Multi-Center Comparison of Dual Lumen Versus Single Lumen Ureteroscopes
| Status: | Recruiting |
|---|---|
| Healthy: | No |
| Age Range: | 18 - Any |
| Updated: | 1/20/2018 |
| Start Date: | April 2014 |
| End Date: | April 2019 |
| Contact: | Jaime Landman, MD |
| Email: | landmanj@uci.edu |
| Phone: | 714-456-3330 |
Urolithiasis (kidney stones) is a common disease process affecting people all across the
world. Usually, if the stone size is small, it is able to pass through the urinary system and
exit the bladder on its own with no treatment. However, when the size of the stone is bigger,
it can get trapped in the kidney or the ureter, causing significant pain for the patient and
potentially obstructing urine flow. If this occurs, surgical treatment is necessary for the
removal of the stone. The surgical procedure often employed involves the use of a
ureteroscope, which is a device that includes a camera and channels for working instruments
such as a grasper and laser fiber to be placed during a procedure. Ureteroscopes that are
currently in use are flexible and have the ability to treat stones that may otherwise be
inaccessible in the kidney. Most flexible ureteroscopes in clinical use currently only have
one channel therefore only allowing one instrument to be used at a time. Recently, a new type
of ureteroscope has been introduced in the market that offers the advantage of having two
working channels where two instruments can be inserted for use during stone treating
procedure. This can potentially decrease procedure time for patients affected by kidney
stones.
The purpose of this research is to compare the efficacy and safety of the ureteroscopes that
have only one channel for instrument insertion with the newer ureteroscope that has two
channels for utilization during stone treatment.
world. Usually, if the stone size is small, it is able to pass through the urinary system and
exit the bladder on its own with no treatment. However, when the size of the stone is bigger,
it can get trapped in the kidney or the ureter, causing significant pain for the patient and
potentially obstructing urine flow. If this occurs, surgical treatment is necessary for the
removal of the stone. The surgical procedure often employed involves the use of a
ureteroscope, which is a device that includes a camera and channels for working instruments
such as a grasper and laser fiber to be placed during a procedure. Ureteroscopes that are
currently in use are flexible and have the ability to treat stones that may otherwise be
inaccessible in the kidney. Most flexible ureteroscopes in clinical use currently only have
one channel therefore only allowing one instrument to be used at a time. Recently, a new type
of ureteroscope has been introduced in the market that offers the advantage of having two
working channels where two instruments can be inserted for use during stone treating
procedure. This can potentially decrease procedure time for patients affected by kidney
stones.
The purpose of this research is to compare the efficacy and safety of the ureteroscopes that
have only one channel for instrument insertion with the newer ureteroscope that has two
channels for utilization during stone treatment.
Study design
This study will be prospective, multi-institutional randomized controlled trial comparing
single lumen and dual lumen ureteroscopes. Specifically, a new double-lumen ureteroscope will
be compared in a multicenter trial with the currently existing single-lumen ureteroscopes in
patients undergoing ureteroscopy for stones in the kidney and ureter.
Patient Recruitment and Randomization
All patients presenting to the Department of Urology at University of California, Irvine,
University of Toronto and North Shore-LIJ Health System requiring a flexible ureteroscopy for
treatment of their kidney or ureteral stone disease will be approached for enrolment in the
study, assuming the inclusion and exclusion criteria detailed below are met. After discussion
of the study with potential participants, interested parties will be given a copy of the
consent form. The investigator will review and explain the consent form with the potential
subject. All information about the study will be provided. Ample time will be given for
individuals to ask questions regarding participation and to have questions answered prior to
signing the consent form. If so desired, those interested will be given a copy of the consent
form to take home so that they may have the opportunity to discuss participation further with
family and/or advisors. If an individual chooses to enroll, the consent form will be signed
before procedure begins. Once an individual joins the study and informed consent is obtained,
the subject will receive a signed copy of the consent form. Individuals may chose not be
enrolled in the study or may withdraw from the study at any time without repercussions to
subsequent care.
Patients agreeing to participate in the study will be randomized on the day of surgery.
Stratified block randomization will be utilized to balance the number of patients with
different stone sizes (>1cm, <1cm), kidney, proximal and distal ureteral stones between the
two groups.
Device description
The Wolf Cobra Richard (Wolf Endoscopy, Vernon Hills, IL), a dual-lumen flexible ureteroscope
is currently the only existing device with two working channels utilized in the operating
room. Wolf Cobra has a shaft size of 9.9F. Each of the Cobra's two channels is 3.3 F in size
(smaller compared with regular ureteroscopes 3.6F) but give a larger total cross-sectional
area when two combined together. Atraumatic 6 Fr. distal tip dilates to a 9.9 Fr. sheath for
ease of entry.
