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.