The Presence of Ureteral Calculi Upon Supine PCNL Completion: Occlusion Balloon Catheter Versus 5FR Ureteral Catheter
Phase: NA
Conditions: Kidney Stones
Sponsor: Icahn School of Medicine at Mount Sinai

The Presence of Ureteral Calculi Upon Supine PCNL Completion: 
Occlusion Balloon Catheter Versus 5FR Ureteral Catheter  
PI: Mantu Gupta, MD, FRCS
NCT06798753
Document Date:  12-15-2025

The Presence of Ureteral Calculi upon supine 
PCNL Completion: Occlusion Balloon Catheter 
versus 5FR Ureteral Catheter
Principal Investigator*: Mantu Gupta, MD
Funded by: Icahn School of Medicine at Mount Sinai
Study Number: STUDY-24-01650
Version Date:  August 1, 2025
Effective Date: 12/15/2025
End Date:12/14/2026

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1.1
SYNOPSIS 
Title:
The Presence of Ureteral Calculi upon supine PCNL Completion: Occlusion 
Balloon Catheter versus 5FR Ureteral Catheter
Study Description:
An occlusion balloon catheter provides the ability to occlude the exit of the 
renal pelvis during percutaneous nephrolithotomy (PCNL), and potentially 
prevents the migration of stone fragments into the ureter. The necessity for it 
might be questioned during supine PCNL due to the upward oblique position 
of the kidney. The objective of the study is to compare the presence of 
ureteral stone fragments upon completion of supine PCNL with and without 
using an occlusion balloon catheter (OBC). 
Objectives*:
Comparing the rate of ureteral stone fragments upon completion of PCNL 
while using OBC versus 5FR ureteral catheter (5FR-UC).
Endpoints*:
Primary: Endoscopic identification of ureteral stone fragments 
Secondary: Length of procedure, Intraoperative complications, stent 
placement
Study Population:
An estimated sample size of 98 patients (49 in each arm) will provide sufficient 
power and significance (a=0.05, power=0.8) to detect a minimal difference of 
20% in the primary outcome between the groups. To account for potential 
dropouts, particularly due to inability to access the kidney with the 
ureteroscope in patients with a tight ureter, we plan to enroll 12 additional 
patients (6 in each arm), bringing the total planned enrollment to 110 patients 
(55 per arm).
Description of Sites/Facilities 
Enrolling Participants:
All procedures and subject consent will be performed at the following 
locations: 1070 Park Ave; 5 East 98th street 6th floor, 425 W. 59th. Street, 4th 
Floor; 625 Madison Avenue, 2nd Floor, and Mount Sinai West which are all 
Mount Sinai approved sites in which the PI practices and operates. 
Description of Study 
Intervention/Experimental 
Manipulation:
Patients enrolled will be randomized for OBC arm or 5FR-UC arm. According to 
randomization the selected catheter will be inserted retrogradely at the 
beginning of the procedure. The rest of the procedure will be performed 
according to standard of care. Before the surgeon completes the procedure, 
an antegrade flexible ureteroscopy will be performed after removing the 
Occlusion Balloon Catheter / 5FR-UC, and identification of ureteral calculi will 
be recorded (number, size, location).
Study Duration*:
18-24 months
Participant Duration:
1 day
1.2
SCHEMA 
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Patient eligibility will be confirmed during initial presentation of urinary tract stone. The 
patient’s provider will determine if surgery will be performed based upon available imaging 
studies and urologic standard of care.  If so, the provider will explain the specifics of the study to 
the patient and ask if he or she is willing to speak to a member of the research team for more 
information. 
If the patient is willing, a member of the research team will approach the patient after the 
provider has introduced the study and the patient agrees to learn more.
Once informed consent has been achieved, patients will be enrolled into the study, randomized 
to OBC or 5FR-UC arms, and undergo the PCNL operation on the scheduled date. Antegrade 
Flexible ureteroscopy will be performed at the of the procedure through the percutaneous 
access.
1.3
SCHEDULE OF ACTIVITIES 

Once informed consent has been achieved, patients will be enrolled into the study

Randomization to OBC or 5FR-UC arms will be performed just before the operation

OBC or 5FR-UC will be inserted retrogradely at the beginning of the procedure.

If OBC was placed, the balloon will be inflated under endoscopic/fluoroscopic guidance
before the initiation of the nephrolithotomy.

Rest of the procedure will be performed according to standard of care.

