Normal human ejaculatory duct anatomy: a study of cadaveric and surgical specimens.

PURPOSE: W examined the anatomy of the ejaculatory ducts in normal men and correlated findings with theories of ejaculatory duct obstruction.

MATERIALS AND METHODS: Gross and microscopic anatomical studies were performed on cadaveric and operative specimens derived from radical prostatectomy.

RESULTS: Histologically, the ejaculatory ducts are a continuation of the seminal vesicles. However, the thick muscle wall of the seminal vesicle is not present within the ejaculatory duct. Normal ejaculatory duct luminal and wall dimensions are remarkably uniform among men. A luminal diameter of greater than 2.3 mm. defines a dilated system statistically.

CONCLUSIONS: The largely collagenous ejaculatory ducts may serve as simple semen conduits instead of muscular tubes with spasmodic, sphincteric or peristaltic properties. The anatomical findings presented suggest several possible mechanisms for the prevention of urinary reflux into the ejaculatory ducts.