Benign prostatic hypertrophy
Description, Causes and Risk Factors:
The prostate is a walnut-sized sex gland located at the base of the bladder. Its function is to secrete a fluid which helps carry semen in the urethra. When enlarged, the prostate may interfere with normal urine flow by pressing against the urethra. This causes symptoms of urinary hesitancy, frequent and/or painful urination, increased risk of urinary tract infections and urinary retention. The condition of an enlarged prostate is medically referred to as Benign Prostatic hypertrophy.
Benign prostatic hypertrophy (BPH) is a histologic diagnosis characterized by proliferation of the cellular elements of the prostate. Cellular accumulation and gland enlargement may result from epithelial and stromal proliferation, impaired preprogrammed cell death (apoptosis), or both. BPH involves the stromal and epithelial elements of the prostate arising in the periurethral and transition zones of the gland. The hyperplasia presumably results in enlargement of the prostate that may restrict the flow of urine from the bladder.
BPH is considered a normal part of the aging process in men and is hormonally dependent on testosterone and dihydrotestosterone (DHT) production. An estimated 50% of men demonstrate histopathologic BPH by age 60 years. This number increases to 90% by age 85 years; thus, increasing gland size is considered a normal part of the aging process.
Prostate volume may increase over time in men with BPH. In addition, peak urinary flow, voided volume, and symptoms may worsen over time in men with untreated BPH. The risk of AUR (acute urinary retention) and the need for corrective surgery increases with age.
The cause of BPH is not well understood. No definite information on risk factors exists. For centuries, it has been 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 researchers believe that factors related to aging and the testes may spur the development of BPH.
Throughout their lives, men produce both testosterone (a potent androgenic hormone produced chiefly by the testes; responsible for the development of male secondary sex characteristics) and small amounts of estrogen (a general term for female steroid sex hormones that are secreted by the ovary and responsible for typical female sexual characteristics). As men ages, the amount of active testosterone in the blood decreases, leaving a higher proportion of estrogen. Studies done on animals have suggested that BPH may occur because the higher amount of estrogen within the gland increases the activity of substances that promote cell growth.
Another theory focuses on dihydrotestosterone (DHT), a substance derived from testosterone in the prostate, which may help control its growth. Most animals lose their ability to produce DHT as they age. However, some research has indicated that even with a drop in the blood's testosterone level, older men continue to produce and accumulate high levels of DHT in the prostate. This accumulation of DHT may encourage the growth of cells. Scientists have also noted that men who do not produce DHT do not develop BPH.
The prevalence of Benign prostatic hypertrophy in white and African-American men is similar. However, BPH tends to be more severe and progressive in African-American men, possibly because of higher testosterone levels, 5-alpha-reducatase activity, androgen receptor expression, and growth factor activity in this population. The increased activity leads to an increased rate of prostatic hyperplasia and subsequent enlargement and its sequelae.
Sex: Benign prostatic hypertrophy occurs only in males. Women do not have prostate glands.
Age: Benign prostatic hypertrophy is a common problem that affects the quality of life (QOL) in approximately one third of men older than 50 years. BPH is histologically evident in up to 90% of men by age 85 years.
The symptoms of BPH may involve problems emptying the bladder or problems with bladder storage.
Symptoms related to bladder emptying include:
Symptoms related to bladder storage include:
- Difficulty starting a urine stream (hesitancy and straining).
- Decreased strength of the urine stream (weak flow).
- Feeling that the bladder is not completely empty.
- Dribbling after urination.
- An urge to urinate again soon after urinating.
- Pain during urination (dysuria).
Your symptoms may become worse during cold weather or as a result of physical or emotional stress.
You may first notice symptoms of Benign prostatic hypertrophy yourself, or your doctor may find that your prostate is enlarged during a routine checkup. When BPH is suspected, you may be referred to an urologist, a doctor who specializes in problems of the urinary tract and the male reproductive system. Several tests help the doctor identify the problem and decide whether surgery is needed. The tests vary from patient to patient, but the following are the most common.
- Waking at night to urinate (nocturia).