Antegrade flexible ureteroscopy will be performed after removing the Occlusion Balloon
Catheter / 5FR Ureteral Catheter

Identification of ureteral stone fragments will be recorded, and any identified stone will
be removed.
2
INTRODUCTION
2.1
STUDY RATIONALE 
PCNL is a procedure to remove renal stones via a small skin incision, providing percutaneous access to 
the kidney. Before creating the access, a ureteral catheter is inserted retrogradely to allow for optional 
pyelography for guidance.
Historically, PCNL was performed exclusively in the prone position, where the kidney's orientation 
increased the likelihood of stone fragments migrating into the ureter, making an occlusion balloon 
catheter (OBC) necessary. An OBC is a specialized catheter with an inflatable balloon at its tip that can 
temporarily block the renal pelvis exit, preventing fragment migration into the ureter.
In supine PCNL, the patient lies on their back with the flank elevated, causing the kidney to tilt obliquely 
with the upper pole lower and more posterior. This positioning may naturally retain small fragments 
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within the kidney, reducing the need for an OBC. A 5FR ureteral catheter (5FR-UC), without an inflatable 
balloon, may suffice, offering cost savings and a shorter procedure time. 
2.2
BACKGROUND 
Kidney stones are a prevalent urological condition, affecting approximately 1 in 11 individuals in the 
United States and causing significant morbidity due to pain, obstruction, and infection [1]. Percutaneous 
nephrolithotomy (PCNL) is a common surgical procedure for the removal of large or complex kidney 
stones [2]. During the procedure, stone fragments may migrate from the kidney into the ureter during 
fragmentation. These migrations might be missed by surgeons, placing patients at risk of obstructing 
uropathy.
The 5FR ureteral catheter (5FR-UC) is an open-ended small-caliber tube inserted at the beginning of 
PCNL to facilitate visualization of the collecting system using fluoroscopy and assist with renal access. 
The occlusion balloon catheter (OBC) is a type of ureteral catheter equipped with a small inflatable 
balloon at its tip. When inflated, the balloon can help prevent the migration of stone fragments [3,4]. 
While most surgeons retrogradely insert a 5FR-UC, primarily for percutaneous access, at our institution, 
OBCs are used in most PCNLs.
During PCNL, if the OBC is placed retrogradely into the renal pelvis and inflated, it occludes the pelvic 
exit, potentially preventing stone fragments from entering the ureter. The adoption of OBCs is evolving, 
including their use in ureteroscopy and PCNL, with theoretical benefits for stone-free rates and 
complication prevention. However, there is no supporting data, and no established guidelines currently 
exist for their use.
In supine PCNL, patients are positioned such that the upper pole of the kidney is oriented more 
medially, caudally, and posteriorly, which may make it a favorable site for fragment migration. Our aim 
is to compare the use of OBCs and 5FR-UCs during PCNL and assess their roles in minimizing stone 
fragment migration into the ureter.
2.3
RISK/BENEFIT ASSESSMENT 
2.3.1
KNOWN POTENTIAL RISKS 
There will be no risk of physical harm to subjects due to study interventions. Both the OBC and 5FR-UC 
are approved tools commonly used during stone surgeries, and both are FDA-approved. The PCNL 
procedure will be performed according to standard care protocols, with antegrade flexible ureteroscopy 
considered an acceptable adjunct procedure during PCNL if needed. In this study, antegrade ureteroscopy 
will be performed for all patients to assess and clear any ureteral fragments.
All patients will have the associated risk of increased operative time due to antegrade ureteroscopy. 
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2.3.2
KNOWN POTENTIAL BENEFITS 
No benefits are expected to participation.
2.3.3
ASSESSMENT OF POTENTIAL RISKS AND BENEFITS 
Other than the extremely small risk of compromising protected health information and minimal 
prolongation of the surgery (by 5-10 minutes), we do not foresee any unusual risks other than PCNL’s 
regular known risks. 
3
OBJECTIVES AND ENDPOINTS 
OBJECTIVES
ENDPOINTS
JUSTIFICATION FOR 
ENDPOINTS
PUTATIVE 
MECHANISMS OF 
ACTION
Primary
Compare rate of ureteral 
stone fragments upon 
completion of PCNL while 
using OBC versus 5FR-UC
Endoscopic 
identification of 
ureteral stone 
fragments 
Endoscopic identification is 
the gold standard for ureteral 
stone identification.
N/A
Secondary
Compare procedural 
outcomes of OBC and 5FR-UC
1) Length of 
procedure 
2) Intraoperative 
complications 
3) stent placement 
Common procedural 
outcomes of endourologic 
procedures
N/A
4
STUDY DESIGN
4.1
OVERALL DESIGN
Once informed consent has been achieved, patients will be enrolled into the study, and 
randomization to OBC or 5FR-UC arms will be performed just before the operation. OBC or 5FR-
UC will be inserted retrogradely at the beginning of the procedure. The rest of the procedure 
will be performed according to the standard of care. Upon completion of the procedure, 
antegrade flexible ureteroscopy will be performed after removing the ureteral catheter (which 
ever was inserted) and identification of ureteral stone fragments will be recorded. Length of 
procedure, intraoperative complications and stent placement would also be recorded during the 
procedure.
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4.2
SCIENTIFIC RATIONALE FOR STUDY DESIGN

