The undescended testis refers to the lack of subsidence (descent) of one or both testes in the scrotum (scrotum) and is the most common congenital (congenital) malformation of boys with 2-4% of all term infants. Despite its mild presentation, undescended testicles can significantly increase male health impair and demand extensive medical and economic resources. Because the undescended testis represents the only recognized risk factor for a testicular tumor and often compromises the subsequent fertility.
The so-called prevalence (disease frequency) in the 3rd month of life is 1-1.9% and in the 18th month 0.8-1.5%. A frequently suspected increase in frequency could not be confirmed. Striking is a higher frequency of operation than expected on the basis of prevalence data. This indicates that too many pendulum testicles are operated on.
In the unborn child, the testes develop in the abdominal cavity at the level of the upper lumbar vertebrae. In the course of pregnancy they migrate first to the edge of the pelvis and from there from the seventh month of pregnancy on the inguinal canal in the scrotum.
The testicles are not isolated in the scrotum, but are attached to the spermatic cord (Funiculus spermaticus). It is a bundle of vessels, nerve fibers and the vas deferens, which pulls from the testicles through the inguinal canal into the abdomen.
The "migration" of the testicle towards the scrotum in the embryonic period is called Descensus testis. For a normal duration of pregnancy, both testes should reach the scrotum until birth.
Various factors can hamper complete testicular descent. One speaks then of a Maldescensus testis. Depending on the height of his hike, the descent stops, the affected testes remain either in the abdominal cavity or in the inguinal canal. It is therefore higher than normal, hence the term "undescended testicles".
In a secondary undescended testicles, the testes return to the inguinal canal or even the abdomen, after he was initially in the scrotum. This happens, for example, through growth disorders or scarring after certain operations.
Depending on the location of the affected testicle, there are basically three different variants of undescended testicles:
- Abdominal testicles (abdominal retention): In this form, the migration of the testis has already stopped in the abdomen.
- Inguinal testicles (retention testis inguinalis): The testes are located in the area of the inguinal canal and can not be displaced into the scrotum. This is the most common form of undescended testicles.
- Sliding testes (retention testis prescrotalis): The testes are located in the lowest part of the inguinal canal, just above the scrotum. Although it is possible to push the gliding odor gently into the scrotum, it then slides back to its original position because the spermatic cord is too short.
- Pendelhoden (also: "Wanderhoden"): Although the testicle lies in the scrotum, it is drawn into the inguinal canal by reflex-like tension of a muscle running in the spermatic cord, the cremaster muscle. For example, cold, stress or sexual arousal triggers the Kremaster reflex.
- Testicularectomy: In this extremely rare anomaly, the testes are out of their normal path, such as in the thigh or perineum.
Unlike the aforementioned forms of undescended testicles, a pendulum testis is not pathological and does not cause any complications. He therefore does not need to be treated.
In connection with an undescended testicle is sometimes also referred to as a so-called cryptorchidism. These two terms do not mean the same thing. Also, the cryptorchidism is not a variant of the undescended testicles.
"Cryptorchidism" is just a generic term for not being able to feel a testicle. This is true for an abdominal testicle, but also if a testicle is not created (testicular agenesis). In the same way, it can also lie in other places, outside of the abdomen and inguinal canal (testicular ectopia) and therefore can not be felt.
At first, most of the time, there are no immediate symptoms due to an undescended testicle. However, if timely treatment is not provided, serious complications may sometimes occur later.
Babies and children with undescended testicles usually have no direct symptoms, such as pain or hormonal imbalances. The affected testicles are not correct, but are normally trained.
In adolescence, however, it can become a psychological burden with increasing sexual awareness when one or both testicles are not in the scrotum. But as a rule, an undescended testicle is treated before the first birthday, so it usually comes not at all.
Even if a therapy was given early, a past undescended testis can lead to complications in the course. These are usually noticeable only in adulthood.
An undescended testicle from the beginning associated with increased risks in terms of infertility and testicular cancer. In those affected, the wrongly positioned and even the correctly positioned testes are fundamentally at greater risk of developing complications later in the course (primary damage).
In addition, a permanently elevated ambient temperature additionally damages the testes (secondary damage). While in the scrotum namely a temperature of about 33 degrees Celsius, it is in the inguinal canal or abdominal cavity two to four degrees warmer.
The higher the temperature and the longer the testicle is exposed to it, the more the risk of long-term consequences increases. Correspondingly, in connection with abdominal testes, complications are more often encountered than with inguinal canes or gliding hives, because it is warmer in the abdominal cavity than in the inguinal canal.
In some cases, the false position of the testes favors a testicular torsion, ie rotation of the testicle on the spermatic cord. This laces the vessels that feed the testicles. If the torsion is not treated very quickly, the testicle dies.
