Plain English Summary
Background and study aims
Renal (or kidney) stones are stones that can develop in the kidneys. They are quite common. Many go undetected and are passed out painlessly in the urine. However, they can cause a blockage in the urinary system. Such blockages can cause severe pain. Large kidney stones can be removed by a surgical procedure called percutaneous nephrolithotomy (PCNL). This involves using a thin telescopic instrument called a nephroscope which is passed through the kidney to either pull out the stone r break it into smaller pieces using a laser or pneumatic energy. The procedure requires precise puncture with a needle of the collecting system of the kidney in specific positions which are called as “papillae”. These sites are considered to less prone to bleeding either during or after the surgery. However, there is evidence to suggest that there is no significant bleeding risk if the puncture is made in other positions of the collecting system such as the “infundibulum”, a site that allows easier approach is easier movement of the instrument. This study is looking at whether this is the case.
Who can participate?
Patients with large renal stones.
What does the study involve?
Participants are randomly allocated to one of two groups. Those in group 1 undergo
percutaneous nephrolithotomy with access to the papilla. Those in group 2 undergo the surgery with
access to the infundibulum. All participants are monitored for complications after surgery and whether they need any blood transfusions. They are followed up for three months after surgery.
What are the possible benefits and risks of participating?
Not provided at time of registration
Where is the study run from?
University Hospital of Patras (Greece)
When is the study starting and how long is it expected to run for?
June 2015 to June 2017
Who is funding the study?
University of Patras (Greece)
Who is the main contact?
Professor Evangelos Liatsikos
Randomized trial comparing the surgical outcome and morbidity of the accesses to fornix- papilla to the accesses to the infundibulum of the calyx of the kidney during percutaneous nephtrolithotomy.
The traditional practice of percutaneous nephtrolithotomy uses an access for the pelvicalyceal system through the papilla-fornix of the renal calyx. The access through the infundibulum of the renal calyx is considered as prone to bleeding is performed only in difficult cases in which the papillary access is not possible. The clinical experience of our institution shows that there is no difference in complication rates and morbidity between the papillary and the infundibular access. The current randomized study aims to provide high quality data on the comparison of the above approaches.
Scientific Board of the University Hospital of Patras, 6th Hygeonomic Region of Greece, 27/05/2015, ref: 11393/16-6-2015
Randomised controlled trial
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Not available in web format, please use the contact details to request a patient information sheet. An informed consent form is available in Greek.
Lithiasis of the urinary tract. Large stone in the renal pelvicalyceal system.
Participants are randomly allocated to one of two groups:
Group 1: Undergo percutaneous nephtrolithotomy with access and tract dilation to the papilla of the desired calyx (control)
Group 2: Undergo percutaneous nephtrolithotomy with access and tract dilation to the infudibulum of the desired calyx (intervention)
The intervention performed in all patients is the percutaneous nephrolithotomy (PCNL) which is performed for the management of large renal stones. PCNL is performed with the patient in prone position after the patient is intubated and a ureteral catheter has been inserted to pelvicalcyceal system of the kindey that is going to be treated. Under fluoroscopic guidance the desired renal calyx puncture is made with the use of a 18G needle. The common practice is to puncture the fornix-papilla of the desired calyx (control arm). The procedure can also be performed by puncturing the infundibulum of the desired renal calyx (intervention). The rest of the procedure is performed by inserting appropriate guidewires and dilating the tract to the pelvicalyceal system at a diameter of 30Fr with the use of Amplatz dilators or Balloon dilator. A nephroscope is inserted and the stones to be treated and are detected and removed with the use of clamp or ultrasound lithotripter. At the end of the procedure a Malecot nephrostomy tube is left in place.
The patients are discharged on the 2-3 postoperative day based on the presence of clear urine in the Malecot tube. An KUB x-ray or KUB CT scan are performed for the confirmation of the stone free status on the discharge day after the removal of the Malecot catheter. Blood and serum examinations take place during the hospitalization of the patients.
Primary outcome measure
1. The hemoglobin drop on the first postoperative day and discharge day
2. Need for transfusion during the first postoperative month
Secondary outcome measures
1. Operative time
2. Number of accesses performed
3. Stone free rate (at discharge and 3 months)
4. Complications rate (during the 4 weeks and 3 months postoperatively)
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
Renal stones >2cm in maximal diameter with indication for percutaneous nephrolithotomy.
Target number of participants
Participant exclusion criteria
1. Single kidney
2. Ureteral stone in the same system
3. Stone in diverticulum
4. Concomitant urinary infection
5. Congenital anomalies of the urinary tract
6. Skeletal anomalies
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
University Hospital of Patras
Department of Urology (4th floor) Rion
University of Patras
Funding Body Type
private sector organisation
Funding Body Subtype
Results and Publications
Publication and dissemination plan
The results of the study will be published in an international journal as soon as they are available.
Intention to publish date
Participant level data
Not expected to be available
Basic results (scientific)
See additional file (ISRCTN14679893_BasicResults_23Oct18.pdf)
2017 results in: https://www.ncbi.nlm.nih.gov/pubmed/27869481
- ISRCTN14679893_BasicResults_23Oct18.pdf Uploaded 23/10/2018