Material and Method
A retrospective evaluation of the data from patients who had SULL
between January 2011 and January 2020 for ureteral stones was performed.
Patients who underwent SULL following insertion of a double J stent
(DJS) or nephrostomy for decompression in obstructive uropathy due to
urolithiasis were excluded from the study. The patient cohort with DJS
prior to SULL were identified as those in whom DJSs were inserted for
passive dilatation due to the inability to pass the ureteroscope into
the target ureter in the first procedure. The clinical data from the
second ureteroscopy (URS) was included. Furthermore, patients with
positive preoperative PBUC results, patients who had SULL as an
adjunctive treatment to simultaneous shock wave lithotripsy (SWL), and
patients who underwent SULL as a diagnostic procedure were omitted from
the review. Additionally, patients with conditions such as
immunosuppression, diabetes, preoperative fever and renal failure were
excluded from the study as they had a higher risk of developing sepsis.
Preoperatively, PBUC and whole blood analysis were obtained from all
patients. Intravenous prophylactic antibiotics (cefazolin or
fluoroquinolone) were given during the induction of anesthesia in
patients with negative PBUC results prior to surgery. All patients were
investigated preoperatively with intravenous urography or non-contrast
spiral tomography.
A post-op review was conducted in the urology ward on the day following
surgery. Body temperatures of 38°C and above were documented. The
presence of two or more of the following was described as SIRS:
temperature >38 °C or <36 °C, heart rate
>90 beats/minute, respiratory rate >20/minute,
and white cell count >12,000/mm3 or <4000/mm3.
From patients with fever or SIRS, blood cultures (BC) and PBUC were
collected. The study only included the patients who fulfilled the SIRS
criteria in the first week following the surgical procedure.
The study group was separated into two cohorts as the normal group and
the SIRS group. A comparison between the groups was made evaluating the
demographic characteristics, stone characteristics [number, diameter
(mm), volume (mm3), density (Hounsfield Unit)], duration of the
surgery, length of hospital stay (LOS), presence of previous DJS,
history of ipsilateral stone surgery (ISS), preoperative PBUC
positivity, history of recurrent urinary tract infection (UTI) and
length of time between PBUC and SULL. The recurrent UTI definition
provided in the EAU guidelines as at least three UTIs/year or two UTIs
in the last six months was used in the study (5).
All surgeries were performed in the lithotomy position under general
anesthesia or spinal anaesthesia. An 8.0/ 9.8F Karl Storz semirigid
ureteroscope was advanced through the ureter after the insertion of a
0.035-inch polytetrafluoroethylene-coated guidewire (Boston Scientific,
Marlborough, Massachusetts). A 200 µm holmium-YAG laser (Lisa laser
Sphinx, US) was used for performing laser lithotripsy. The stone
fragmentation procedure was ceased when clinically insignificant
residual fragments of less than 4 mm in diameter was achieved. In all
cases of impacted stones, Double J stent (4F or 4.7F) was inserted. This
decision was made by the endourologist in charge of the surgery on the
basis of the operation time and the severity of the adjacent ureteral
wall edema.
Kidney-ureter-bladder (KUB) radiography was carried out to evaluate the
presence of residual stones on the first day following surgery. On
postoperative day one following SULL, patients whose DJS position was
verified to be normal by KUB radiography with no complications were
discharged. An assessment was made at the postoperative first month for
DJS removal and at the third postoperative month for review of residual
stones with KUB radiography and urinary ultrasound or NCCT scan. A
procedure was described as successful if stone-free on the third
postoperative month.
Categorical variables are presented by providing numbers and
percentages. Descriptive statistics (mean, standard deviation, minimum,
median, maximum) are used to define continuous variables. The
Shapiro-Wilk test was applied in order to determine if the distribution
of continuous variables was natural. A comparison of the mean values of
two different groups was made using the independent t-test sample or the
Mann-Whitney U test. By utilizing Fisher’s exact test, the percentages
of the categorical variables were compared. When p-values were
<0.05, statistical significance was considered. In an attempt
to identify predictors of SIRS, univariable and multivariable binary
logistic regression analyses were executed. Statistical analysis was
performed using the Statistical Package for the Social Sciences version
21 software package (IBM SPSS Statistics; IBM Corp., Armonk, NY).