1. Department of Anatomy, Shiga University of Medical Science, Otsu, Shiga, 520–2192 Japan,
2. Department of Second Surgery, Shiga University of Medical Science, Otsu, Shiga, 520–2192 Japan,
3. Graduate School of Nutritional and Environmental Science, University of Shizuoka, Yada, Shizuoka, 422–8526 Japan