Randomization is performed to create equal groups of OBC and 5FR-UC

Antegrade flexible ureteroscopy is performed since it is the gold standard for ureteral stone 
identification. 
4.3
JUSTIFICATION FOR INTERVENTION
Surgical interventions for kidney stones will be performed regardless of participation in this study.  
4.4
END-OF-STUDY DEFINITION
This investigation will finish once all participants are enrolled. Follow up is not part of the protocol, so as 
the last enrolled patient completes his procedure, the study ends. 
5
STUDY POPULATION
5.1
INCLUSION CRITERIA
•
Adults aged 18 years and older.
•
Diagnosed with kidney stones and scheduled for PCNL.
•
Able and willing to provide informed consent.
5.2
EXCLUSION CRITERIA
•
Pregnant women 
•
Urinary tract anomalies such as urinary diversion, previous ureteral reconstruction surgeries, 
horseshoe kidney, solitary kidney, duplicated system, urinary stricture disease, ureteropelvic 
junction obstruction, pelvic kidney, stone in calyceal diverticulum.
•
Prone procedure
5.3
STRATEGIES FOR RECRUITMENT AND RETENTION
Patients will be recruited from the practice of Dr. Mantu Gupta and Dr. William Atallah.  Together, they 
have one of the busiest kidney stone practices in the area providing ample patients to recruit into the 
study.  We do not anticipate any issues with retention as patient involvement occurs for one day, which 
is the day of surgery. 
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6
STUDY INTERVENTION(S) OR EXPERIMENTAL MANIPULATION(S)
6.1
STUDY INTERVENTION(S) OR EXPERIMENTAL MANIPULATION(S) ADMINISTRATION
6.1.1
STUDY INTERVENTION OR EXPERIMENTAL MANIPULATION DESCRIPTION
OBC or 5FR-UC will be inserted retrogradely at the beginning of the procedure, and both are considered 
standard of care either way. The rest of the procedure will be performed according to the standard of 
care. Upon completion of the procedure, antegrade flexible ureteroscopy will be performed after 
removing the ureteral catheter (which ever was inserted) and identification of ureteral stone fragments 
will be recorded. Any identified stone will be removed. Antegrade flexible ureteroscopy is considered an 
acceptable adjunct procedure during PCNL if needed.
6.2
FIDELITY
6.2.1
INTERVENTIONIST TRAINING AND TRACKING
Dr. Mantu Gupta, professor of urology at Mount Sinai West Hospital will be performing the procedures.  
Dr. Gupta is a world-renowned expert in these operative techniques.
Dr. William Atallah will also be performing the procedures. He is assistant Professor of Urology at the 
Kidney Stone Center of Mount Sinai, director of Quality Improvement and Patient Relations at Mount 
Sinai West & Morningside Hospital, Chief of Endourology at Elmhurst Hospital.
6.3
MEASURES TO MINIMIZE BIAS: RANDOMIZATION AND BLINDING
There will be randomization to minimize bias. There will be no blinding. 
7
STUDY INTERVENTION/EXPERIMENTAL MANIPULATION DISCONTINUATION AND 
PARTICIPANT DISCONTINUATION/WITHDRAWAL
7.1
DISCONTINUATION OF STUDY INTERVENTION/EXPERIMENTAL MANIPULATION
No discontinuation will take place as the surgical procedures being performed are part of subjects’ 
standard clinical care.
7.2
PARTICIPANT DISCONTINUATION/WITHDRAWAL FROM THE STUDY
