Ureteral StoneNCT07601932
Patient Positioning for Treatment of Proximal Ureteral Stones
A study testing Reverse Trendelenburg Position and T-Tilt Position in people with Ureteral Stone, run by Icahn School of Medicine at Mount Sinai at 1 site in United States.
Trial summary
Ureteroscopic management of proximal ureteral stones presents technical challenges including stone retropulsion, prolonged operative time, and conversion to intrarenal treatment. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Ureteral Stone
- What is being tested?
- Reverse Trendelenburg Position and T-Tilt Position
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 54 participants
- Where
- 1 siteUnited States
- Study dates
- 21 May 2026to Dec 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adults aged 18 years and older.
- Diagnosed with kidney stones and scheduled for fURS.
- Stone burden > 1 cm and/or multiple stones will be eligible.
- Able and willing to provide informed consent.
Who cannot join
- Pregnant persons as determined by pre-operative urine pregnancy test (standard of care at the institution)
- Untreated UTI
- Patients with urinary anomalies (e.g., urinary diversion, ureteral reconstruction, horseshoe kidney)
- Single stone < 1 cm
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Mount Sinai West
New York, New York, 10019
Mantu Gupta, MD, 212-241-1272, Mantu.gupta@mountsinai.org
Blair Gallante, MPH, 212-241-1272, blair.gallante@mountsinai.org
About this study
Official title: Optimal Patient Positioning and Strategy for the Treatment of Proximal Ureteral Stones
Ureteroscopic management of proximal ureteral stones presents technical challenges including stone retropulsion, prolonged operative time, and conversion to intrarenal treatment. Reverse Trendelenburg positioning has been shown to reduce proximal stone migration and operative time in ureteral stones, while the T-tilt position improves intrarenal stone clearance. The optimal strategy for proximal ureteral stones (treating stones in situ using reverse Trendelenburg versus pushing stones into the kidney followed by intrarenal treatment in T-tilt) remains unknown.
This randomized controlled trial compares these two strategies, with primary focus on operative time as a measure of procedural efficiency.
A total of 54 patients (27 per arm) will be enrolled at Mount Sinai West.
Read the detailed description
Ureteroscopy has become a primary modality for the management of ureteral and renal calculi due to its high efficacy, minimally invasive nature, and favorable safety profile. Despite advances in flexible ureteroscopy, laser lithotripsy, and access technologies, proximal ureteral stones remain technically challenging, largely due to their tendency to migrate retrograde into the kidney, leading to prolonged operative time, increased need for flexible ureteroscopy, and lower procedural efficiency.
Stone retropulsion is influenced by laser energy, irrigation flow, ureteral anatomy, and gravitational forces. Several mechanical and laser-based strategies have been explored to mitigate migration, though results have been variable. Patient positioning represents a simple and cost-neutral intervention that may alter stone behavior intraoperatively without requiring additional devices.
Reverse Trendelenburg positioning has recently been shown to reduce proximal stone migration and improve operative efficiency during ureteroscopic treatment of ureteral stones. In a randomized controlled trial, patients positioned in reverse Trendelenburg experienced lower rates of retropulsion, reduced need for conversion to flexible ureteroscopy, and shorter operative times compared with standard positioning. However, this study included stones across multiple ureteral segments and did not focus specifically on proximal ureteral stones, which may have distinct anatomical and migration characteristics.
Conversely, T-tilt positioning has been investigated in the context of intrarenal stone treatment. Prior randomized evidence demonstrated that T-tilt positioning during retrograde intrarenal surgery resulted in higher stone-free rates, likely due to improved gravitational alignment of calyces and enhanced fragment clearance. These findings suggest that positioning may also optimize intrarenal lithotripsy efficiency once stones migrate into the kidney.
For proximal ureteral stones, two competing operative strategies are commonly used in clinical practice: (1) in situ ureteral treatment with efforts to prevent migration, potentially optimized by reverse Trendelenburg positioning, or (2) intentional pushback of the stone into the kidney followed by intrarenal lithotripsy under positioning conditions favorable for fragment clearance, such as T-tilt.
The decision to use one strategy over another is based on surgeon preference. Currently, there are no guidelines or standards favoring either approach. To date, no randomized study has directly compared these two positioning-based strategies for proximal ureteral stones. Given that operative time is strongly associated with anesthesia exposure, procedural cost, complication risk, and resource utilization, it represents a clinically meaningful and objective primary endpoint to evaluate procedural efficiency between approaches.
This study seeks to address an important gap in endourologic practice by determining the optimal positioning strategy for proximal ureteral stone management, with the goal of improving operative efficiency, reducing procedural burden, and informing evidence-based surgical decision-making.
