The prostate is a walnut-sized gland that forms part of the male reproductive system. The gland is made of two lobes enclosed by an outer capsule. The prostate is located in front of the rectum and just below the bladder. It also surrounds the urethra (through which urine passes on its way out of the body). Although all functions of the prostate are not known, one of the main roles is to secrete fluid into the urethra to accompany the passage of sperm during male orgasm. The fluid, a significant component of semen, energizes the sperm and increases the survival of sperm in the vagina.
It is common for the prostate gland to become enlarged as a person grows older. This condition is called "benign prostatic hyperplasia" (BPH), or "benign prostatic hypertrophy". As a man matures, the gland goes through two main periods of growth. The first occurs early in puberty, when the prostate doubles in size. Then, at about age 25, the gland begins growing again. This second phase may ultimately result in BPH.
Although the prostate grows during most of a man's life, the enlargement doesn't usually cause problems for many years. BPH rarely causes symptoms before age 40, but more than half of men in their sixties and up to 90 percent in their seventies and eighties have symptoms of BPH.
As the prostate enlarges, the capsule surrounding it stops it from expanding and causes the gland to press against the urethra. The bladder wall becomes thicker and irritable and begins to contract even when it contains small amounts of urine. Over time, the bladder loses the ability to empty completely. The narrowing of the urethra and partial bladder emptying cause many of the problems associated with BPH.
Because of the prostate's role in sex and urination, many people feel uncomfortable talking about it. Still, prostate enlargement is a common part of aging, and as life expectancies rises, BPH becomes more common. In 2000, there were 4.5 million visits to physicians for BPH in the United States.
The cause of BPH is not well understood, nor do we have good information on risk factors. It has been long known that BPH occurs mainly in older men and that it doesn't develop in men whose testes were removed before puberty. For this reason, some believe that factors related to aging and the testes may cause BPH.
Throughout their lives, men produce both testosterone (male hormone), and small amounts of estrogen, a female hormone. As men age, the amount of testosterone in the blood diminishes, leaving a higher proportion of estrogen. Animal studies suggest that BPH may occur because the higher amount of estrogen increases the activity of substances that promote prostate cell growth.
Another theory focuses on dihydrotestosterone (DHT), a substance derived from testosterone in the prostate. It is felt that this may help control gland growth, and it has been found that most animals lose their ability to produce DHT as they age. Some research has indicated that even with a drop in the blood's testosterone level, older men continue to produce high levels of DHT and that this accumulation in the prostate may encourage the growth of cells. It has also been noted that men who do not produce DHT do not develop BPH.
Another theory is that BPH may develop as a result of "instructions" given to cells early in life. By this theory, BPH occurs because cells in one section of the gland follow such instructions and are reactivated later in life. These cells then deliver signals to other cells instructing them to grow or making them more sensitive to hormones.
Many symptoms of BPH result from blockage of the urethra and gradual loss of bladder function with incomplete emptying of the bladder. Though symptoms vary, the most common ones involve problems with urination:
- a hesitant, interrupted, weak urine stream
- urgency and leaking or dribbling
- more frequent urination, especially at night
Interestingly, the size of the gland does not always determine how severe the symptoms will be. Some with greatly enlarged glands have few symptoms while others, whose glands are less enlarged, have more blockage and greater problems.
Occasionally, an individual may not know he has any obstruction until he is suddenly unable to urinate at all. This so-called "acute urinary retention," may be triggered by over-the-counter cold or allergy medicines that contain a decongestant drug known as a "sympathomimetic." Such drugs can prevent the bladder opening from relaxing. If there is a partial obstruction, retention can also can be precipitated by alcohol, cold temperatures, or a long period of physical immobility.
In eight out of 10 cases, symptoms like those above suggest BPH. However, they can also signal other, more serious conditions. These conditions, including prostate cancer, can be ruled out only by a urologist's examination.
Over time, severe BPH can cause serious problems Urinary retention and bladder strain may lead to urinary tract infections, bladder or kidney damage, bladder stones, and incontinence. If the bladder is permanently damaged, treatment for BPH may prove ineffective. Finding BPH early lowers the risk of developing such complications.
Patients sometimes notice symptoms of BPH themselves, while in other cases, the doctor finds that the prostate is enlarged during a routine exam. When BPH is suspected, you may be referred to a urologist. Several tests will help him/herr identify characterize the problem and decide if surgery is needed. The tests chosen can vary, but among the most common are:
Digital Rectal Examination (DRE)
The doctor inserts a gloved finger into the rectum and feels the part of the prostate next to the rectum. This gives the doctor a general idea of the size and condition of the gland.
Prostate-Specific Antigen (PSA) Blood Test
To rule out cancer as a cause of the symptoms, the doctor will likely recommend a "PSA" blood test. PSA (prostate specific antigen), is a protein produced by prostate cells, and levels often are frequently elevated in men with prostate cancer.
. While the FDA has approved a PSA test for use in conjunction with digital rectal examination to help detect prostate cancer, much remains unknown about the interpretation of PSA levels. There are limitations on the test's ability to discriminate between cancer and benign prostate conditions.
