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

Menoufia University

Status: Not yet enrolling

Conditions: Renal Calculi

Treatments: Procedure: Lithotomy Position; Procedure: Lateral position

Study type: Interventional

Funder types: Other

Identifiers

NCT07310966

Patient position in RIRS

Details and patient eligibility

About

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.

Enrollment: 70 estimated patients

Sex: All

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

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

Exclusion criteria

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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70 participants in 2 patient groups

Lithotomy position group

Active Comparator group

Description:

patients of this group undergo RIRS in Lithotomy position

Treatment:

Procedure: Lithotomy Position

Lateral position group

Active Comparator group

Description:

patients of this group undergo RIRS in lateral position

Treatment:

Procedure: Lateral position