- Conditions
- Ureteral Stone
- Being tested
- Reverse Trendelenburg Position, T-Tilt Position
- Medical subject headings
- Ureterolithiasis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Reverse Trendelenburg PositionProcedure or surgery
Patients will be positioned in reverse Trendelenburg at a 20 degree incline with the use of a digital protractor. Lithotripsy will be performed within the ureter with attempts to prevent proximal migration and until all fragments are removed.
T-Tilt PositionProcedure or surgery
Stone will be intentionally relocated into the kidney when feasible, followed by intrarenal lithotripsy in T-tilt position. In the T-tilt position the table is angled 15-degree Trendelenburg and 15-degree airplane away from the surgical side kidney with the use of a digital protractor. This allows fragments to rest in a superior and medial position away from the lower pole to facilitate removal.
| Study group | Role | What they receive |
|---|---|---|
| Reverse Trendelenburg Position | Experimental | Participants undergo ureteroscopic lithotripsy in reverse Trendelenburg positioning with attempted in situ treatment of the proximal ureteral stone to minimize proximal migration. Receives: Procedure: Reverse Trendelenburg Position |
| T-Tilt Position | Active comparator | Participants undergo intentional relocation of the proximal ureteral stone into the kidney followed by intrarenal lithotripsy performed in the T-tilt position. Receives: Procedure: T-Tilt Position |
What is being measured
The primary outcome is the main question the study is designed to answer.
Total operative time
Operative time will be used to compare procedural efficiency
Measured: Immediately postoperatively on the day of surgery
Secondary outcomes (4)
Proportion of participants stone-free
Proportion of participants without residual stone fragments on postoperative CT imaging
Measured: From Week 4 to Week 6 postoperatively
Proportion of procedures requiring additional equipment or procedural maneuvers
Proportion of procedures requiring additional equipment or procedural maneuvers beyond the initially planned operative strategy to complete stone treatment
Measured: Immediately after completion of surgery on the day of procedure
Proportion of strategy failure
Proportion of cases in which the randomized operative strategy could not be successfully executed intraoperatively
Measured: Assessed immediately at completion of surgery on the day of procedure
Incidence of Complications
Incidence of postoperative complications, defined as any Clavien-Dindo complications, emergency department visits, or readmission related to the procedure. Outcome is recorded as the occurrence of a complication event (yes or no). Each participant is counted once, and the outcome is recorded as a binary variable indicating whether any of these events occurred or did not occur.
Measured: Through postoperative day 30
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 May 2026
- Study start21 May 2026
- Primary completionNov 2027 (estimated)
- Study completionDec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Ureteral StoneStudies of the same condition, open and under way.
- More trials run by Icahn School of Medicine at Mount SinaiThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 54 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Icahn School of Medicine at Mount Sinai
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Mantu Gupta, Icahn School of Medicine at Mount Sinai
- Investigators
- Mantu Gupta, MD, Principal investigator, Icahn School of Medicine at Mount Sinai
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07601932
- Sponsor's protocol ID
- STUDY-26-00168
- Status last verified
- Jun 2026
- First submitted
- 14 May 2026
- Last updated
- 4 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: protecting participant privacy/confidentiality
Study at a glance
From the registry record, last updated by the sponsor on 4 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Optimal Patient Positioning and Strategy for the Treatment of Proximal Ureteral Stones
- ClinicalTrials.gov ID
- NCT07601932
- Acronym / sponsor ID
- STUDY-26-00168
- Conditions
- Ureteral Stone
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 54 participants (estimated)
- Lead sponsor
- Icahn School of Medicine at Mount SinaiUniversity, hospital or other
- Study start
- 21 May 2026 (actual)
- Primary completion
- Nov 2027 (estimated)
- Study completion
- Dec 2027 (estimated)
- First posted
- 22 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Ureteroscopic management of proximal ureteral stones presents technical challenges including stone retropulsion, prolonged operative time, and conversion to intrarenal treatment. Reverse Trendelenburg positioning has been shown to reduce proximal stone migration and operative time in ureteral stones, while the T-tilt position improves intrarenal stone clearance. The optimal strategy for proximal ureteral stones (treating stones in situ using reverse Trendelenburg versus pushing stones into the kidney followed by intrarenal treatment in T-tilt) remains unknown.
This randomized controlled trial compares these two strategies, with primary focus on operative time as a measure of procedural efficiency.
A total of 54 patients (27 per arm) will be enrolled at Mount Sinai West.
Detailed description
Ureteroscopy has become a primary modality for the management of ureteral and renal calculi due to its high efficacy, minimally invasive nature, and favorable safety profile. Despite advances in flexible ureteroscopy, laser lithotripsy, and access technologies, proximal ureteral stones remain technically challenging, largely due to their tendency to migrate retrograde into the kidney, leading to prolonged operative time, increased need for flexible ureteroscopy, and lower procedural efficiency.
