1. Reproduction Center; Yokohama City University Medical Center; Yokohama Japan
2. Department of Urology; Juntendo University Urayasu Hospital; Chiba Japan
3. Department of Urology; Graduate School of Medicine; Chiba University; Chiba Japan
4. Department of Nephro-urology; Nagoya City University Graduate School of Medical Science; Nagoya Japan
5. Department of Urology; Toho University School of Medicine; Tokyo Japan
6. Department of Urology; Graduate School of Medicine; Yamaguchi University; Yamaguchi Japan
7. Department of Urology; Dokkyo Medical University Koshigaya Hospital; Saitama Japan
8. Department of Urology and Andrology; Kansai Medical University; Osaka Japan
9. Faculty of Medicine; Division of Urology; Department of Surgery Related; Kobe University Graduate School of Medicine; Kobe Japan
10. Department of Urology; Osaka University Graduate School of Medicine; Osaka Japan
11. Division of Male Infertility; Center for Human Reproduction; International University of Health and Welfare; Sanno Hospital; Tokyo Japan