In addition, inguinal and gliding hernias sometimes develop weak spots in the inguinal canal, through which intestines can break in from the abdominal cavity. It then protrudes a so-called hernia bag with intestinal components in the inguinal canal. Such a hernia (inguinal hernia) usually manifests itself as a painless swelling in the groin. However, it should be treated soon to prevent the intestinal circulation from being disturbed.
It is well known that the testes for sperm production need a temperature of 32 to 37 degrees Celsius. Therefore, the testicles are outside the body. This is not the case with undescended testicles, and the higher body temperature means that the primordial gonocytes (gonocytes) can not develop into the sperm cells (spermatocytes). In the course of the semen production decreases and infertility threatens. The number of primordial germ cells decreases rapidly until the age of three. Therefore, the therapy of undescended testicles should be completed by the 18th month of life.
In one-sided undescended testis, the frequency of infertility is similar to that in the rest of the population.
Almost all non-treated patients with bilateral undescended testicles are infertile, even after one treatment, it is still a third.
Testicular cancer is rare, with one percent of cancers in men. It is suspected a connection with a low sperm count. But the risk of contracting it is 20 to 40 times higher if testicular elevation was not treated or treated too late. The highest risk have thereby abdominal testes and testicles, which hang in not intended places (testicle ectopia). In 60% of cases, testicular cancer develops between the ages of 20 and 40 years. The prognosis and thus the chances of recovery are very good at early detection of the tumor.
An undescended testicle usually has several causes, in many cases genetic factors are the basis. Due to certain defects in the genetic material of the unborn child the correct testicular descent during pregnancy is disturbed. In this case, a Maldescensus testis can occur isolated or in the context of genetic syndromes, ie together with other malformations and other symptoms of disturbed development.
Direct triggers of an undescended testicle are, for example, anatomical malformations that mechanically impede the descent of the testicle (prune-belly syndrome, gastroschisis, omphalocele). Or an inadequate release of important messengers during pregnancy. For a faultless testicular descent, especially the hormones HCG (human chorionic gonadotropin), GnRH (gonadotropin releasing hormone) and the male sex hormone testosterone are important.
An undescended testicle can also be caused by external influences. The causes without genetic background include, for example:
- Smoking during pregnancy
- Alcohol consumption during pregnancy
- Diabetes mellitus of the mother
- Environmental factors such as certain pesticides
- Pregnancy by the artificial introduction of sperm directly into the uterine cavity (intrauterine insemination)
There are several diagnostic methods that help the doctor to detect undescended testicles and to classify them accurately.
Because the undescended testicles are a relatively common congenital malformation, the scrutum and groin scrutiny is a routine neonatal procedure.
The doctor begins the examination by palpating the scrotum and groins. For babies, the examiner pulls the legs of the child to the abdomen, whereby the mother can assist. By palpation would already be noticed if a scrotum is missing in the scrotum or there is a inguinal cord.
In order to determine the type of undescended testicles, the doctor tries to stroke the testicle with one hand repeatedly from the bar down and pull gently with the other hand into the scrotum. If he succeeds and the testicles go back into the inguinal canal after releasing it, it is a sliding bottom. If one can not move the testicle out of the inguinal canal, it is a groin testicle.
The physical examination should be performed by the doctor in a warm and relaxed environment. Because cold and stress can trigger the so-called Kremaster reflex and thus disturb the investigation.
The Kremaster muscle is a thin strand of muscle that surrounds testes and spermatic cords and pulls into the inguinal canal. When he contracts, he pulls the testicles up towards the groin. A pendulum testicle can thus slide into the inguinal canal through the Kremaster reflex and thus appear like a groin or sliding floor.
If a testicle is not palpable in either the scrotum or the groin, ultrasound (sonography) or magnetic resonance imaging (MRI) may help. While these procedures are not 100 percent reliable, most of the hidden testicles can be traced. The MRI can facilitate the orientation of a testicle especially in very thick patients.
In the event that both testes are neither palpable, nor can be found using the imaging methods, there are special blood tests. It examines the blood on certain messenger substances, which are mainly produced by the testes.
Especially the testosterone content is instructive if the doctor can not feel testicles. For if these are still present - for example, in the abdominal cavity - then there is more testosterone in the blood, as if they were not created. In order for the test to be more meaningful, HCG, a special hormone that boosts testosterone release from the testes, is injected into the patient three to four days before blood collection (HCG stimulation test).
Alternatively, one can determine the blood concentration of inhibin-B. This substance also arises in certain testicular cells and therefore serves as a marker for existing testes.
If the blood tests show normal or elevated levels of testosterone or inhibin B, then it can be assumed that the patient has testes. The next step is followed by the laparoscopy to find the hidden testicles. On the other hand, if the blood tests are negative, the patient is unlikely to have testicles.
