Vol 15 No 03 May-June 2018 5
Purpose: Transurethral lithotripsy (TUL) is a major modality for the endoscopic management of ureteral stones.
Ureteral spasm makes access for ureters difficult, which causes impaction of the ureteroscope, ureteral dislodge,
and a low success rate of endoscopic surgeries. This study described the outcomes of a new endoscopic surgical
experience by use of 40-degree warm saline irrigation during TUL compaired with routine ambient air irrigation
in TUL.
Materials and methods: In this randomized clinical trial from 2014 to 2015, 150 patients with ureteral stone with
balanced randomization were divided into two parallel groups. Patients underwent TUL in the first group with
20–25 degree saline irrigation and in the second group with 40-degree saline irrigation. One surgical team with the
same semi-rigid instrument performed all TULs and the other steps were similar in both groups. Complete stone
fragmentation was measured as the primary outcome and the duration of procedure, retrograde stone migration and
all and any intraoperative complications were the secondary measurements.
Result: While comparing warm saline irrigation with cold saline irrigation, the rate of access to upper ureter was
95% versus 72%, stone retropulsion frequency was 10.7% versus 30.7% and the stone-free rate was 96% versus
76% respectively (P < .05). There was no ureteroscope impaction and ureteral dislodge in both groups.
Conclusion: Using warm saline irrigation in endoscopic surgeries results in better surgical outcomes including
a lower ureteral spasm rate, greater ureteral muscle relaxation and better access to the upper ureteral zone, and a
lower rate of complications, such as ureteroscope impaction, ureteral dislodge and stone retropulsion.
Keywords: lithotripsy; ureteroscopy; ureteral dislodge; warm saline; irrigation.
INTRODUCTION
Endoscopic ureteral surgeries are the most common urologic surgeries, including diagnostic ureteros-
tomy, strictures and obstruction treatments, stone lith-
otripsy, resection and fulguration of ureteral tumors.(1)
Urolithiasis is a common urological problem. Ureteral
stones can cause severe morbidity and pain. After failed
medical therapy and if intervention is indicated, then
various modalities would be available, such as extra
corporeal shock wave lithotripsy (ESWL) and ureter-
oscopic management.(1–3) The choice of intervention
depends on many factors, including stone size and lo-
cation, available instruments and surgical team experi-
ence. Transurethral lithotripsy (TUL) is a major modal-
ity for endoscopic management of ureteral stones. One
of the risk factors in difficult access of ureters is ureteral
spasm, which causes the impaction of the ureteroscope,
ureteral dislodge, and a low success rate of endoscopic
surgeries. Difficult access and retrograde stone migra-
tion are two main problems during TUL, which could
require additional instruments such as ureteral dila-
tors, stone retrieval devices, or additional procedures
like Re-TUL or ESWL(4, 5), which can cause additional
morbidity and cost. By the invention and use of new
endoscopic instruments, ureteral endoscopic surgeries
are more common. Nowadays, diagnostic ureteroscopy,
TUL, ureteral stones, treatment of ureteral obstructions
and resection and fulguration of ureteral tumors are the
1Department of Urology, Mashhad University of Medical Sciences, Mashhad-IRAN.
2Department of Community Medicine, Mashhad University of Medical Sciences, Mashhad-IRAN.
*Correspondence: Department of Urology, Mashhad University of Medical Sciences,Mashhad-IRAN.
Tel:09151842487. Email: alirezaakhavan30@yahoo.com.
Received February 2017 & Accepted October 2017
most common endoscopic urologic surgeries.
Transurethral lithotripsy is one of the best modalities
for ureteral stone management. TUL with semi-rigid
ureteroscope is one of the most common techniques
for this purpose. However, difficult ureteral access and
retrograde stone migration are some of the common
problems associated with this method.(5–7) Additional
medications or interventions like tamsulosin therapy,
lidocaine jelly, Dj placement, re-TUL or ESWL could
be necessary to manage migrated or residual fragments.
(2,9-14) There are some maneuvers, such as the reverse
Trendelenburg position, to prevent stone retropulsion,
and there are some devices like stone baskets, N-trap
and stone cone that can solve the problem. All of these
entail additional morbidity and costs.(2,4,8,15,16) The thick-
ening of the tip to the end of the ureteroscope instru-
ment may result in ureteral spasm and ureteroscope
impaction, and result in ureteral spasm and difficultness
in procedures of endoscopic surgery. In such situations,
ureteral dislodge may occur as well. Since 1993, with
the use of the first pneumatic lithoclast device in Iran in
the urological department of Ghaem Hospital in Mash-
had, ureteral endoscopic surgeries began, and everyday,
many patients underwent TUL and other endoscopic
procedures. After a few years, we found out that in cases
of cold water irrigation during TUL, we had more ure-
teral spasms around the ureteroscope instrument, which
led to lower access to the upper ureter. We also had two
ENDOUROLOGY AND STONE DISEASE
The Evaluation of the Result of Warm Normal Saline Irrigation in Ureteral Endoscopic Surgeries: A
Randomized Clinical Trial
Mohammadali Mohammadzadeh Rezaei1, Alireza Akhavan Rezayat1, Mahmoud Tavakoli1*,Lida Jarahi2
cases of ureteroscope impaction in the ureter, which re-
sulted in ureteral dislodge during 10 years. In the last
two decades, with the use of warm 40-degree saline ir-
rigation during TUL, we had better surgical outcomes,
and ureteral dislodge or ureteroscope impaction were
not seen. In this study, we describe our experience and
outcomes of warmed saline irrigation during semi-rigid
ureteroscopy and TUL in patients with ureteral stone.
