TZ-RIRS
Triple-Zero Retrograde Intrarenal Surgery (TZ-RIRS) Versus Conventional Retrograde Intrarenal Surgery (C-RIRS): Development and Internal Validation of the Novel TZ-STONE Feasibility Score
Sponsor study identifier
observational
688
1 country
1
Study Start
January 1, 2020
Actual (reported)Primary Completion
December 31, 2025
Actual (reported)Study Completion
December 31, 2025
Actual (reported)This study evaluates a new minimally invasive surgical technique for treating kidney stones called Triple-Zero Retrograde Intrarenal Surgery (TZ-RIRS). Traditionally, RIRS is performed using three standard tools: X-ray guidance (fluoroscopy), a plastic tube to keep the ureter open (ureteral access sheath or UAS), and a stent placed before surgery to widen the ureter. While effective, these tools expose patients to radiation, can cause ureteral injuries, and require an extra procedure for the preoperative stent. The "Triple-Zero" approach aims to eliminate all three: zero fluoroscopy, zero UAS, and zero preoperative stents. Because this technique is technically demanding, the researchers also developed a new tool called the "TZ-STONE score." This score uses five pre-operative factors (stone size, location, blockage, number of stones, and stone density) to predict which patients are the best candidates for this simplified surgery. The study compares the safety and success rates of patients who underwent the Triple-Zero approach with those who had conventional RIRS. The researchers aim to see if the Triple-Zero approach achieves similar stone-free rates while reducing radiation exposure, minimizing ureteral injuries, and avoiding the need for a preoperative stent.
Registry-reported information. Elapsed time and enrollment totals alone do not measure study progress or recruitment pace.
December 31, 2025
Actual (reported)Click on a node to explore related trials.
Dates and qualifiers reported by the registry. Estimated dates do not confirm that a milestone has occurred.
January 1, 2020
Actual (reported)December 31, 2025
Actual (reported)December 31, 2025
Actual (reported)October 24, 2026
Actual (reported)October 30, 2026
Actual (reported)Complete TZ-RIRS Success
Completion of the surgical procedure without intraoperative fluoroscopy, without rescue ureteral access sheath (UAS) placement, and without a preoperative stent.
Intraoperative (during the surgical procedure)
Stone-Free Rate (≤4 mm)
3 months postoperatively
Stone-Free Rate (≤2 mm)
3 months postoperatively
Patients who underwent Triple-Zero Retrograde Intrarenal Surgery (TZ-RIRS), defined as zero fluoroscopy, zero ureteral access sheath (UAS), and zero preoperative stenting
Patients who underwent conventional retrograde intrarenal surgery (C-RIRS) utilizing fluoroscopy, a ureteral access sheath (UAS), and routine preoperative stenting
A fluoroscopy-free, sheathless RIRS technique performed using an Olympus URF-V2R digital flexible ureteroscope and a 30-watt Karl Storz Holmium:YAG laser, without preoperative stenting.
Adult patients (≥18 years) with unilateral renal stones who were scheduled to undergo retrograde intrarenal surgery. The study included a prospective cohort of patients treated with the Triple-Zero technique and a retrospective cohort treated with conventional RIRS. Patients with complex anatomy, active infection, or those requiring preoperative stenting were excluded.
Government Super Speciality Hospital, Srinagar
Srinagar, Jammu and Kashmir, 190005, India
Waseem ASHRAF, MBBS, MS, MCh
Government Super Speciality Hospital, Shireen Bagh, Srinagar
688 participants (actual enrollment reported by the registry).
First Submitted
October 24, 2026
First Posted
October 30, 2026
Study Start
January 1, 2020
Actual (reported)Evaluation of Different Treatment Modalities for Lower Pole and Renal Pelvis Stones
Stone-Free Rate (Zero Fragments)
3 months postoperatively
Operative Time
Intraoperative
Complications
Up to 3 months postoperatively
Standard RIRS utilizing intraoperative fluoroscopy, placement of a 9.5/11.5 Fr ureteral access sheath (UAS), and a preoperative double-J stent.
Contact the study team to confirm eligibility.
Primary Completion
December 31, 2025
Actual (reported)Study Completion
December 31, 2025
Actual (reported)Last Updated
October 30, 2026
Record last verified: 2026-10
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Source: ClinicalTrials.gov.
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