An interventional study of Ureteroscopic Lithotripsy in Ureteric Stone, sponsored by The University of Hong Kong. Completed at 1 site in Hong Kong. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-26.
Sponsored by The University of Hong Kong · Not applicable, Interventional, and Treatment
Background: Ureteroscopic lithotripsy (URSL) is the standard treatment for ureteric stones. Conventional URSL employs routine fluoroscopy for guidewire positioning, scope advancement, stent placement, and complication detection. While facilitating the procedure, this approach exposes patients and operating theatre staff to ionizing radiation, with attendant long-term health risks and occupational hazards from lead apron use. Retrospective and prospective case series have suggested that URSL can be performed safely with limited or no fluoroscopy using direct endoscopic visualization and tactile feedback. However, no randomized controlled trial has directly compared the stone clearance rates and radiation exposure between these two approaches.
Purpose: This two-center prospective randomized controlled trial aims to evaluate the feasibility and radiation exposure of limited-fluoroscopy URSL and to compare its complication profile, operative outcomes, and stone-free rates against conventional fluoroscopy-guided URSL.
Study question: Does a limited-fluoroscopy protocol significantly reduce intraoperative radiation dose without compromising the success rate, safety, or operative efficiency of ureteroscopic lithotripsy?
Methods: A total of 60 adult patients (≥18 years) with ureteric stones scheduled for URSL will be randomized in a 1:1 ratio to either the limited-fluoroscopy arm (fluoroscopy used only at surgeon's discretion for safety, with primary reliance on endoscopic landmarks) or the conventional arm (routine fluoroscopy throughout the procedure). The primary endpoint is radiation exposure (mGy). Secondary endpoints include stone-free rate at follow-up, operative time, intraoperative and postoperative complications, and need for auxiliary procedures.
Background and Rationale
Ureteric stone is a common urological condition. Ureteroscopic lithotripsy (URSL), with its minimal invasive nature and high stone clearance rate, has been the standard for treatment of ureteric stone. In conventional URSL, fluoroscopy is used routinely. Advantages of routine fluoroscopy include road mapping for difficult retrograde access in case of impacted stone or ureteric stricture, confirmation of position of guidewire or ureteric stent, and looking for complications such as extravasation of contrast or ureteric perforation. However, routine fluoroscopy also has its disadvantages. Patients suffering from ureteric colics already had exposure to various degrees of radiation during investigative procedures such as X-ray and computed tomography; routine fluoroscopy may further expose them to unnecessary radiation. Routine fluoroscopy also poses radiation hazards to surgeons and staff in the operating theatre. In addition, there are reports on occupational safety issues such as back pain attributed to lead apron. Furthermore, insertion of guidewire and ureteric stent can be accomplished by direct visualization through ureteroscope or cystoscope and tactile feedback instead of routine fluoroscopy.
In view of the potential advantage of URSL with limited fluoroscopy, different studies have looked into the feasibility of performing URSL with limited or even no fluoroscopy. Mandhani reported complete clearance of distal ureteric stones in 99 out of 110 patients by URSL with no fluoroscopy. Tepeler, Hsi and Olgin reported that URSLs can be performed safely and effectively with limited or no fluoroscopy. Unfortunately, all these studies are retrospective reviews or prospective series without randomization. More importantly, the stone clearance rate between limited fluoroscopy URSL and conventional URSL was never compared. Without a randomized controlled trial studying the two approaches of URSL for ureteric stone, it would be difficult to determine the superiority of one approach over the other.
Aim of Study
To evaluate feasibility and radiation exposure in limited-fluoroscopy ureteroscopic lithotripsy (URSL) and to compare its complication and outcome with conventional URSL.
Trial Design and Setting
This is a prospective randomized controlled trial conducted across two centers. Patients who undergo URSL for ureteric stone and consent to the study will be randomized to 2 groups: limited fluoroscopy URSL and conventional URSL with routine fluoroscopy.
In the limited fluoroscopy URSL group, guidewire insertion, endoscopic advancement, stone fragmentation and ureteric stent placement will be completed under direct endoscopic view and tactile feedback. Stand-by fluoroscopy will be available and the operating surgeon can always obtain fluoroscopic image during the procedure in the same way as conventional URSL at his discretion. Upon completion of the operation, limited retrograde pyelogram will be performed to rule out complication and to confirm the position of ureteral stent.
In the conventional URSL group, fluoroscopy will be used upon guidewire insertion, endoscopic advancement, stone fragmentation and ureteral stent placement. Completion retrograde pyelogram will be performed to look for extravasation.
Study Population
Inclusion criteria include all patients 18 years of age or older who decided for URSL as the treatment for ureteric stone. Exclusion criteria include patients who are unable to consent, no stone upon ureteroscopy, known ureteric stricture or complicated ureteral anatomy, stone in solitary kidney and bilateral ureteric stones. Patients are free to withdraw from the study at any time and will continue to be managed as per usual. Their data will be used and analyzed according to the intention-to-treat principle.
