Anatomy-Lexicon

Vas deferens

anatomy

The spermatic duct (lat. Deferens duct) represents a 35-40 cm long tube, which is characterized by a thick layer of muscle.

The smooth muscles, which ensure the optimal forward transport of the sperm, are divided into three layers. A distinction is thus made between an inner longitudinal layer, a middle ring layer and the outer longitudinal layer of the muscles.

The vas deferens are encased by blood and lymph vessels of the testicle as well as muscle and nerve fibers that wrap around it like a network. The totality of all structures is called the spermatic cord.

course

The spermatic duct uses in its course from the epididymis to the injection channel (lat. Ejaculatory duct) various own body structures as a guide rail.

It begins at the terminal part of the epididymis. The epididymis rests on the testicle so that men can feel the beginning of the spermatic cord above the testicle themselves. In terms of consistency and shape, it is comparable to "hard-boiled spaghetti", which, however, can no longer be followed in the direction of the bar.

In the following, the spermatic duct runs through the inguinal canal; this offers protection against excessive kinking. The spermatic duct initially runs laterally outwards towards the flank and then towards the urinary bladder. It crosses both blood vessels and the ureter to finally reach the prostate. Here it forms the injection channel with the excretory duct of the seminal vesicle, another male sex gland. This leads through the prostate and flows into the urethra.

Function of the spermatic duct

The function of the spermatic duct consists in Transport of the sperm from their place of production, the epididymis, to the injection channel in the context of a Ejaculation.

The sperm transport is achieved by rhythmically tensing and relaxing individual sections of the spermatic duct muscles. Through this undulating motion the seminal fluid enters the outlet duct of the injection channel.

The starting signal for the muscle activity is given by nerves leading to the Sympathetic and thus belong to an independent part of our nervous system. The increasing mechanical stimulation from the outside leads to the activation of these nerve fibers, which in turn cause the contraction of the smooth muscles in the vas deferens.

Diseases of the spermatic duct

Vas deferensitis

Inflammation of the vas deferens is usually the result of an ascending infection from the urethra or an inflammation that extends across the prostate due to its anatomical proximity.

Read more on the topic: Inflammation of the prostate

The inflammation causes the soft tissues of the vas deferens to swell; Nerve fibers become overly sensitized. As a result, the inflammatory process can spread along the vas deferens towards the testicles and manifest as testicular inflammation there.

The symptoms of vas deferitis vary widely and range from pain to swollen lymph nodes in the groin to an increased body temperature. Since the spermatic duct muscles are tense, especially during ejaculation, pain or uncomfortable pulling during orgasm can occur.

Read more on the subject at: Spermatic duct pain and Drawing in the testicle

The cause of the inflammation is mostly intestinal bacteria that get into the urethra due to inadequate genital hygiene and from there rise to the vas deferens. The mucous membrane of the urogenital organs forms a good breeding ground for the bacteria, as it is moist and warm due to the good blood circulation. Bacteria that are transmitted as part of sexually transmitted diseases can also trigger inflammation of the vas deferens. Therefore, an infection with chlamydia or the causative agent of syphilis through unprotected sexual intercourse must always be ruled out.

In general, an isolated sperm duct inflammation is extremely unlikely. Therefore, you should always look for the trigger, which can be both in front of and behind the vas deferens.

You can read more about this topic at: Inflammation of the vas deferens

Swollen vas deferens

If the spermatic duct is swollen, this can primarily have two causes.

On the one hand, it can itself be thickened as part of an inflammation due to fluid retention, on the other hand it can appear swollen due to an inflammation of the structures around it. For example, there may be an accumulation of fluid in the scrotum, a so-called Hydrocele.

Read more on the topic: Hydrocele

In reality, it is not always possible to clearly distinguish whether closely adjacent structures are affected in isolation by a pathological process or whether this affects several structures. Since the spermatic duct runs in the spermatic cord and is encased here by muscles, blood vessels, nerves and connective tissue, the doctor always assesses all of the structures mentioned.

This explains why the symptoms and their respective localization are decisive for routine diagnostics. The symptoms are the same as with inflammation of the vas deferens and can be more or less intense depending on the degree of swelling. If the inner cavity of the vas deferens is narrowed, the sperm concentration in the ejaculate can be reduced and this can lead to infertility.

Clogged vas deferens

If the vas deferens are blocked, sperm can no longer get from the epididymis to the injection channel, so that a blocked vas deferens clinically manifests itself as male sterility.

Read more on the topic: Infertility in men

An isolated closure of the vas deferens is not painful and does not lead to functional abnormalities with regard to the male's sexuality. It is a purely mechanical obstacle that hinders the transport of the sperm.

Only when the injection channel is relocated, i.e. the union of the vas deferens with the duct of the vesicle gland, does the ejaculate build up. This congestion of semen just before it flows into the urethra can cause pain in the pelvic area. These usually occur shortly after orgasm, but can also manifest as chronic pain in the lower pelvis.

