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Completed

NCT Number: NCT07289230

Sheathless, Traditional, and Suction Access Sheath RIRS for Renal Stones ≤2 cm

This completed randomized clinical study was designed to compare three different techniques of retrograde intrarenal surgery (retrograde intrarenal surgery) for the treatment of kidney stones that are 2 centimeters or smaller. Retrograde intrarenal surgery is a minimally invasive procedure in which a flexible scope is passed through the urinary tract to reach the kidney and fragment the stone.

The clinical study included three groups of patients. The first group underwent retrograde intrarenal surgery using a traditional ureteral access sheath, which is a hollow tube placed in the ureter to facilitate the passage of instruments and help control pressure inside the kidney. The second group underwent retrograde intrarenal surgery using a suction ureteral access sheath, which combines the function of a traditional sheath with gentle suction to help remove stone fragments and reduce internal pressure. The third group underwent sheathless retrograde intrarenal surgery, in which the flexible surgical scope is inserted directly without the use of any ureteral access sheath.

The purpose of this clinical study was to determine whether these three approaches differ in terms of stone clearance, operative time, intraoperative complications such as bleeding or fluid leakage, and early postoperative complications such as fever or infection. All participants were adults with a single kidney stone between 1 and 2 centimeters, normal kidney function, and no active infection or anatomical abnormalities. All procedures were performed at Ain Shams University Hospitals using the same surgical equipment and technique to ensure comparability between groups.

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Key information

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Ain Shams University Hospitals - Department of Urology

Cairo, Cairo Governorate, 11511, Egypt

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adult patients aged 18 years or older.
  • Symptomatic unilateral single renal stone with a maximal diameter from 1 centimeter to 2 centimeters.
  • Normal kidney function based on routine laboratory tests.
  • Patients willing and able to provide written informed consent to participate in the clinical study.

Exclusion criteria

  • Patients with active urinary tract infection (UTI) until appropriate treatment is completed and infection is cleared.
  • Patients with anatomical abnormalities of the urinary tract (for example, congenital or acquired structural abnormalities).
  • Pregnant patients.
  • Patients who are medically unfit for general anesthesia.
  • Patients with multiple renal stones in the same kidney or bilateral renal stones.

Treatment and study plan

Traditional ureteral access sheath retrograde intrarenal surgery

Procedure

This intervention involves performing retrograde intrarenal surgery using a traditional ureteral access sheath to facilitate entry of the flexible ureteroscope and maintain controlled intrarenal pressure. The procedure includes endoscopic fragmentation of renal calculi using a holmium:yttrium-aluminum-garnet laser device and placement of a double-J ureteral stent at the end of surgery.

Suction ureteral access sheath retrograde intrarenal surgery

Procedure

This intervention uses a suction ureteral access sheath that provides continuous negative pressure during retrograde intrarenal surgery. The system assists in evacuation of stone debris and helps control intrarenal pressure while the flexible ureteroscope and holmium:yttrium-aluminum-garnet laser device are used for stone fragmentation. A double-J ureteral stent is placed after the procedure.

Sheathless retrograde intrarenal surgery

Procedure

This intervention involves performing retrograde intrarenal surgery without the use of any ureteral access sheath. The flexible ureteroscope is introduced directly over a guidewire to access the renal collecting system for laser fragmentation of the stone using a holmium:yttrium-aluminum-garnet laser device. A double-J ureteral stent is inserted following completion of the procedure.

Primary outcomes

  1. Stone-free rate assessed by non-contrast computed tomography of the urinary tract

    Time frame: One month after surgery (non-contrast computed tomography of the urinary tract performed approximately 30 days postoperatively)

    Stone-free status is evaluated using non-contrast computed tomography of the urinary tract performed after surgery. Residual stone fragments are classified into four grades: Grade A, no stones detected (absolute stone-free); Grade B, residual fragments less than or equal to 2 millimeters (relative stone-free); Grade C, residual fragments 2.1 to 4 millimeters (relative stone-free); and Grade D, residual fragments greater than 4 millimeters (significant residual stones). The primary endpoint is the proportion of patients achieving stone-free status, defined as Grade A (absolute stone-free) and, in a secondary analysis, Grades A to C combined (clinically insignificant residual fragments).

Secondary outcomes

  1. Operative time for retrograde intrarenal surgery

    Time frame: During the surgical procedure on the day of surgery

    Operative time is measured in minutes from the insertion of the endoscopic instruments at the beginning of retrograde intrarenal surgery until completion of the procedure, including placement of the double-J ureteral stent. The metric is the mean operative time and distribution of operative time for each study arm.

Sponsors and collaborators

Lead sponsor

Ain Shams University

Other

Registry information

Official study title

A Comparative Study Between Sheathless RIRS, Traditional Access Sheath RIRS, and Suction Access Sheath RIRS in the Management of Renal Stones ≤ 2 cm: A Randomized Controlled Clinical Trial

Important dates

Study start
2024
Primary completion
2025
Study completion
2025
First posted
Dec 17, 2025
Registry last updated
Dec 17, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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