Evaluation of Retrograde Intra Renal Surgery in the T-tilted Position (RIRS)

July 15, 2025 updated by: Emad mamdouh adly tawfeik, Ain Shams University

Evaluation of the T-tilted Position in Retrograde Intrarenal Surgery Using Flexible and Navigable Suction Access Sheath.

To evaluate the effect of the T-tilted position on the stone-free rate compared to the standard lithotomy position in retrograde intrarenal surgeries.

Common positions include the Trendelenburg position, where the patient is tilted head-down to help gravity move stones from the upper calyces to the renal pelvis, and the modified lateral decubitus position, which improves access to the lower renal poles. A more recent approach, the modified T-tilt position, combines a slight Trendelenburg tilt with lateral positioning, offering optimal access to both the upper and lower calyces while maintaining patient comfort

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Retrograde intrarenal surgery is a minimally invasive technique for managing renal stones, especially those in the renal pelvis and calyces. It is the standard of care for renal stones less than 2 cm. Due to the new advancements in endoscopes, ureteral access sheaths, and laser devices,retrograde intra renal surgery has been successful in managing stones with larger sizes.

The stone-free rate following flexible ureteroscopy for renal stones smaller than 2 cm is generally high, with most studies reporting stone free ratio between 80% and 95%.

Variations in stone free ratio can be attributed to factors such as stone composition, location, surgeon experience, intraoperative complications, type of laser and endoscopies Anatomical variations of the kidney especially The stone free ratio is mainly related to stone volume. The more the stone volume and greater risk of residual stones.

suction sheath was developed to enhance the stone free ratio and lower incidence of residual fragments.

Patients position was suggest to lower the postoperative residual rate. Common positions include the Trendelenburg position, where the patient is tilted head-down to help gravity move stones from the upper calyces to the renal pelvis, and the modified lateral decubitus position, which improves access to the lower renal poles. A more recent approach, the modified T-tilt position, combines a slight Trendelenburg tilt with lateral positioning, offering optimal access to both the upper and lower calyces while maintaining patient comfort.

We aimed throughout our study to evaluate the impact of the T-tilted position on stone free rate in retrograde intra renal surgery using flexible suction sheath.

METHODS This study aims to compare two patient positioning techniques during retrograde intrarenal surgery to assess their impact on the stone-free rate. Patients will be randomly assigned to one of two groups: Group A (standard lithotomy position) and Group B (T-Tilt position). The allocation process will use sealed envelopes prepared by an independent third party to ensure unbiased distribution. Both patients and the research team, including data collectors and statisticians, will be blinded to the intervention type to minimize bias. The study will evaluate whether the T-Tilt position improves stone free rate compared to the traditional lithotomy position, potentially optimizing retrograde intra renal surgery outcomes.

Surgical procedure The study will involve a consistent surgical approach to minimize variability. All procedures will be conducted under general anesthesia, with preoperative evaluation based on the American Society of Anesthesiologists physical status classification. Each patient will undergo cystourethroscopy, followed by selective catheterization with a 6F ureteric catheter. The main surgical procedure will be flexible ureteroscopy, performed according to the surgeon's standard technique, without special maneuvers like stone displacement. For patients with large stone burdens, an access sheath will be used to facilitate efficient stone removal. Stone characteristics, including size, location, and renal anatomy, will be recorded for analysis.

At the end of the procedure, an endoscopic examination of the pelvicalyceal system will be performed to assess stone fragmentation and the presence of residual fragments or dust. This examination will be video-recorded for post-operative assessment. The primary outcome of the study will be the comparison of stone free rate between the two positioning groups, while secondary outcomes will include the evaluation of perioperative complications, operative time, postoperative pain, hospital stay, and cost analysis.

Study Type

Interventional

Enrollment (Estimated)

160

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Egypt
    • Abbassia, Cairo
      • Cairo, Abbassia, Cairo, Egypt
        • Recruiting
        • Ainshams university hospitals
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • All patients above the age of 16 years of either sex who did not have a pre-existing ureteral stent presented to the Urology clinic in our university hospitals with kidney stones with size up to 2.5cm (estimated by CTUT as the greatest dimension or the summation of the greatest dimensions).

Exclusion Criteria:

  • Previous open renal surgery or renal trauma.
  • Patients with renal anomalies.
  • Patients with untreated or active UTI.
  • Patients who suffer from medical conditions that preclude the application of Trendelenburg position (lung disease, congestive heart failure).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: standard group
Patients will be placed in regular lithotomy position with operating table at 0 degrees of tilting.
Procedure: standard lithotomy position
Patients will be placed in regular lithotomy position with operating table at 0 degrees of tilting.
Experimental: T-tilted group
Patients will be placed at the T-Tilt position (15 degrees Trendelenburg and 15 degrees away from the surgical side kidney).
Procedure: T-tilting of the patient during surgery
Patients will be placed at the T-Tilt position (15 degrees Trendelenburg and 15 degrees away from the surgical side kidney) during surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
stone free rate in the T-tilted position during surgery
Time Frame: the duration of the study of at least 6 months
Follow up visits will be scheduled after 2 weeks; computed tomography urinary tract (CTUT) will be performed to identify stone-free rates and the procedure will be considered successful if no stones can be identified >4mm.
the duration of the study of at least 6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Ain Shams University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 1, 2025

Primary Completion (Estimated)

October 30, 2025

Study Completion (Estimated)

December 31, 2025

Study Registration Dates

First Submitted

February 21, 2025

First Submitted That Met QC Criteria

March 2, 2025

First Posted (Actual)

March 5, 2025

Study Record Updates

Last Update Posted (Actual)

July 17, 2025

Last Update Submitted That Met QC Criteria

July 15, 2025

Last Verified

July 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • RIRS in T-tilted position

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Stone, Kidney

Clinical Trials on standard lithotomy position

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Ireland

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe