Access Sheaths With Aspiration for Renal RetrOgrade Surgery, Randomized CompArative Outcomes

NCT07678255 | Not Yet Recruiting

• 2 other identifiers: ARROCA01SICEIA-2026-000838
• Study Type: interventional
• Target: 156
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to learn whether the ClearPetra ureteral access sheath (Coloplast) is more effective than the Navigator ureteral access sheath (Boston Scientific) in treating intrarenal kidney stones of 1-3 cm in adult patients undergoing flexible ureteroscopy (RIRS). The main questions it aims to answer are: Does ClearPetra achieve a higher stone-free rate at 1 month post-intervention compared to Navigator, as assessed by non-contrast abdominal-pelvic CT scan? Does ClearPetra reduce total surgical time compared to Navigator? Does ClearPetra lower the retreatment rate at 3 months compared to Navigator? Does ClearPetra present a rate of clinically significant complications (Clavien-Dindo ≥ II) that is lower than or similar to Navigator? Researchers will compare flexible ureteroscopy using the ClearPetra vacuum-assisted flexible ureteral access sheath to flexible ureteroscopy using the Navigator standard rigid ureteral access sheath, to see if ClearPetra leads to higher stone clearance rates while maintaining a comparable safety profile. Participants will: Undergo flexible ureteroscopy (RIRS) using one of two randomly assigned ureteral access sheaths (ClearPetra or Navigator), determined by computer-generated randomization immediately before surgery Have a non-contrast abdominal-pelvic CT scan at 1 month post-intervention to assess stone-free status Have a non-contrast abdominal-pelvic CT scan at 3 months post-intervention to evaluate residual fragments and the need for retreatment Attend follow-up visits at 1 month and 3 months post-surgery for clinical assessment and complication recording The study will be conducted at the Urology Department of Hospital Universitario Virgen del Rocío (Seville, Spain), a tertiary reference centre. A total of 156 patients will be randomized in a 1:1 ratio (78 per group), with pre-defined subgroup analyses stratified by stone size (1-2 cm vs. \>2 cm). The outcome assessor evaluating CT images for stone-free rate will be blinded to treatment allocation (single-blind).

Conditions

Urolithiasis; Nephrolithiasis; Kidney Calculi; Ureteroscopy

Keywords

Flexible ureteroscopy; Retrograde intrarenal surgery; RIRS; Ureteral access sheath; ClearPetra; Navigator; Stone-free rate; Laser lithotripsy; Intrarenal lithiasis; Vacuum-assisted sheath; Clavien-Dindo; Stone fragmentation; Endourology; Urinary tract calculi

Outcome Measures

Primary Outcomes (1)

• Stone-Free Rate (SFR) at 1 Month Post-Intervention

  Proportion of patients with complete absence of residual lithiasis or presence exclusively of fragments ≤2 mm on non-contrast abdomino-pelvic CT scan performed at 30 ±7 days post-intervention. Assessed by a blinded outcomes assessor using standardised multiplanar CT reconstruction. Dichotomous variable: stone-free (yes/no). A sensitivity analysis will apply a stricter definition (0 mm, complete absence of any fragment).

  30 days (±7 days) after surgical intervention

Secondary Outcomes (13)

• Stone-Free Rate (SFR) at 3 Months Post-Intervention

  90 days (±14 days) after surgical intervention

• Stone Volume Reduction Rate at 1 Month

  30 days (±7 days) after surgical intervention

• Immediate Endoscopic Stone-Free Rate

  Intraoperative (at procedure completion, Day 0)

• Immediate Fluoroscopic Stone-Free Rate

  Intraoperative (at procedure completion, Day 0)

• Retreatment Rate at 3 Months

  Up to 90 days (±14 days) after surgical intervention

Other Outcomes (1)

• Subgroup Analysis of SFR at 1 Month by Stone Size

  30 days (±7 days) after surgical intervention

Study Arms (2)

ClearPetra Vacuum-Assisted Ureteral Access Sheath

EXPERIMENTAL

Flexible ureteroscopy (RIRS) for intrarenal lithiasis (1-3 cm) using the ClearPetra® ureteral access sheath (Coloplast) - a tip-flexible sheath with integrated continuous vacuum aspiration system for active removal of stone fragments and irrigation fluid throughout the procedure. Laser lithotripsy (Holmium:YAG or Thulium) is applied for stone fragmentation. Accessory instruments (retrieval basket, stone cone) are used per standardised protocol. Follow-up includes non-contrast CT at 1 and 3 months post-intervention.

Device: ClearPetra ureteral access sheath

Navigator® Standard Rigid Ureteral Access Sheath

ACTIVE COMPARATOR

Flexible ureteroscopy (RIRS) for intrarenal lithiasis (1-3 cm) using the Navigator® ureteral access sheath (Boston Scientific) - a standard rigid sheath without active aspiration. Laser lithotripsy (Holmium:YAG or Thulium) is applied for stone fragmentation. Accessory instruments (retrieval basket, stone cone) are used per standardised protocol. Follow-up includes non-contrast CT at 1 and 3 months post-intervention

Device: Navigator ureteral access sheath

Interventions

ClearPetra ureteral access sheath DEVICE

Tip-flexible ureteral access sheath with integrated continuous vacuum aspiration system (Coloplast). Placed transurethrally prior to flexible ureteroscopy to maintain stable ureteral access and actively evacuate stone fragments and irrigation fluid throughout the RIRS procedure. Used in combination with laser lithotripsy (Holmium:YAG or Thulium) for fragmentation of intrarenal stones of 1-3 cm. Accessory instruments (retrieval basket, stone cone) employed per standardised intraoperative protocol.

