Ductus deferens

The ductus deferens, less correctly known as the vas deferens, forms part of the male internal genitalia where it transports sperm from the epididymis to the ejaculatory duct. In modern anatomic nomenclature, it is no longer referred referred to as the vasvas deferens as it is not a vessel.

Gross anatomy

The ductus deferens is is a paired 30-45 cm muscular small caliber tube tube that connects the epididymis to the ejaculatory duct ¹. 

Course

The ductus deferens is the continuation of the tail of the epididymis and runs in the spermatic cord through the scrotum, inguinal canal and into the abdominal cavity, where it is extra-peritoneal. There it travels laterally through the pelvis, passing over (anterior to) the ureter and inferior to the bladder, where it unites with the duct of the seminal vesicle to form the ejaculatory duct in the prostate ^1, 2. In the prostate, the ejaculatory duct empties into the prostatic urethra.

Variant anatomy

• Artery of the ductus deferens from the inferior vesicle artery or directly from the internal iliac artery
• Agenesis of the ductus deferens is rare and is commonly associated with other urogenital abnormalities such as seminal vesicle agenesis (bilateral or unilateral) and renal agenesis ². 

Radiological appearance

Plain radiography

• it is not usually seen seen unless it iscalcified; this occurs particularly particularly in diabetics

Ultrasound

• tubular structure medial to the seminal vesicle ²

CT

• tubular structures running posteriorly along the pelvic side wall ²

MRI

• T1W and T2W: low signal tubular structure running from the deep inguinal ring to the ejaculatory duct²