Morphology of ejaculatory ducts: A systematic review

Abstract

The morphology of human ejaculatory ducts has not been well established. The objective of this study was to describe macroscopic and microscopic anatomy of ejaculatory ducts. We conducted a systematic review using MEDLINE, Scopus, PubMed, and Cochrane databases. Search terms were: "ejaculatory ducts," "seminal colliculus," "prostatic utricle," "anatomy," "histology," "radiology," and "embryology." We only included studies assessing adult (>18 years) humans published before November 1, 2019. We excluded studies describing pathological ducts and case reports. Independent authors extracted data using predefined criteria. Fourteen studies were included in the qualitative synthesis. Usually, the ejaculatory ducts entered the prostate by piercing the central part of its base. Most studies identified an anteromedial curve of the ducts at the outset within the prostate, their subsequent course being a straight path towards the seminal colliculus, their terminal parts diverging immediately before joining the prostatic urethra. However, the morphology of the terminal part of the ducts was inconsistent. The mean length of the ducts ranged from 1.4 to 2.2 cm. In conclusion, the luminal diameter gradually decreased as the ducts traveled towards the seminal colliculus. Ejaculatory ducts angulate anteromedially at their onset within the prostate and travel straight towards the seminal colliculus. Their terminal parts diverge immediately before joining the prostatic urethra. However, the reported dimensions of the ducts differ among studies.

Diagnosis and management of infertility due to ejaculatory duct obstruction: summary evidence

“…The epididymis is in continuity with the vas deferens, which in turn join the emerging ducts from the seminal vesicles to form the ejaculatory ducts (EDs). The EDs usually penetrate the central zone of the prostate and empty into the prostatic urethra on either side of the seminal colliculus (9). While the prostatic fluid accounts for approximately 0.5mL of the ejacula-te, the seminal vesicles (SVs) produce an alkaline fluid with prostaglandins and fructose, which comprises 1.5-2.0mL (~50-80%) of the seminal fluid.…”