Initial Drainage Method and Flexible Ureteroscopy Outcomes in Calculous Anuria

Impact of Initial Drainage Method on Flexible Ureteroscopy Outcomes in Patients Presenting With Calculous Anuria: A Multicenter Prospective Randomized Controlled Trial

Calculous anuria caused by obstructing upper ureteral stones in a solitary functioning kidney is a urological emergency requiring urgent decompression. Both retrograde JJ ureteral stenting and percutaneous nephrostomy are commonly used emergency drainage methods. However, limited evidence is available regarding whether the initial drainage method affects subsequent definitive flexible ureteroscopy/retrograde intrarenal surgery outcomes.

This multicenter prospective randomized controlled trial will compare emergency JJ ureteral stent drainage versus percutaneous nephrostomy drainage in adult patients presenting with calculous anuria due to a single upper ureteral stone in a solitary functioning kidney. After renal functional improvement, clinical stabilization, and appropriate urine culture management, all participants will undergo standardized definitive flexible ureteroscopy/retrograde intrarenal surgery. The study will assess renal functional recovery, first-session surgical success, stone-free rate, operative parameters, complications, and microbiological outcomes.

Study Overview

• Status: Recruiting
• Conditions: Acute Kidney Injury; Obstructive Uropathy; Calculous Anuria; Upper Ureteral Stone
• Intervention / Treatment: Procedure: Initial JJ Ureteral Stent Drainage; Procedure: Initial Percutaneous Nephrostomy Drainage

Detailed Description

This is a multicenter prospective randomized controlled trial comparing two emergency drainage strategies before definitive flexible ureteroscopy/retrograde intrarenal surgery in patients presenting with calculous anuria.

Adult patients with calculous anuria caused by a single upper ureteral stone in a solitary functioning kidney will be assessed for eligibility. Eligible participants will be randomized in a 1:1 ratio to emergency retrograde JJ ureteral stent drainage or emergency percutaneous nephrostomy drainage. Randomization will be performed using a computer-generated random sequence, with allocation concealment using sequentially numbered opaque sealed envelopes.

Participants assigned to the JJ stent group will undergo emergency retrograde placement of a 6 Fr JJ ureteral stent under cystoscopic guidance. Participants assigned to the percutaneous nephrostomy group will undergo emergency ultrasound-guided placement of an 8 Fr nephrostomy tube. After drainage, participants will be monitored for urine output recovery, renal functional improvement, symptom relief, and clinical stabilization.

Definitive flexible ureteroscopy/retrograde intrarenal surgery will be scheduled after renal functional improvement, clinical stabilization, and negative or appropriately treated urine culture. The definitive procedure will be performed using a standardized operative strategy. Ureteral access sheath use, successful insertion, need for adjunctive ureteral maneuvers, operative time, laser time, fluoroscopy time, postoperative stenting, complications, and hospital stay will be recorded.

The primary outcome is renal functional recovery after initial drainage and definitive surgery, assessed using serial serum creatinine measurements at presentation, 24 to 48 hours after drainage, before definitive surgery, postoperative day 1, and follow-up. Secondary outcomes include first-session definitive surgery success, stone-free rate, technical operative variables, intraoperative and postoperative complications, microbiological culture patterns, and predictors of surgical success or postoperative complications.

Participants will be followed for approximately one month after definitive surgery by clinical assessment, laboratory evaluation, and imaging for assessment of renal function, complications, and stone clearance.

