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NCT Number: NCT06809582

Impact of Surgical Position on Stone-Free Rates in Retrograde Intrarenal Surgery

The goal of this clinical trial is to determine whether the surgical position during retrograde intrarenal surgery (RIRS) affects stone-free rates in adults with kidney stones. The main questions it aims to answer are:

* Does the modified lithotomy position result in a higher stone-free rate compared to the standard lithotomy position? * Are there differences in complication rates between the two surgical positions?

Researchers will compare patients undergoing RIRS in the standard lithotomy position to those in the modified lithotomy position (30-degree Trendelenburg with elevated surgical side) to assess its impact on stone clearance and surgical outcomes.

Participants will:

* Be randomly assigned to one of two surgical positions * Undergo RIRS with standard surgical procedures * Have follow-up imaging to assess stone clearance after surgery

This study aims to improve surgical techniques and patient outcomes in kidney stone treatment.

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Key information

Conditions

Stone, Kidney Calculi Female Urogenital Diseases Female Urogenital Diseases and Pregnancy Complications Kidney Calculi Kidney Diseases Male Urogenital Diseases Nephrolithiasis Pathological Conditions, Anatomical Pathological Conditions, Signs and Symptoms Stone;Renal Stones, Kidney Urinary Calculi Urogenital Diseases Urolithiasis Urologic Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Presence of single or multiple kidney stones, with the largest stone ≤2 cm
  • Age ≥18 years
  • Provided written informed consent to participate in the study
  • Indicated for retrograde intrarenal surgery (RIRS) as a treatment approach

Exclusion criteria

  • Severe cardiovascular disease (e.g., heart failure)
  • Congenital kidney anomalies (e.g., horseshoe kidney, ectopic kidney)
  • Concurrent ureteral stones
  • Pregnancy or planning pregnancy
  • History of previous kidney surgery on the same side
  • Active urinary tract infection (UTI)
  • Coagulopathy or use of anticoagulant therapy that cannot be stopped before surgery

Treatment and study plan

The T-Tilt position

Procedure

The T-Tilt position is a modified lithotomy position used during retrograde intrarenal surgery (RIRS). In this position:

The patient is placed in a 30-degree Trendelenburg position, meaning the head is slightly lower than the feet.

The surgical side is elevated at a 30-degree angle to improve access to the kidney.

This modified positioning is designed to enhance stone clearance, particularly by facilitating the movement of stone fragments away from the lower kidney calyces, where residual stones often remain. Researchers will compare this position to the standard lithotomy position to determine its impact on stone-free rates and surgical outcomes.

Primary outcomes

  1. Stone-Free Rate After Retrograde Intrarenal Surgery

    Time frame: 6 weeks post-surgery

    The percentage of participants with no residual kidney stones (≤4 mm fragments) on non-contrast computed tomography (CT) at 6 weeks postoperatively.

Secondary outcomes

  1. Postoperative Complication Rate

    Time frame: Within 30 days post-surgery

    he percentage of participants experiencing any postoperative complications, classified according to the Clavien-Dindo grading system.

Other outcomes

  1. Rehospitalization Rate

    Time frame: Within 30 days post-surgery

    The percentage of participants requiring hospital readmission due to complications related to the surgical procedure

  2. Total Laser Energy Used

    Time frame: Intraoperative

    The total Holmium:YAG laser energy (Joules) applied during stone fragmentation

Study contacts

Contact information is provided by the study sponsor or research team.

Murat Gulsen

CONTACT

[email protected]

+905062357421

Sponsors and collaborators

Lead sponsor

Ondokuz Mayıs University

Other

Registry information

Official study title

Does the Positioning in Retrograde Intrarenal Surgery Affect Stone-Free Rates? A Prospective Randomized Controlled Trial

Acronym: POS-RIRS-RCT

Important dates

Study start
2025
Primary completion
2025
Study completion
2026
First posted
Feb 5, 2025
Registry last updated
Aug 15, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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