Clinical trial Recruiting at 2 sites Observational Ages 18 and up

Retrograde renal access with RetroPerc for percutaneous kidney stone removal

Official title: RetroPerc®-A Prospective, Multi-institutional Trial of Efficacy of the RetroPerc Device

Run by University of Kansas Medical Center · NCT07071831 · Data updated 2026-11-12

This study tries RetroPerc® to obtain kidney access during supine percutaneous nephrolithotomy in adults with 1.5–3 cm kidney stones.

Quick facts

Study typeObservational
Ages18 Years and up
SexAll
Enrollment150 (estimated)
SponsorUniversity of Kansas Medical Center
Academic / other
Locations2 sites (Tampa, Florida and 1 other locations)
StatusRecruiting
StartedDecember 6, 2024
Main results expectedApril 2027
Study endsDecember 2027
Registry record updatedMay 4, 2026
Trial IDNCT07071831 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Adults (≥18 years) planning supine PCNL for renal stones totaling 1.5–3 cm who do not have exclusion criteria such as pregnancy, severe hydronephrosis, prior ipsilateral PCNL, uncorrected UTI, BMI >45, or uncorrectable coagulopathy.

Probably not a fit

Patients with BMI over 45, severe hydronephrosis (renal pelvis >20 mm), prior ipsilateral PCNL, active urinary infection, uncorrectable bleeding disorders, pregnancy, or ASA ≥4 are excluded and unlikely to benefit from this protocol's findings.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This is a prospective observational study that follows adults scheduled for supine percutaneous nephrolithotomy who will have renal access obtained using the RetroPerc® device. Because RetroPerc® is already in clinical use, investigators will collect standardized, prospective data on access technique, anatomic measurements, procedural details, and short-term outcomes that are not reliably available from retrospective chart review. Participants are enrolled at participating U.S. academic centers and receive the device as part of routine care rather than as an experimental therapy. The study will compare procedural variables and complications across cases to better characterize factors associated with successful and safe retrograde nephrostomy access.

Why it matters

Potential benefit: If successful, the findings could improve how urologists obtain percutaneous kidney access with RetroPerc®, potentially lowering complications and improving procedural consistency.

How similar studies have gone: Retrograde nephrostomy access with devices like RetroPerc® is already used in routine practice and prior reports support its safety, but prospective data focusing on specific procedural variables remain limited.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Renal stone or total linear sum of 1.5-3cm cm in maximum dimension (largest diameter in axial or coronal)--- multiple stones should be summed to determine stone size.
* Age \>=18 years of age
* Gender: both men and women included.
* Ethnic background: all ethnicities will be included in the study population and the specific ethnic diversity present in the study population will reflect the geographic distributions of the participating institutions.
* Plan for PCNL in the supine position

Exclusion Criteria:

* Active pregnancy
* BMI \>45
* Severe Hydronephrosis - renal pelvis diameter \> 20mm
* Flank window \< 4 cm are ineligible for puncture
* Previous ipsilateral PCNL
* Currently with "useful" nephrostomy tube on ipsilateral side
* Uncorrectable coagulopathies
* Untreated urinary tract infection
* Subjects with significant morbidities such as American Society of Anesthesiologists (ASA) score ≥ 4, severe spinal cord injuries, severe cardiopulmonary insufficiency, uncontrolled diabetes, neurological disorders, bedbound, anticipated life expectancy less than 5 years, or any other comorbidity, that in the opinion of the principal investigator could represent an increased peri-operative risk for the subject;
* Ipsilateral partial nephrectomy
* History of ipsilateral ureteral reimplantation or ureteral reconstruction;
* History of Simple or radical prostatectomy
* History of cystectomy
* History of calyceal diverticula stone;
* History of renal donation or transplant;
* Any other previous pelvic surgical treatment that could put the subject at greater procedural complication risk or technical difficulty;
* Ureteral ipsilateral stricture, untreated;
* Ureteral stricture, untreated (not to include "tight" ureter);
* Any other bladder, ureteral or kidney congenital genitourinary abnormalities (e.g. Horseshoe kidney, ipsilateral duplicated or partially duplicated collecting system, ipsilateral ectopic kidney, cross-fused ectopia, bifid renal pelvis with no horizontally directed calyces, solitary kidney, etc.) preventing the ability to direct a puncture laterally or render the subject stone free;
* Have participated in any other clinical trial within the last 3 months, and/or plans to participate in any other investigational or invasive clinical trial during this study;
* If female, breast-feeding, or if childbearing age, is not using contraception between screening and 90 days post-op;
* Subject has current or recent history of substance abuse (e.g. recreational drugs, narcotics, or alcohol) requiring intervention;
* Is a prisoner or ward of the state;
* Is unable to meet the treatment and follow up protocol requirements.

Where it's running

  • University of South Florida
    Tampa, Florida, United States
    Recruiting
  • University of Kansas Medical Center
    Kansas City, Kansas, United States
    Recruiting

Study contacts

  • Principal investigator: Bristol Whiles, MD — University of Kansas Medical Center
  • Study coordinator: Research Program Manager
  • Email: jledesma2@kumc.edu
  • Phone: 913-588-8721

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How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 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.