• Study Type: Interventional
• Enrollment (Estimated): 90
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Hany F Badawy, MD; Phone Number: +201149525028; Email: Hanyfathy86@gmail.com

Study Locations

• Egypt
  • Tanta, Egypt
    • Recruiting
    • Department of Urology- Tanta University Hospitals
    • Contact: I, MD; Phone Number: +201060245430; Email: MMohamed.elmaadawy@med.tanta.edu.eg
    • Principal Investigator: I Elmaadawy, MD
  • Beni Suweif Governorate
    • Banī Suwayf, Beni Suweif Governorate, Egypt
      • Recruiting
      • Department of Urology- Beni-Suef University Hospitals
      • Contact: Hany F Badawy, MD; Phone Number: +201149525028; Email: Hanyfathy86@gmail.com
      • Principal Investigator: Hany F Badawy, MD
  • Minya Governorate
    • Minya, Minya Governorate, Egypt
      • Recruiting
      • Department of Urology- Minia University Hospitals
      • Contact: M Abdelmalek, MD; Phone Number: +20 11 00464753
      • Principal Investigator: M Abdelmalek, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Adults aged 18 years or older.
• Calculous anuria secondary to a single upper ureteral stone.
• Solitary functioning kidney, whether anatomical or functional.
• Single upper ureteral stone confirmed by non-contrast computed tomography.
• Stone size from 6 mm to 20 mm in maximum diameter.
• Patient considered suitable for either initial JJ ureteral stent drainage or percutaneous nephrostomy drainage.
• Candidate for definitive treatment by flexible ureteroscopy/retrograde intrarenal surgery.
• Documented renal functional improvement and clinical stabilization before definitive RIRS.
• Negative or appropriately treated urine culture before definitive RIRS.
• Ability and willingness to provide written informed consent.

Exclusion Criteria:

• Multiple stones or bilateral stones not fitting the solitary-kidney study design.
• Renal pelvic, distal ureteral, or multiple ipsilateral stones.
• Stone burden greater than 20 mm.
• Septic shock, hemodynamic instability, or need for emergency dialysis at presentation.
• Pyonephrosis requiring a non-randomized drainage decision.
• Anatomical abnormalities affecting endoscopic access, such as horseshoe kidney, pelvic kidney, ureterocele, or ureteral stricture.
• Previous ipsilateral ureteral reconstructive surgery.
• Uncorrected coagulopathy.
• Pregnancy.
• Genitourinary malignancy.
• Inability to complete follow-up.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: JJ Ureteral Stent Drainage Group; Participants randomized to this arm will undergo emergency retrograde placement of a 6 Fr double-J ureteral stent under cystoscopic guidance for decompression of calculous anuria caused by a single upper ureteral stone in a solitary functioning kidney. After renal functional improvement, clinical stabilization, and appropriate urine culture management, definitive flexible ureteroscopy/retrograde intrarenal surgery will be performed according to the standardized study protocol.	Procedure: Initial JJ Ureteral Stent Drainage; Retrograde cystoscopic placement of a 6 Fr JJ ureteral stent for initial upper urinary tract decompression in patients presenting with calculous anuria due to a single upper ureteral stone in a solitary functioning kidney. After renal functional improvement, clinical stabilization, and appropriate urine culture management, participants will undergo standardized definitive flexible ureteroscopy/retrograde intrarenal surgery.
Active Comparator: Percutaneous Nephrostomy Drainage Group; Participants randomized to this arm will undergo emergency ultrasound-guided placement of an 8 Fr percutaneous nephrostomy tube for decompression of calculous anuria caused by a single upper ureteral stone in a solitary functioning kidney. After renal functional improvement, clinical stabilization, and appropriate urine culture management, definitive flexible ureteroscopy/retrograde intrarenal surgery will be performed according to the standardized study protocol.	Procedure: Initial Percutaneous Nephrostomy Drainage; Ultrasound-guided placement of an 8 Fr percutaneous nephrostomy tube for initial upper urinary tract decompression in patients presenting with calculous anuria due to a single upper ureteral stone in a solitary functioning kidney. After renal functional improvement, clinical stabilization, and appropriate urine culture management, participants will undergo standardized definitive flexible ureteroscopy/retrograde intrarenal surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Serum Creatinine From After Initial Drainage to After Definitive RIRS	Serum creatinine will be measured in mg/dL at 24-48 hours after initial drainage and on postoperative day 1 after definitive tratment of stone by retrograde intrarenal surgery. The primary outcome will compare the change in serum creatinine from the post-drainage value to the post-RIRS value between the JJ ureteral stent drainage group.	From 24-48 hours after initial drainage to postoperative day 1 after definitive RIRS

