Results
There were 56 patients in Group 1 and 95 patients in Group 2. The
demographic characteristics of the patients and the stone-related
variables were similar between the groups. The preoperative serum
creatinine level, the rate of preoperative double J stenting and the
rate of hydronephrosis were also similar between the groups. The mean
number of ESWL sessions and the mean duration between the last ESWL
session and RIRS in Group 1 were 2.9 ± 1.0 times and 68.4 ± 69.9 days,
respectively (Table 1).
The stone-free rates of Group 1 and Group 2 were 94.6% and 93.7%,
respectively (p = .893). The mean operation time was 63.3 ± 24.5 min for
Group 1 and 63.4 ± 25.6 min for Group 2 (p = .997). The fluoroscopy
screening time and hospitalization time were significantly higher in the
Group 1 patients. Peroperative and postoperative complications were
similar between the groups (Table 2). All of the peroperative
complications in both groups were classified as Grade 1 on the
Clavien-Dindo classification scale, which included mucosal erosion and
mild bleeding. A total of 7 (12.5%) patients in Group 1 had
postoperative complications, including postoperative fever that required
antibiotherapy. Among the patients in Group 2, 10 (10.5%) had
postoperative complications, including fever (8 patients) and urosepsis
(2 patients).
In order to evaluate the possible predictive effect of ESWL on the
efficacy and safety of RIRS for proximal ureter stone treatment, a model
of variables composed of age, sex, number of ESWL sessions, the duration
between ESWL and RIRS, stone density, presence of hydronephrosis and
stone volume was formed. According to this group analysis, the duration
between ESWL and RIRS (in weeks) was found to be a predictive factor for
stone-free status. On the other hand, the AUC (0.662) was found to be
statistically non-significant (p = .126) and the Youden index was low
(0.400); hence, it was suggested that the time from ESWL to RIRS had no
discriminatory ability. Nonetheless, all patients who underwent RIRS
after duration of 10 weeks post-ESWL were stone-free, and the cut-off
duration of 10 weeks from ESWL to RIRS had reasonable/favourable
discriminating ability with 51% sensitivity and 88% specificity. The
OR for the duration between ESWL and RIRS was 1.27 (95% CI: 1.11-1.44)
for each week. The relation between the model variables and the
operation time, hospitalization time and complications are given in
Table 3.