Pan African Clinical Trials Registry
South African Medical Research Council, South African Cochrane Centre
PO Box 19070, Tygerberg, 7505, South Africa
Telephone: +27 21 938 0835 or +27 21 938 0967
Email: pactradmin@mrc.ac.za Website: pactr.samrc.ac.za
Trial no.: PACTR202510474240715 Date of Registration: 22/10/2025
Trial Status: Registered in accordance with WHO and ICMJE standards
TRIAL DESCRIPTION
Public title SUFLEX study : Suction-Enhanced PCNL versus Flexible Endoscopy with Suction Assistance for Lower Pole Stones
Official scientific title Suction enhanced percutaneous nephrolithotomy(PCNL) versus flexible and navigable suction sheath(FANS) –Assisted retrograde intrarenal surgery( RIRS) for management of lower pole renal stones: A prospective Randomized study
Brief summary describing the background and objectives of the trial Percutaneous nephrolithotomy (PCNL) remains the gold-standard treatment for renal calculi ≥2 cm. However, the evolution of endoscopic technology has expanded the role of flexible ureteroscopy (f-URS) as a minimally invasive alternative for smaller stones. f-URS offers several advantages over PCNL, including reduced tissue trauma, lower complication rates, and shorter hospital stays. Yet, conventional f-URS has limitations such as incomplete stone clearance and residual dust, leading to postoperative colic and hematuria. Recent innovations introduced a flexible vacuum-assisted ureteral access sheath (FANS/f-UAS), which enhances irrigation control, suction efficiency, and intrarenal pressure regulation. These advances have improved stone-free rates and operative efficiency, positioning f-URS with FANS as a strong contender to mini-PCNL. However, comparative prospective data directly evaluating suction-enhanced PCNL versus FANS-assisted RIRS for lower pole stones remain limited. This study aims to fill that gap. The present study aims to evaluate and compare the efficacy and safety of two suction-integrated endourological techniques—suction-enhanced mini-percutaneous nephrolithotomy (mini-PCNL) and flexible and navigable suction sheath (FANS)–assisted retrograde intrarenal surgery (RIRS)—in the management of lower-pole renal stones measuring less than 2 cm. Specifically, the study seeks to assess and compare operative outcomes including stone-free rate, operative time, intra- and postoperative complications, need for postoperative stenting, and hospital stay, in order to determine which approach offers superior efficiency, safety, and patient recovery profile.
Type of trial RCT
Acronym (If the trial has an acronym then please provide)
Disease(s) or condition(s) being studied Urological and Genital Diseases
Sub-Disease(s) or condition(s) being studied
Purpose of the trial Treatment: Surgery
Anticipated trial start date 15/11/2025
Actual trial start date
Anticipated date of last follow up 30/11/2026
Actual Last follow-up date
Anticipated target sample size (number of participants) 100
Actual target sample size (number of participants)
Recruitment status Not yet recruiting
Publication URL
Secondary Ids Issuing authority/Trial register
STUDY DESIGN
Intervention assignment Allocation to intervention If randomised, describe how the allocation sequence was generated Describe how the allocation sequence/code was concealed from the person allocating the participants to the intervention arms Masking If masking / blinding was used
Parallel: different groups receive different interventions at same time during study Randomised Simple randomization using a randomization table created by a computer software program Sealed opaque envelopes Open-label(Masking Not Used)
INTERVENTIONS
Intervention type Intervention name Dose Duration Intervention description Group size Nature of control
