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

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 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 ...

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 The seminal vesicles (also called vesicular glands, or seminal glands) are a pair of two convoluted tubular glands that lie behind the urinary bladder of some male mammals. They secrete fluid that partly composes the semen. The vesicles are 5� ...

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 chara ...

during which they will have involuntary contractions of the pelvic musculature. This is contrary to some other forms of

anejaculation Anejaculation is the pathological inability to ejaculate despite an erection in males, with (''orgasmic'') or without (''anorgasmic'') orgasm. Causes It can depend on one or more of several causes, including: * Sexual inhibition * Pharmacologic ...

. 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 compo ...

. 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 sper ...

. 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 Paramesonephric ducts (or Müllerian ducts) are paired ducts of the embryo that run down the lateral sides of the genital ridge and terminate at the sinus tubercle in the primitive urogenital sinus. In the female, they will develop to form the fal ...

the obstruction can be acquired due to an inflammation caused by

chlamydia Chlamydia, or more specifically a chlamydia infection, is a sexually transmitted infection caused by the bacterium '' Chlamydia trachomatis''. Most people who are infected have no symptoms. When symptoms do appear they may occur only several we ...

prostatitis Prostatitis is an umbrella term for a variety of medical conditions that incorporate bacterial and non-bacterial origin illnesses in the pelvic region. In contrast with the plain meaning of the word (which means "inflammation of the prostate"), the ...

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, ...

of the prostate and other pathogens. In addition,

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

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

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 combinat ...

. Since the

contain a viscous,

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

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 ketonic 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 galactose, that are absorb ...

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 pregna ...

will reveal aspermia/

. In contrast, if both vasa deferentia are obstructed (which may be the result of intended

sterilization Sterilization may refer to: * Sterilization (microbiology), killing or inactivation of micro-organisms * Soil steam sterilization, a farming technique that sterilizes soil with steam in open fields or greenhouses * Sterilization (medicine) rende ...

), 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

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 testosteron ...

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 chromos ...

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

. In addition, if an obstruction of the vasa deferentia 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

. 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 Retrograde ejaculation occurs when semen which would be ejaculated via the urethra is redirected to the urinary bladder. Normally, the sphincter of the bladder contracts before ejaculation, sealing the bladder which besides inhibiting the relea ...

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 frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies ...

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

cyst A cyst is a closed sac, having a distinct envelope and division compared with the nearby tissue. Hence, it is a cluster of cells that have grouped together to form a sac (like the manner in which water molecules group together to form a bubble) ...

s 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 ...

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 excreted from the body through the urethra. Cellul ...

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 body. The deflated balloon catheter is positioned, then infl ...

. 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 o ...

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 Urology (from Greek οὖρον ''ouron'' "urine" and ''-logia'' "study of"), also known as genitourinary surgery, is the branch of medicine that focuses on surgical and medical diseases of the urinary-tract system and the reproductive organ ...

References

External links