Laparoscopy is an operative procedure for examining the abdominal area. Through a small incision into the abdominal wall, the laparoscope - a long, thin tube with camera - is inserted into the abdominal cavity of the patient. The laparoscope is equipped with a light source and displays everything enlarged. A rinsing and suction device ensures that the examiner has a clear view.
With the help of laparoscopy, the doctor can scan the entire abdomen for the hidden testicles, without the need for major surgery. The method leaves only very small scars and is also called "keyhole surgery".
The laparoscopy is not only an examination method, but can also be used to correct the undescended testicles. However, the surgeon must introduce additional instruments into the abdominal cavity via further cuts.
The treatment of an undescended testicle has the goal to shift the wrong testicle (s) early into the scrotum. On the one hand, one tries to reduce the risk of later complications. On the other hand, he is then palpable and in the future a physical examination accessible.
To prevent the testes from being exposed to an elevated temperature for too long, therapy should be given as early as possible and completed at the latest at the end of the twelfth month of life. During the first six months, one waits, however, because in this time the too high-lying testicles may even descend by themselves.
There are basically two different treatment approaches. Conservative therapy attempts to achieve testicular descent using certain hormones. However, the operative relocation of the testicle has a greater chance of success.
In some cases, testicular descent succeeds in giving the patient special hormones. One uses messengers, which are also responsible for the natural testes descent during pregnancy: GnRH and HCG. The attending physician can administer the hormones individually or in combination. GnRH is available as a nasal spray, HCG only as a syringe.
The closer a testicle is to the scrotum, the more likely hormone therapy will succeed. Overall, the success rate is moderate. Only one out of every five patients reaches a testicular descent, with the two hormones hardly differing in their effectiveness.
In addition, this form of therapy is associated with some side effects. The treated babies sometimes grow pubic hair, the penis can also grow unusually in size and occasionally occur in the genital area.
The chances of success of an operative treatment of undescended testicles are significantly greater than with hormone therapy. However, the surgical displacement of a false testicle is demanding. The surgeon should therefore have sufficient experience with this procedure.
Every operation involves general risks. These include, for example, bleeding, wound infections or injuries to adjacent structures, such as nerves. Special complications after orchidopexy include:
- Shriveled testicles (testicular atrophy). In rare cases injury to the supplying vessels causes the testis to atrophy. After an autograft, this happens in 20-30% of the patients.
- Separation of the vas deferens with subsequent restriction of fertility
- Recurring undescended testicles (recurrence). To operate a testicle elevation a second time, is associated with further complications, because after the first operation usually scarring arise.
The complications mentioned are - apart from the testicular atrophy after autotransplantation rare. They face a high success rate of surgical procedures: 70-90% of the operations of an undescended testicle are successful.
Depending on the location of the testicle, two different surgical procedures are used: open and laparoscopic surgery.
Laparoscopic testicle elevation surgery
An abdominal testicle can not only be detected with the laparoscope, but also operated on. If it is relatively close to the inguinal canal, it can be immediately exposed and laid over the inguinal canal into the scrotum (laparoscopic orchidopexy). If it is more than three centimeters from the inguinal canal, surgery is usually performed in two steps.
First, the testicles and spermatic cord are released only from the surrounding tissue. Only six months later, the shift to the scrotum ("two-time operation after Fowler-Stephens") takes place.
If it turns out during the examination that a testicle is missing, for example, if the spermatic cord ends blind, break off the laparoscopy.
Open undescended surgery
If an upstanding testicle is palpable or recognizable in the groin during the ultrasound examination, an open operation via the groin (inguinal) usually follows. The doctor makes a small incision in the area of the abdominal fold and exposes the inguinal or sliding hive and the associated spermatic cord.
Using the inguinal canal, he feels his finger in the scrotum and places a small pouch in it, into which he subsequently shifts the testicles. It is important to expose the testicles and spermatic cord in such a way that in their new position, no train affects them. So that the testicle does not return to the old position after its displacement, the surgeon sews it additionally with a thin thread on the inside of the scrotum (orchidopexy).
Autotransplantation, like inguinal orchidopexy, is an open surgical procedure. However, this method is not used for inguinal testicles but for certain forms of the abdominal testes. It may be that the vessels that supply the abdominal testicles are too short to lay in the scrotum.
Then separate the testicle from its vessels first and then connect it with vessels from the abdominal wall closer to the scrotum. Thus, the testes on the one hand continues to be supplied with blood, on the other hand, you can now shift it into the scrotum.
An undescended testicle can hardly be prevented. However, the pregnant woman can save her unborn child from risk factors through a healthy lifestyle.
If the developmental disorder is genetically determined, it can hardly be prevented. Parents who know that testicular elevation has already occurred in one of the two families, but should alert the pediatrician and specifically monitor the baby for undescended testicles.