1. Department of Anesthesiology and Pain Medicine, Jeju National University Hospital, Jeju National University School of Medicine, Jeju, Korea.
2. Department of Urology, Inje University Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
3. Department of Urology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
4. Department of Urology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.