Two cases of the double inferior venae cavae

Two cases of the double inferior venae cavae (IVC) were found during the student dissection practice in 1997 in Gifu University School of Medicine. On the first case (70-year-old male), the calibers of the right and left IVC were 15 mm and 13 mm, respectively. An anastomosis (4-mm caliber) ran obliquely from the left internal iliac vein to the right IVC. On the second case (86-year-old male), the calibers of the right and left IVC were 15 mm and 10 mm, respectively. We found no anastomosis between the right and left IVC. Each IVC was observed behind the ureter. Both cases belong to Type BC of the classification of McClure and Butler (1925), that is based on the combinations of the right and left IVC, and on their location to the ureters. Both cases also belong to Type II-b-2 of the classification of Takemoto et al. (1978), that is based on the calibers of the right and left IVC and on the running course of the interiliac vein. These are the first and second cases among 808 cadavers in Gifu University School of Medicine and the 93rd and 94th cases in Japan since 1901.