Failed Insertion of Ureteral Access Sheath During Flexible Ureterorenoscopy

June 21, 2023 updated by: Ufuk Çağlar, Haseki Training and Research Hospital

Failed Insertion of Ureteral Access Sheath During Flexible Ureterorenoscopy: A Randomized Controlled Trial Comparing Second Session Flexible Ureterorenoscopy or Same Session Mini Percutaneous Nephrolithotomy

Percutaneous nephrolithotomy (PNL) is the gold standard recommended treatment technique for kidney stones larger than 20 mm. For kidney stones between 10 - 20 mm, both shock wave lithotripsy (SWL) or flexible ureterorenoscopy (f-URS) are recommended as the first choice of treatment and PNL is recommended as the second. In patients who are planned to undergo f-URS, a ureteral access sheath (UAS) is placed in the ureter at the beginning of the operation in order to provide a better image, reduce intra-renal pressure, easier stone fragment retrieval and shorter operative time. In certain cases, such as ureteral stricture, kink or edema, the ureteral access sheath may not be able to successfully inserted into the ureter. At this stage, double-J (JJ) stent can be inserted into the ureter to create passive dilatation, and a second f-URS session can be scheduled a few weeks later. Another option is to perform PNL operation to the patient in the same session. In this randomized prospective study, we aimed to compare these two different surgical approaches in terms of patient comfort and surgical success in patients with kidney stones between 10 - 20 mm in which access sheath insertion was failed in the initial f-URS session.

Study Overview

Detailed Description

Patients with renal calculi between 1 - 2 cm in diameter who were admitted to a tertiary health institution were evaluated prospectively. Patients who were unsuitable for shock wave lithotripsy (SWL) treatment or who did not benefit from SWL sessions were included in the study. Randomization was performed using a random number table with a central computerized system. Before the procedure, the patients were asked to complete the Turkish language validated form of the Short Form - 36 (SF - 36) questionnaire.

A total of 48 patients in whom ureteral access sheath insertion has failed during initial flexible ureterorenoscopy (f-URS) session were randomly divided into 2 groups. Group 1 underwent a JJ stent insertion and procedure terminated, while group 2 underwent mini percutaneous nephrolithotomy (mPNL) operation in the same session after prone positioning. Group 1 underwent f-URS 4-6 weeks later. One month after the operation, stone-free status was evaluated with computed tomography (CT) and detection of residual fragments of any size was defined as failure. The patients were asked to fill out the SF-36 questionnaire one month after the last surgery. Operative and postoperative data, SF-36 results, success, and complications were compared between the groups. The operation time included the time from initiation of cystoscopy to removal of amplatz for the mPNL group. For the F-URS group, it was calculated as the sum of the times between cystoscopy and fluoroscopy control of the JJ stent in both sessions.

Surgical technique All surgeries were performed by the same team of experienced surgeons in with high expertise in endourology. A guidewire was placed in the ureter in the lithotomy position. Ureterorenoscopy was performed with an 8 Fr ureterorenoscope for active dilatation. An 11 - 13 Fr or 9.5 / 11.5 Fr UAS was attempted to be placed under fluoroscopy by the surgeon of the procedure. In cases where the UAS could not inserted, a 26 cm, 4.8 Fr JJ stent was placed under fluoroscopy in the f-URS group, and the procedure was terminated. In the mPNL group, same session mPNL procedure was performed.

After initial JJ stent placement, patients in group 1 underwent a second f-URS session, 4 - 6 weeks later. After the JJ stent was removed, an 11 - 13 Fr UAS was placed in the ureter. Digital flexible ureterorenoscope was used as the flexible ureteroscope. Stone fragmentation was performed in dusting mode using a Ho:YAG laser with a 272 µ probe. After fragmentation, a 26 cm 4.8 Fr JJ stent was inserted into the ureter. The JJ stent was removed at 4 - 6 weeks postoperatively.

For patients in group 2, after placing a 5 Fr ureteral open-ended catheter, patients were positioned in prone position and access was performed to the appropriate calyx with an 18-gauge percutaneous access needle using the triangulation technique accompanied by fluoroscopy, in the first session. After the guidewire was introduced into the pelvicalyceal system, sequential dilatation was applied with Amplatz dilatators, and a 21 Fr metallic sheath was placed. Stones were fragmented with a yttrium-aluminum-garnet (Ho:YAG) Laser lithotripter. At the end of the procedure, a 14 Fr nephrostomy catheter was placed in according to the residual stone, hemorrhage, and perforation status. In other cases, the procedure was concluded as totally tubeless. Postoperative routine intravenous analgesia was not applied to all patients.

