1. Department of Plastic and Reconstructive Surgery, Kyoto Prefectural University of Medicine, Kyoto 602‐8566, Japan
2. Department of Digestive Surgery, Kyoto Prefectural University of Medicine, Kyoto 602‐8566, Japan
3. Department of Otorhinolaryngology, Kyoto Prefectural University of Medicine, Kyoto 602‐8566, Japan