PATIENTS AND METHODS
Study population
The participants of this study were patients who were
diagnosed with ureteral stone. From May 2014 to May
2015, 150 consecutive patients with 170 ureteral stones
were treated at our Urologic Department with pneu-
matic TUL (TULp). Active urinary tract infection,
pregnancy, bilateral stones or single functional kidney
were the exclusion criteria. In this study, the criteria for
successful operation are the small size of the remain-
ing stone (less than 4 mm) and patients without urinary
tract obstruction and hydronephrosis and those totally
asymptomatic. Sample size was determined based on
the study of John TT, with the statistical formula of
comparable proportions with a dichotomous outcome
between two samples: Type I error of 0.05 and Type II
error of 0.2, p1 = 0.87 and p2 = 0.68. These resulted in
75 samples in each group.
Study design
This study was a prospective single-center, paral-
lel-group randomized clinical trial with balanced ran-
domization. The block size was 4 and all possible bal-
anced combinations of assignment within the block
were calculated. Blocks were then randomly chosen to
determine the patients’ assignment into the groups: all
block sizes were the same and the SPSS software was
used for block randomization.
After the local ethics committee’s approval and in-
formed consent, the patients included were randomly
allocated into two groups using block randomization
method, so that each group contained 75 patients. Pa-
tients and analyzers were blinded to the randomization
group. The co-researcher determined patient allocation
and one assistant with the surgeon made the interven-
tions and measured outcomes.
Patients who underwent TULp with ambient tempera-
ture irrigation (22–24°C) were assigned to Group 1, and
patients who underwent TULp with warmed irrigation
fluid (40C) were assigned to Group 2. In all patients,
routine complete blood count, blodd urea nitrogen,
Creatinine, urine analysis and culture were performed
preoperatively, and prophylactic intravenous antibiot-
ics were administered. Using general anesthesia in the
lithotomy position, a semi-rigid ureteroscopy was per-
formed (8–8.9 semi-rigid ureteroscope–Wolf, Germa-
ny), and safety wire was placed. After ureteral access
and identification of the stone in the ureter, the stone
Warm saline in TUL-Mohammadzadeh Rezaei et al.
Table 1. Demographic characteristics of patients in the intervention and control groups
Ambient air group (Group 1) 40°c irrigation fluid (Group 2) P-value
sex Female Number (%) 32 (42.7) 25 (33.3) 0.23
Male Number (%) 43 (57.3) 50 (66.7)
Age, years; mean (SD) 33.4 (8.6) 35.9 (8.8) 0.08
Table 2. Results of 40°c warmed irrigation fluid versus ambient air group
Ambient air group (Group 1) 40°c irrigation fluid (Group 2)
P-value
Stone side Right 35 38 0.62
46.7% 50.7%
Left 40 37
53.3% 49.3%
Stone location Upper ureter 7 8 0.65
9.3% 10.7%
Mid ureter 23 18
30.7% 24.0%
Lower ureter 45 49
60.0% 65.3%
Fragmentation / migration Complete with out migration 52 67 0.002
69.3% 89.3%
Incomplete or migrated 23 8
30.7% 10.7%
stenting none 51 65 0.006
68.0% 86.7%
dj 24 10
32.0% 13.3%
complications no 50 59 0.09
66.7% 78.7%
yes 25 16
33.3% 21.3%
Stone free at 2w free 57 72 < 0.001
76.0% 96.0%
residue 18 3
24.0% 4.0%
Re TUL/ ESWL no 57 72 < 0.001
76.0% 96.0%
yes 18 3
24.0% 4.0%
Endourology and Stone Diseases 6
Vol 15 No 03 May-June 2018 7
was fragmented by pneumatic device (TULp). All steps
were similar in Group 1 and 2. The only difference was
the irrigating fluid temperature. The duration of the
procedure, complete stone fragmentation, retrograde
stone migration and any intraoperative complications
were recorded for each patient. The next day, KUB was
performed to assess the probable stone migration or re-
sidual stone fragments. Two weeks later, patients were
re-evaluated by sonography and spiral CT scan.
Outcome assessment
Complete stone fragmentation was measured as the pri-
mary outcome and the duration of procedure, retrograde
stone migration and any intraoperative complications
were the secondary measurements.
