This study compares two techniques used during RIRS for the treatment of kidney stones measuring up to 20 mm. During RIRS, surgeons often use a device called a UAS to help pass instruments into the urinary system and to assist with the removal of stone fragments. A traditional UAS allows irrigation fluid and small fragments to flow out passively. A newer type, known as a suction UAS, applies controlled negative pressure to help clear stone fragments more effectively and may reduce pressure inside the kidney during the procedure.

The purpose of this study is to determine whether the suction UAS offers better clinical outcomes than the traditional UAS. The main outcomes assessed include the SFR, the duration of surgery, and complications after the procedure such as fever, sepsis, urinary infection, calyceal injury, or ureteral injury.

In this randomized study, adult patients undergoing RIRS for a single renal stone were assigned to either the suction UAS or the traditional UAS. All patients were followed after surgery to assess stone clearance and any complications. The results of this study aim to provide evidence on whether suction UAS improves safety or effectiveness in RIRS compared with the traditional approach.

Inclusion Criteria:

• Adults aged eighteen years or older
• Male or female participants
• Presence of a single kidney stone measuring up to twenty millimeters
• Candidate for retrograde intrarenal surgery according to clinical evaluation
• Able and willing to provide informed consent

Exclusion Criteria:

• Active or untreated urinary infection
• History of open kidney surgery or kidney trauma
• Contraindications to anesthesia, including uncontrolled diabetes, severe cardiac disease, or significant coagulation disorders
• Presence of ureteral narrowing or obstruction at the junction between the ureter and the kidney
• Positive urine culture that does not resolve after appropriate treatment

Individual participant data collected during the study will be made available after removal of all direct identifiers. The shared data will include demographic information, clinical characteristics, surgical details, and outcome measurements related to stone clearance and postoperative events. Data will be provided only for the purpose of scientific research and verification of study findings.

Data will be available starting six months after publication of the main study results. The data will remain accessible for a period of five years from the date of release.

Researchers who wish to access the data must submit a written request that includes a summary of the research objectives and the intended use of the data. Approval will require review by the study investigators. Upon approval, data will be shared through a secure data transfer method. Recipients must agree not to attempt to reidentify participants and must use the data only for the approved research purpose.