Stone retropulsion is influenced by laser energy, irrigation flow, ureteral anatomy, and gravitational forces. Several mechanical and laser-based strategies have been explored to mitigate migration, though results have been variable. Patient positioning represents a simple and cost-neutral intervention that may alter stone behavior intraoperatively without requiring additional devices.
Reverse Trendelenburg positioning has recently been shown to reduce proximal stone migration and improve operative efficiency during ureteroscopic treatment of ureteral stones. In a randomized controlled trial, patients positioned in reverse Trendelenburg experienced lower rates of retropulsion, reduced need for conversion to flexible ureteroscopy, and shorter operative times compared with standard positioning. However, this study included stones across multiple ureteral segments and did not focus specifically on proximal ureteral stones, which may have distinct anatomical and migration characteristics.
Conversely, T-tilt positioning has been investigated in the context of intrarenal stone treatment. Prior randomized evidence demonstrated that T-tilt positioning during retrograde intrarenal surgery resulted in higher stone-free rates, likely due to improved gravitational alignment of calyces and enhanced fragment clearance. These findings suggest that positioning may also optimize intrarenal lithotripsy efficiency once stones migrate into the kidney.
For proximal ureteral stones, two competing operative strategies are commonly used in clinical practice: (1) in situ ureteral treatment with efforts to prevent migration, potentially optimized by reverse Trendelenburg positioning, or (2) intentional pushback of the stone into the kidney followed by intrarenal lithotripsy under positioning conditions favorable for fragment clearance, such as T-tilt.
The decision to use one strategy over another is based on surgeon preference. Currently, there are no guidelines or standards favoring either approach. To date, no randomized study has directly compared these two positioning-based strategies for proximal ureteral stones. Given that operative time is strongly associated with anesthesia exposure, procedural cost, complication risk, and resource utilization, it represents a clinically meaningful and objective primary endpoint to evaluate procedural efficiency between approaches.
This study seeks to address an important gap in endourologic practice by determining the optimal positioning strategy for proximal ureteral stone management, with the goal of improving operative efficiency, reducing procedural burden, and informing evidence-based surgical decision-making.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Reverse Trendelenburg Position | Experimental | Procedure: Reverse Trendelenburg PositionParticipants undergo ureteroscopic lithotripsy in reverse Trendelenburg positioning with attempted in situ treatment of the proximal ureteral stone to minimize proximal migration. |
| T-Tilt Position | Active comparator | Procedure: T-Tilt PositionParticipants undergo intentional relocation of the proximal ureteral stone into the kidney followed by intrarenal lithotripsy performed in the T-tilt position. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Adults aged 18 years and older.
- Diagnosed with kidney stones and scheduled for fURS.
- Stone burden > 1 cm and/or multiple stones will be eligible.
- Able and willing to provide informed consent.
Key exclusion criteria (4 listed)
- Pregnant persons as determined by pre-operative urine pregnancy test (standard of care at the institution)
- Untreated UTI
- Patients with urinary anomalies (e.g., urinary diversion, ureteral reconstruction, horseshoe kidney)
- Single stone < 1 cm
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Reverse Trendelenburg PositionPatients will be positioned in reverse Trendelenburg at a 20 degree incline with the use of a digital protractor. Lithotripsy will be performed within the ureter with attempts to prevent proximal migration and until all fragments are removed. | Procedure or surgery | Reverse Trendelenburg Position |
| T-Tilt PositionStone will be intentionally relocated into the kidney when feasible, followed by intrarenal lithotripsy in T-tilt position. In the T-tilt position the table is angled 15-degree Trendelenburg and 15-degree airplane away from the surgical side kidney with the use of a digital protractor. This allows fragments to rest in a superior and medial position away from the lower pole to facilitate removal. | Procedure or surgery | T-Tilt Position |
Primary outcome
Total operative time
Time frame: Immediately postoperatively on the day of surgery
Operative time will be used to compare procedural efficiency
4 secondary outcomes
Proportion of participants stone-free
Time frame: From Week 4 to Week 6 postoperatively
Proportion of procedures requiring additional equipment or procedural maneuvers
Time frame: Immediately after completion of surgery on the day of procedure
Proportion of strategy failure
Time frame: Assessed immediately at completion of surgery on the day of procedure
Incidence of Complications
Time frame: Through postoperative day 30
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Jun 2026.
- Individual participant dataSharing planned: No. protecting participant privacy/confidentiality
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Comparison of Suction and Conventional Ureteral Access Sheaths in Kidney Stone Surgery
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Mantu Gupta, MD principal investigator
Icahn School of Medicine at Mount Sinai
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Reverse Trendelenburg Position and T-Tilt Position in people with Ureteral Stone, run by Icahn School of Medicine at Mount Sinai at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 4 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Mantu Gupta, MD (212-241-1272, mantu.gupta@mountsinai.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Total operative time (time frame: Immediately postoperatively on the day of surgery). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Jun 2026.