The purpose of this study is to determine the effective regimen for definitive surgical therapy of bilateral kidney stones. It is unknown whether patients who undergo simultaneous bilateral percutaneous nephrolithotomy (PCNL) experience improved post-operative outcomes compared to patients who have staged unilateral procedures.

Purpose:

The aim of this research is to determine an effective regimen for definitive surgical therapy of bilateral kidney stones. It is unknown whether patients who undergo simultaneous bilateral percutaneous nephrolithotomy (PCNL) experience improved post-operative outcomes compared to patients who have staged unilateral procedures.

Hypothesis and Justification The gold standard for surgical management of large kidney stones is percutaneous nephrolithotomy (PCNL). A large renal stone burden has been defined as >20mm. In addition, PCNL has improved stone-free rates for lower pole calculi >10mm compared to alternative treatments. Guidelines encourage removal of staghorn calculi for surgical candidates (Assimos et al., 2016). Patients with bilateral large stone burdens have been managed with one of two general options: (i) a single procedure in which both kidneys are operated upon or (ii) two separate procedures in which only one kidney is addressed per procedure. However, there are no prospectively performed peer-reviewed studies directly comparing the two practices. The investigators seek to determine whether there is a significant difference in patient outcomes based on the surgical regimen chosen.

The investigators hypothesize that in comparison to unilateral PCNL (U-PCNL), simultaneous bilateral PCNL (SB-PCNL) under one anesthetic results in comparable

1. stone free rates
2. re-intervention rates for residual stones and
3. perioperative complication rates

Objectives

The objectives are:

1. To provide clinical data on outcomes following simultaneous bilateral and staged percutaneous nephrolithotomy for renal and ureteral calculi
2. To determine patient preference with respect to simultaneous versus staged PCNL

Research Design This study will be a prospective, non-randomized, multi-centre, non-blinded trial. Participants will be accrued through the Vancouver General Hospital Stone Center who have been referred for bilateral stones or have been seen in consultation for bilateral stones at the Department of Urologic Sciences and are scheduled for a percutaneous nephrolithotomy (PCNL). Consent forms and Letters of Introduction outlining the study will be given to patients by a research coordinator once the decision is made to book surgery. Patients will have at least 24 hours to decide to participate. Patients will receive surgical management for their stones in the form of PCNL. A computed tomography (CT) scan of the kidneys will be performed post-operatively by week 6 to determine if any residual stone fragments are present. Patients will be seen in follow up at 3 months in clinic after undergoing a follow up CT KUB, renal ultrasound, or KUB as necessary to evaluate stone clearance.

Inclusion Criteria:

All subjects with a clinical diagnosis of struvite calculi will potentially be included. Specific inclusion criteria include the following:

1. Age >18 years
2. Any patient with bilateral stone burden eligible and appropriate for PCNL procedure
3. Medically fit for definitive surgical management of stone.

Exclusion Criteria:

Patients with any of the following characteristics will not be eligible for the present study:

1. Those with medical comorbidities preventing them from safely undergoing definitive surgical therapy.
2. Patients who are unable to provide informed consent.
3. Patients who are planned for alternative procedures (ureteroscopy, extracorporeal shock wave lithotripsy)
4. Anyone who is unable to give their informed consent
5. Anyone under the age of 19
6. Anyone who, in the opinion of the PI, is unfit or unsuitable to participate in the study

The University of British Columbia is the main site of the study, therefore all data will be transferred from the subsites to the University of British Columbia, and no transfer of data to the subsites. Any data transfer will be de-identified.