FANS-Optimization of Irrigation and Suction Parameters in RIRS A RCT

This is a prospective, single-center, single-blinded, randomized controlled trial evaluating two predefined irrigation and suction pressure configurations using the ClearPetra™ 11/13 Fr Flexible and Navigable Suction Access Sheath (FANS) during retrograde intrarenal surgery (RIRS).

Approximately 100 adult patients undergoing flexible ureteroscopy for treatment of kidney stones with a total stone burden of 1.0 to 2.5 cm will be enrolled. Participants will be randomized in a 1:1 ratio to one of two treatment groups. The high-flow group will undergo RIRS using irrigation at 250 mmHg with an automated irrigation pump and suction at 200 mmHg. The moderate-flow group will undergo RIRS using irrigation at 150 mmHg and suction at 120 mmHg.

The primary objective is to evaluate the effect of these irrigation and suction settings on procedural and postoperative outcomes. The primary outcome is stone-free status assessed by postoperative computed tomography approximately three months after surgery. Stone-free status is defined in the protocol as no residual stone fragments greater than 2 mm.

Secondary outcomes include basket use, total operative time, laser time, total laser energy, and postoperative infection within 30 days. Additional exploratory assessments will evaluate the ability of the FANS sheath to reach the upper and lower pole calyces, sheath length selection, intraoperative deflection characteristics, and the amount of sheath remaining outside the patient during upper-pole access.

Participants will undergo clinical care and follow-up according to standard practice. Follow-up information will be collected approximately three months after surgery, and long-term follow-up will continue for up to 12 months to assess subsequent stone events, additional treatments or reinterventions, and available stone-related imaging.

Inclusion criteria

• 1Male or female participants aged 18 years or older. 2-Undergoing flexible ureteroscopy for retrograde intrarenal surgery. 3-Total stone burden between 1.0 and 2.5 cm.

Exclusion criteria

• 1Undergoing bilateral stone treatment during the same procedure. 2-Known genitourinary anatomical abnormalities. 3-Uncorrected coagulopathy. 4-Urinary diversion. 5-Chronic external urinary catheter. 6-Pregnancy. 7-Immunosuppression. 8-Participation in another clinical research study during the duration of this trial, unless the investigator determines on a case-by-case basis that participation in the other study will not adversely affect the outcomes or integrity of this trial.