Which Patinets Benefit More From Percutaneous Nephrolithotomy? A Location-Based Comparative Analysis of PCNL and RIRS for 1-2 cm Renal Stones

This prospective randomized controlled trial aims to compare the clinical efficacy and safety of Percutaneous Nephrolithotomy (PCNL) and Retrograde Intrarenal Surgery (RIRS) for renal stones measuring 10-20 mm. The study specifically investigates whether the anatomical location of the stone (upper, middle, or lower calyx) influences the success rates and stone-free outcomes of these two surgical modalities. A total of 110 patients were randomized into two equal groups to evaluate primary endpoints, including stone-free rates at the 3-month follow-up, and secondary endpoints such as operative time and complication rates

Study Overview

• Status: Completed
• Conditions: Kidney Calculi Nephrolithiasis Urolithiasis Renal Stone
• Intervention / Treatment: Device: Percutaneous Nephrolithotomy (PCNL); Device: Retrograde Intrarenal Surgery (RIRS)

Detailed Description

n this prospective randomized controlled trial, 110 adult patients diagnosed with a single non-staghorn renal stone measuring 10-20 mm were enrolled. The study was conducted at Kırıkkale High Specialization Hospital between the specified study dates. Participants were randomized in a 1:1 ratio into two treatment arms: Percutaneous Nephrolithotomy (PCNL) and Retrograde Intrarenal Surgery (RIRS). Randomization was implemented using a computer-generated sequence to ensure unbiased allocation.

The primary objective is to compare the stone-free rates (SFR) between the two surgical techniques at the 3-month postoperative mark, as confirmed by non-contrast computed tomography. A secondary and key focus of the study is the impact of stone localization (upper, middle, and lower calyx) on the success of each procedure. Additional outcomes evaluated include total operative time, hospital stay duration, hemoglobin level changes, and postoperative complication rates according to the Clavien-Dindo classification system. The results aim to provide a location-based surgical selection framework for mid-sized renal stones.

• Study Type: Interventional
• Enrollment (Actual): 110
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

Patients aged 18 years or older. Presence of a single, non-staghorn radiopaque renal stone measuring 10-20 mm in diameter.

Stone location in the upper, middle, or lower renal calyx. Patients who provided written informed consent.

Exclusion Criteria:

Patients with untreated urinary tract infections or urosepsis. Patients with uncorrected bleeding disorders or receiving anticoagulant therapy.

Presence of severe skeletal deformities preventing surgical positioning. Patients with morbid obesity (BMI > 40 kg/m²). Presence of anatomical abnormalities (e.g., horseshoe kidney, ectopic kidney). Pregnancy. Multiple renal stones or stones larger than 20 mm

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: PCNL Group; Patients in this group underwent Percutaneous Nephrolithotomy (PCNL) for the treatment of renal stones measuring 10-20 mm. The procedure was performed in the prone or lithotomy position under general anesthesia.	Device: Percutaneous Nephrolithotomy (PCNL); A standard percutaneous approach was used. Under general anesthesia, a nephrostomy tract was established, and the stone was fragmented using a pneumatic or ultrasonic lithotripter.
Active Comparator: RIRS Group; Patients in this group underwent Retrograde Intrarenal Surgery (RIRS) using a flexible ureterorenoscope and laser lithotripsy for the treatment of renal stones measuring 10-20 mm.	Device: Retrograde Intrarenal Surgery (RIRS); The procedure was performed using a flexible ureterorenoscope. Stones were fragmented using a Holmium:YAG laser fiber after reaching the renal pelvis and calyces retrogradely.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Stone-Free Rate (SFR)	The percentage of patients who are completely free of stones or have only clinically insignificant residual fragments (less than 3 mm). This will be evaluated using non-contrast computed tomography (NCCT)	3 months postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total Operative Duration	The time from the initial incision or insertion of the endoscope until the completion of the procedure and dressing, measured in minutes	During the surgical procedure (intraoperative)
Change in Hemoglobin Levels	The difference between preoperative and postoperative hemoglobin levels to assess blood loss.	Within 24 hours postoperatively.
Postoperative Complications	The frequency and severity of complications classified according to the Clavien-Dindo classification system	From surgery up to 30 days postoperatively.
Length of Hospital Stay	The total number of days the patient remained in the hospital following the procedure.	From the day of surgery until hospital discharge (typically 1-3 days).

Collaborators and Investigators

• Sponsor: Kırıkkale University

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2012
• Primary Completion (Actual): September 15, 2013
• Study Completion (Actual): November 1, 2013

Study Registration Dates

• First Submitted: May 10, 2026
• First Submitted That Met QC Criteria: May 10, 2026
• First Posted (Actual): May 15, 2026

Study Record Updates

• Last Update Posted (Actual): May 15, 2026
• Last Update Submitted That Met QC Criteria: May 10, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Kidney Calculi Nephrolithiasis Urolithiasis Renal Stone
• Additional Relevant MeSH Terms: Surgical Procedures, Operative; Minimally Invasive Surgical Procedures; Endoscopy; Urologic Surgical Procedures; Urogenital Surgical Procedures; Laparoscopy; Nephrolithotomy, Percutaneous
• Other Study ID Numbers: 12/14-06

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No