MIP Versus PCNL for Kidney Stone Disease
MIP Versus PCNL for Kidney Stone Disease
The decision to use standard percutaneous nephrolithotomy (PCNL) versus mini-percutaneous
 nephrolithotomy (MIP) has been a subject of much debate in the urological community. The
 investigators propose a randomized controlled trial to compare the operative outcomes and
 complications of mini-percutaneous nephrolithotomy (mini-PCNL) versus standard PCNL for renal
 stones. The results of this study will help guide the decision making regarding these two
 procedures in the US population and provide further insight into the utility and safety of
 these procedures. A cost analysis will be performed, and it is hypothesized that the reusable
 components of the Storz MIP set will result in lower costs of the mini-PCNL procedure
 compared to standard PCNL.
Presurgical management will follow the standard of care and patients with active urinary
 tract infections will be treated prior to kidney stone surgery. After the informed consent
 process, the subject will be asked to complete the Wisconsin Stone Quality of Life Index
 (WISQOL), an externally validated and internally consistent questionnaire designed
 specifically for kidney stones patients. All patients should receive a computerized
 tomography (CT) scan prior to their procedure as standard of care for assessment of stone
 burden and access planning. This preoperative imaging will be assessed and scored using the
 standardized STONE scoring system, which has been validated for predicting treatment success
 and perioperative complications following PCNL.

 Prior to their procedure patients will be randomized to receive one of the two interventions
 outlined above, only study subjects will be blinded to the randomization. Randomization will
 be conducted centrally for each site to ensure balance of PCNL and mini-PCNL using the
 CCF-Redcap randomization module to ensure proper randomization between sites. Randomization
 can occur at any time after enrollment prior to surgery. Study subjects will be selected from
 a patient pool where PCNL or mini-PCNL would be considered equally viable alternative
 Standard of Care procedures for treatment of kidney stone disease, with neither procedure
 presenting any benefit over the other. The randomization of procedure for this pool of study
 subjects was to guarantee that an equal number of both procedures were performed in the trial
 throughout all centers.

 Patients choosing to participate in this research study will not be informed of which
 procedure they received to minimize any bias regarding postoperative pain and quality of life
 scores. No changes to the disclosure process will be made for any other variations or
 complications during their procedure outside of the research study interventions. Due to the
 time between the initial surgical procedure and postoperative follow-up visit there is a risk
 of unintentional unblinding by other providers involved with the care of study patients and
 access to their medical records. As such patients will be asked at the time of their
 follow-up visit if they remained blinded to their procedure type. Whenever possible patients
 should remain blinded but unblinding is not an exclusion criterion as the primary endpoint,
 change in hemoglobin, should not be affected by this knowledge.

 A pre-operative complete blood count and basic metabolic panel will be obtained. Two
 endoscopic stone procedure types will be investigated in this study. The first, a standard
 percutaneous nephrolithotomy (sPCNL)- performed using a 30 Fr access sheath following balloon
 dilation. The second, a mini percutaneous nephrolithotomy (mPCNL)- performed using an 18 Fr
 access sheath following either balloon dilation or dilation using a single step metal
 dilator. Both procedures will be performed under general anesthesia with the patient in prone
 position. Access technique (triangulation method, ultrasound guided, or endoscopically
 guided) will be at the discretion of the attending surgeon. Stone lithotripter type
 (pneumatic, ultrasonic, or laser) and retrieval method (basket, forceps) will similarly be at
 the discretion of the urologist. Placement of ureteral stents will be left up to the
 discretion of the surgeon. Placement of nephrostomy tubes will be recorded as a protocol
 deviation and the indication for placement recorded. Whenever possible a single access tract
 will be used for the procedure and if multiple access sites are required it will be recorded
 as a protocol deviation. Following completion of the procedure and closure of the access
 tract, pressure will be applied to the surgical site for one minute. Patients with plans for
 a staged bilateral PCNL should only be enrolled for their first operation and should complete
 the quality-of-life questionnaire and imaging requirements described below prior to their
 second procedure.

 Renal pelvis pressure monitoring is not part of the standard of care and is included as an
 outcome for research purposes only. There is no additional risk to the patient when
 monitoring this pressure and patients will be informed of this during the informed consent
 process.

 Using a flexible cystoscope, a 5 Fr open-ended ureteral catheter will be positioned in the
 ureteropelvic junction for recording renal pelvis pressures. Following placement, the
 catheter will be secured and attached to arterial line pressure transducer positioned at the
 level of the kidney and connected to an invasive blood pressure (IBP) port. The arterial line
 pressure transducer will be fixed to IV pole at the level of the kidney and adjusted during
 the case if the patient bed is repositioned during the case. Transducer tubing should be
 flushed with normal saline to remove any air and pressure should be zeroed without any
 pressure being applied to the surgical site. Pressure monitoring and zeroing should be
 established after obtaining access but prior to active stone fragmentation or extraction and
 continue until closure of the access tract.

