Retrograde renal access with RetroPerc for percutaneous kidney stone removal

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

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

Quick facts

• Study type: Observational
• Enrollment: 150 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: University of Kansas Medical Center (Academic / other)
• Locations: 2 sites (Tampa, Florida and 1 other locations)
• Trial ID: NCT07071831 on ClinicalTrials.gov

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.

Who should consider this trial

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.

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.

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 performed: 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.

Eligibility 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 this trial is running

Tampa, Florida and 1 other locations

• 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

Conditions Renal Stones; kidney stones