for people ages 18 years and up (full criteria)
at San Francisco, California
study started
estimated completion
Principal Investigator
by Thomas Chi



This is a prospective randomized study, comparing quality of life in renal stone patients undergoing surgical treatment with ureteroscopy (URS) versus percutaneous nephrolithotomy (PNL).

Official Title

Randomized Controlled Clinical Trial Comparing Ureteroscopic to Percutaneous Removal for the 1-2 cm Calculus Measuring Quality of Life as the Primary Outcome


In United States, the prevalence of renal stone is 8.8% with slight predomination in male than female. They can be symptomatic marked by symptoms of flank pain, hematuria or urinary tract infection, or completely asymptomatic and incidentally discovered. Three modalities are accepted as treatment options for renal stone, including shockwave lithotripsy (SWL), percutaneous nephrolithotomy (PNL) and ureteroscopy (URS). While some standard guidelines were proposed for appropriate treatment selection with regard to stone size, no recommendations or guidelines exist for the surgical management of 1-2 cm renal stones. Both PNL and URS are equally accepted as treatment options for stones at this size. The selection of either procedure currently is left to the treating surgeon can be influenced by anatomical or stone factors as well as patient preference. For URS, frequent requirement for postoperative ureteral stents may result in significant morbidity and a detriment to quality of life owing to irritating bladder symptoms caused by the stent itself. PNL rarely requires postoperative ureteral stent but it may bring longer operative time and hospitalization. PNL therefore may be a treatment option that preserves quality of life compared to URS for patients presenting with the 1-2 cm sized kidney or ureteral stone. One reasonable way to evaluate efficacy of treatment options is to assess patient's quality of life resultant from the selected modality. Quality of life for renal stone formers is an important but under-studied facet of nephrolithiasis management that should be incorporated into clinical decision making. The short form-36 health survey questionnaire (SF-36) is a patient-reported survey of health status. It has been validated and is commonly used to determine the efficacy of a given health treatment in many settings, including urologic intervention. The Ureteral Stent Symptom Questionnaire (USSQ) is a validated and widely accepted instrument to evaluate the impact of ureteral stents on quality of life. The investigators plan to use these two questionnaires as a standard outcome measurement to compare impact on quality of life in patients randomized to undergo two different modalities (PNL versus URS) of stone treatment.


Kidney Calculi Quality of Life Nephrolithiasis Calculi Ureteroscopy Percutaneous nephrolithotomy Ureteral stent (double-J stent) Percutaneous nephrostomy tube


You can join if…

Open to people ages 18 years and up

  • Patient with a renal or proximal ureteral stone measuring 1-2 cm in size on preoperative ultrasound, computed tomography, or plain radiographic imaging

You CAN'T join if...

  • Serious illness likely to cause death within the next 5 years, so as to exclude significant metabolic derangements that might lead to adverse surgical outcome.
  • Stones with measured size larger than 2 cm or smaller than 1 cm.
  • Patients with ureteral or renal anatomy or stones located in a position judged to be unsafe for randomization.
  • Pregnancy.


  • University of California, San Francisco accepting new patients
    San Francisco California 94143 United States

Lead Scientist at UCSF


accepting new patients
Start Date
Completion Date
University of California, San Francisco
Study Type
Last Updated