Data Collection
Data collected from patients will include demographic data, laterality, location, size and number of stone, laser energy used, need of stent placement during operation, operative time and outcome, radiation exposure, intra-operative and post-operative complication, stone free rate and need of auxiliary procedure upon follow up.
Statistical Analysis
The sample size calculation rationale is based on the following: the mean radiation exposure of conventional URSL was 46.4 mGy and a mean radiation dose of 1.1 mGy in limited fluoroscopy URSL was reported. To prove the difference in radiation dose with estimated 90% power and a prediction of 20% dropout, the calculated sample size required for the primary endpoint is 60 patients, with 30 patients in each group.
Patient demographic data including age and sex, laterality, location, size and number of stone, laser energy used, need of stent placement during operation, operative time and outcome, radiation exposure, intra-operative and post-operative complication, stone free rate and need of auxiliary procedure upon follow up will be analyzed statistically. The chi-square statistic is used for categorical variables and the t-test is used for continuous variables to compare difference between the two groups with statistical significance considered at p\<0.05. The intention-to-treat principle is adopted. All participants are analyzed in their assigned groups. SPSS will be used for all statistical analyses.
Primary End-point
Radiation exposure of limited-fluoroscopy URSL
Secondary End-points
Success rate of limited-fluoroscopy URSL
Operative time
Complication
Stone free rate
Need of auxiliary procedure
Data Access, Handling and Ethics
To protect patient privacy, all research data will be handled in line with Hospital Authority's or Hospital's policy in handling/storage/destruction of patients' medical records. They would be locked in cabinets where the department/ward keep patients' medical records. Electronic data would be saved in secured computer of the hospital with restricted access. USB Device would not be used for patient information for personal data. Personal data (name, HKID, address and any other personal identifiable information) should not be recorded on the projects' data sheets or electronic files. A study code will be used. Any documents or electronic files containing personal identifiable information would be considered as part of the medical record and will be dealt with the same stringent regulations of security according to the hospital policies. The principal investigator/co-investigator will be responsible for the execution of data protection. This study complies with the requirements of ICH-GCP.
There is no conflict of interest in this study. Previous retrospective studies and prospective series demonstrated feasibility and safety of limited/no fluoroscopy URSL. In our current trial, fluoroscopy will be provided at the surgeon's discretion in the limited fluoroscopy arm to ensure smooth and safe URSL. No additional financing or insurance requirements are necessary.
84 studies on the registry are indexed under Ureterolithiasis; 19 are open to participants now.
This study's enrollment of 60 is below the median of 101 across 66 interventional studies indexed under Ureterolithiasis.
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Exclusion Criteria:
Patients undergo ureteroscopic lithotripsy with fluoroscopy reserved for safety backup only. Guidewire insertion, endoscopic advancement, stone fragmentation, and ureteric stent placement are performed under direct endoscopic visualization and tactile feedback. Stand-by fluoroscopy is available at the operating surgeon's discretion. Upon completion, a limited retrograde pyelogram is performed to exclude extravasation and confirm stent position.
Procedure: Ureteroscopic Lithotripsy
Patients undergo ureteroscopic lithotripsy with routine fluoroscopy employed at standard procedural steps: during guidewire insertion, endoscopic advancement, stone fragmentation, and ureteric stent placement. A completion retrograde pyelogram is routinely performed to look for contrast extravasation or ureteric perforation.
Procedure: Ureteroscopic Lithotripsy
Surgical procedure performed under general or regional anaesthesia using a semi-rigid or flexible ureteroscope to access the ureteric stone. Stone fragmentation is achieved using a holmium:YAG laser with energy settings determined by stone composition and size. Fragments may be retrieved using endoscopic baskets or forceps. Ureteric stent placement and retrograde pyelography are performed as clinically indicate
Also known as: Holmium laser lithotripsy, Endoscopic stone fragmentation, URSL
Total intraoperative radiation exposure in limited-fluoroscopy versus conventional URSL
Time frame: Intraoperative
Success rate of limited-fluoroscopy URSL
Time frame: Intraoperative
Operative time
Total operative duration measured from cystoscope insertion to completion of stent placement or final endoscopic check.
Time frame: Intraoperative
Intraoperative and postoperative complications
Time frame: Intraoperative and up to 30 days postoperatively
Stone-free rate
Proportion of patients with complete stone clearance as determined by imaging at post-operative follow-up.
Time frame: At 4 weeks postoperatively
Need for auxiliary procedures
Time frame: Up to 3 months postoperatively
Plan to share: Undecided
This study is completed, as verified in Aug 2016. You cannot join it, but the record below documents what was studied.
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