controlled Trial
Condition: Renal Calculi
MeSH terms: Kidney Calculi; Nephrolithiasis; Calculi
Study type: Interventional

Summary: 
      Shock wave lithotripsy (SWL) is recommended for kidney stones < 20 mm. However, the stone
      clearance of lower pole calculi after SWL is limited, thus leading to an extended indication
      for mini-percutaneous nephrolithotripsy (PCNL) even for stones between 10 and 20 mm in many
      centers. This trend is further promoted by introduction of super-mini PCNL (SMP), which is
      postulated to be less invasive compared to mini-PCNL due to the miniaturized instruments.
      However, this issue remains controversial.

      On the other hand, improvements in endoscopy technology have made retrograde stone removal
      more attractive. This has led to an increasing use of RIRS as a primary treatment although it
      is recommended only as 2nd-line option by current guidelines. However, the treatment of
      symptomatic lower pole calculi is a challenge for RIRS because of lower clearance rates.

      The purpose of this study is to evaluate the efficacy and safety of SMP and RIRS for the
      treatment for symptomatic lower pole calculi renal calculi measuring 10-20 mm.
    

Detailed description: 
      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).

      RIRS

      The patient is placed in the lithotomy position, Cystoscopy and retrograde pyelogram were
      preformed, and a 0.035'' flexible tip guidewire is placed into the renal pelvis. A 12 Fr/ 14
      Fr ureteral access sheath (UAS) is advanced into the proximal ureter over the guidewire, and
      a P5 or P6 Olympus flexible ureteroscope is passed through the UAS. The stones are fragmented
      using a 200um holmium laser fibre at a 8-25 weeks energy setting. Some fragments are removed
      using a stone basket for stone analysis, and the remaining stone fragments smaller than 2 mm
      were left for spontaneous passage. A 5 Fr or 6Fr pigtail stent is placed at the conclusion of
      the procedure. Double J stents were removed post-operative 2 weeks.

      Data collection

      Data for the 2 groups-demographic characteristics,hemoglobin(HB) decrease, postoperative
      pain, duration of postoperative, hospital stay, complications (modified Clavien system),
      stone clearance (SFR after day 1 and final SFR) and the need for auxiliary treatment are
      compared.

      Mean study endpoint: The primary endpoint was the SFR at 3-months after surgery.

      Secondary endpoint: Complications, duration of postoperative and hospital stay. re-SMP,
      ureteroscopy and SWL are considered as auxiliary treatments. Demographic characteristics
      include age, sex, BMI, stone size and location, etc…

      The stone size is defined as the maximum diameter as determined by CT scans.

      Degree of hydronephrosis are assigned as follow: none (no calyx or pelvic dilation), mild
      (pelvic dilatation alone), moderate (mild calyx dilation), or severe (severe calyx dilation
      or calyx dilation accompanied by renal parenchyma atrophy).

      Definition of operation time:

      For SMP: recorded from the time of the first percutaneous renal puncture to the completion of
      the stone removal.

      For RIRS: recorded from insertion of an endoscope into the urethra to the completion of stent
      placement.

      Hospital stay are rounded to the nearest whole day and calculated from the day of surgery to
      the day of discharge.

      Postoperative pain (visual analogue scale(VAS), use of analgesics) and Postoperative comfort
      scores (Bruggrmann comfort scale，BCS) will be recorded.

      The rate of hemoglobin decrease is assessed by comparing the preoperative Hb level with
      24-hour postoperative Hb level.

      SFR is assessed by KUB and ultrasound at 1-day after operation.

      Non-contrast CT is obtained for all patients at 3 month after the operation to evaluate the
      final SFR, allowing time for the spontaneous passage of stone fragments.

      Stone-free status are defined as either the absence of any residual stone fragments or the
      presence of clinically insignificant residual stone fragments in the kidney which were
      defined as ≦ 3mm, asymptomatic, non-obstructive and non-infectious stone particles.

      If the procedure is considered as successful, the pigtail stent is removed as outpatient
      after 2 weeks. Follow-up including non-contrast CT will be generally scheduled in 3 month.

      Bleeding severity is judged by the treating physician, and transfusions are administered
      according to local practice guideline.

      Complications of all patients are recorded according to modified Clavien classification
      system.
    

Intervention name(s): Super-Mini Percutaneous Nephrolithotomy; Retrograde Intrarenal Surgery
Intervention type(s): Procedure; Procedure
Intervention description(s): Patients undergo Super-Mini Percutaneous Nephrolithotomy; Patients undergo Retrograde Intrarenal Surgery
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Super-Mini Percutaneous Nephrolithotomy; SMP; Retrograde Intrarenal Surgery; RIRS; Randomized Controlled Trial; RCT