Treatment of Upper Urinary Tract Stones With a Diameter≤2cm by Intelligent Pressure-controlled Flexible Ureteroscope

January 20, 2022 updated by: Guohua Zeng

Treatment of Upper Urinary Tract Stones With a Diameter≤2cm by Flexible Ureteroscope With Intelligent Control of Renal Pelvic Pressure(FURL-ICP): a Multicenter, Parallel, Randomized Controlled Trial

The aim of this trial is to compare the efficacy and safety of flexible ureteroscope with intelligent control of renal pelvic pressure (FURL-ICP) and traditional flexible ureteroscope(f-URL) in the treatment of upper urinary stones ≤ 2cm in diameter. It is designed as a multicenter, parallel randomized controlled trial with two arms. At least 449 patients with upper urinary stones ≤ 2cm in diameter will be invited to participant in this study. Patients will be assigned to intervention group (FURL-ICP group) or control group (f-URL) by a simple random sampling technique with a rate of 1:1. The baseline of participants include demographic data, urine analysis, blood cell analysis, blood biochemical analysis, and urinary computer tomography (CT) with a slice thickness of 2mm. The primary outcomes are postoperative stone-free rate (SFR) of one month by CT scan and postoperative fever rate (body temperature > 38.5 ℃ within 3 days after operation). Secondary outcomes include operating time, degree of ureteral injury, SFR of one day.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

  1. Background Urinary stone is a common disease with a prevalence rate of 5-15%. It has a recurrence rate of 50% for 5-10 years, and about 75% for 20 years. It is a heavy healthy burden to the population. Flexible ureteroscope lithotripsy(f-URL) is a first-line treatment for renal stone ≤ 2cm in diameter. It has the advantage of less trauma, low complications and fast recovery. It is also suitable for upper ureteral calculi, residual calculi after percutaneous nephrolithotomy (PCNL) It can also be combined with PCNL for the treatment of complex renal calculi.

    The postoperative stone free rate of f-URL varies drastically due to different sizes of residual stone. The Chinese consensus of flexible ureteroscopy recommended that stone ≤ 4mm in diameter should be considered as clinical insignificant residual stone. When residual stone was defined as ≤ 3mm, the stone free rate for one-month was 90% of renal stones ≤ 20 mm, and was 74.4% for stone of 10-25 mm. It would not cause significant symptoms when the residual stone ≤ 2 mm. Based on this definition, Fatih A's randomized trial showed that the stone free rate of f-URL for renal calculi ≤ 20 mm was 85.7%. It was only 30% for stone > 20 mm of single procedure，86.6% of secondary procedure, and 100% for tertiary procedure. When the residual stone was defined as ≤ 1 mm, the stone free rate of f-URL was 64.7% for a single procedure, 92% for secondary procedure, and the overall stone free rate was 85.1% and 100% for stone > 20 mm and ≤ 20 mm respectively by a retrospective study. When the stone free rate was defined as complete stone clearance, it was 71% after one month of single f-URL for renal stone >30mm .

    Postoperative infection is a common complication of f-URL. The key point to avoid postoperative infection includes to treat urinary infection, to keep a low flow perfusion and renal pelvic pressure (RPP) during operation, and to control the operation time. The renal pelvic pressure depends on the size of ureteral sheath and flexible ureteroscope, the flow of perfusion and outflow of traditional f-URL. It is difficult to realize real-time monitoring and regulation of renal pelvic pressure during the operation.

    To realize a high stone free rate and a low postoperative infection rate of f-URL, a new system named flexible ureteroscope with intelligent control of renal pelvic pressure (FURL-ICP) is designed and used. It has an irrigation and suctioning control platform, uses a ureteral access sheath with a pressure-sensitive tip, enables regulation of the infusion flow precisely, and controls the vacuum suctioning by computerized real-time recording and monitoring of RPP. A stable RPP is kept within a pre-set safe range by pressure feedback technology. The stone power could be sucked out during operation. Previous data showed that postoperative stone free rate was 90% for one day, and 95.6% for one month after operation respectively, and the overall complication rate was 14.4%. The aim of this study is to compare the efficacy and safety for FURL-ICP and f-URL in the treatment of upper urinary calculi with diameter ≤ 2cm.