Study sample size analysis was computed using the G*Power program (effect size 0.5, alfa error 0.05, power 0.80). Statistical analysis was performed with 'Statistical Package for the Social Sciences' (SPSS) 25 program. The normality assessment of the distribution of the data was analyzed with the Shapiro-Wilk test and Q - Q plot. For continuous covariates, normality and homogeneity of each variable were evaluated and Student's or Welch's t-test was performed. Mann - Whitney U test was used for skewed data. Quantitative data were presented as mean ± standard deviation or median (IQR) values. Chi-square test or Fisher exact test (where the 20% of expected cell counts were less than 5) was used to compare qualitative data. The normality of the differences in SF - 36 data before and after the procedure was evaluated with the Skewness test and Q - Q plot. Paired-sample t - test was used to compare SF - 36 data before and after the procedure. The data were analyzed at 95% confidence level and the values with P < .05 were noted statistically significant.

Study Type

Interventional

Enrollment (Actual)

48

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 Locations

    • Sultangazi
      • Istanbul, Sultangazi, Turkey, 34265
        • Haseki Training and Research Hospital

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients with renal calculi between 1 - 2 cm in diameter
  • Patients who were unsuitable for SWL treatment or who did not benefit from SWL sessions

Exclusion Criteria:

  • Patients with kidney anomalies, (malrotated and horseshoe kidneys, kidneys with duplicated systems)
  • Pregnant patients
  • Patients younger than 18 years of age
  • Patients who did not consent for inclusion in the study

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
Active Comparator: Flexible Ureterorenoscopy
Underwent a JJ stent insertion and underwent f-URS 4-6 weeks later (Group 1).
A guidewire was placed in the ureter in the lithotomy position. Ureterorenoscopy was performed with an 8 Fr ureterorenoscope for active dilatation. An 11 - 13 Fr or 9.5 / 11.5 Fr UAS was attempted to be placed under fluoroscopy by the surgeon of the procedure. In cases where the UAS could not inserted, a 26 cm, 4.8 Fr JJ stent was placed under fluoroscopy and the procedure was terminated. Patients underwent a second f-URS session, 4 - 6 weeks later. After the JJ stent was removed, an 11 - 13 Fr UAS was placed in the ureter. Digital flexible ureterorenoscope was used as the flexible ureteroscope. Stone fragmentation was performed in dusting mode using a Ho:YAG laser with a 272 µ probe. After fragmentation, a 26 cm 4.8 Fr JJ stent was inserted into the ureter. The JJ stent was removed at 4 - 6 weeks postoperatively.
Active Comparator: Mini Percutaneous Nephrolithotomy
Underwent mPNL operation in the same session after prone positioning (Group 2).
A guidewire was placed in the ureter in the lithotomy position. Ureterorenoscopy was performed with an 8 Fr ureterorenoscope for active dilatation. An 11 - 13 Fr or 9.5 / 11.5 Fr UAS was attempted to be placed under fluoroscopy by the surgeon of the procedure. In cases where the UAS could not inserted, patients were positioned in prone position and access was performed to the appropriate calyx with an 18-gauge percutaneous access needle using the triangulation technique accompanied by fluoroscopy, in the same session. After the guidewire was introduced into the pelvicalyceal system, sequential dilatation was applied with Amplatz dilatators, and a 21 Fr metallic sheath was placed. Stones were fragmented with a yttrium-aluminum-garnet (Ho:YAG) Laser lithotripter. At the end of the procedure, a 14 Fr nephrostomy catheter was placed in according to the residual stone, hemorrhage, and perforation status. In other cases, the procedure was concluded as totally tubeless.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Short Form-36 parameters
Time Frame: Before surgery - 1 month after surgery
In order to evaluate the quality of life of the patients, pre- and postoperative SF-36 form values will be compared.
Before surgery - 1 month after surgery

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The success of the surgery
Time Frame: Before surgery - 1 month after surgery
Stone-free rates of the patients will be evaluated by computed tomography after surgery.
Before surgery - 1 month after surgery

Collaborators and Investigators

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

Investigators

  • Study Director: Mehmet Akbulut, Assoc. Prof, Haseki Training and Research Hospital

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.

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)

September 10, 2020

Primary Completion (Actual)

September 10, 2021

Study Completion (Actual)

December 1, 2021

Study Registration Dates

First Submitted

June 12, 2023

First Submitted That Met QC Criteria

June 12, 2023

First Posted (Actual)

June 22, 2023

Study Record Updates

Last Update Posted (Actual)

June 23, 2023

Last Update Submitted That Met QC Criteria

June 21, 2023

Last Verified

June 1, 2023

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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