Twisted vas deferens

When the testicle rotates around the spermatic cord, it is called testicular torsion.

This rotation kinks blood vessels that supply both the testes and the vas deferens. The reduced blood flow is usually expressed by the strongest pain. This pain should be perceived as an absolute warning signal, as tissue damage to the testicle can occur within a short time. Due to its location in the scrotum, it only has a limited supply of blood vessels, which cannot be compensated for in any other way.

As a reaction to the insufficient supply, the testicles swell and, depending on the degree of twist, can take on a deep red to purple-bluish color. Any movement or manipulation of the testicle is painful and cannot be improved by changing the position of the testicle.

A twisting of the spermatic cord must be corrected promptly by a surgical procedure. Here, the structures are untwisted and fixed again so that a renewed testicular torsion is prevented.

Read more on this topic: Twisted testicles - what to do?

Lump on the spermatic duct - what could be behind it?

Nodular changes in the spermatic duct and spermatic cord can have various causes.

One of these causes are so-called sperm granulomas. These are formed when sperm get into the surrounding tissue through injuries in the vas deferens, e.g. caused by a vasectomy. The body reacts to the cells recognized as foreign in this environment and an inflammatory reaction occurs.

A granuloma is ultimately the accumulation of inflammatory cells around the sperm and the body's attempt to encapsulate the cells from the surrounding tissue and then break them down. Sperm granulomas usually regress on their own after a while, but surgical removal may be necessary in some cases.

Read more on the subject at: Sperm granulomas

Another cause of palpable nodules can be calcifications in the vas deferens, which can develop in the context of tuberculosis.

In the area of the groin there are also a number of lymph nodes, which, for example, are enlarged in the case of inflammation and can be felt from the outside. These can be misinterpreted as knots of the spermatic cord or vas deferens.

If you suspect swelling of the lymph nodes in the groin and would like to know the possible symptoms, read more on this topic under: Swelling of the lymph nodes in the groin.

Contraception methods for men

Vasectomy - cutting the vas deferens

A vasectomy is the cutting or ligation of the vas deferens during an operation.

The aim of this procedure is to make men sterile. It is all about preventing the escape of sperm during ejaculation without making any other functional changes.

Read more on the topic: sterilization

After the surgery, erection and ejaculation are still possible. The ejaculate remains unchanged in terms of quantity and consistency; it differs from the previous ejaculate only in the lack of sperm.

It is important to know that the man has the same ability to experience an orgasm after the operation as before and that his sexuality is not impaired by it.

The formation of the hormone testosterone is also unchanged, so that there are no hormone fluctuations after the procedure. The vasectomy does not result in any noticeable, externally visible physical changes. Only small scars from the incisions on the scrotum can be seen.

Compared to other methods of contraception, cutting the vas deferens is a very safe method of contraception, as the Pearl Index proves. The Pearl Index is a parameter that shows the reliability of a contraceptive method. It indicates how many out of a hundred women get pregnant every year despite using a method of contraception. The smaller the Pearl Index, the safer the contraceptive method. The vasectomy has a Pearl Index of almost zero and is therefore safer than, for example, the birth control pill for women.

Are you also interested in other contraception methods? Read more about this at: prevention

A disadvantage of this method of contraception for men is that it is possible to reverse the procedure (refertilization), but success cannot be guaranteed. Therefore, family planning should be safely completed before a man decides to take this step.

Last but not least, the man should be aware that this operation will not be covered by the statutory health insurance if there is no medical necessity, but is a self-paying health service.

Read more on this topic at: Vasectomy - The sterilization of the man

What is a spermatic duct valve?

A spermatic duct valve is a new method of contraception. When closed, the valve prevents the sperm from being transported from the testes via the vas deferens into the urethra and thus into the ejaculate. With an orgasm there is still an ejaculation, but it does not contain any sperm, which excludes fertilization and pregnancy.

The device is implanted into the vas deferens on each side in an operation performed under local anesthesia. Effects on the libido or other side effects are not yet known, but the onset, like any operation, involves certain risks, such as bleeding or infections.

Can a spermatic duct tear?

The vas deferens consists of two strong muscle layers and a connective tissue layer and thus forms a very resistant structure. The special arrangement of the muscle and connective tissue fibers also allow a dynamic reaction to the changing pressure conditions and make tearing of the vas deferens practically impossible.

Nevertheless, injuries to the vas deferens can occur. This is a possible complication, especially with surgical interventions on neighboring structures, but it is very rare. Furthermore, inflammation can lead to injuries.

If previous interventions, e.g. a vasectomy, have caused scarring on the vas deferens, this can influence the behavior under high pressure conditions, e.g. during ejaculation, and occasionally lead to pain. A rupture of the spermatic duct remains very unlikely even then.