Introduction & Objectives
The decision about the choice of proximal ureteral stone therapy depends on many factors and sometimes urologists have difficulty choosing treatment. We planned to evaluate the factors affecting success of semirigid ureterorenoscopy (URS) using the “decision tree” method.
Material & Methods
From January 2005 to November 2015, the data of consecutive patients treated for proximal ureteral stone were retrospectively analyzed. A total of 920 patients with proximal ureteral stone treated with semirigid URS were included in the evaluation. All statistically significant attributes were tested with the decision tree method.
The model created with the decision tree was calculated to have sensitivity = 0.993, and accuracy= 0.857. While URS treatment was successful in 752 patients (81.7%), it was unsuccessful in 168 patients (18.3%). According to the decision tree method, the most important factor affecting success of URS appears to be whether the stone is impacted to the ureteral wall. The second most important factors affecting treatment were intramural stricture requiring dilatation if the stone is impacted, and the size of the stone if not impacted.
Our study suggests that impacted stone, intramural stricture requiring dilatation and stone size may have strong impact on the success rate of semirigid URS for proximal ureteral stone. Further studies with population-based and longitudinal design should be conducted to confirm this finding.