Study to Assess Duration of Ureteral Rest Prior to Ureteral Reconstruction Surgery
Conditions: Ureteral Stricture
Sponsor: Northwestern University

PROTOCOL TITLE:  Prospective, single arm study to assess duration of ureteral rest 
prior to ureteral reconstruction surgery
PRINCIPAL INVESTIGATOR:
Ziho Lee
Department of Urology
312-926-5564
Ziho.lee@nm.org
VERSION DATE:
1.1
STUDY SUMMARY:
Investigational Agent(s) 
(Drugs or Devices)
IND / IDE / HDE # 
Indicate
Special Population(s)
☐ Children 
☐ Children who are wards of the state 
☐ Adults Unable to Consent  
☐ Cognitively Impaired Adults 
☐ Neonates of Uncertain Viability 
☐ Pregnant Women 
☐ Prisoners (or other detained/paroled individuals) 
☐ Students/Employees 
Sample Size
20-25
Funding Source
None
Indicate the type of 
consent to be obtained
☒ Written 
☐ Verbal/Waiver of Documentation of Informed 
Consent
☐ Waiver of HIPAA Authorization 
☐ Waiver/Alteration of Consent Process  
Site
☐ Lead Site (For A Multiple Site Research Study)
☐ Data Coordinating Center (DCC)
Research Related 
Radiation Exposure
☒ Yes 
☐ No 
DSMB / DMC / IDMC
☐ Yes 
☐ No
IRB #: STU00219828 Approved by NU IRB for use on or after 10/25/2023 through 10/12/2024.

OBJECTIVES:
Our objective is to assess the effect of duration of ureteral rest, defined as time from 
conversion of ureteral stent to percutaneous nephrostomy, on stricture length prior to 
ureteral reconstruction surgery. The null hypothesis is that we will observe no difference 
in ureteral stricture length when evaluated at two weeks of rest compared to six weeks 
of ureteral rest. 
BACKGROUND:
In the setting of ureteral strictures, it is well accepted that ureteral rest, defined as the 
absence of a ureteral stent or percutaneous nephroureteral tube, improves outcomes 
for ureteral reconstruction surgery.1 Ureteral rest allows for stricture maturation and 
decreases inflammation allowing for easier dissection and improved intraoperative 
discernment of stricture margins. However, the optimal duration of rest has not been 
established and varies by surgeon preference and experience, ranging from 1-6 weeks. 
Percutaneous nephrostomy tubes, the alternative for drainage that allows for ureteral 
rest in the setting of a ureteral stricture, require patients to have an external hardware 
device and can be quite cumbersome. A shorter period of rest would be preferred if 
possible, however not if this were to compromise surgical outcomes. Shorter periods of 
rest may not allow for full stricture maturation, however this process has never been 
formally evaluated overtime. 
All patients at our institution undergo an endoscopic evaluation in the operating room to 
evaluate stricture location, length, caliber, and quality prior to definitive ureteral 
reconstruction. The exact timing of this prior to definitive ureteral reconstruction is 
variable based on surgeon and patient availability, but generally all patients undergo at 
least six weeks of ureteral rest. 
Endoscopic instruments are routinely used during all ureteral reconstruction cases, 
however a formal endoscopic evaluation with antegrade and or retrograde pyelograms 
to reassess stricture length are not always routinely performed. We propose a 
prospective, single arm study where patients will undergo endoscopic evaluation in the 
operating room after two weeks of ureteral rest, and then again on the day of ureteral 
reconstruction surgery (approximately 6 weeks of ureteral rest). Participation in this 
study would only expose patients to approximately 5 minutes of additional anesthetic 
time, however, would expose patients to a small amount of additional radiation during 
their definitive ureteral reconstruction surgery, estimated at 1-4mSv, approximately 1-2 
additional x-rays. 
STUDY ENDPOINTS:
The primary study endpoint is determination of ureteral stricture length measured by 
antegrade or retrograde pyelogram at two and six weeks of ureteral rest.
IRB #: STU00219828 Approved by NU IRB for use on or after 10/25/2023 through 10/12/2024.

