[Twelve years of ureterorenoscopy: evolution of the technique].

In the last ten years the diagnostic and therapeutical approach to ureteral neoplasms and stones changed their feature, due to improvement of the ureteroscopy. The passage through flexible to rigid and finally semirigid ureteroscopes permitted reduction of invasiveness with higher results. The positive changes to the energy sources, in regard to cost-benefit, it was versus ballistic energy. Ureteroscopy should now be considered as a simple and safe technique, with minimal morbidity and invasiveness and also short operative times.