 Continuous data monitoring and recording will be achieved via attaching the IBP port either
 on a portable vital signs monitor or the main anesthesia monitoring system. Data points
 should be recorded continuously whenever possible. Data will be either extracted manually
 from the portable monitor or automatically through the anesthesia monitoring system. Analysis
 of these data points to determine the mean RPP, time above >30mmHg, and maximum RPP can be
 conducted at the individual sites and included as part of their data set transfer or
 deidentified data sets can be sent to CCF for analysis of those endpoints.

 Post-operatively, patients will be admitted to the hospital and monitored per usual clinical
 procedure. A complete blood count will be obtained on postoperative day 0, preferably in
 recovery, and on postoperative day 1. A basic metabolic panel will also be obtained prior to
 discharge. Further laboratory tests will be dictated by the patients' clinical status and
 length of stay. If patient length of stay exceeds one day the final complete blood count
 prior to discharge will also be recorded.

 Along with their standard postoperative day 1 labs, an additional red topped tube (4-10ml)
 for IL-6 and procalcitonin will also be collected. This sample will need to be processed with
 several hours of collection using a centrifuge and the serum aliquots placed in cryovials
 prior to freezing. Individual research sites will be responsible for the lab draw, centrifuge
 process, freezing, and shipping of IL-6 and procalcitonin serum samples. These may be stored
 on site and shipped in bulk periodically or upon conclusion of patient enrollment per the
 preference of the study coordinator at each site. All these samples will be analyzed in bulk
 at the conclusion of the recruitment period.

 Since higher irrigating pressures during PCNL have been linked to higher rates of the
 systemic inflammatory response (SIRS) this will also be included as a secondary endpoint. The
 criteria for SIRS will be defined as any two of the following conditions: heart rate >90
 beats per minute, respiratory rate >20 respirations per minute, serum white blood cell count
 greater than 12,000/high power field or less than 4,000/high power field and temperature
 >38.0 ⁰C or <36.0 ⁰C.

 Postoperative complications will be classified using the Clavien-Dindo system which has been
 modified for use following percutaneous nephrolithotomy. Standard of care procedures will be
 followed for patients requiring postoperative blood transfusions. Postoperative pain
 management will be left up to the discretion of the attending surgeon. The patient will be
 discharged from the hospital per the usual clinical protocols with a planned clinic visit
 between 4 and 6 weeks after surgery. In the interval following surgery readmissions, ED
 visits, and reoperations for study patients should be recorded.

 As part of the standard of care for PCNL patients, both a renal ultrasound and a kidney,
 ureter, and bladder x-ray study obtained between 4 and 6 weeks postoperatively. Imaging will
 be reviewed by a blinded radiologist for assessment of stone free rate, defined as no visible
 stone fragments on either imaging set. Any discrepancies between ultrasound and x-ray
 modalities will be resolved with a follow-up CT scan.

 If a patient receives a postoperative CT scan for another indication, this scan will take the
 place of the KUB and U/S for determining stone free rate. Additional data points such as
 parenchymal thickness at target calyx will for also be assessed for swelling/fluid
 accumulation.

 The WISQL questionnaire, the same administered following initial consent, will be given at
 the 4-6 week follow-up visit to track any differences in quality of life between the two
 procedures. The WISQOL questionnaire specifically asks for the patients to provide answer
 statements that reflect their quality of life over the past four weeks. For the purposes of
 the second instance of the questionnaire, study subjects will be instructed to answer with
 respect to their symptoms since their procedure, to encompass patients who may have their
 follow-up visit scheduled more than four weeks from their procedure date.

 The timeline for study subject participation and the required tests is presented below.

 Procedures Preoperative POD0 POD1 Weeks 4-6 Informed consent X CT Scan X WISQOL Survey X X
 CBC X X X BMP or CMP X X Randomization X Intraoperative RPP X Serum sample (IL-6 and PCT) X
 KUB and renal U/S X
Inclusion Criteria:

 -  Patients with planned PCNL and a preoperative CT scan

 -  Urologist obtained access and prone positioning during surgery

 -  Tract dilation performed either using balloon dilator or a single step mini-PCNL
 dilation

 -  Age: ≥18 years' old

 -  Stone size: 10-25mm

 -  Gender: Male and female patients

 -  Patients of all ethnic backgrounds

 -  Capable of giving informed consent

 -  Capable and willing to fulfill the requirements of the study

 -  Pre-existing indwelling nephrostomy tube or ureteral stent permitted

 Exclusion Criteria:

 -  Anticoagulated or history of coagulopathy (with the exception of daily 81 mg aspirin)

 -  Conversion to open procedure

 -  Multiple access tracts

 -  Inability to give informed consent or unable to meet requirements of the study for any
 reason