The secondary endpoint is ureteral stricture quality at two and six weeks of ureteral rest 
(example, transformation from narrowing to complete obliteration).
STUDY INTERVENTION(S)  / INVESTIGATIONAL AGENT(S):
No investigational agents will be used.
PROCEDURES INVOLVED:
Prior to surgery: Patients who have been identified and meet inclusion criteria for this 
study will be approached by a study team member either in the clinic or the pre-op area 
prior to the initial endoscopic evaluation surgery. 
Day of endoscopic evaluation: After consent is obtained, all patients will undergo routine 
endoscopic evaluation of their stricture as determined by the surgeon. This usually 
includes cystoscopy, antegrade and retrograde pyelogram, and ureteroscopy. The 
fluoroscopy images will be saved in the EMR. This is all standard of care procedure that 
would occur regardless if the decides to be a part of the study.
Day of definitive ureteral repair: After consent is obtained, all patients will undergo 
repeat endoscopic evaluation with antegrade and or retrograde pyelogram prior to 
definitive ureteral repair. This is the only research related procedure that is outside 
the standard of care. Patients routinely undergo endoscopic evaluation the day of 
surgery already however do not always have a formal antegrade and retrograde 
pyelogram obtained. Participation in the study will guarantee that they will undergo this 
evaluation, although many patients undergo this repeat evaluation already as 
determined by the surgeon.
After surgery: All patients undergoing ureteral reconstruction surgery will have a 
preoperative CT scan. Using this, we will measure the height of the L5 vertebrae. We 
will extrapolate stricture length on retrograde pyelogram by using this measurement for 
scale. All stricture length measurements will be done by the same researcher and they 
will be blinded to timing of when the images were obtained. Ureteral stricture quality will 
also be graded as either a narrowed segment or obliterated segment, with obliteration 
defined as inability of any contrast to pass through the segment on retrograde or 
antegrade pyelogram. Luminal diameter will also be measured.
Post-surgery: All patients will return to clinic for standard of care follow up. All patients 
will be included regardless of their follow up postoperatively as the purpose of the study 
is to determine stricture maturation preoperatively. 
SHARING RESULTS WITH PARTICIPANTS
Results will not be shared with participants.
INCLUSION AND EXCLUSION CRITERIA
Inclusion criteria:

>18 years of age
IRB #: STU00219828 Approved by NU IRB for use on or after 10/25/2023 through 10/12/2024.


Undergoing ureteral reconstruction surgery for ureteral stricture with conversion 
of an indwelling stent to a percutaneous nephrostomy tube for ureteral rest

Willing to sign informed consent form

Able to read and understand informed consent form
Exclusion criteria:

<18 years of age

Inability to provide informed consent

Members of vulnerable patient populations 
PARTICIPANT POPULATION(S)
Accrual 
Number:
Category/Group:
(Adults/Children 
Special/Vulnerable 
Populations)
Consented:
Maximum Number to be 
Consented or 
Reviewed/Collected/Screen
ed
Enrolled:
Number to 
Complete the 
Study or Needed 
to Address the 
Research 
Question
Adults
80
20-25
Local
Study-wide
Total:
80
20-25
RECRUITMENT METHODS
Potential subjects will be identified during their pre-operative clinic visit. Physician-
investigators will review the medical chart to ensure the patient meets inclusion and 
exclusion criteria. Potential subjects will then meet with a member of the study team to 
read the consent in detail and discuss the study in full.
WITHDRAWAL OF PARTICIPANTS
Decision to participate is completely voluntary, and patients will be notified at the start of 
the study that if they choose not to participate, then they will continue with our standard 
care. If a subject wishes to withdraw from the study, they may do so verbally or written 
request to the research team. A subject may be withdrawn from the study by the 
physician investigator if determined to be in the subject’s best interest for medical 
reasons.
RISKS TO PARTICIPANTS
The risks of this study are a potential very minimal increase in anesthetic time, predicted 
to be no more than five minutes. The anesthetic agent is completely determined by the 
anesthesiologist and is the same agent that is used for the definitive repair. We have no 
IRB #: STU00219828 Approved by NU IRB for use on or after 10/25/2023 through 10/12/2024.