Data analysis was performed using SPSS software
(Statistical Package for the Social Sciences, V. 16.0;
SPSS Inc., Chicago, IL, USA), by using T-test and chi-
squared test. A P-value less than 0.05 was considered
statistically significant.
RESULTS
Of 150 patients, 93 (62%) were male, and 57 (28%)
were female. The mean age of the participants was
34.06 years (SD = 9.4), with no significant difference
between male and female (Table 1).
In both groups, the locations of stones were in similar
sites of ureter (P =. 65) and the location of stones in
both groups was not significantly correlated with the
results (Table 2).
The mean (SD) of stone size in Group 1 (cold saline
irrigation) was 8.7(1.8) millimeters, while in Group 2
(warm saline irrigation), it was 9.8(2.5), (P = .001). Since
the mean size of stones in the 40-degree irrigation fluid
group was greater than in the control group, this showed
that even in larger stones, the use of warm saline irriga-
tion was more successful.
Warmed irrigation fluid improved TULp results. The
rates of re-intervention (Re TUL or ESWL) was 24%
and 4% in Groups 1 and 2 respectively. The mean (SD)
time of TULp in Group 1 was 27.6 (6.6) minutes while
in Group 2 it was 24.4 (69), (P = .004). Two weeks
later, TULP stone-free rates by KUB/USG or CT were
76% in Group 1 and 96% in Group 2. We analyzed
data on the time of operation, stone-free rates at two
weeks, rates of complications, and need to re-intervene
in both groups. The rates of complications (bleeding,
failed access, mucosal tear) were 33.3% and 21.32% in
Groups 1 and 2. The rate of access to the upper ureter
with warm saline irrigation was 95% against 72% with
cold saline irrigation. Lower stone retropulsion with
warm saline irrigation was 10.7% against 30.7% with
cold saline irrigation. We have not seen any uretrescope
impaction and ureteral dislodge in both groups.
DISCUSSION
By using warm saline irrigation in endoscopic surgeries,
we described better surgical outcomes: these included
lower ureteral spasm rate, more ureteral muscle relax-
ation, and better access to the upper ureteral zone and
lower rate of complications like uretroscope impaction
and ureteral dislodge. In this study, we used warmed
irrigation fluid during TULp to improve ureteral access,
prevent stone retropulsion and increase stone free rate,
with minimal cost and morbidity. We compared these
outcome measures between two groups. Group 1, with
ambient temperature irrigation fluid, and Group 2, with
40C irrigation fluid. The results were in favor of Group
2, which showed better ureteral access, lower stone ret-
ropulsion, and a greater stone-free rate. Also, the mean
operative time was in favor of Group 2. This demon-
strates warmed irrigation fluid as an effective way to
improve TULp results. There were some limitations to
our study. We did not have access to flexible ureter-
oscopy and could not compare our results with it. We
also feel that a larger series is required to confirm our
results. We did not have a flexible ureteroscope and that
was the main limitation of our study. However, flexible
ureteroscopy is more expensive, and a well-done TULp
could be an acceptable alternative to laser lithotripsy,
and is also more cost-effective.
The reason of these method success is due to ureteral
muscle relaxation with use of warm saline irrigation.
This may facilitate ureteroscope passage and better
stone access and also no use of high pressure saline irri-
gation, which may lead to the stone being pushed back.
This ureteral dilatation may also facilitate spontaneous
passage of small stones.(20)
In the study performed by Basiri and coworkers, stone
removal was performed by the use of balloon for ureter-
al dilatation and electrohydraulic and basket combina-
tion in 60 patients: the rate of success was 84.6%, which
was lower than our success rate (96% of our patients
were stone-free).(17)
In another study by Tanagho and coworkers in general
urology stone removal by basketing under fluoroscopy,
a 60–70% success rate was reported, which, too, was
lower than our success rate.(18)
In another study by Takashi Yagisawa and coworkers
in 2001, they describe the 91% rate of succession in tra-
ditional ureteroscopic pneumatic lithotripsy, which was
lower than our success rate as well.(19)
According to the same paper with the same method is
used in this study, comparison of the results is not pos-
sible.
CONCLUSIONS
We found that warmed irrigating fluid (40°C) can im-
prove TULP results in terms of ureteral access, preven-
Table 3. Comparison of complications between 2 groups
complications Total
none bleeding failed access mucosal tear
Count
group ambient air 50 12 7 6 75
% within group 66.7% 16.0% 9.3% 8.0% 100.0%
40°C Count 59 14 0 2 75
% within group 78.7% 18.7% 0.0% 2.7% 100.0%
Total Count 109 26 7 8 150
% within group 72.7% 17.3% 4.7% 5.3% 100.0%
Warm saline in TUL-Mohammadzadeh Rezaei et al.
tion of stone retropulsion, and the stone-free rate. It en-
tails no additional cost or morbidity for patients.
CONFLICT OF INTEREST
The authors declare no conflict of interest.
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Endourology and Stone Diseases 8