Comparison of Lithotomy Versus Lateral Position in Retrograde Intrarenal Surgery for Lower Calyceal Stones Less Than 2 cm

NCT07310966 | Not Yet Recruiting

• 1 other identifier: Patient position in RIRS
• Study Type: interventional
• Target: 70
• Locations: 1 country
• Sites: 1

Brief Summary

Retrograde intrarenal surgery (RIRS) is an established minimally invasive treatment for renal stones, particularly for lower calyceal stones less than 2 cm, offering acceptable stone-free rates with low morbidity. However, stone clearance in the lower calyx remains technically challenging due to unfavorable anatomy, limited scope deflection, and gravity-dependent fragment retention. Patient positioning during RIRS has been suggested as a modifiable factor that may influence endoscopic access, stone relocation, and surgical ergonomics. The lithotomy position is conventionally used during RIRS, while the lateral position has been proposed to facilitate stone migration and improve lower calyceal access through gravitational assistance. Existing studies comparing patient positioning during RIRS are limited, with most evidence derived from retrospective analyses or non-randomized designs. Therefore, this randomized controlled trial aims to compare lithotomy versus lateral positioning during RIRS for lower calyceal stones less than 2 cm in terms of operative and clinical outcomes.

Conditions

Renal Calculi

Keywords

lithotomy position; lateral position; lower calyx; FURS; RIRS

Outcome Measures

Primary Outcomes (1)

• Stone Free Rate

  Stone-free rate (SFR), defined as no clinically significant residual stones on non-contrast 3-mm-cuts CT, measured as yes or no

  1 month

Secondary Outcomes (2)

• Operative time

  The operative time

• Complications

  1 month

Study Arms (2)

Lithotomy position group

ACTIVE COMPARATOR

patients of this group undergo RIRS in Lithotomy position

Procedure: Lithotomy Position

Lateral position group

ACTIVE COMPARATOR

patients of this group undergo RIRS in lateral position

Procedure: Lateral position

Interventions

Lateral position PROCEDURE

Patients undergo RIRS in lateral position

Lateral position group

Lithotomy Position PROCEDURE

Patients undergo RIRS in lithotomy position

Lithotomy position group

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults aged ≥18 years.
• Single or multiple lower calyceal renal stones with stone size \<2 cm confirmed by NCCT.
• Negative urine culture.
• Presented cases.

You may not qualify if:

• Multiple stones involving renal pelvis or other calyces.
• Anatomical anomalies affecting ureteroscope access (horseshoe kidney, malrotation, ureteral strictures).
• Pregnancy.
• Prior ipsilateral renal surgery.

Sponsors & Collaborators

• Menoufia University: lead

Study Sites (1)

Menoufia Faculty of Medicine

Shebin El-Kom, Menoufia, 32511, Egypt

Location

MeSH Terms

Conditions

Kidney Calculi

Condition Hierarchy (Ancestors)

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

Central Study Contacts

Ammar Alorabi

CONTACT

+201067608011; ammar.alorabi95@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Dr

Study Record Dates

• First Submitted: December 16, 2025
• First Posted: December 30, 2025
• Study Start: January 1, 2026
• Primary Completion: May 1, 2026
• Study Completion (Estimated): June 1, 2026
• Last Updated: December 30, 2025

Record last verified: 2025-12

Locations

EG (1)