A dilator (210) for dilating the tissue of a corpora cavernosum of a penis. The dilator includes a handle (212), a stem (214) and an intermediate portion (216) connecting the handle and the stem. A dilation portion (218) includes an exterior surface defining a groove (219) configured to leave at least one section or segment of the tissue in the corpora cavernosum undisturbed and un-dilated. A kit of parts including a dilator and a penile prosthetic insert (20) is also disclosed.
