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.