“…The observation that the epidural venous plexus is contained in connective tissue is not new (Chaynes et al, 1998; Clemens, 1961; Dommissee, 1957; Frykholm, 1951; Gillot, 1980; Ludinghausen von, 1967; Parkin & Harrison, 1985; Plaisant, Sarrazin, Cosnard, Schill, & Gillot, 1996; Schellinger et al, 1990; Shimizu, 2006; Wiltse, 2000) and has an embryological basis (Breit et al, 2013; Dun, 2006; Hamid, Fallet‐Bianco, Delmas, & Plaisant, 2002; Munkacsi, 1990; Sensenig, 1949). Once the vascular nature of the PDM is recognized, the anatomical relations of the PDM can be obtained from the study of the anatomy of the epidural venous plexus in the spinal canal (Batson, 1940; Breschet, 1828‐1832; Chaynes et al, 1998; Clemens, 1961; Gillot, 1980; Groen, Groenewegen, van Alphen, & Hoogland, 1997; Plaisant et al, 1996) and neural foramen (Dommisse, 1975; Frykholm, 1951; Hasue et al, 1983; Hayashi et al, 1977; Magro, 1981; Walther, 1885). Anatomical and radio‐graphical descriptions of the epidural venous plexus in the existing literature correlate well with observations made in this study (Drasin, Daffner, Sexton, & Cheatham, 1976; Meijenhorst, 1982).…”