  2. Objective To compare the efficacy and safety of FURL-ICP and traditional FURL for the treatment of ≤ 2cm upper urinary stones.
  3. Trial Design and Participants The trial is designed as a multicenter, parallel, randomized controlled trial with two arms. Patients will be recruited from 12 Chinese tertiary medical centers. Each participating center performed >50 f-URLs per month. Patients with upper urinary tract stones scheduled for f-URL will be invited in this study.
  4. Randomization and masking Central randomized allocation will be used without stratification. Participants will be assigned by a simple random sampling technique with a rate of 1:1. A randomization list is generated by a statistician and securely stored at a password-protected computer of the sponsor's center. Only one protocol-blinded coordinator will know the password and reveal the assignments in sequence to each center. The allocation is revealed before the surgery day. One-side superiority test is designed to compare the efficacy and safety of FURL-ICP and f-URL.
  5. Sample size Sample size is estimated by SFR of one month for f-URL. Complete stone free is defined as residual stone ≤ 2mm in diameter. The SFRs of FURL-ICP and traditional f-URL are presumed to be 90% (PT) and 75% (PC) respectively, based on previous data. 5% is considered as an inferior margin. The sample size is calculated with the formulas of a one-side superiority test comparing two proportions. The minimum sample size for each group was 224, and at least 449 cases are needed in the study. (https://www.cnstat.org/statx/compute.html).
  6. Intervention methods:

（1）Operation methods of intervention group(FURL-ICP)： Each procedure is completed under general anesthesia in supine lithotomy position with 60-90° oblique on the affected side upward. A semi-rigid ureteroscopy is used to check the urinary tract system and to place a 0.032-inch guidewire. A pressure measuring ureteral access sheath (UAS) (11/13.8Fr) is inserted into the proximal ureter along the guidewire without fluoroscopic guidance. A 7.5 Fr flexible ureteroscopy is used to check the delivery location of the UAS, mucosa of renal pelvis and ureter. After adjusting the UAS in suitable position, the pressure sensory and suctioning channels are connected to the irrigation and suctioning platform. After being injected with water, a zero calibration is performed for the pressure sensory system. A fully automatic mode is selected on the platform. The perfusion flow is set between 50 to 150 mL/min. The RPP control value is set between -15 to -5 mmHg. The renal pelvic pressure alarm value is set between 20 to 30mmHg. During the operation, a holmium laser is used to break stones into powder (fiber diameter 200 µm), and the flexible ureteroscopy is moved back and forward slightly to suck out the stone particles inside the sheath gap. Particles larger than the sheath gap but smaller than the UAS is sucked out by intermittently withdrawing the flexible ureteroscopy without basketing. A 4-6Fr ureteral stent is left for 2 weeks after the operation. Stone composition is analyzed. If the UAS is failed to be placed, ureteral stent will be placed for 2 weeks and a second stage FURL-ICP will be performed.

（2）Operation methods of control group（traditional f-URL）： Each procedure is completed under general anesthesia in lithotomy position. A semi-rigid ureteroscopy is used to place a 0.032-inch guidewire. A pressure measuring ureteral access sheath (UAS) (11/13.8Fr) is inserted into the proximal ureter along the guidewire without fluoroscopic guidance. The irrigation and suctioning platform will be not used. A 7.5 Fr flexible ureteroscopy is used to break the stone with a holmium laser (fiber diameter 200 µm). A basket is used to remove the stone fragments. A 4-6Fr ureteral stent is left for 2 weeks after the operation. Stone composition is analyzed. If the UAS is failed to be placed, ureteral stent will be placed for 2 weeks and a second stage traditional f-URL will be performed.

