A Prospective Comparison of Fluoroscopic, Sonographic or Combined Approach for Renal Access in Percutaneous Nephrolithotomy

A Prospective Comparison of Fluoroscopic, Sonographic or Combined Approach for Renal Access in Percutaneous Nephrolithotomy

A Prospective and Randomized Comparison of Fluoroscopic, Sonographic or Combined Approach for Renal Access in Percutaneous Nephrolithotomy

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.

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.

Patients in Combined-guided group undergo MPCNL using US combined with fluoroscopy-guided renal access.

Stone-free status is assessed by kidneys-ureter-bladder (KUB) or/ and noncontrast CT at day 1 after MPCNL. A stone-free state is defined as no residual stones of diameter >4 mm.

Complication is defined as any adverse event occurred intraoperatively or ≤ 30 days postoperatively. Complications included fever, systemic Inflammatory Response Syndrome, septic shock, extravasations, bleeding necessitating transfusion, and sever bleeding necessitating selective renal artery embolization.

Change in hemoglobin concentration is assessed by comparing the preoperative hemoglobin level with 24-hour postoperative hemoglobin level.

Inclusion Criteria: Normal renal function. American society of Anesthesiology (ASA) score 1 and 2. Absence of congenital abnormalities. Kidney stones of diameter > 2.0cm (including multiple and staghorn stones) Exclusion Criteria: Patients with congenital anomalies, e.g. ectopic kidney, polycystic, horseshoe, or malrotated kidney. Patients who underwent transplant or urinary diversion. Patients with solitary kidney. Patients will be excluded from the study if they undergoing MPCNL have purulent fluid in the initial puncture.

Department of Urology, Minimally Invasive Surgery Center, The First Affiliated Hospital of Guangzhou Medical University

Lu MH, Pu XY, Gao X, Zhou XF, Qiu JG, Si-Tu J. A comparative study of clinical value of single B-mode ultrasound guidance and B-mode combined with color doppler ultrasound guidance in mini-invasive percutaneous nephrolithotomy to decrease hemorrhagic complications. Urology. 2010 Oct;76(4):815-20. doi: 10.1016/j.urology.2009.08.091. Epub 2010 Jun 25.

Mozer P, Conort P, Leroy A, Baumann M, Payan Y, Troccaz J, Chartier-Kastler E, Richard F. Aid to percutaneous renal access by virtual projection of the ultrasound puncture tract onto fluoroscopic images. J Endourol. 2007 May;21(5):460-5. doi: 10.1089/end.2006.0168.

Yan S, Xiang F, Yongsheng S. Percutaneous nephrolithotomy guided solely by ultrasonography: a 5-year study of >700 cases. BJU Int. 2013 Nov;112(7):965-71. doi: 10.1111/bju.12248. Epub 2013 Jul 26.

Li X, Long Q, Chen X, He D, He H. Real-time ultrasound-guided PCNL using a novel SonixGPS needle tracking system. Urolithiasis. 2014 Aug;42(4):341-6. doi: 10.1007/s00240-014-0671-2. Epub 2014 Jun 26. Erratum In: Urolithiasis. 2014 Oct;42(5):473. Dalin, He [corrected to He, Dalin].

Agarwal M, Agrawal MS, Jaiswal A, Kumar D, Yadav H, Lavania P. Safety and efficacy of ultrasonography as an adjunct to fluoroscopy for renal access in percutaneous nephrolithotomy (PCNL). BJU Int. 2011 Oct;108(8):1346-9. doi: 10.1111/j.1464-410X.2010.10002.x. Epub 2011 Jan 20.

Opondo D, Gravas S, Joyce A, Pearle M, Matsuda T, Sun YH, Assimos D, Denstedt J, de la Rosette J. Standardization of patient outcomes reporting in percutaneous nephrolithotomy. J Endourol. 2014 Jul;28(7):767-74. doi: 10.1089/end.2014.0057. Epub 2014 Apr 16.

Basiri A, Ziaee AM, Kianian HR, Mehrabi S, Karami H, Moghaddam SM. Ultrasonographic versus fluoroscopic access for percutaneous nephrolithotomy: a randomized clinical trial. J Endourol. 2008 Feb;22(2):281-4. doi: 10.1089/end.2007.0141.

Desai M, Jain P, Ganpule A, Sabnis R, Patel S, Shrivastav P. Developments in technique and technology: the effect on the results of percutaneous nephrolithotomy for staghorn calculi. BJU Int. 2009 Aug;104(4):542-8; discussion 548. doi: 10.1111/j.1464-410X.2009.08472.x. Epub 2009 Mar 6.

Zhu W, Li J, Yuan J, Liu Y, Wan SP, Liu G, Chen W, Wu W, Luo J, Zhong D, Qi D, Lei M, Zhong W, Zhang Z, He Z, Zhao Z, Lu S, Wu Y, Zeng G. A prospective and randomised trial comparing fluoroscopic, total ultrasonographic, and combined guidance for renal access in mini-percutaneous nephrolithotomy. BJU Int. 2017 Apr;119(4):612-618. doi: 10.1111/bju.13703. Epub 2016 Nov 28.