Control Group Suction enanced mini PCNL Not applicable Patient Position and Anesthesia • All procedures are performed under general anesthesia. • The patient is placed in the prone position after initial ureteric catheter insertion in lithotomy. • A 5-Fr ureteric catheter is placed into the renal pelvis under cystoscopic guidance to allow retrograde contrast injection for pelvicalyceal system opacification. Access and Tract Dilation • Under fluoroscopic guidance, a puncture is made into the desired lower calyx using an 18-gauge needle. • Correct positioning is confirmed by urine aspiration and contrast injection. • A guidewire is advanced into the renal pelvis. • Sequential dilation is performed using metal or Amplatz dilators up to 14–18 Fr, according to the chosen sheath size. • A mini-nephroscope (12–14 Fr) is then introduced through the Amplatz sheath connected to a vacuum suction system (suction-enhanced setup). Stone Fragmentation and Extraction • Stones are fragmented using Holmium:YAG laser or pneumatic lithotripter. • Simultaneous suction irrigation is applied through the specially designed sheath, allowing continuous fragment evacuation and reduction of intrarenal pressure. • Stone clearance is confirmed visually and fluoroscopically. Drainage and Closure • A nephrostomy tube (10–14 Fr) may be placed at the end of the procedure, or a tubeless approach may be used if complete clearance and minimal bleeding are observed. • A ureteric stent may be inserted based on intraoperative findings. • The access site is closed with a single absorbable suture and sterile dressing applied. 50 Active-Treatment of Control Group
Experimental Group Flexible and Navigable Suction Sheath Assisted Retrograde Intrarenal Surgery Not applicaple Patient Position and Anesthesia • The procedure is performed under general anesthesia with the patient in lithotomy position. • A 0.035-inch hydrophilic guidewire is introduced into the renal pelvis under fluoroscopic control via ureteral access. Ureteral Access and Sheath Insertion • A FANS (Flexible and Navigable Suction) ureteral access sheath (typically 12/14 Fr or 11/13 Fr) is advanced over the guidewire to the renal pelvis. • The FANS sheath is connected to a vacuum suction system capable of maintaining controlled negative pressure (−10 to −20 kPa). • Continuous irrigation is maintained via the integrated inflow channel, allowing controlled inflow–outflow balance and intrarenal pressure regulation. Flexible Ureteroscope Navigation and Lithotripsy • A digital flexible ureteroscope is advanced through the FANS sheath into the lower calyx. • Stones are fragmented using Holmium:YAG laser (200–272 µm fiber) in dusting or pop-dusting mode (energy 0.8–1.2 J, frequency 15–30 Hz). • The suction mechanism allows simultaneous evacuation of dust and fragments, maintaining clear vision and minimizing pressure spikes. Stone Clearance and Confirmation • After complete disintegration, visual inspection of all calyces is performed to confirm stone clearance. • Fluoroscopy or intraoperative ultrasound may be used to confirm the absence of significant residuals. • Small fragments and dust are aspirated through the sheath under negative pressure. Postoperative Drainage • A 6-Fr double-J stent is placed in all patients to ensure adequate drainage and prevent ureteral edema. • No urethral catheter is usually required beyond the immediate postoperative period. 50
ELIGIBILITY CRITERIA
List inclusion criteria List exclusion criteria Age Category Minimum age Maximum age Gender
1. Adults 2. Single lower-pole renal stone ≤ 20 mm (on NCCT). 3. Normal renal anatomy and unobstructed pelvicalyceal system. 4. Unilateral stones with preserved renal function. 5. Medically fit for general anesthesia. 6. Written informed consent obtained. 1. Stones > 20 mm, staghorn or multiple calyceal stones. 2. Abnormal renal anatomy (horseshoe, duplex, malrotated kidney, PUJ obstruction, diverticulum). 3. Concomitant ureteric stones or ureteral pathology. 4. Active urinary tract infection or untreated bacteriuria. 5. Bleeding diathesis or anticoagulant use not correctable. 6. Pregnancy. 7. Severe comorbidities precluding anesthesia. 8. Previous renal surgery on the same side. 9. Solitary kidney, CKD patients or inability to complete follow-up. 80 and over: 80+ Year,Adolescent: 13 Year(s)-17 Year(s),Adult: 18 Year(s)-44 Year(s),Aged: 65 Year(s)-79 Year(s),Middle Aged: 45 Year(s)-64 Year(s) 18 Year(s) 85 Year(s) Both
ETHICS APPROVAL
