Materials and Methods
The data of 949 patients, who underwent RIRS for renal and proximal
ureteral stones at HSU Izmir Bozyaka Training and Research Hospital and
HSU Ankara Diskapi Training and Research Hospital between March 2015 and
June 2020, were retrospectively analyzed. Patient data obtained included
age, sex, body mass index (BMI), history and physical examination
findings, specific comorbidities, and the American Society of
Anesthesiologists (ASA) physical status class risk. All patients were
evaluated with a detailed history before the operation. Stone
parameters, namely number, diameter, location and CT attenuation value
of the stone, previous treatments applied for the stone, operative time,
fluoroscopy time, and stone burden (length x width x π x 0.25) were
recorded. For multiple stones, the sum of each stone’s volume was used.
The patients were evaluated preoperatively with complete blood count,
serum creatinine, bleeding and clotting times, and urine culture
analyses. Those with growth in urine cultures were operated on after
antibiotherapy was administered for a sufficient time and the control
urine cultures were sterile. Patients with missing data and/or those
that did not undergo post-operative first-month non-contrast CT were
excluded from the study. Patients who underwent diagnostic ureteroscopy
but did not have related data were also not included in the study.
Ethics approval was obtained from the Ethics Committee.
All operations were performed under general anesthesia in the dorsal
lithotomy position. First, ureteroscopy was performed with a semirigid
ureteroscope to provide mechanical dilatation and place a guide wire.
Then, according to the surgeon’s preference, a ureteral access sheath
(UAS) ( Flexor 9.5/11.5Fr or 12/14Fr, Cook Medical Bloomington,
IL, USA, Navigator 11/13Fr, Boston Scientific, Natik, MA, USA) was
placed over the guide wire under fluoroscopic control. In cases whereas
UAS could not be placed, the operation was performed with a sheath. If
the flexible ureteroscope could not reach the kidney over the guide
wire, a double-J (DJ) stent was placed and left for passive dilatation,
and the operation was postponed. All the RIRS procedures were performed
using flexible ureteroscopes (Flex-X2, Karl Storz Endoscope, Tuttligen,
Germany), and the stones were fragmented with a Holmium laser using a
6-14 W range. If needed, some fragments were removed with tipless
nitinol stone baskets. The procedure was terminated after stone-free
status was confirmed by both ureteroscopic inspection and fluoroscopy
(leaving only ungraspable gravel or fragments <2mm) or if the
surgeon decided to terminate the surgery due to complications, such as
bleeding. At the end of the operation, a DJ stent was placed according
to the surgeon’s preference.
All patients were evaluated with non-contrast CT at the first month
after RIRS to evaluate stone-free status. Residual fragments of
<2mm were accepted as insignificant. The results were compared
in terms of the predictive capability of stone-free status and
complications. Intraoperative complications were assessed using SCC, and
postoperative complications were graded according to MCCS [9,10].