Clinical trial NCT02739919: Bacterial Analysis of Kidney Stones Removed by Percutaneous Nephrolithotomy
Official title: Bacterial Analysis of Kidney Stones Removed by Percutaneous Nephrolithotomy
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Urolithiasis
Keywords: Kidney stones
Renal Calculi
Lead sponsor: University of British Columbia
Sponsor class: OTHER
First posted: 2016-04-15
Enrollment: 6
Sex: ALL
Minimum age (years): 19
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_ONLY
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients at Vancouver General Hospital that are diagnosed with a kidney stone and scheduled to undergo percutaneous nephrolithotomy.

Brief summary: The aim of this research is to use a controlled laboratory setting to determine whether bacteria isolated from kidney stones of patients play a role in the formation of non-infectious kidney stones. It is well known that struvite stones are associated with active bacterial infection, however the role of bacteria in the formation of non-infection stones (like calcium oxalate) is not well characterized and there are theories that bacteria are involved in the making of these stones.

Detailed description: Kidney stone disease is common, affecting nearly 10% of the population with increasing prevalence and increasing cost associated to treat this disease. While struvite stones (composed of magnesium, ammonium and phosphate crystals) have been associated with the presence of infection, the association between bacteria and non-infection stones is not well characterized. Previous studies have found bacteria present in stones of patients without active infection and with negative pre-operative urine tests.

There are various compositions of kidney stones, including calcium oxalate, calcium phosphate, struvite and uric acid, with calcium oxalate being the most common. It is well known that struvite stones are associated with active infection, however the role of bacteria in the formation of other types of kidney stones, including calcium oxalate, is not well understood. The investigators hypothesize that bacteria present in the urinary tract of patients without active infection have the ability to facilitate calcium oxalate crystal formation by providing a surface for stones to grow. An understanding of the role of bacteria in the formation of non-infection stones could help prevent stone formation by altering the bacteria present within patients to decrease or eliminate their risk of kidney stone disease.

Eligibility criteria: Inclusion Criteria:

* Over the age of 18
* Diagnosed with or have a high index of suspicion of having a kidney stone and scheduled to undergo percutaneous nephrolithotomy.
* Medically fit for definitive surgical management of stone

Exclusion Criteria:

* Those with medical comorbidities preventing them from safely undergoing definitive surgical therapy.
* Patients who are unable to provide informed consent.
* 18 years old or younger
* Diagnosed with an infection stone
* Urinary tract infection within 3 months before date of operation
* Antibiotic use within 3 month before date of operation

Primary outcomes:
measure: Amount of stone formation in artificial urine with isolated bacteria from non-infection kidney stones compared to control measured using FTIR-Microscopy and SEM (concentration measured in mg/mL).
timeFrame: Through study completion, approximately 2 years
measure: Bacteria isolated from non-infection kidney stone compared to those identified on pre-operative urine test quantified by simple serial dilution and CFU counting (measured in CFU/mL) and identified using DNA sequencing.
timeFrame: Through study completion, approximately 2 years
Secondary outcomes:
Other outcomes:
Locations:
city: Vancouver
country: Canada
facility: The Stone Centre, VGH/UBC
state: British Columbia
Study officials:
affiliation: University of British Columbia
name: Dirk Lange, MSc, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: University of British Columbia
name: Ben H Chew, MD
role: STUDY_DIRECTOR
References: