The Effect of Anesthesia Type on RIRS

RIRS with flexible ureteroscopy is usually performed under general anesthesia, spinal anesthesia. Anesthesia type is decided in the basis of medical condition of a patient and patient's preference. This study is a prospective observational study. During operation after induction of anesthesia, surgeons will be asked how visual stability of surgical field on monitor is (scale from 0 to 10). According to anesthesia type (general anesthesia, spinal anesthesia), 34 patients will be enrolled and investigated in each group. Investigators will compare the scale for visual stability of surgical field during RIRS.