Study Type

Interventional

Enrollment (Anticipated)

449

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • China
    • Jiangxi
      • Ganzhou, Jiangxi, China, 341000
        • Recruiting
        • The Affiliated Ganzhou Hospital of Nanchang University (Ganzhou People's Hospital)
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • The diameter of single stone or cumulative maximum diameter for multiple stones is less than or equal to 2cm
  • American Society of Anesthesiology scores of 1to 2
  • All patients participate in this study voluntarily and signed informed consent

Exclusion Criteria:

  • Uncontrolled urinary tract infection
  • Patients with pyonephrosis are found during operation
  • The patients with abnormal anatomy (heterotopic kidney, horseshoe kidney, duplicate kidney), ureteral stricture, urethral stricture and urinary diversion
  • Severe hydronephrosis
  • Renal function was decompensated (serum creatinine > 178 μmol/L)
  • Severe systemic hemorrhagic disease
  • Patients who underwent bilateral surgery at the same time
  • Severe deformity of hip joint and difficult position

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Flexible ureteroscope with intelligent control of renal pelvic pressure(FURL-ICP)
Patients will be placed in supine lithotomy position with 60-90° oblique on the affected side upward. A pressure measuring ureteral access sheath (UAS) (11-14Fr) is inserted into the proximal ureter along the guidewire without fluoroscopic guidance. The pressure sensory and suctioning channels are connected to the irrigation and suctioning platform.
Device: Flexible ureteroscope with intelligent control of renal pelvic pressure
After adjusting the UAS in suitable position, the pressure sensory and suctioning channels are connected to the irrigation and suctioning platform. After being injected with water, a zero calibration is performed for the pressure sensory system. A fully automatic mode is selected on the platform. The perfusion flow is set between 50 to 150 mL/min. The RPP control value is set between -15 to -5 mmHg. The renal pelvic pressure alarm value is set between 20 to 30mmHg. During the operation, a holmium laser is used to break stones into powder (fiber diameter 200 µm), and the flexible ureteroscopy is moved back and forward slightly to suck out the stone particles inside the sheath gap. Particles larger than the sheath gap but smaller than the UAS is sucked out by intermittently withdrawing the flexible ureteroscope without basket.
No Intervention: Traditional flexible ureteroscope(f-URL)
Each procedure is completed under general anesthesia in lithotomy position. A semi-rigid ureteroscopy is used to place a 0.032-inch guidewire. A pressure measuring ureteral access sheath (UAS) (11-14Fr) is inserted into the proximal ureter along the guidewire without fluoroscopic guidance. The irrigation and suctioning platform will be not used. A 7.5 Fr flexible ureteroscopy is used to break the stone with a holmium laser (fiber diameter 200 µm). A basket is used to remove the stone fragments. A 4-6Fr ureteral stent is left for 2 weeks after the operation. Stone composition is analyzed. If the UAS is failed to be placed, ureteral stent will be placed for 2 weeks and a second stage traditional f-URL will be performed.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Stone free rate for one month
Time Frame: One month after surgery
Stone free rate for one month after surgery by CT scan with a thickness of 2mm.
One month after surgery

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Stone free rate for one day
Time Frame: One day after surgery
Stone free rate for one day after surgery by X-ray.
One day after surgery
Postoperative fever rate
Time Frame: Within 3 days after operation
Postoperative fever rate (body temperature > 38.5°C within 3 days after operation
Within 3 days after operation
Operating time
Time Frame: During the operation
Operating time
During the operation
Degree of ureteral injury
Time Frame: During the operation
Degree of ureteral injury
During the operation

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Guohua Zeng

Collaborators

The First Affiliated Hospital of Nanchang University
Henan Provincial People's Hospital
First Affiliated Hospital of Jinan University
Southern Medical University, China
Fujian Provincial Hospital
People's Hospital of Guangxi
The First Affiliated Hospital of Xiamen University
The Affiliated Hospital of Guangdong Medical College
Jiangxi Provincial People's Hopital
First People's Hospital of Yulin
The Affiliated Ganzhou Hospital of Nanchang University

Investigators

  • Study Chair: Guohua Zeng, Doctor, The First Affiliated Hospital of Guangzhou Medical University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 11, 2021

Primary Completion (Anticipated)

July 31, 2022

Study Completion (Anticipated)

July 31, 2022

Study Registration Dates

First Submitted

October 6, 2021

First Submitted That Met QC Criteria

January 20, 2022

First Posted (Actual)

January 21, 2022

Study Record Updates

Last Update Posted (Actual)

January 21, 2022

Last Update Submitted That Met QC Criteria

January 20, 2022

Last Verified

January 1, 2022

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • MRER(49)2021

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

IPD Plan Description

When the study is finished, we will shared data with other researchers.

Study Data/Documents

  1. Study Protocol
    Information identifier: zxt4

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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