A dual-channel ureteroscope may provide several advantages. Having additional working channel
enables better irrigation than a single-channel ureteroscope. It is achieved by continuous
inflow and outflow, which might significantly, improve intraoperative visualization and
maintains a clear field of view by efficient cleaning of blood, debris, and stone, even when
utilizing multiple instruments simultaneously. Usually, multiple passes with different
instruments requires the surgeon to reposition the ureteroscope in order to change the
instruments which can potentially reduce efficiency and increase the length of operative
time. The second working channel will allow the surgeon to use multiple instruments
simultaneously while maintaining the flow and efficiently treat the stone or other pathology
(Figure 1). This feature may offer technical advantages
Outcomes
Preoperatively, all patients will undergo a diagnostic imaging (CT, KUB, US) to identify the
stone burden and location. Follow up imaging will be standardized across all participating
institutions and will include CT or KUB imaging after the procedure to identify residual
stones.
The primary outcome of the study will be the procedure time (minutes). This will be measured
from the start of the endoscopic access to the end of the procedure including complete
fragmentation and stone fragment removal.
The following data will also be recorded and serve as the secondary outcomes:
1. Stone clearance rate (Will be defined by URS and postoperative imaging)
2. Total ureteroscopy time
3. Stone fragmentation time (this time will be recorded from start of first lithotripsy
till complete stone fragmentation)
4. Stone clearance time
5. Overall procedure time (including positioning, URS procedure, extubation)
6. Requirement for a second procedure
7. Intraoperative complications
8. Immediate postoperative complications
9. Postoperative complications within 30 days of the procedure
10. Surgeon's opinion and comfort (rank from 1-10?)
11. Visibility using a questionnaire or rank from 1 to 10.
12. Ureteroscope durability
Additionally, patient demographics and clinical characteristics such as age, gender, Charlson
comorbidity index, ASA, BMI, previous medical and surgical history will be collected. Stone
characteristics such as size, location, density (HU) will be recorded. For each patient,
three (width, length and depth) largest diameters of the stone will be measured from
preoperative CT and volume will be calculated for accurate stone measurements. All
preoperative and postoperative outcomes will be compared based on the stone characteristics
such as size, location and type of stone (HU)
Deflection Angles
New single lumen and double lumen ureteroscopes will be used for the purpose of this study.
To avoid any confounding factors, these scopes will be used exclusively on patients who are
involved in the trial. Every week each ureteroscope will be assessed for maximal deflection,
which is defined as the angle between the tangents of the deflection point and the tip of the
ureteroscopes, as described by Monga and Parkin9,10. In order to calculate the angle, a
photocopy of the ureteroscope while in maximal deflection will be taken. Both upward and
downward angles of deflections will be measured three times and the mean value will be
subsequently calculated for each type of ureteroscope prior to first usage. These
measurements will be performed after each week of usage. After the last case of the study,
the maximal angle of deflection for each of the two types of ureteroscopes will be measured
again and will be compared to the measurement at the beginning of the study.
Fatigability Fatigability of a given ureteroscope is defined as decrease of the maximum
amount of deflection of the tip4. The fatigability of each ureteroscope will be measured by
subtracting the mean value of maximal deflection at the end of the study from the maximum
deflection measured at the beginning of the study.
Subjective Assessments
After each procedure, the surgeon that performs the endoscopic procedure will be asked to
rate the image quality of the scope by filling out a questionnaire from 1-10 (1 being poor
and 10 being excellent visualization). These subjective assessments will be the investigators
secondary outcomes. Additionally, the ease of deflection and overall scope performance will
be asked.
Once each ureteroscope reaches a point where it will require repair, it will be shipped to
the manufacturing company. The reason for repair will be recorded, and the type and cost of
each repair will be documented.
This study will be prospective, multi-institutional randomized controlled trial comparing
single lumen and dual lumen ureteroscopes. Specifically, a new double-lumen ureteroscope will
be compared in a multicenter trial with the currently existing single-lumen ureteroscopes in
patients undergoing ureteroscopy for stones in the kidney and ureter.
Patient Recruitment and Randomization
All patients presenting to the Department of Urology at University of California, Irvine,
University of Toronto and North Shore-LIJ Health System requiring a flexible ureteroscopy for
treatment of their kidney or ureteral stone disease will be approached for enrolment in the
study, assuming the inclusion and exclusion criteria detailed below are met. After discussion
of the study with potential participants, interested parties will be given a copy of the
consent form. The investigator will review and explain the consent form with the potential
subject. All information about the study will be provided. Ample time will be given for
individuals to ask questions regarding participation and to have questions answered prior to
signing the consent form. If so desired, those interested will be given a copy of the consent
form to take home so that they may have the opportunity to discuss participation further with
family and/or advisors. If an individual chooses to enroll, the consent form will be signed
before procedure begins. Once an individual joins the study and informed consent is obtained,
the subject will receive a signed copy of the consent form. Individuals may chose not be
enrolled in the study or may withdraw from the study at any time without repercussions to
subsequent care.
Patients agreeing to participate in the study will be randomized on the day of surgery.
Stratified block randomization will be utilized to balance the number of patients with
different stone sizes (>1cm, <1cm), kidney, proximal and distal ureteral stones between the
two groups.