ClearPetra Vacuum-Assisted Ureteral Access Sheath

Navigator ureteral access sheath DEVICE

Standard rigid ureteral access sheath without active aspiration mechanism (Boston Scientific). Placed transurethrally prior to flexible ureteroscopy to maintain stable ureteral access during the RIRS procedure. Used in combination with laser lithotripsy (Holmium:YAG or Thulium) for fragmentation of intrarenal stones of 1-3 cm. Accessory instruments (retrieval basket, stone cone) employed per standardised intraoperative protocol.

Navigator® Standard Rigid Ureteral Access Sheath

Eligibility Criteria

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

You may qualify if:

• Age ≥18 years
• Diagnosis of intrarenal lithiasis with maximum stone diameter of 1-3 cm on preoperative non-contrast abdomino-pelvic CT scan
• Candidate for treatment by flexible ureteroscopy (RIRS) as indicated by the treating urologist
• Attended at the Department of Urology, Hospital Universitario Virgen del Rocío (Seville, Spain)
• Willing and able to provide written informed consent
• Able to comply with the study follow-up schedule (CT scan at 1 and 3 months post-intervention)

You may not qualify if:

• Active urinary tract infection or urosepsis at the time of the planned intervention
• Known ureteral stricture precluding passage of a ureteral access sheath
• Pregnancy
• Prior urinary diversion incompatible with transurethral access (e.g., urinary conduit, neobladder)
• Bleeding disorder or anticoagulant/antiplatelet therapy that cannot be safely interrupted perioperatively
• Stone diameter \<1 cm or \>3 cm on preoperative CT
• Inability to provide informed consent (cognitive impairment, language barrier without interpreter availability)
• Simultaneous participation in another clinical trial that could interfere with the outcomes of this study

Sponsors & Collaborators

• Hospitales Universitarios Virgen del Rocío: lead

Study Sites (1)

Virgen del Rocio University Hospital

Seville, Seville, 41013, Spain

Location

Related Publications (3)

• Danilovic A, Cavalanti A, Rocha BA, Traxer O, Torricelli FCM, Marchini GS, Mazzucchi E, Srougi M. Assessment of Residual Stone Fragments After Retrograde Intrarenal Surgery. J Endourol. 2018 Dec;32(12):1108-1113. doi: 10.1089/end.2018.0529.

  PMID: 30398369 BACKGROUND

• Cui D, Ma Q, Xie S, Wang G, Li G, Chen G. Comparison of the effectiveness of two adjustable negative pressure ureteral access sheaths combined with flex ureteroscopy for </= 2 cm renal stones. Sci Rep. 2024 Feb 27;14(1):4745. doi: 10.1038/s41598-024-55333-w.

  PMID: 38413652 BACKGROUND

• Berquet G, Prunel P, Verhoest G, Mathieu R, Bensalah K. The use of a ureteral access sheath does not improve stone-free rate after ureteroscopy for upper urinary tract stones. World J Urol. 2014 Feb;32(1):229-32. doi: 10.1007/s00345-013-1181-5. Epub 2013 Oct 29.

  PMID: 24166287 BACKGROUND

MeSH Terms

Conditions

Urolithiasis; Nephrolithiasis; Kidney Calculi

Condition Hierarchy (Ancestors)

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

Study Officials

• Paula Rodríguez-Marcos, MD

  Department of Urology. Unit of Urolithiasis. Virgen del Rocio University Hospital, Seville, Spain

  PRINCIPAL INVESTIGATOR

• Rafael A Medina-López, PhD

  Department of Urology. Unit of Uro-Oncology. Virgen del Rocio University Hospital, Seville, Spain

  STUDY DIRECTOR

Central Study Contacts

Miguel A. Gómez-Luque, MD

CONTACT

+34623976808; miguel.gomez.luque.sspa@juntadeandalucia.es

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Eligible patients are randomised in a 1:1 ratio to one of two parallel arms: flexible ureteroscopy (RIRS) using the ClearPetra® vacuum-assisted ureteral access sheath (experimental arm) versus flexible ureteroscopy using the Navigator® standard rigid ureteral access sheath (control arm). Randomisation is performed immediately before surgery using a computer-generated sequence with allocation concealment via sequentially numbered opaque sealed envelopes. Both arms receive the same surgical procedure (RIRS with laser lithotripsy) and identical follow-up schedule (CT at 1 and 3 months). The sole difference between arms is the ureteral access sheath device employed.

Study Record Dates

• First Submitted: June 25, 2026
• First Posted: July 1, 2026
• Study Start (Estimated): September 15, 2026
• Primary Completion (Estimated): September 1, 2029
• Study Completion (Estimated): May 1, 2030
• Last Updated: July 1, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF
• Time Frame: IPD and supporting information will be available beginning 6 months after publication of the primary results article and will remain available for a minimum of 5 years following initial data availability. Requests submitted after this period will be considered on a case-by-case basis.
• Access Criteria: Access to IPD will be granted to researchers who provide a methodologically sound research proposal, approved by their institutional review board where applicable. Requests must be submitted to the principal investigator (Dr. Enrique Argüelles Salido, Hospital Universitario Virgen del Rocío, Seville, Spain) via institutional email. Data will be transferred via a secure, password-protected platform under a signed data sharing agreement. Data will not be used for commercial purposes.

Locations

ES (1)