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).