Materials and Methods
Between January 2018 and October 2020, the data of 134 patients who
underwent srURS due to single and primary upper ureteral stones that
could not be passed naturally were included in our study and analyzed
retrospectively. The retrospective study design was chosen because it
would be unethical for surgeons to intentionally cause stone migration
during surgery. The necessary permissions were obtained from the local
ethics committee (protocol number: 2017-KAEK-189_2020.11.11_02) for
the use and analysis of this data. The patients were divided into two
groups according to the development of push-up during surgery. Group 1
comprised 73 patients without stone push-up, and our standard srURS
procedure was applied to this group. Group 2 contained the remaining 61
patients, who underwent fURS due to spontaneous stone push-up. Surgeries
were performed by four surgeons experienced in endourological
procedures. Preoperative complete blood count, routine biochemical
analysis (glucose, creatinine, electrolytes), complete urinalysis, and
urine culture were obtained from all patients. Patients with signs of
infection and pyuria were operated on after receiving appropriate oral
therapy and obtaining a sterile urinalysis result. Patients with
persistent urinary infections were not included in the study.
Furthermore, the data of patients with irreversible
hydroureteronephrosis for any reason, stones reported to be enclaved
during surgery, a history of nephrocalcinosis, a history of a urinary
anomaly, a history of nephrectomy, a history of chronic renal failure,
and a JJ stent in the preoperative period were not included in the
evaluation.
Surgical Procedures
Before srURS, cystourethroscopy was performed on patients. A Stone
Cone® was placed in the ipsilateral ureter under
fluoroscopy during cystoscopy. Ureteral access was made with a 9.5F
semi-rigid ureterorenoscope (Karl Storz, Tuttlingen, Germany) under the
guidance of a guidewire. After the stone was reached by the
ureterorenoscope, it was dusted with a 272 μm holmium: YAG laser (Ho YAG
Laser; Dornier MedTech; Munich, Germany / Dornier Med-Tech GmbH, Medilas
H20 and HSolvo, Wessling, Germany) at a frequency of 8-12 Hz and energy
level of 0.8-1.5 W. No stone was extracted at the end of the procedure.
The procedure was completed by placing a JJ stent in the ureter. At the
end of the procedure, a 16F Foley catheter was placed in the patient’s
urethra. The time from entrance into the urethral meatus to the end of
JJ stent placement was recorded as the surgical time.
fURS was performed on patients who developed stone push-up during
ureteral access or Stone Cone® placement for upper
ureteral stones. Our standard srURS procedure was carried out for
dilatation. Then, a ureteral accessory sheath (UAS) (Elite Flex, Ankara,
Turkey) was placed over the guidewire into the ureter. Following this,
the stones were reached by advancing the flexible ureteroscope (Flex-X2,
Karl Storz, Tuttlingen, Germany / Karl Storz, Flex X2, GmbH, Tuttlingen,
Germany). The stones were dusted with a 272 μm laser. No stone fragment
was extracted. A JJ stent was placed in the ureter. At the end of the
procedure, a 16F Foley catheter was placed in the patient’s urethra.
When srURS was used but was not effective, it was not included in the
surgery time. The time from the entrance to the urethral meatus to the
end of JJ stent placement after starting to fURS was recorded as the
surgical time.
Patient Follow-Up
On the first postoperative day, patients received direct urinary system
radiography to check for the presence of opaque stones and
ultrasonography to check for the presence of non-opaque stones. All
patients underwent non-contrast computed tomography in the first month
postoperatively. JJ stents were removed three weeks postoperatively in
all patients. The procedure was considered successful for patients with
a residual stone fragment of 2 mm or less. Follow-up or medical
expulsive therapy was applied to patients with residual stone fragments
larger than 2mm. A summary of Clavien-Dindo classification for
complications is given in Table 2.8
Statistical Analysis
All statistical analyses were performed with the IBM®SPSS® Statistics version 25 data analysis program (IBM
Corp. Released 2017. IBM® SPSS®Statistics version 25.0. Armonk, NY: IBM Corp). The distributions were
determined according to the skewness and kurtosis values. Normally
distributed data were given as mean ± standard deviation, while median
(minimum-maximum) values were given when no normal distribution was
observed. Student t-tests and Mann-Whitney U tests were used for
numerical data to compare the two groups. A chi-squared test was used
for categorical data. The significance level for the p-value was 0.05.