Interest in monitoring intrarenal pressure (IRP) during flexible ureteroscopy (fURS) has grown, especially due to its potential association with improved postoperative efficiency and safety. A prominent technique for managing IRP during fURS is the use of ureteral access sheaths (UAS), which are known to reduce IRP. Suction-equipped access sheaths provide additional benefits by continuously evacuating dust and stone fragments during the procedure, potentially enhancing stone-free rates. However, IRP during suctioning procedures has yet to be thoroughly investigated. The aim of this study is to compare the IRP during fURS using UAS with and without suctioning technique.

Interest in monitoring intrarenal pressure (IRP) during flexible ureteroscopy (fURS) has grown, especially due to its potential association with improved postoperative efficiency and safety. With advances in technology, precise tools like the LithoVue™ Elite now enables continuous IRP measurement, facilitating accurate data collection throughout the procedure. A prominent technique for managing IRP during fURS is the use of ureteral access sheaths (UAS), which are known to reduce IRP. Suction-equipped access sheaths provide additional benefits by continuously evacuating dust and stone fragments during the procedure, potentially enhancing stone-free rates (SFR). However, IRP during suctioning procedures has yet to be thoroughly investigated. This study is a randomized controlled trial comparing continuous intrarenal pressure (IRP) measurements during flexible ureteroscopy (fURS) using a suctioning ureteral access sheath (UAS) versus a non-suctioning UAS. The study will be conducted over an 18-month period and will include all patients over 18 years of age who are scheduled to undergo fURS for a stone burden greater than 1 cm and/or multiple stones. Patients who are pregnant, have an untreated urinary tract infection (UTI), urinary tract anomalies such as urinary diversion, ureteral reconstruction, or horseshoe kidney, or who have a single stone smaller than 1 cm will be excluded from participation. All procedures will take place at Mount Sinai West, with patients enrolled from the practices of two endourology-trained specialists, Dr. William Atallah and Dr. Mantu Gupta. Participants will be randomized to either the suctioning-UAS arm using the ClearPETRA Flexible and Navigable Suction UAS or the non-suctioning-UAS arm using the BSC Navigator device.

INCLUSION CRITERIA

• Adults aged 18 years and older.
• Diagnosed with kidney stones and scheduled for fURS.
• Stone burden > 1 cm and/or multiple stones will be eligible.
• Able and willing to provide informed consent.

EXCLUSION CRITERIA

• Pregnant persons as determined by pre-operative urine pregnancy test (standard of care at our institution)
• Untreated UTI
• Patients with urinary anomalies (e.g., urinary diversion, ureteral reconstruction, horseshoe kidney)
• Single stone < 1 cm

To to protect participant privacy

Surgeon will not be blinded to the UAS type (suctioning vs. non-suctioning) but will be blinded to IRP measurements during the procedure.