Patients will be considered enrolled in the study once consent has been signed.  Participants may 
discontinue or withdraw from the study for any reason and at any point in time through the conclusion of 
the study.  
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7.3
LOST TO FOLLOW-UP
There is no follow-up.
8
STUDY ASSESSMENTS AND PROCEDURES
8.1
ADVERSE EVENTS AND SERIOUS ADVERSE EVENTS
8.1.1
DEFINITION OF ADVERSE EVENTS
Any untoward medical occurrence, unintended sign, symptom, illness or disease temporally associated 
with the study protocol regardless of the suspected cause.
8.1.2
DEFINITION OF SERIOUS ADVERSE EVENTS
An Adverse Event that is considered “serious” if it meets at minimum one of the three Seriousness 
reporting criterions below:
1. Led to death,
2. Led to a serious injury which:
a. Resulted in a life-threatening illness or injury, or
b. Resulted in a permanent impairment of a body structure or a body function, or
c. Resulted in medical or surgical intervention to prevent life-threatening illness or injury or 
permanent impairment to a body structure or a body function
8.1.2.1
RELATIONSHIP TO STUDY INTERVENTION/EXPERIMENTAL MANIPULATION
All AEs will be assessed for relationship to the study protocol based on the following definitions:
Not Related: There is no clear evidence that the AE has a relationship to the study protocol and can be 
attributed to an underlying or concurrent illness/clinical condition or an effect of another device, drug or 
treatment.
Related: There is a clear causal relationship of the AE to the marketed device or procedure beyond 
reasonable doubt.
8.1.3
TIME PERIOD AND FREQUENCY FOR EVENT ASSESSMENT AND FOLLOW-UP
There is no follow-up.
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8.1.4
ADVERSE EVENT REPORTING 
Adverse events must be reported to the IRB as soon as possible and no later than 2 working days after 
the PI first becomes aware of the event. The PI or designee must record all AE information that can be 
gathered within the reporting timeframe and enter it onto the AE eCRF.
Relevant follow-up information should be submitted to the IRB as soon as it becomes available and/or 
upon request.  
8.1.5
SERIOUS ADVERSE EVENT REPORTING 
See section 7.1.4
8.1.6
REPORTING EVENTS TO PARTICIPANTS 
All SAE’s or AE’s will be reported to affected participants by the principal investigator directly.
9
STATISTICAL CONSIDERATIONS 
9.1
STATISTICAL HYPOTHESES
9.2
SAMPLE SIZE DETERMINATION
An estimated sample size of 98 patients (49 in each arm) will provide sufficient power and significance 
(a=0.05, power=0.8) to detect a minimal difference of 20% in the primary outcome between the groups. 
To account for potential dropouts, particularly due to inability to access the kidney with the ureteroscope 
in patients with a tight ureter, we plan to enroll 12 additional patients (6 in each arm), bringing the total 
planned enrollment to 110 patients (55 per arm).
9.3
POPULATIONS FOR ANALYSES
All enrolled subjects will be included for analyses. 
9.4
STATISTICAL ANALYSES
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9.4.1
GENERAL APPROACH
After sufficient patient enrollment, we will analyze our data:

