ClinicalTrials.gg
Active, not recruitingNCT00169806Updated Jan 23, 2025

Randall's Plaque Study: Pathogenesis and Relationship to Nephrolithiasis

An interventional study of videotape for mapping of renal anatomy and papillary biopsy in Nephrocalcinosis, Renal Calculi and Hypercalciuria, sponsored by Indiana Kidney Stone Institute. Active, not recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-01-23.

Sponsored by Indiana Kidney Stone Institute · Not applicable, Interventional, and Prevention

From the registry’s dates

  • Primary completion was expected by Dec 2025, 11 months ago, but the record still lists the study as active, not recruiting.
Phase
Not applicable
Study type
Interventional
Enrollment
600
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study summary

Kidney stones are very common. They affect 3-5% of the population in the United States. Many people are hospitalized for the treatment of kidney stones and some may die. Better understanding of what causes kidney stones is useful in both the treatment and prevention of kidney stones. However, exactly what causes kidney stones is unknown.

The most common type of kidney stones contains calcium, which sometimes is attached to a part of the kidney important in producing the final urine, called the papilla. The investigators have noticed that persons who form kidney stones seem to have more papilla with stones attached. They propose to study these areas of the papilla, called Randall's plaques (named after their discoverer), in patients undergoing surgery for kidney stones.

Read the detailed description

In order to attempt to explain the pathogenesis of renal calculi, the investigators videotape and document the location and characteristics of each stone, papillae and calyces. One or more small papillary biopsies are taken for analysis to help determine the point of origin of the kidney stone and histological studies are undertaken to determine tissue differences amongst different types of stone formers. Approximately one month after surgery, metabolic studies are undertaken to further review potential causes of stone formation.

02

Conditions studied

  • Nephrocalcinosis
  • Renal Calculi
  • Hypercalciuria
  • Hyperparathyroidism
  • Cystinuria

Keywords

  • Randall's Plaque
  • Kidney stones
03

In context

Nephrocalcinosis

22 studies on the registry are indexed under Nephrocalcinosis; 8 are open to participants now.

This study's planned enrollment of 600 is above the median of 71 across 10 interventional studies indexed under Nephrocalcinosis.

Browse Nephrocalcinosis studies →

Lead sponsor

Indiana Kidney Stone Institute is the lead sponsor of 16 studies on the registry; none are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Patients of Methodist Urology in Indianapolis, IN who are undergoing endoscopic procedures for nephrolithiasis or other urologic disease.
  • Upper urinary tract endoscopic or PERC procedure for kidney stones removal
  • General medical health allowing surgical procedure
  • Ability to complete all the necessary components of the study
  • Able to sign an

Exclusion criteria

Exclusion Criteria:

  • Poor general medical health
  • Bleeding diathesis
  • Inability or unwillingness to comply with post-surgical follow-up
Terms in these criteria, in plain language(1)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

05

Study design

Phase
Not applicable
Primary purpose
Prevention
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
600 participants (estimated)

Study arms

  • Other
    cohort

    Subjects who are scheduled to undergo a percutaneous kidney stone removal who do not have complicated comorbidities

    Other: videotape for mapping of renal anatomy and papillary biopsy

Interventions

  • Othervideotape for mapping of renal anatomy and papillary biopsy

    Subjects who enroll in this study will have their renal anatomy videotaped for mapping purposes. Stone location and characteristics will be documented as will papilla and calyces. One or more papillary biopsies will be taken for analysis.

06

What researchers measure

Primary outcomes

  1. To find out why people form stones by comparing 24 urine collections, biopsy and anatomy to other patients who do not form stones and other patients who do form stones to see if the differences are significant

    Time frame: One year from study completion

07

Study locations

1 site
08

Timeline

Tracking since Sep 25, 2026
Not marked actual or estimatedDates not marked actual or estimated

The record gives a start of Nov 1998, a primary completion of Dec 2025 and a completion of Dec 2025. It does not say whether these dates are actual or estimated.

How these figures are worked out, and which studies are left out of them.

Registered
Sep 12, 2005
First posted
Sep 15, 2005
Start
Nov 1998
Primary completionEst.
Dec 2025
CompletionEst.
Dec 2025
Last update
Jan 23, 2025
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Jan 23, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT00169806
Lead sponsor
Indiana Kidney Stone Institute
Collaborators
Indiana University School of Medicine, University of Chicago
Responsible party
James Lingeman (James Lingeman, MD, Indiana Kidney Stone Institute) — Principal investigator
First posted
Sep 15, 2005
Start date
Nov 1998
Primary completion
Dec 2025 (estimated)
Completion
Dec 2025 (estimated)
Last update
Jan 23, 2025

Study contacts

James Lingeman, MD
principal investigator · IU Health Physicians Urology

Oversight

Data monitoring committee
Yes
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is active, not recruiting, as verified in Jan 2025. You cannot join it, but the record below documents what was studied.

Follow this study

Get an email when the registry record changes — status, dates, results — or when someone posts here.

Sign in to follow

Discussion

Questions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.

Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.

Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.

Start the discussion