Ejaculatory duct obstruction (EDO) is a pathological condition which is characterized by the obstruction of one or both

ejaculatory duct The ejaculatory ducts (''ductus ejaculatorii'') are paired structures in male anatomy. Each ejaculatory duct is formed by the union of the vas deferens with the duct of the seminal vesicle. They pass through the prostate, and open into the ureth ...

s. Thus, the efflux of (most constituents of)

semen Semen, also known as seminal fluid, is an organic bodily fluid created to contain spermatozoa. It is secreted by the gonads (sexual glands) and other sexual organs of male or hermaphroditic animals and can fertilize the female ovum. Semen i ...

is not possible. It can be congenital or acquired. It is a cause of

male infertility Male infertility refers to a sexually mature male's inability to impregnate a fertile female. In humans it accounts for 40–50% of infertility. It affects approximately 7% of all men. Male infertility is commonly due to deficiencies in the semen, ...

and/or pelvic pain. Ejaculatory duct obstruction must not be confused with an obstruction of the vas deferens.

Cause

If both ejaculatory ducts are completely obstructed,

due to aspermia/

azoospermia Azoospermia is the medical condition of a man whose semen contains no sperm. It is associated with male infertility, but many forms are amenable to medical treatment. In humans, azoospermia affects about 1% of the male population and may be seen ...

. They will suffer from a very low volume of

which lacks the gel-like fluid of the seminal vesicles or from no semen at all while they are able to have the sensation of an

orgasm Orgasm (from Greek , ; "excitement, swelling") or sexual climax is the sudden discharge of accumulated sexual excitement during the sexual response cycle, resulting in rhythmic, involuntary muscular contractions in the pelvic region charac ...

during which they will have involuntary contractions of the pelvic musculature. This is contrary to some other forms of anejaculation. In addition, it is reported to be a cause for pelvic pain, especially shortly after

ejaculation Ejaculation is the discharge of semen (the ''ejaculate''; normally containing sperm) from the male reproductory tract as a result of an orgasm. It is the final stage and natural objective of male sexual stimulation, and an essential componen ...

. In case of proven fertility but unresolved pelvic pain, even one or both partially obstructed ejaculatory ducts may be the origin of pelvic pain and

oligospermia Terms oligospermia, oligozoospermia, and low sperm count refer to semen with a low concentration of sperm and is a common finding in male infertility. Often semen with a decreased sperm concentration may also show significant abnormalities in sperm ...

. Ejaculatory duct obstruction may result in a complete lack of

( aspermia) or a very low-volume semen (

) which may contain only the secretion of accessory prostate glands downstream to the orifice of the ejaculatory ducts. In addition to the congenital form which is often caused by cysts of the müllerian duct the obstruction can be acquired due to an inflammation caused by chlamydia, prostatitis,

tuberculosis Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, in ...

of the prostate and other pathogens. In addition,

calculus Calculus, originally called infinitesimal calculus or "the calculus of infinitesimals", is the mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizations of arithm ...

was reported to mechanically block the ejaculatory duct, leading to infertility. However, in many patients, there is no history of an inflammation and the underlying cause simply remains unknown.

Diagnosis

Low-volume, runny/fluid

(

) or no semen at all ( dry ejaculation/ aspermia) are a logical consequence of an obstruction downstream of the seminal vesicles which contribute most to the volume of the semen. Usually, men will be able to observe a runny/fluid, low-volume

by themselves during

masturbation Masturbation is the sexual stimulation of one's own genitals for sexual arousal or other sexual pleasure, usually to the point of orgasm. The stimulation may involve hands, fingers, everyday objects, sex toys such as vibrators, or combinatio ...

. Since the seminal vesicles contain a viscous,

alkaline In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a base (chemistry), basic, ionic compound, ionic salt (chemistry), salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as ...

fluid rich in fructose, a chemical analysis of the

of affected men will result in a low concentration of

fructose Fructose, or fruit sugar, is a Ketose, ketonic monosaccharide, simple sugar found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and galacto ...

and a low pH. A microscopic

semen analysis A semen analysis (plural: semen analyses), also called seminogram or spermiogram, evaluates certain characteristics of a male's semen and the sperm contained therein. It is done to help evaluate male fertility, whether for those seeking pregnancy ...

will reveal aspermia/

. In contrast, if both

vasa deferentia The vas deferens or ductus deferens is part of the male reproductive system of many vertebrates. The ducts transport sperm from the epididymis to the ejaculatory ducts in anticipation of ejaculation. The vas deferens is a partially coiled tube w ...

are obstructed (which may be the result of intended sterilization), a

will also reveal aspermia/

, but an almost normal volume of the

, since the efflux of the seminal vesicles is not hindered. This is because approx. 80% of the volume of the

is the gel-like fluid originating from the seminal vesicles whereas the fraction from the

testicles A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testostero ...

epididymis The epididymis (; plural: epididymides or ) is a tube that connects a testicle to a vas deferens in the male reproductive system. It is a single, narrow, tightly-coiled tube in adult humans, in length. It serves as an interconnection between the ...

