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

Ain Shams University

Status: Completed

Conditions: Urolithiasis; Renal Calculi; Nephrolithiasis; Kidney Calculi

Treatments: Procedure: Suction ureteral access sheath retrograde intrarenal surgery; Procedure: Sheathless retrograde intrarenal surgery; Procedure: Traditional ureteral access sheath retrograde intrarenal surgery

Study type: Interventional

Funder types: Other

Identifiers

NCT07289230

FMASU_MS400_2025

Details and patient eligibility

About

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.

Enrollment: 90 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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90 participants in 3 patient groups

Traditional Ureteral Access Sheath Retrograde Intrarenal Surgery

Active Comparator group

Description:

Participants in this arm underwent retrograde intrarenal surgery (retrograde intrarenal surgery) using a traditional ureteral access sheath. A flexible ureteroscope was advanced through an 11 French by 13 French ureteral access sheath positioned near the ureteropelvic junction. Irrigation was maintained at 50 to 100 milliliters per minute. Stone fragmentation was performed using a holmium:yttrium-aluminum-garnet laser device. All patients received a six French double-J stent at the end of the procedure. Intraoperative complications were recorded, and postoperative imaging was performed for outcome assessment.

Treatment:

Procedure: Traditional ureteral access sheath retrograde intrarenal surgery

Suction Ureteral Access Sheath Retrograde Intrarenal Surgery

Experimental group

Description:

Participants in this arm underwent retrograde intrarenal surgery (retrograde intrarenal surgery) with the use of a suction ureteral access sheath. An 11 French suction ureteral access sheath was inserted over a guidewire and positioned in the renal pelvis. The suction system was connected to a vacuum device, with negative pressure set between 2 and 7 kilopascals to facilitate evacuation of stone fragments and reduce intrarenal pressure. The same flexible ureteroscope and holmium:yttrium-aluminum-garnet laser lithotripsy technique were used as in the traditional arm. A six French double-J stent was inserted at the end of the operation. All intraoperative and postoperative findings were documented.

Treatment:

Procedure: Suction ureteral access sheath retrograde intrarenal surgery

Sheathless Retrograde Intrarenal Surgery

Experimental group

Description:

Participants in this arm underwent sheathless retrograde intrarenal surgery (retrograde intrarenal surgery), in which the flexible ureteroscope was inserted directly over a guidewire without the placement of any ureteral access sheath. Stone fragmentation was performed using a holmium:yttrium-aluminum-garnet laser device. A six French double-J stent was placed at the end of the procedure. Any intraoperative complications, such as bleeding or extravasation, were documented, and postoperative imaging was conducted to assess stone clearance.

Treatment:

Procedure: Sheathless retrograde intrarenal surgery