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
First-Session Definitive RIRS Success Rate	First-session definitive RIRS success will be defined as successful completion of flexible ureteroscopy/retrograde intrarenal surgery for the target upper ureteral stone in the planned first definitive session without the need to abort the procedure or schedule an additional unplanned definitive stone procedure during the same treatment pathway. The proportion of participants achieving first-session success will be compared between the JJ ureteral stent drainage group and the percutaneous nephrostomy drainage group.	During the definitive RIRS procedure
Stone-Free Rate After Definitive RIRS	Stone-free rate will be defined as the proportion of participants with no detectable residual target stone fragment on follow-up non-contrast computed tomography performed 4 weeks after definitive flexible ureteroscopy/retrograde intrarenal surgery. Stone-free rate will be compared between the JJ ureteral stent drainage group and the percutaneous nephrostomy drainage group	4 weeks after definitive RIRS
During the definitive RIRS procedure	Total operative time will be measured in minutes from insertion of the cystoscope or ureteroscope to completion of the definitive flexible ureteroscopy/retrograde intrarenal surgery procedure. Mean or median operative time will be compared between the JJ ureteral stent drainage group and the percutaneous nephrostomy drainage group.	During the definitive RIRS procedure
Need for Ureteral Stenting After Definitive RIRS	The need for postoperative ureteral stent placement after definitive flexible ureteroscopy/retrograde intrarenal surgery will be recorded. The proportion of participants requiring postoperative stenting will be compared between both drainage groups	At the end of the definitive RIRS procedure
Intraoperative Complications During Definitive RIRS	Intraoperative complications will include ureteral mucosal injury, false passage, ureteral perforation, bleeding affecting visualization, and procedure interruption. The incidence of intraoperative complications will be compared between both drainage groups.	During the definitive RIRS procedure
Postoperative Infectious Complications After Definitive RIRS	Postoperative infectious complications will include fever greater than 38°C, systemic inflammatory response syndrome, or sepsis after definitive flexible ureteroscopy/retrograde intrarenal surgery. The incidence of postoperative infectious complications will be compared between both drainage groups.	From definitive RIRS to 4 weeks after definitive RIRS

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ureteral Access Sheath Insertion Success Rate	Ureteral access sheath insertion success will be defined as successful placement of a ureteral access sheath during definitive flexible ureteroscopy/retrograde intrarenal surgery without the need for active ureteral dilatation, semirigid ureteroscopy assistance, or abandonment of sheath placement. The proportion of successful ureteral access sheath insertion will be compared between the JJ ureteral stent drainage group and the percutaneous nephrostomy drainage group.	During the definitive RIRS procedure

Collaborators and Investigators

• Sponsor: Beni-Suef University
• Investigators: Principal Investigator: Hany F Badawy, MD, Faculty of medicine BeniSuef University

Study record dates

Study Major Dates

• Study Start (Actual): May 6, 2026
• Primary Completion (Estimated): March 1, 2027
• Study Completion (Estimated): April 1, 2027

Study Registration Dates

• First Submitted: May 30, 2026
• First Submitted That Met QC Criteria: May 30, 2026
• First Posted (Actual): June 4, 2026

Study Record Updates

• Last Update Posted (Actual): June 4, 2026
• Last Update Submitted That Met QC Criteria: May 30, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Retrograde intrarenal surgery; Double-J ureteral stent; Percutaneous nephrostomy
• Additional Relevant MeSH Terms: Urogenital Diseases; Male Urogenital Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urolithiasis; Renal Insufficiency; Ureteral Diseases; Acute Kidney Injury; Ureterolithiasis
• Other Study ID Numbers: FMB050526-ANURIA-RIRS

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared because the study includes individual-level clinical, laboratory, radiological, operative, and microbiological data from patients presenting with an emergency urological condition. Only aggregated and de-identified study results will be reported. Any future sharing of individual participant data would require additional approval from the Research Ethics Committee and an appropriate data-sharing agreement.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No