View "The Prostate-Specific Antigen (PSA) Test: Questions and Answers" from the National Cancer Institute
Rectal Ultrasound and Prostate Biopsy
If there is a suspicion of prostate cancer, your doctor may recommend a rectal ultrasound test. For this, a probe inserted in the rectum directs sound waves at the prostate and the echo patterns form an image of the gland. To see if an abnormal-looking area is a tumor, the doctor can use the images to guide a biopsy needle to the suspicious area.
Urine Flow Study
The doctor may have the patient urinate into a special device that measures how quickly the urine is flowing. A reduced flow often suggests BPH.
Here, the doctor inserts a small tube through the opening of the urethra after a solution numbs the inside of the penis. The tube, called a cystoscope, contains a lens and light system that allows the doctor see the inside of the urethra and the bladder. With this test the doctor can determine the size of the prostate and characterize any obstruction.
Some researchers question the need for early treatment when the gland is just mildly enlarged. The results of studies indicate that such treatment may not be needed because as many as one-third of all mild cases become asymptomatic without treatment. They suggest regular checkups to watch for early problems. If the condition begins to cause a major problem for the patient, then treatment will be recommended. Since BPH can cause urinary tract infections,it is best to clear up infection before treating the BPH itself.
Treatments commonly used for BPH:
The FDA has approved several drugs to relieve common symptoms associated with an enlarged prostate. Finasteride (Proscar) and dutasteride (Avodart) inhibit production of the hormone DHT Terazosin (Hytrin), doxazosin (Cardura), tamsulosin (Flomax) and alfuzosin (Uroxatral) act by relaxing the smooth muscle of the prostate and bladder neck
Minimally Invasive Therapy
When drugs are ineffective, one may consider a number of procedures that relieve BPH symptoms but are less invasive than conventional surgery. Approved in 1996, transurethral microwave procedures use microwaves to heat and destroy excess prostate tissue. Called "transurethral microwave thermotherapy" (TUMT), the device sends computer-regulated microwaves through a catheter to heat selected portions of the prostate. The procedure takes about an hour and can be performed on an outpatient basis. TUMT does not appear to produce erectile dysfunction or incontinence.
Also in 1996, FDA approved "transurethral needle ablation" (TUNA) for the treatment of BPH. The system marketed under the name "Prostiva" delivers low-level radiofrequency energy through twin needles to burn away a well-defined region of the enlarged prostate. No incontinence or impotence has been observed.
"Water-induced thermotherapy" uses heated water to destroy excess tissue in the prostate. A catheter is positioned in the urethra so that a treatment balloon rests in the middle of the prostate and computer controls the temperature of the water which flows into the balloon to heat the surrounding prostate.
The best long-term solution for patients with BPH involves removal of the enlarged part of the prostate. Only the tissue that is pressing against the urethra is removed. Surgery usually relieves both the obstruction and incomplete bladder emptying.
"Transurethral resection of the prostate" (TURP) is used for most BPH prostate surgeries. An instrument called a resectoscope is inserted through the penis. It contains a light, valves for controlling irrigating fluid, and an electrical loop that cuts tissue and seals blood vessels. The surgeon removes the obstructing tissue one piece at a time. Transurethral procedures are less traumatic than open forms of surgery and require a shorter recovery period. A possible side effect of TURP is retrograde ejaculation wherein semen flows backward into the bladder during climax instead of out the urethra.
When transurethral procedure cannot be used, open surgery may be done. This is usually reserved for cases where the gland is greatly enlarged, when there are complicating factors, or when the bladder has been damaged and needs to be repaired.
In1996, the FDA approved a surgical procedure that employs side-firing laser fibers and Nd: YAG lasers to vaporize prostate tissue. The doctor passes the laser fiber through the urethra into the prostate using a cystoscope and then delivers several bursts of energy, destroying prostate tissue. Among the advantages of laser surgery over TURP are the reduced blood loss and quicker recovery than the standar ZURP.
A newer. laser-based treatment allows doctors to relieve
BPH on an outpatient basis. "Photoselective vaporization
of the prostate" (PVP) uses a high-energy laser to
destroy prostate tissue and seal the treated area.
Though patient's requiring hospitalization will feel pretty well when leaving the hospital, it takes a couple of months to heal completely. During the recovery period, certain problems can occur, including:
- Voiding difficulties- the urinary stream is stronger right after surgery, but can take awhile before you can urinate completely normally again. Patients may feel a sense of urgency when they urinate, but this will gradually lessen.
- Incontinence- there can be temporary problems controlling urination, but long-term incontinence rarely occurs.
- Bleeding- In the first few weeks after transurethral surgery, the scab inside the bladder may loosen, and blood may suddenly appear. The bleeding will usually stop after a short period of bed rest aided by the drinking of fluids. If your urine is so red that it is difficult to see through it (or if it contains clots), the patient should contact the doctor.
Many men worry about whether surgery will affect their ability to enjoy sex. Some believe that sexual function is rarely affected, but others claim that TURP can cause problems in up to 30 percent of cases. While it may take some time for sexual function to return fully, most men are able to enjoy sex again. The exact length of time depends on how long after symptoms appeared surgery was done.
Patients able to maintain an erection shortly before surgery will most often be able to have erections afterward. However, surgery cannot usually restore function that was lost before the operation. A prostate procedure frequently does make men sterile by causing retrograde ejaculation, or "dry climax." Most men find little or no difference in the sensation of orgasm, or sexual climax, before and after surgery.