We will calculate mean, median, IQR and standard deviation for continuous variables; 
frequencies and percentages for categorical variables.

We will compare the baseline characteristics between the groups (OBC vs. 5FR-UC) 
using chi square test, Fischer exact test, t-test and Mann-Whitney test. 

We will evaluate the endpoints and compare them between the groups using regression 
models. 
9.4.2
ANALYSIS OF THE PRIMARY ENDPOINT(S)
Identification of ureteral calculi:

Rates of ureteral calculi identification will be calculated for each group

Using Fischer exact/Chi square tests we will compare those rates between the groups

Using regression models, we will estimate any association between the type of ureteral 
catheter and ureteral calculi, and with multivariate analysis we will adjust for competing 
factors.
9.4.3
ANALYSIS OF THE SECONDARY ENDPOINT(S)
Length of procedure: we will compare the median/mean procedure time between the groups using 
Mann-Whitney test/T-test.
Intraoperative complications: we will compare the rates between the groups using Fischer exact/Chi-
square test. 
Stent placement: we will compare the rates between the groups using Fischer exact/Chi-square test.
10
SUPPORTING DOCUMENTATION AND OPERATIONAL CONSIDERATIONS
10.1 REGULATORY, ETHICAL, AND STUDY OVERSIGHT CONSIDERATIONS
10.1.1 INFORMED CONSENT PROCESS
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The standard informed consent process for research outlined in SOP HRP-090 will be followed. 
10.1.1.1 CONSENT PROCEDURES AND DOCUMENTATION
Subjects will be recruited from Dr. Mantu Gupta’s and Dr.  William Atallah’s practice. Patients will be 
recruited during the initial presentation to the operative room. 
Potential subjects will be informed of the study at their preoperative visit and may sign the consent at 
that time if they feel comfortable.  If subjects require time for further contemplation, the consent may be 
signed on the day of surgery in the preoperative area (prior to administration of any anesthesia).  This 
gives potential subjects at least 24 hours to consider the study and review the consent form.
Given the simplicity of the nature of subject involvement, we anticipate that no more than 5 minutes will 
generally be required to explain the consent form.  However, longer and more extensive discussions will 
be available to those who request or require.  All potential subjects will be verbally informed that their 
participation is completely optional and that their decision of whether or not to participate does not 
impact their care in any manner.  Subjects will be asked to verbally repeat and summarize their 
involvement in the study.  A copy of the consent form will be provided to the subject directly after signing 
the form.
10.1.2 CONFIDENTIALITY AND PRIVACY 
The data will be housed in Mount Sinai’s REDCap database. The data includes identifiers (name, MRN, 
phone number, email address, elements of dates) and will be stored with protected passwords.  The data 
will be stored with protected passwords. The data will be reported in aggregate and anonymized. 
10.1.3 FUTURE USE OF STORED SPECIMENS AND DATA 
The data will be retained for at least 6 years after publication, per regulations. 
10.1.3.1 DATA COLLECTION AND MANAGEMENT RESPONSIBILITIES 
Data collection will be the responsibility of the research staff at the site under the supervision of the site 
investigator. The investigator will be responsible for ensuring the accuracy, completeness, legibility, and 
timeliness of the data reported.
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All source documents will be completed in a neat, legible manner to ensure accurate interpretation of 
data.  
Hardcopies of the study visit worksheets will be provided for use as source document worksheets for 
recording data for each participant consented/enrolled in the study.  Data recorded in the electronic case 
report form (eCRF) derived from source documents will be consistent with the data recorded on the 
source documents. 
Clinical data (including adverse events (AEs), concomitant medications, and expected adverse reactions 
data) and clinical laboratory data will be entered into the electronic data capture (EDC) system, a 21 CFR 
Part 11-compliant data capture system. The data system includes password protection and internal quality 
checks, such as automatic range checks, to identify data that appear inconsistent, incomplete, or 
inaccurate. Clinical data will be entered directly from the source documents.
The data safety will be monitored by the PI 
10.1.3.2 STUDY RECORDS RETENTION 
Study documents will be retained until at least 6 years have elapsed since the formal discontinuation of 
clinical development of the study intervention. These documents should be retained for a longer period, 
however, if required by local regulations. No records will be destroyed without the written consent of the 
principal investigator.
The data will be kept until its publication at most six years.
10.1.4 PROTOCOL DEVIATIONS  
This protocol defines a protocol deviation as any noncompliance with the clinical trial protocol, 
International Council on Harmonisation Good Clinical Practice (ICH GCP), or Manual of Procedures (MOP) 
requirements. The noncompliance may be either on the part of the participant, the investigator, or the 
study site staff. As a result of deviations, corrective actions will be developed by the site and implemented 
promptly. 
It will be the responsibility of the site investigator to use continuous vigilance to identify and report 
deviations within 5 working days of identification of the protocol deviation, or within 5 working days of 
the scheduled protocol-required activity. All deviations will be addressed in study source documents. 
Protocol deviations will be sent to the reviewing Institutional Review Board (IRB) per their policies. The 
site investigator will be responsible for knowing and adhering to the reviewing IRB requirements.
The PI will be responsible for any vigilance and monitoring of the data.
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FUNDING
None
12
REFERENCES 
Include a list of relevant literature and citations for all publications referenced in the text of the protocol. 
Use a consistent, standard, modern format, which might be dependent upon the required format for the 
anticipated journal for publication (e.g., N Engl J Med, JAMA, etc.).  The preferred format is International 
Committee of Medical Journal Editors (ICMJE). 
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10.1080/02841850500335028. PMID: 16498941.
4. Qi S, Li Y, Liu X, Zhang C, Zhang H, Zhang Z, Xu Y. Clinical efficacy, safety, and costs of percutaneous occlusive
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Effective Date: 12/15/2025
End Date:12/14/2026