1. Department of Urology, Dentistry and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan
2. Division of Surgery, Nishi Fukuyama Hospital, 340-1 Matsunagacho, Fukuyama City, Hiroshima 729-0104, Japan