A Prospective Comparison of Fluoroscopic, Sonographic or Combined Approach for Renal Access in Percutaneous Nephrolithotomy
Condition: Urolithiasis
MeSH terms: Urolithiasis
Study type: Interventional

Summary: 
      Purpose:

      The aim of this present study is to compare the result of fluoroscopy, ultrasonography (US)
      and US combined with fluoroscopy in the guidance of minimally invasive percutaneous
      nephrolithotomy (MPCNL).

      Methods:

      The investigators will enroll 450 patients who are candidates for MPCNL in our study. By
      simple random sampling technique, patients will be assigned to three 150-patient groups
      (group 1, US-guided MPCNL, group 2, fluoroscopy-guided MPCNL and group 3, US combined with
      fluoroscopy-guided MPCNL). In addition to approaches in guidance of MPCNL, the rest of the
      procedure is the same in all three groups.The end point of the study is the comparison of
      outcome of procedure including stone free rate, transfusion rate, operation time, access
      time, length of stay and complications.
    

Detailed description: 
      Purpose:

      Recently, PCNL or MPCNL is widely used as the most popular choice to treat patients with all
      types of renal stones. Successful puncture to the desired renal calyx is the key step for the
      operation. Nowadays puncture for renal access can be achieve using not only US guidance but
      fluoroscopy guidance as well. However, it is clear that there is a lack of randomized
      controlled data comparing fluoroscopy, US and US combined with fluoroscopy in the guidance of
      MPCNL. Consequently, we performed this randomized controlled trial to obtain higher grade
      evidence.The aim of this present study is to compare the result of fluoroscopy, US and US
      combined with fluoroscopy in the guidance of MPCNL.

      Methods:

      We will enroll 450 patients who are candidates for MPCNL in our study. By simple random
      sampling technique, patients will be assigned to three 150-patient groups (group 1, US-guided
      MPCNL, group 2, fluoroscopy-guided MPCNL and group 3, US combined with fluoroscopy-guided
      MPCNL).

      All the patients will be diagnosed definitely before operations with kidney, ureter, and
      bladder (KUB), intravenous pyelography (IVP), US and/or CT.

      All procedures are performed by urologists in our center, with assistance from an endourology
      fellow.

      Surgical technique:

      Under general or epidural anaesthesia, each patient is initially placed in the lithotomy
      position, and a 5 Fr ureteric catheter is advanced to the kidney and fixed with a 16 Fr Foley
      catheter. Then the patient is turned to the prone position.

      Group 1: US-guided MPCNL The puncture is made with an 18-gauge needle using an ultrasound
      probe. After the desirable calix is reached, a flexible-tip guidewire is introduced. We
      attempt to manipulate the guidewire down to the ureter. If this is not successful, the second
      choice is to allow the guidewire to coil in a more distant calix. The length of the needle
      from skin to the collecting system is measured to ensure that the length of dilator is
      appropriate. The access tract is dilated from 8 Fr to a maximum 18/20 Fr using fascial
      dilator. We defined access to the collecting system as gaining entry to the targeted urinary
      system and desired calix.

      Lithotripsy is performed using either pneumatic lithotriptor or holmium laser. When multiple
      nephrostomy tracts are necessary to remove the stones, same technique is employed for each of
      the tracts.

      Complete stone clearance is confirmed using US at completion of the procedure. We routinely
      put a double J ureteral catheter into the ureter which is to be removed about 3-4 weeks later
      after the operation in the out-patients clinic. At the end of the procedure nephrostomy tubes
      are placed in both groups. The tubes are removed when the drainage from nephrostomy tubes
      being grossly clear.

      Group 2 fluoroscopy-guided MPCNL Patients in group 2 have the standard fluoroscopy-guided
      renal access before MPCNL. Air or contrast medium is injected through the ureteral catheter,
      the target calix is identified. For tract dilatation fascial dilators are used under
      fluoroscopic guidance.

      Complete stone clearance is confirmed fluoroscopically at completion of the procedure.

      The rest of the procedure is the same as described for patients in group 1.

      Group 3 US combined with fluoroscopy-guided MPCNL:

      Under the guidance of ultrasound, the coaxial needle is placed in the desired calyx. A
      floppy-tipped guidewire is then passed through the needle into the collecting system. The
      working channel is then dilated under X-ray.

      US and X-ray check for residual stone fragments are performed at the end of the procedure.

      The rest of the procedure is the same as described for patients in group 1.

      Data collection:

      Data for the three groups -demographic characteristics, access success, access time, duration
      of radiation exposure, site of target calix, site of access, Hb decrease, duration of
      postoperative hospital stay, complications (modified Clavien system), stone clearance (SFR
      after single procedure and final SFR) and the need for auxiliary treatment - are compared.

      The primary end point of the study is the comparison of outcome of procedure including stone
      free rate, transfusion rate, operation time, access time, length of stay and complications.
    

Intervention name(s): US-guided renal access; Fluoroscopy-guided renal access; US combined with fluoroscopy-guided renal access
Intervention type(s): Procedure; Procedure; Procedure
Intervention description(s): Patients undergo MPCNL using only US-guided renal access.; Patients undergo MPCNL using only fluoroscopy-guided renal access.; Patients undergo MPCNL using US combined with fluoroscopy-guided renal access
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: PCNL; MPCNL; guidance; puncture