Material and Method:
After obtaining the approval of the local ethic committee and the
informed consent from all patients in the study, we retrospectively
analysed the medical records of all the patients who underwent FURS for
renal stones larger than 20 mm in size between 2010 and 2019 in our
tertiary academic centre. All operations were performed after
appropriate antibiotic prophylaxis including second generation
cefalosporine group and confirmation of no bacterial growth in
preoperative urine culture. Patients who have concomitant ureter or
bladder stones, presence of nephrostomy catheter during FURS, renal
abnormality and operated under antibiotic suppression were excluded from
the study.
Postoperative urinary infective complications such as fever,
pyelonephritis and sepsis were investigated. The operated patients who
had the body temperature lasting over 38 degrees for 48 hours or any
body temperature over 39 °C was considered as infective fever after the
exclusion of postoperative atelectasis. When the infection source
established and the presence of two or more following Systemic
inflammatory response syndrome (SIRS) criteria (body temperature
< 36 °C or > 38 °C; heart rate > 90
beats/min; respiratory rate > 12/min or PaCO2 <32
mmHg; white blood cell count > 12,000 or < 4000/
mm3) determined in that case, it was accepted as
sepsis.
The investigated parameters were age, body mass index (BMI), OT, size,
surface area, density and location of the stones, usage of the UAS, the
presence of the infection and stone free rates. The data were analyzed
by forming two groups according to whether the OT was less than 60
minutes and more, whether the UAS was used and whether an infection
occurred. In addition, independent risk factors that may affect
postoperative urinary infection development were also investigated by
logistic regression analysis. And, a ROC curve analysis was applied to
determine a cut-off value in OT terms, where infection rates increase
more.
Stone characteristics in terms of the size and density of all patients
were evaluated with non-contrast abdominal computed tomography (CT) and
the radio-opacity features of the stones were assessed with
kidney-ureter-bladder (KUB) X-ray graphy, preoperatively. The
longest/total longest diameter of stones was determined as stone size.
Stone surface area was calculated using the formula: length x width x
(π) x 0.25. Residual stones were evaluated with non-contrast abdominal
CT or KUB radiogram in postoperative first month according to opacity of
the stones. OT was defined as the time that passed between the beginning
of the procedure when the device is inserted into the ureteral orifice
and the moment of removing the FURS.