Observation vs Upfront Surgery for Asymptomatic Kidney Stones in Children and Adults

Is this trial a fit for you?

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

What this trial studies

The Observational Approach versus Surgical Intervention for Asymptomatic Stone (OASIS) trial compares observation with upfront surgical treatment (URS or SWL) for asymptomatic, non-obstructive kidney stones 4–10 mm. It uses randomized assignment to either observation or surgery, with an optional non-randomized observational cohort for those who decline randomization. Outcomes focus on patient-centered measures and life disruption, alongside safety and healthcare utilization. The study is conducted across several U.S. centers with CHOP as lead sponsor and PCORI involvement, aiming to inform personalized management decisions.

Why it matters

Who can join: the full rules

Inclusion Criteria:

1. Individuals age 6 or older
2. Diagnosis of kidney stone disease (nephrolithiasis)
3. Asymptomatic, non-obstructive kidney stones measuring 4 to 10 mm (inclusive)

   * Asymptomatic is defined as the absence of abdominal pain, flank pain, gross hematuria, and nausea and/or vomiting in the last 3 months that in the judgement of the site PI could be attributable to kidney stones.
   * Non-obstructive is defined as a stone in a renal calyx or stones in multiple renal calyces on CT, ultrasound, and/or x-ray obtained within 6 months of screening.
4. Informed consent and if appropriate, child assent.
5. Willingness to be randomized to surgery or observation Note: subjects otherwise eligible who decline randomization may be enrolled in a parallel observational cohort.
6. Fluent in English or Spanish
7. Willingness to be audio- and/or video- recorded during interviews

Exclusion Criteria:

1. Untreated hydronephrosis or caliectasis
2. Pain (e.g., renal colic, abdominal pain) or gross hematuria attributed to kidney stones.
3. Recurrent symptomatic urinary tract infections (≥3 in 12 months or ≥2 in 6 months). A symptomatic urinary tract infection is defined as having at least one bladder or voiding symptom (e.g., frequency, urgency, dysuria) with bacteriuria (≥105 colony forming units/mL of no more than 2 urinary tract pathogens).
4. Stone in the renal pelvis, ureter, bladder or urethra
5. Pregnant females
6. Solitary kidney, transplant kidney, urinary diversion, medullary sponge kidney
7. Anatomic abnormality of the kidney (e.g., horseshoe kidney)
8. Parents/guardians or subjects who, in the opinion of the Investigator, may be non-compliant with study schedules or procedures

Where it's running

• University of California, Irvine
  Irvine, California, United States Recruiting
• The Children's Hospital of Philadelphia
  Hatboro, Pennsylvania, United States Recruiting
• University of Minnesota
  Minneapolis, Minnesota, United States Not yet recruiting
• Columbia University Medical Center
  New York, New York, United States Not yet recruiting

Study contacts

• Principal investigator: Gregory E Tasian, MD, MSc, MSCE — Children's Hospital of Philadelphia
• Study coordinator: Rebecca D McCune, BS, MS
• Email: mccuner@chop.edu
• Phone: 267-909-6030

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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.