- Frequent urination.
- A sudden, uncontrollable urge to urinate.
- If a man suddenly becomes unable to pass any urine at all, this condition is called acute urinary retention.
- Digital Rectal Examination (DRE).
- Prostate-Specific Antigen (PSA) Blood Test.
- Rectal Ultrasound and Prostate Biopsy.
- Urine Flow Study.
Men who have Benign prostatic hypertrophy with symptoms usually need some kind of treatment at some time. However, a number of researchers have questioned the need for early treatment when the gland is just mildly enlarged. The results of their studies indicate that early treatment may not be needed because the symptoms of BPH clear up without treatment in as many as one-third of all mild cases. Instead of immediate treatment, they suggest regular checkups to watch for early problems. If the condition begins to pose a danger to the patient's health or causes a major inconvenience to him, treatment is usually recommended.
Since Benign prostatic hypertrophy can cause urinary tract infections, a doctor will usually clear up any infection with antibiotics before treating the BPH itself. Although the need for treatment is not usually urgent, doctors generally advise going ahead with treatment once the problems become bothersome or present a health risk.
The following section describes the types of treatment that are most commonly used for BPH.
Drug Treatment: Over the years, researchers have tried to find a way to shrink or at least stop the growth of the prostate without using surgery. The FDA has approved six drugs to relieve common symptoms associated with an enlarged prostate.
Finasteride (Proscar), FDA-approved in 1992, and dutasteride (Avodart), FDA-approved in 2001, inhibit production of the hormone DHT, which is involved with prostate enlargement. The use of either of these drugs can either prevent progression of growth of the prostate or actually shrink the prostate in some men.
The FDA also approved the drugs terazosin (Hytrin) in 1993, doxazosin (Cardura) in 1995, tamsulosin (Flomax) in 1997, and alfuzosin (Uroxatral) in 2003 for the treatment of BPH. All four drugs act by relaxing the smooth muscle of the prostate and bladder neck to improve urine flow and to reduce bladder outlet obstruction. The four drugs belong to the class known as alpha blockers. Terazosin and doxazosin were developed first to treat high blood pressure. Tamsulosin and alfuzosin were developed specifically to treat Benign prostatic hypertrophy.
Recently found that using finasteride and doxazosin together is more effective than using either drug alone to relieve symptoms and prevent BPH progression. The two-drug regimen reduced the risk of BPH progression by 67 percent, compared with 39 percent for doxazosin alone and 34 percent for finasteride alone.
There are also different kinds of over-the-counter herbal medicine on the market. However, these preparations are not generally recommended because their effect has not been completely documented. Those which do have some supporting evidence are saw palmetto and beta-sitosterol plant extracts and rye grass pollen extract.
Minimally Invasive Therapy: Because drug treatment is not effective in all cases, researchers in recent years have developed a number of procedures that relieve BPH symptoms but are less invasive than conventional surgery.
Transurethral microwave procedures: In 1996, the FDA approved a device that uses microwaves to heat and destroy excess prostate tissue. In the procedure called transurethral microwave thermotherapy (TUMT), the device sends computer-regulated microwaves through a catheter to heat selected portions of the prostate to at least 111 degrees Fahrenheit. A cooling system protects the urinary tract during the procedure.
The procedure takes about 1 hour and can be performed on an outpatient basis without general anesthesia. TUMT has not been reported to lead to erectile dysfunction or incontinence.
Although microwave therapy does not cure Benign prostatic hypertrophy, it reduces urinary frequency, urgency, straining, and intermittent flow. It does not correct the problem of incomplete emptying of the bladder. Ongoing research will determine any long-term effects of microwave therapy and who might benefit most from this therapy.
Transurethral needle ablation: In 1996, the FDA approved the minimally invasive transurethral needle ablation (TUNA) system for the treatment of BPH. The TUNA system delivers low-level radiofrequency energy through twin needles to burn away a well-defined region of the enlarged prostate. Shields protect the urethra from heat damage. The TUNA system improves urine flow and relieves symptoms with fewer side effects when compared with transurethral resection of the prostate (TURP). No incontinence or impotence has been observed.