, which contains the

spermatozoa A spermatozoon (; also spelled spermatozoön; ; ) is a motile sperm cell, or moving form of the haploid cell that is the male gamete. A spermatozoon joins an ovum to form a zygote. (A zygote is a single cell, with a complete set of chromosomes, ...

accounts for only 5–10% of the volume of the

. In addition, if an obstruction of the

is the cause for the azoospermia, the concentration of

in the semen will also be normal, since the fructose comes primarily from the fluid stored in the seminal vesicles. If the seminal-vesicles contain

, but the semen does not, the obstruction must be downstream of the seminal vesicles and the ejaculatory ducts are very likely to be obstructed, provided that other causes for a dry ejaculation/ aspermia such as a retrograde ejaculation are ruled out. Attempts are sometimes made to diagnose an ejaculatory duct obstruction by means of medical imaging, e.g. transrectal

ultrasound Ultrasound is sound waves with frequency, frequencies higher than the upper audible limit of human hearing range, hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hea ...

or MRI, or by transrectal needle-aspiration of the seminal vesicles. However transrectal ultrasound has a relatively low sensitivity of approx. 50% and thus is only a tool to rule-out cysts in the region of the orifices but is not sufficient to rule out an obstruction of the ejaculatory ducts due to other causes. In approx. 50% of cases of unexplained low-volume azoospermia MRI and TRUS do not reveal any pathological findings, because it is difficult to see alterations in a narrowed, scarred duct with these methods. Due to the blockage of ejaculatory ducts, enlarged seminal vesicles are frequently seen in patients with ejaculatory duct obstructions. However, this is again neither a proof of an obstruction nor do normal-sized seminal vesicles rule-out an obstruction of the ejaculatory ducts.

Treatment

A method to treat ejaculatory duct obstruction is transurethral resection of the ejaculatory ducts (TURED). This operative procedure is relatively invasive, has some severe complications, and has led to natural pregnancies of their partners in approximately 20% of affected men. A disadvantage is the destruction of the valves at the openings of the ejaculatory ducts into the

urethra The urethra (from Greek οὐρήθρα – ''ourḗthrā'') is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males. In human females and other primates, the urethra con ...

such that

urine Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excretion, excreted from the body through the urethra. Cel ...

may flow backwards into the seminal vesicles. Another, experimental approach is the recanalization of the ejaculatory ducts by transrectal or transurethral inserted

balloon catheter A balloon catheter is a type of "soft" catheter with an inflatable "balloon" at its tip which is used during a catheterization procedure to enlarge a narrow opening or passage within the Human body, body. The deflated balloon catheter is positione ...

. Though much less invasive and preserving the anatomy of the ejaculatory ducts, this procedure is probably not completely free of complications either and success rates are unknown. There is a clinical study currently ongoing to examine the success rate of recanalization of the ejaculatory ducts by means of

balloon dilation Angioplasty, is also known as balloon angioplasty and percutaneous transluminal angioplasty (PTA), is a minimally invasive endovascular procedure used to widen narrowed or obstructed arteries or veins, typically to treat arterial atheroscleros ...

. Usually, affected men have a normal production of

in their

, so that after spermatozoa were harvested directly from the testes e.g. by TESE, or the seminal vesicles (by needle aspiration) they and their partners are potentially candidates for some treatment options of

assisted reproduction Assisted reproductive technology (ART) includes medical procedures used primarily to address infertility. This subject involves procedures such as in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), cryopreservation of gametes ...

e.g.

in-vitro fertilisation In vitro fertilisation (IVF) is a process of fertilisation where an egg is combined with sperm in vitro ("in glass"). The process involves monitoring and stimulating an individual's ovulatory process, removing an ovum or ova (egg or eggs) ...

. Note that in this case, most of the treatment (e.g. ovarian stimulation and

transvaginal oocyte retrieval Transvaginal oocyte retrieval (TVOR), also referred to as oocyte retrieval (OCR), is a technique used in in vitro fertilization (IVF) in order to remove oocytes from the ovary of a woman, enabling fertilization outside the body. Transvaginal oocy ...

) is transferred to the female partner.

Prevalence

Ejaculatory duct obstruction is the underlying cause for 1–5% of

. Since ejaculatory duct obstruction is a relatively rare cause of infertility, this possibility may be unfamiliar to some

physicians A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through th ...

, even some urologists.

References

External links