Has the study received appropriate ethics committee approval Date the study will be submitted for approval Date of approval Name of the ethics committee
Yes 12/05/2025 Research Ethics Committee at Faculty of Medicine Tanta University
Ethics Committee Address
Street address City Postal code Country
2 El Geesh Street, Medical Campus Tanta 31527 Egypt
OUTCOMES
Type of outcome Outcome Timepoint(s) at which outcome measured
Primary Outcome Stone-Free Rate (SFR) at 1 month, CT-confirmed (NCCT ≤2 mm fragments counted as residual; i.e., SFR = no fragments >2 mm). Initial 3 days postoperative and at 1 month by Non contrast CT urinary tract
Secondary Outcome • Operative time (skin incision/endoscope-in to final scope out or nephrostomy/stent placement; minutes). • Complications within 30 days, Clavien–Dindo graded; also report fever ≥38.5 °C, urosepsis, transfusion. • Fluoroscopy time (seconds) and radiation dose (mGy·cm² if available). • Post-op stenting (yes/no; dwell time). • Length of stay (days). • Retreatment/auxiliary procedures within 3 months. • Post-op pain (NRS at 6–12–24 h) and analgesic consumption (morphine-equivalents). • Hemoglobin drop (g/dL) and creatinine change (mg/dL). Complications and retreatment rates will be assessed during 3 months postoperatively
RECRUITMENT CENTRES
Name of recruitment centre Street address City Postal code Country
Tanta University Hospital 2 El Geish Street Tanta Egypt
FUNDING SOURCES
Name of source Street address City Postal code Country
Tanta University Faculty of Medicine 2 El Geesh street, Medical Campus Tanta Egypt
SPONSORS
Sponsor level Name Street address City Postal code Country Nature of sponsor
Primary Sponsor Tanta University Hospital 2 El Geesh Street, Medical Campus Tanta Egypt University
COLLABORATORS
Name Street address City Postal code Country
CONTACT PEOPLE
Role Name Email Phone Street address
Principal Investigator Hussein Mamdoh hussein.nasr@med.tanta.edu.eg 002001064447063 Urology and Nephrology Centre, Medical Campus, 2 ElGeish street
City Postal code Country Position/Affiliation
Tanta Egypt Lecturer and consultant of Urology
Role Name Email Phone Street address
Scientific Enquiries Mohammed Lotfi Amer drmlamer@med.tanta.edu.eg 00201001862621 Urology and Nephrology Centre, Medical Campus, 2 ElGeish street
City Postal code Country Position/Affiliation
Tanta Egypt Lecturer and consultant of Urology
Role Name Email Phone Street address
Public Enquiries Mohamed ElMaadawy Mohamed.elmaadawy@med.tanta.edu.eg 00201060245430 Urology and Nephrology Centre, Medical Campus, 2 ElGeish street
City Postal code Country Position/Affiliation
Tanta Egypt Lecturer and consultant of Urology
REPORTING
Share IPD Description Additional Document Types Sharing Time Frame Key Access Criteria
Yes Individual participant data will be available (including data dictionaries). Individual participant data that underlie the results reported in this article, after deidentification (text, tables, figures, and appendices), will be available. The study protocol will be available. Data will be available immediately following publication. No end date. Data will be available to researchers who provide a methodologically sound proposal for any type of analysis. Proposals should be directed to drmlamer@med.tanta.edu.eg. To gain access, data requestors will need to sign a data access agreement. Data are available for 5 years at a third-party website (link to be included later). Study Protocol Immediately after publication Any researcher who provides a methodologically sound proposal and signs a data access consent form.
URL Results Available Results Summary Result Posting Date First Journal Publication Date
No
Result Upload 1: Result Upload 2: Result Upload 3: Result Upload 4: Result Upload 5:
Result URL Hyperlinks Link To Protocol
Result URL Hyperlinks
Changes to trial information
Section Name Field Name Date Reason Old Value Updated Value
Eligibility Age group 22/10/2025 PACTR Admin Adult: 19 Year-44 Year, Middle Aged: 45 Year(s)-64 Year(s), Aged: 65+ Year(s), 80 and over: 80+ Year Adolescent: 13 Year-18 Year, Adult: 19 Year-44 Year, Middle Aged: 45 Year(s)-64 Year(s), Aged: 65+ Year(s), 80 and over: 80+ Year