Limitations
Our study is retrospective in nature, which may lead to selection bias. We tried to overcome this limitation by including all cases operated for kidney and upper ureteral stones during the study period. The data of four different centres were included in the study. While the multicentric nature of the study increases the quality, doubts about the technique arise from different surgeons operating. However, the surgeons in different centres have at least five years of experience and the surgical steps used are similar. Removal of the use of balloons and coaxial dilators from the study provides method harmony and shows the direct effect of our technique. Other conditions, such as previous same-side ureteroscopy or JJ stent and known renal anatomical abnormalities that may overshadow the effectiveness of sURS for optical ureteral dilatation and selection of the correct UAS size, have been excluded from the study. Other drawbacks of the study are that while operation and fluoroscopy times are calculated, the duration of UAS has not been calculated, and the lack of long-term follow-ups and stenosis rates.
Acknowledegements: None
Conflicts of interest: The authors have declared that they have no conflicts of interest.
Funding: None