way of knowing the agent and dose that will be used as this is determined by the 
attending anesthesiologist and is dictated by the larger ureteral reconstruction surgery. 
There is no significant increased risk to less than five minutes of additional anesthesia 
beyond the general risks of anesthesia that are discussed with the patient by the 
anesthesiologist. We believe this is not a significant increase as the overall length of 
theses surgeries ranges 3-4 hours, sometimes longer depending on the repair and 
individual patient factors. We do not anticipate any increase in equipment costs to the 
hospital as all the equipment required for the antegrade and retrograde pyelogram is 
currently already pulled for all ureteral reconstruction cases. There is a nominal 
increase in radiation risk to the patient, estimated to be ~1-4 mSv (expected radiation 
dose would be less than what would be associated with a ureteral stent which is ~4.7 
mSv). 
Additional risks include breach of privacy and confidentiality.
POTENTIAL BENEFITS TO PARTICIPANTS
Repeat endoscopic evaluation of the stricture length may allow for better intraoperative 
surgical planning and efficiency as we will better delineate stricture length and location 
prior to deciding on the surgical repair. 
DATA MANAGEMENT AND CONFIDENTIALITY
All information obtained from the medical record will be kept secured in a password-
secured REDCap database and only accessed by study personnel. Manual entry will be 
performed, and double entry verification will occur between research staff and study 
personnel. Data will undergo regular backups during data entry. All data will be de-
identified from the patient, and the key for the de-identification process will be 
maintained in a secure location. The presentation of the results of this study will 
maintain patient confidentiality.
Enrollment for this study is expected to be completed within 24 months of initiation.
Identifiable data will be kept until data analysis is complete. A limited data set will be 
kept for a minimum of 7 years.
PROVISIONS TO MONITOR THE DATA TO ENSURE THE SAFETY OF 
PARTICIPANTS
Data will be collected and stored electronically in REDCap and will only be accessible to
members of the study team.
PROVISIONS TO PROTECT THE PRIVACY INTERESTS OF PARTICIPANTS
Data resulting from this study will not be linked to subjects. Subjects will not be referred 
to by name of initial in any publications.
ECONOMIC BURDEN TO PARTICIPANTS
Participants will not be responsible for any cost related to participation in this research 
study.
IRB #: STU00219828 Approved by NU IRB for use on or after 10/25/2023 through 10/12/2024.

CONSENT PROCESS
Enrollment into the study will be performed by a qualified research coordinator.
After the patient completes their pre-surgical enrollment paperwork in the clinic, they will 
then be met in a private room away from the treating physicians by a qualified research 
coordinator who will discuss their potential enrollment and complete any research 
paperwork. Some patients may be approached via telephone with virtual consent.
NON-ENGLISH SPEAKING PARTICIPANTS
This study will provide access to participants with limited to no English proficiency and 
we will follow the IRB to effectively communicate the study to the participants during 
recruitment, consent, and the duration of the study. This study will utilize the short form 
consenting process as described by the IRB. This short form consent will attest to the 
information in the informed consent and will be presented orally or by the participant’s 
legal authorized representative. We will provide the short form to the participant or legal 
authorized representative. The short form will be signed and confirmation that the 
participant was consented in the language that is understandable by the participant, the 
person will be authorized by the IRB, there will be a witness to the presentation, the 
short form will be signed by the witness, the written summary will be signed by the 
witness and person obtaining consenting and finally a copy of the oral summary and 
short form will be given to the participant. 
 
Once the participant is enrolled, we will adhere to the IRB standard requirements for 
non-English speaking participants and obtain certified translations of the documents 
related to the study.
PROTECTED HEALTH INFORMATION (PHI AND HIPAA)
This research study will involve the collection of Protected Health Information (PHI) from 
the patient’s electronic medical record (EMR). PHI will also be created in this study: the 
questionnaires participants will be asked to complete will collect health information 
which may otherwise not be captured in the EMR.
HIPAA Authorization will be obtained from all participants. The following information 
may be collected for each participant:

Name

Medical Record Number

Telephone number

Email address
QUALIFICATIONS TO CONDUCT RESEARCH AND RESOURCES AVAILABLE
Persons involved in this study have experience with patient care and the handling of 
sensitive information. Dr. Lee is an assistant professor of urology here at Northwestern 
who specializes in reconstructive urology. Other staff, including residents, research 
coordinators, medical students, and nursing will have appropriate oversight by the PI. 
Staff are familiar with study sites at Northwestern Memorial Hospital / Northwestern 
Medical Group and Northwestern University culture. Facilities for conducting this 
IRB #: STU00219828 Approved by NU IRB for use on or after 10/25/2023 through 10/12/2024.

research are adequate, including clinic space, secure computer workstations, and 
availability of access to other Northwestern University resources including the EDW. All 
persons assisting with research will be adequately informed regarding the protocol and 
research procedures and will have access to both text of the protocol and an “open-door 
policy” to promote a culture of questions, transparency, and communication.
Reference
1. Lee Z, Lee M, Lee R, et al. Ureteral Rest is Associated With Improved Outcomes in 
Patients Undergoing Robotic Ureteral Reconstruction of Proximal and Middle Ureteral 
Strictures. Urology. 2021;152:160-166. doi:10.1016/j.urology.2021.01.058
IRB #: STU00219828 Approved by NU IRB for use on or after 10/25/2023 through 10/12/2024.