Results
The mean age of the 656 patients who underwent RIRS was 46.1 ± 14.2
(16–88) years. 305 (52.5%) of the surgeries were performed for the
left kidney and 276 (47.5%) of the surgeries were performed for the
right kidney. While the mean stone burden was 169.5 ± 141 (16–1500)
mm2, the mean stone density was 962.1 ± 327.2
(184–2240) HU. Preoperative clinical and demographic data of patients
are shown in Table 1 .
The success rate of the RIRS was 73.3%. According to the multivariate
logistic regression analysis, independent risk factors associated with
failure were stone burden >200 mm2 (Odds
Ratio (OR): 4.1; 95% Confidence lnterval (CI): 1.8–9.2; p: 0.001), the
location of the stone in the lower pole (OR: 2.1; 95% Cl: 1.3–3.9; p:
0.013), surgical duration >60 minutes (OR: 1.9; 95% Cl:
1.2–3.2; p: 0.007), high modified S-ReCS (OR: 15.2; 95% Cl: 4.9–46.6;
p <0.001) and high R.I.R.S score (OR: 7.2; 95% Cl: 1.6–31.5;
p: 0.009) (Table 2).
The mean surgical duration was 54.3 ± 18.3 (20–120) min, and the
patients were hospitalised for a mean period of 1.8 ± 3.9 (1–75) days
postoperatively. While intraoperative complications were observed in
30.3% of the patients, postoperative complications occurred in 27.2%
of them. Perioperative and postoperative data of the patients are shown
in Table 3 .
Infective complications were detected in 47 (8.1%) patients who
underwent RIRS. A total of 27 (4.6%) had only fever, 15 (2.5%) had
urinary infection, 2 (0.3%) had sepsis and 3 (0.5%) had septic shock.
According to the urinary culture results of 20 patients with
postoperative urinary tract infection, sepsis and septic shock, 8 (40%)
had Escherichia coli , 5 (25%) Pseudomonas aeoruginosa and
4 (20%) Enterococcus faecalis . Candida glabrata ,Candida dubliniensis and Klebsiellapneumoniae growths were
detected each in one patient, each (5% per patient). According to the
multivariate logistic regression analysis, the independent risk factors
for the development of infective complications were found to be patients
aged >50 years (OR: 1.8; 95% CI: 1–3.4; p: 0.049),
surgical duration of >60 minutes (OR: 1.9; 95% Cl:
1.1–3.5; p: 0.027) and a high R.I.R.S score (OR: 8.9; 95% CI:
1.9–42.4; p: 0.006) (Table 4) .
ROC curves were used to evaluate the effectiveness of the scoring
systems in predicting infective complications in the RIRS procedure(Figure 1) . ROC curve analysis showed that the R.I.R.S scoring
system can be used as a marker to predict infective complications. (Area
under the curve (AUC): 0.619, CI: 0.55–0.69; p: 0.007) The cut-off
point for the R.I.R.S scoring system was found to be 5.5 points using
Youden’s test. When patients with kidney stones who scored above this
score in the preoperative period were grouped as ‘patients with
infective complications’, the sensitivity of this scoring system was
found to be 0.894, and its specificity was 0.35. RUTS and modified
S-ReCS were far from predicting infective complications. (AUC: 0.515,
CI: 0.429–0.601; p: 0.73 and AUC: 0.542, CI: 0.457–0.626; p: 0.345,
respectively) (Table 5) .