Before serving their role in fertilizing oocytes, spermatozoa must exit the testis and pass through a complex excurrent ductal system, which includes the efferent ductules, epididymis and vas deferens leading to the ejaculatory duct. Pathological conditions in any part of the excurrent ductal system obviously may have a significant impact on spermatozoa transport, resulting in subfertility or infertility.
Typically, azoospermia is evident when complete obstruction occurs bilaterally. It should, however, be noted that the finding of some sperm in the ejaculate does not rule out the presence of obstruction. In fact, partial obstruction of the excurrent ductal system, which is an underdiagnosed clinical entity, can occur, leading to impaired quantity as well as quality of sperm in semen. Proper diagnosis and treatment of obstruction can result in improved semen parameters. buy ampicillin
By far the most common cause of excurrent ductal obstruction is previous vasectomy. In addition, various inflammatory conditions , particularly those involving the epididymides, are among the prevalent etiologies of excurrent ductal obstruction. Other conditions that can lead to obstructive or, as some investigators preferred, secretory azoospermia (the inability to release sperm to ejaculate) are summarized in Table 3.
TABLE 3 Common causes of obstructive or secretory azoospermia
|Congenital absence of vas deferens Ejaculatory duct obstruction or cysts|
|Obstruction at prostatic utricle|
|Malformation of excurrent ductal system|
|Anejaculation or retrograde ejaculation|
|Postradiation ductal fibrosis|
|Vasal or epididymal injury from surgeries|
|Bladder neck injury|
|Drugs or medical therapy|
|Excurrent ductal injuries|