Comparing Efficiency and Stone-Free Rates Mini PCNL vs Flex URS

Not Applicable

Not yet recruiting

• Conditions: Kidney Stones; Nephrolithiasis; Urolithiasis

• Registration Number: NCT07072598
• Lead Sponsor: Northwestern University

Brief Summary

The objective of the study is to compare the stone free rates with ureteroscopy utilizing the ClearPETRA suction ureteral access sheath, and mini-PCNL; both procedures and ClearPETRA sheaths are standard of care and are used regularly for stone treatment. Our primary objective is to assess the complete stone free rate with both procedures.

Detailed Description

With the advent of mini-PCNLs, some endourologists have been utilizing the technique to treat renal calculi up to 3cm in size with better stone free rates and similar comorbidity compared to ureteroscopy. These procedures require percutaneous renal access, and it is associated with greater length of stay and fluoroscopy time.

The ClearPETRA ureteral access sheath has shown great promise with improving stone free rates, decreasing intra-renal pressure and delivering some of the benefits of mini-PCNL without the added risk associated with obtaining percutaneous renal access.

The ClearPETRA flexible suction ureteral access sheath anecdotally improves efficiency and allows endourologists to better clear stone debris when compared to traditional ureteral access sheaths. We have yet to see a comparison between suction ureteral access sheaths and mini-PCNL with the suction renal access sheath.

Study Hypothesis: Compared to traditional access sheaths, using ClearPETRA access sheaths will result in an improvement in stone free rates with both modalities, with lower complications. Using ClearPETRA access sheaths in both modalities compared to traditional access sheaths should result in less of a difference in stone free rates between the ureteroscopy group and the mini-PCNL group.

Study Timeline

• Study First Submitted: 2025-06-24
• Status Verified: 2025-07
• Study Start: 2025-07-01
• Study First Submitted QC: 2025-07-09
• Last Update Submitted: 2025-07-09
• Study First Posted: 2025-07-18
• Last Update Posted: 2025-07-18
• Primary Completion: 2026-07
• Study Completion: 2026-11-01

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 80

Inclusion Criteria

• Patients 18 years or older
• Have a CT scan showing renal stones 1-3cm in length
• Patients who will be able to read, understand, and complete patient questionnaires

Exclusion Criteria

• Pregnant individuals

• Those with anomalous renal anatomy

• Patients with a urinary diversion (ex: Ileal conduit, reservoir, bladder substitute, etc.)

• Any condition rendering patient medically unfit to undergo either procedure (Bleeding diasthesis)

• Patients who lack decisional capacity

• Patients who are non-english speakers*

  • Non-recruitment of non-english speakers is due to the study being a small pilot study that is used to assess the stone free rate for patients treated with a ureteroscopy or mini-PCNL using ClearPETRA suction access sheaths in a small portion of our patient population seeking treatment for stones. The team also does not possess the bandwidth or personnel to consent patients who are non-English speaking.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Stone free rate	4 weeks post-procedure	Stone free rate (no residual stone) on post-procedure CT

Secondary Outcome Measures

Name	Time	Method
Surgery time	Procedure day (1 day)	Surgery time (minutes)
Unplanned hospital visits	90 days postoperatively	Unplanned hospital visits (ED/clinic)
Need for additional procedure	90 days postoperatively	Need for additional procedure (within 90 days postoperatively)
Length of stay	Perioperatively (starting at Baseline/Procedure Date)	Length of stay hospital stay (if admitted post-procedure, or readmitted)
Complication rate	Procedure day (1 day)	Complication rate (Clavien-Dindo) (%)
Occurrence of post-procedure sepsis	Perioperatively (starting at Baseline/Procedure Date)	Post-op sepsis
Hospital / patient costs (in total for procedure and any necessary postoperative hospital admissions or procedures related to the initial procedure).	Perioperatively (starting at Baseline/Procedure Date)
Inability to access ureter	Procedure day (1 day)	Intra-operative complications including inability to access the ureter ureteroscopically or need to upsize the renal access sheath with the percutaneous approach.
Need to upsize from 18Fr Sheath	Procedure day (1 day)	Need to upsize from 18Fr (PCNL group)

Trial Locations

Locations (1)

Northwestern Memorial Hospital; 🇺🇸 Chicago, Illinois, United States