出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2015/10/22 02:22:53」(JST)
Retrograde ejaculation | |
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Classification and external resources | |
Specialty | Urology |
ICD-10 | N53.1 |
ICD-9-CM | 608.87 |
DiseasesDB | 11438 |
MedlinePlus | 001282 |
Retrograde ejaculation occurs when semen, which would normally be ejaculated via the urethra, is redirected to the urinary bladder. Normally, the sphincter of the bladder contracts before ejaculation forcing the semen to exit via the urethra, the path of least resistance. When the bladder sphincter does not function properly, retrograde ejaculation may occur.
Retrograde ejaculation is sometimes referred to as a "dry orgasm." Retrograde ejaculation is one cause of male infertility.[1] Men often notice during masturbation that they do not have semen release but there is an orgasm.[2] Another underlying cause for this phenomenon may be ejaculatory duct obstruction.
During a male orgasm, sperm are released from the epididymis and travel via small tubes called the vas deferens. The sperm mix with seminal fluid in the seminal vesicles, prostate fluid from the prostate gland, and lubricants from the bulbourethral gland. During climax, muscles at the end of the bladder neck tighten to prevent retrograde flow of semen. In retrograde ejaculation, these bladder neck muscles are either very weak or the nerves controlling the muscles have become damaged.[3]
A malfunctioning bladder sphincter, leading to retrograde ejaculation, may be a result either of:
It can also be caused by a retroperitoneal lymph node dissection for testicular cancer if nerve pathways to the bladder sphincter are damaged, with the resulting retrograde ejaculation being either temporary or permanent. Modern nerve-sparing techniques seek to reduce this risk; however, it may also occur as the result of Green Light Laser prostate surgery. Surgery on the bladder neck accounted for about ten percent of the cases of retrograde ejaculation or anejaculation reported in a literature review.[4]
Retrograde ejaculation is a common side effect of medications, such as tamsulosin, that are used to relax the muscles of the urinary tract, treating conditions such as benign prostatic hyperplasia. By relaxing the bladder sphincter muscle, the likelihood of retrograde ejaculation is increased.
The medications that mostly cause it are antidepressant and antipsychotic medication; patients experiencing this phenomenon tend to quit the medications.[5][6]
Retrograde ejaculation can also be a complication of diabetes, especially in cases of diabetics with long term poor blood sugar control. This is due to neuropathy of the bladder sphincter. Post-pubertal males (aged 17 to 20 years) who experience repeated episodes of retrograde ejaculation are often diagnosed with urethral stricture disease shortly after the initial complaint arises. It is currently not known whether a congenital malformation of the bulbous urethra is responsible, or if pressure applied to the base of the penis or perineum immediately preceding ejaculatory inevitability may have inadvertently damaged the urethra. This damage is most often seen within 0.5 cm of the ejaculatory duct (usually distal to the duct).
Retrograde ejaculation can also result from pinching closed the urethral opening, to avoid creating a mess upon ejaculation (known as Hughes' technique).[7]
Medications to treat high blood pressure, benign prostate hyperplasia, mood disorders, surgery on the prostate and nerve injury (which may occur in multiple sclerosis, spinal cord injury or diabetes).[8]
Diagnosis is usually by way of a urinalysis performed on a urine specimen that is obtained shortly after ejaculation. In cases of retrograde ejaculation, the specimen will contain an abnormal level of sperm.
Especially in case of orgasmic anejaculation, anejaculation can often be confused with retrograde ejaculation, and they share some fundamental aspects of the etiology. Urinalysis is used to distinguish between them.
A physical exam of the genitals is applied to ensure that there are no anatomical problems. The urine will be examined for the presence of semen. If there are no sperm in the urine, it may be due to damage to the prostate as a result of surgery or prior radiation therapy.[9]
The treatment depends on the cause. Medications may work for retrograde ejaculation but only in a few cases. Surgery rarely is the first option for retrograde ejaculation and the results have proven to be inconsistent.[10] Medications do not help retrograde ejaculation if there has been permanent damage to the prostate or the testes from radiation. Medications also do not help if prostate surgery has resulted in damage to the muscles or nerves. Medications only work if there has been mild nerve damage caused by diabetes, multiple sclerosis or mild spinal cord injury.
These medications tighten the bladder neck muscles and prevent semen from going backwards into the bladder. However, the medications do have many side effects and they have to be taken at least 1–2 hours prior to sexual intercourse. In many cases, the medications fail to work at the right time because most men are not able to predict when they will have an orgasm.[citation needed]
If a couple is experiencing infertility as a result of retrograde ejaculation and medications are not helping, the male's ejaculate may be centrifuged and the isolated sperm injected directly into the woman through the use of intrauterine insemination.[3] In more severe cases, in-vitro fertilization with intracytoplasmic sperm injection may be used.[1]
Taoists and some fields of alternative medicine recommend and teach deliberate retrograde ejaculation as a way of "conserving the body's energy". One manner of achieving this is by applying pressure to the perineum during orgasm. It was believed that doing this caused the sperm to travel into the head and nourish the brain, or that energy is conserved physically by keeping the sperm (and thereby, the "intelligence" that created it) in the body.[11] This approach has since been discredited by modern medicine, as the retrograde-ejaculated sperm actually go into the bladder and are simply lost at the next urination.[12] However, there are other Taoist perspectives on the general subject of ejaculation and techniques that do not involve retrograde ejaculation (see Taoist sexual practices).
Due to its aforementioned effects on fertility, there is a potential misconception that inducing this condition can be used as a method of contraception. However, it is neither reliable nor effective, due to some sperm still potentially emerging. Many doctors also do not recommend inducing retrograde ejaculation due to the risk of putting pressure on the pudendal nerve.[citation needed] Such pressure can cause numbness in the penis.[citation needed]
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リンク元 | 「逆行性射精」「逆行射精」「逆行性射精症」 |
関連記事 | 「retrograde」 |
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