Water-induced thermotherapy: This therapy uses heated water to destroy excess tissue in the prostate. A catheter containing multiple shafts is positioned in the urethra so that a treatment balloon rests in the middle of the prostate. A computer controls the temperature of the water, which flows into the balloon and heats the surrounding prostate tissue. The system focuses the heat in a precise region of the prostate. Surrounding tissues in the urethra and bladder are protected. Destroyed tissue either escapes with urine through the urethra or is reabsorbed by the body.
High-intensity focused ultrasound: The use of ultrasound waves to destroy prostate tissue is still undergoing clinical trials in the United States. The FDA has not yet approved high-intensity focused ultrasound.
Surgical Treatment: Most doctors recommend removal of the enlarged part of the prostate as the best long-term solution for patients with Benign prostatic hypertrophy. With surgery for BPH, only the enlarged tissue that is pressing against the urethra is removed; the rest of the inside tissue and the outside capsule are left intact. Surgery usually relieves the obstruction and incomplete emptying caused by Benign prostatic hypertrophy. The following section describes the types of surgery that are used.
Transurethral surgery: In this type of surgery, no external incision is needed. After giving anesthesia, the surgeon reaches the prostate by inserting an instrument through the urethra.
A procedure called transurethral resection of the prostate (TURP) is used for 90 percent of all prostate surgeries done for BPH. With TURP, an instrument called a resectoscope is inserted through the penis. The resectoscope, which is about 12 inches long and 1/2 inch in diameter, contains a light valves for controlling irrigating fluid, and an electrical loop that cuts tissue and seals blood vessels.
During the 90-minute operation, the surgeon uses the resectoscope's wire loop to remove the obstructing tissue one piece at a time. The pieces of tissue are carried by the fluid into the bladder and then flushed out at the end of the operation.
Most doctors suggest using TURP whenever possible. Transurethral procedures are less traumatic than open forms of surgery and require a shorter recovery period. One possible side effect of TURP is retrograde, or backward, ejaculation. In this condition, semen flows backward into the bladder during climax instead of out the urethra.
Another surgical procedure is called transurethral incision of the prostate (TUIP). Instead of removing tissue, as with TURP, this procedure widens the urethra by making a few small cuts in the bladder neck, where the urethra joins the bladder, and in the prostate gland itself. Although some people believe that TUIP gives the same relief as TURP with less risk of side effects such as retrograde ejaculation, its advantages and long-term side effects have not been clearly established.
Open surgery. In the few cases when a transurethral procedure cannot be used, open surgery, which requires an external incision, may be used. Open surgery is often done when the gland is greatly enlarged, when there are complicating factors, or when the bladder has been damaged and needs to be repaired. The location of the enlargement within the gland and the patient's general health help the surgeon decide which of the three open procedures to use.
With all the open procedures, anesthesia is given and an incision is made. Once the surgeon reaches the prostate capsule, he or she scoops out the enlarged tissue from inside the gland.
Laser surgery: In March 1996, the FDA approved a surgical procedure that employs side-firing laser fibers and Nd: YAG lasers to vaporize obstructing prostate tissue. The doctor passes the laser fiber through the urethra into the prostate using a cystoscope and then delivers several bursts of energy lasting 30 to 60 seconds. The laser energy destroys prostate tissue and causes shrinkage. As with TURP, laser surgery requires anesthesia and a hospital stay. One advantage of laser surgery over TURP is that laser surgery causes little blood loss. Laser surgery also allows for a quicker recovery time. But laser surgery may not be effective on larger prostates. The long-term effectiveness of laser surgery is not known.
Newer procedures that use laser technology can be performed on an outpatient basis.
Photoselective vaporization of the prostate (PVP): PVP uses a high-energy laser to destroy prostate tissue and seal the treated area.
Interstitial laser coagulation: Unlike other laser procedures, interstitial laser coagulation places the tip of the fiberoptic probe directly into the prostate tissue to destroy it.
NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.