Mini-PCNL versus flexible ureteroscopy with ClearPETRA for 1–3 cm kidney stones

Comparing Efficiency and Stone-Free Rates After Mini-Percutaneous Nephrolithotomy and Flexible Ureteroscopy With Suction Access Sheaths

Not applicable Interventional Northwestern University · NCT07072598

This trial tests whether using the ClearPETRA suction access sheath with flexible ureteroscopy or with mini‑PCNL helps adults with 1–3 cm kidney stones become stone‑free more often and with fewer complications.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment80 (estimated)
Ages18 Years and up
SexAll
SponsorNorthwestern University Academic / other
Locations1 site (Chicago, Illinois)
Trial IDNCT07072598 on ClinicalTrials.gov

What this trial studies

This interventional comparison enrolls adults with 1–3 cm renal stones to undergo either flexible ureteroscopy using the ClearPETRA suction ureteral access sheath or mini‑PCNL. The primary outcome is the complete stone‑free rate measured by post‑procedure imaging, with secondary outcomes including complications, length of stay, and fluoroscopy time. Both procedures and the ClearPETRA device are in regular clinical use; the study aims to determine whether the suction sheath improves fragment clearance and reduces differences between the two modalities. Participants must be able to consent and complete questionnaires; pregnant people, those with anomalous renal anatomy or urinary diversions, and patients medically unfit for either procedure are excluded.

Who should consider this trial

Good fit: Adults aged 18 or older with a CT showing renal stones between 1 and 3 cm who can read and complete study questionnaires are the intended participants.

Not a fit: People who are pregnant, have anomalous renal anatomy or urinary diversions, are medically unfit for either procedure, or who are non‑English speakers are excluded and unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, this approach could increase stone‑free rates while reducing complications, intrarenal pressure, and hospital stay for people with medium‑sized kidney stones.

How similar studies have performed: Mini‑PCNL has been reported to yield higher stone‑free rates for larger stones and suction ureteral access sheaths like ClearPETRA have shown promise for lowering intrarenal pressure and improving fragment clearance, but direct comparisons between suction‑assisted ureteroscopy and mini‑PCNL remain limited.

Eligibility criteria

Show full inclusion / exclusion criteria
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.

Where this trial is running

Chicago, Illinois

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Kidney StonesNephrolithiasisUrolithiasiskidney stoneUreteroscopyMini-PCNLClearPETRAkidney stone interventional treatment
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.