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

NCT07072598 | Recruiting FDA Device

• 1 other identifier: STU00222993
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 1

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.

Conditions

Kidney Stones; Nephrolithiasis; Urolithiasis

Keywords

kidney stone; Ureteroscopy; Mini-PCNL; ClearPETRA; kidney stone interventional treatment; kidney stone 1cm-3cm

Outcome Measures

Primary Outcomes (1)

• Stone free rate

  Stone free rate (no residual stone) on post-procedure CT

  4 weeks post-procedure

Secondary Outcomes (9)

• Surgery time

  Procedure day (1 day)

• Complication rate

  Procedure day (1 day)

• Unplanned hospital visits

  90 days postoperatively

• Need for additional procedure

  90 days postoperatively

• Length of stay

  Perioperatively (starting at Baseline/Procedure Date)

Study Arms (2)

Ureteroscopy

ACTIVE COMPARATOR

Patients randomized to this arm will have their stones treated using the method of Ureteroscopy in a standardized fashion. A second 0.035in sensor guidewire will then be advanced up to the renal pelvis with placement confirmed by fluoroscopy. Placement of a 12/14Fr ClearPETRA ureteral access sheath will be attempted. If this is unsuccessful, a 11/13Fr ClearPETRA ureteral access sheath will be advanced over the wire. If this is unsuccessful, a 5Fr open ended ureteral catheter will be placed and procedure will be converted to a miniPCNL. Lithotripsy will be performed with the MOSES 2.0 high power Holmium laser with settings of 0.3J and 120Hz or 2J and 20Hz depending on stone location and appearance. Stones will be extracted with the suction access sheath. A ureteral stent will be placed at the conclusion of the procedure.

Device: ClearPETRA suction access sheath

Mini-PCNL

ACTIVE COMPARATOR

Will be performed by first starting with supine flexible cystoscopy to cannulate the ureteral orifice with a 5Fr open ended ureteral catheter. The patient will then be repositioned prone with 1-2 bumps placed transversely across the chest. Contrast will be instilled into the ureteral catheter and renal access will be obtained fluoroscopically with the triangulation technique. Once access is obtained, the tract will be dilated to 20Fr and a 18/20Fr ClearPETRA renal access sheath will be inserted to assess the collecting system. If there is concern that the 20Fr access is not sufficient to clear the stone, the tract will be upsized to 24 or 30Fr. The stones will be evacuated with the Trilogy Lithotripter and/or laser, suction and/or basket extraction. A ureteral stent will be placed at the conclusion of the procedure.

Device: ClearPETRA suction access sheath

Interventions

ClearPETRA suction access sheath DEVICE

Ureteroscopy utilizing the ClearPETRA suction access sheath.

Ureteroscopy

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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.

Sponsors & Collaborators

• Northwestern University: lead
• KARL STORZ Endoscopy-America, Inc.: collaborator

Study Sites (1)

Northwestern Memorial Hospital

Chicago, Illinois, 60611, United States

RECRUITING

MeSH Terms

Conditions

Kidney Calculi; Nephrolithiasis; Urolithiasis

Condition Hierarchy (Ancestors)

Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Urinary Calculi; Male Urogenital Diseases; Calculi; Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms

Central Study Contacts

Alyssa McDonald, MPH

CONTACT

312-695-8146; alyssa.mcdonald@northwestern.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Director of the Endourology/Stone Division

Study Record Dates

• First Submitted: June 24, 2025
• First Posted: July 18, 2025
• Study Start: April 25, 2026
• Primary Completion (Estimated): July 1, 2027
• Study Completion (Estimated): December 1, 2027
• Last Updated: April 30, 2026

Record last verified: 2025-07

Locations

US (1)