Ductus Deferens (Vas Deferens) And Ejaculatory Duct Anatomy

Ejaculatory duct obstruction (EDO) is a congenital or acquired pathologic condition in which the efflux of semen is not possible due to obstruction of one or both of the ejaculatory ducts. [13] This condition causes male infertility and typically presents with symptoms of azospermia, including failure to ejaculate and/or lower abdominal pain. EDO occurs in 1-5% of all male infertility cases. [14] Diagnosis of ejaculatory duct obstruction can often be performed by transrectal ultrasound.

An axial transrectal ultrasound image of normal seminal vesicles is below. The white arrows indicate the ampulla of the vas deferens.

Axial images of the seminal vesicles. White arrows indicate the ampulla of the vas deferens. View Media Gallery

The congenital form of EDO is typically caused by paramesonephric (Mullerian) duct cysts. Acquired forms can be linked to inflammation of the ejaculatory duct secondary extension from prostatitis, orchitis, seminal vesiculitis, and urethritis. These inflammatory diseases can be due to common urinary pathogens as well as sexually transmitted diseases like chlamydia. [13]

Genitourinary tuberculosis can involve the ductus deferens or ejaculatory ducts resulting in obstruction, infertility, and/or chronic pain. Historically, smallpox was also a cause of postinflammatory ejaculatory duct obstruction. Calcifications and infections can partially or totally obstruct the duct. However, in most cases, there is no history of inflammation, and the etiology of EDO remains undetermined.

The ductus deferens can also be congenitally absent. These rare cases are usually associated with cystic fibrosis. However, these males make normal sperm. [15] Adult males undergoing evaluation for infertility are occasionally found to have a mild, undiagnosed form of cystic fibrosis with no other presenting symptoms. [16]