Device description
The Wolf Cobra Richard (Wolf Endoscopy, Vernon Hills, IL), a dual-lumen flexible ureteroscope
is currently the only existing device with two working channels utilized in the operating
room. Wolf Cobra has a shaft size of 9.9F. Each of the Cobra's two channels is 3.3 F in size
(smaller compared with regular ureteroscopes 3.6F) but give a larger total cross-sectional
area when two combined together. Atraumatic 6 Fr. distal tip dilates to a 9.9 Fr. sheath for
ease of entry.
A dual-channel ureteroscope may provide several advantages. Having additional working channel
enables better irrigation than a single-channel ureteroscope. It is achieved by continuous
inflow and outflow, which might significantly, improve intraoperative visualization and
maintains a clear field of view by efficient cleaning of blood, debris, and stone, even when
utilizing multiple instruments simultaneously. Usually, multiple passes with different
instruments requires the surgeon to reposition the ureteroscope in order to change the
instruments which can potentially reduce efficiency and increase the length of operative
time. The second working channel will allow the surgeon to use multiple instruments
simultaneously while maintaining the flow and efficiently treat the stone or other pathology
(Figure 1). This feature may offer technical advantages
Outcomes
Preoperatively, all patients will undergo a diagnostic imaging (CT, KUB, US) to identify the
stone burden and location. Follow up imaging will be standardized across all participating
institutions and will include CT or KUB imaging after the procedure to identify residual
stones.
The primary outcome of the study will be the procedure time (minutes). This will be measured
from the start of the endoscopic access to the end of the procedure including complete
fragmentation and stone fragment removal.
The following data will also be recorded and serve as the secondary outcomes:
1. Stone clearance rate (Will be defined by URS and postoperative imaging)
2. Total ureteroscopy time
3. Stone fragmentation time (this time will be recorded from start of first lithotripsy
till complete stone fragmentation)
4. Stone clearance time
5. Overall procedure time (including positioning, URS procedure, extubation)
6. Requirement for a second procedure
7. Intraoperative complications
8. Immediate postoperative complications
9. Postoperative complications within 30 days of the procedure
10. Surgeon's opinion and comfort (rank from 1-10?)
11. Visibility using a questionnaire or rank from 1 to 10.
12. Ureteroscope durability
Additionally, patient demographics and clinical characteristics such as age, gender, Charlson
comorbidity index, ASA, BMI, previous medical and surgical history will be collected. Stone
characteristics such as size, location, density (HU) will be recorded. For each patient,
three (width, length and depth) largest diameters of the stone will be measured from
preoperative CT and volume will be calculated for accurate stone measurements. All
preoperative and postoperative outcomes will be compared based on the stone characteristics
such as size, location and type of stone (HU)
Deflection Angles
New single lumen and double lumen ureteroscopes will be used for the purpose of this study.
To avoid any confounding factors, these scopes will be used exclusively on patients who are
involved in the trial. Every week each ureteroscope will be assessed for maximal deflection,
which is defined as the angle between the tangents of the deflection point and the tip of the
ureteroscopes, as described by Monga and Parkin9,10. In order to calculate the angle, a
photocopy of the ureteroscope while in maximal deflection will be taken. Both upward and
downward angles of deflections will be measured three times and the mean value will be
subsequently calculated for each type of ureteroscope prior to first usage. These
measurements will be performed after each week of usage. After the last case of the study,
the maximal angle of deflection for each of the two types of ureteroscopes will be measured
again and will be compared to the measurement at the beginning of the study.
Fatigability Fatigability of a given ureteroscope is defined as decrease of the maximum
amount of deflection of the tip4. The fatigability of each ureteroscope will be measured by
subtracting the mean value of maximal deflection at the end of the study from the maximum
deflection measured at the beginning of the study.
Subjective Assessments
After each procedure, the surgeon that performs the endoscopic procedure will be asked to
rate the image quality of the scope by filling out a questionnaire from 1-10 (1 being poor
and 10 being excellent visualization). These subjective assessments will be the investigators
secondary outcomes. Additionally, the ease of deflection and overall scope performance will
be asked.
Once each ureteroscope reaches a point where it will require repair, it will be shipped to
the manufacturing company. The reason for repair will be recorded, and the type and cost of
each repair will be documented.
Inclusion Criteria:
1. Patients >18 years old.
2. Patients with <2 cm total burden of renal or ureteral stones eligible for flexible
ureteroscopic lithotripsy.
Exclusion Criteria:
1. Patients <18 years old.
2. Patients who are not able to give consent for study
3. Patients with active urinary tract infection
4. Pregnant women
5. Patients who have had ureteroscopy, SWL or PCNL for the same stone on the ipsilateral
kidney
We found this trial at
1
site
101 The City Drive South
Orange, California 92868
Orange, California 92868
714-456-7890
Principal Investigator: Jaime Landman, MD
Phone: 714-456-8176
University of California, Irvine Medical Center We are UC Irvine Health. We are a devoted...
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