J Endourol

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J Endourol. 2003 Oct;17(8):659-66

Application of external microwave thermotherapy in urology: past, present, and future.

Gravas S, Laguna MP, De La Rosette JJ.

Department of Urology, Academic Medical Center, University of Amsterdam, Amsterdam, The

Netherlands.

The excellent clinical results of transurethral microwave thermotherapy (TUMT) for the treatment of symptomatic benign prostatic hyperplasia (BPH) gave to TUMT the leading position among the microwave thermotherapy modalities available for the treatment of different urologic conditions.

Research in TUMT has focused on operating software, temperature monitoring, intraprostatic heat distribution, cell-kill calculations, and correlations with clinical variables. Randomized comparisons of

TUMT with other established therapies for BPH, including transurethral resection, have facilitated the evaluation of the clinical outcome, durability, morbidity, and costs of the treatment. The applications of microwave thermotherapy in other urologic diseases are also presented in this review.

Publication Types:

Review

Review, Tutorial

The prostate gland is an organ that surrounds the urinary urethra in men. It secretes fluid which mixes with sperm to make semen. The urethra carries urine from the bladder, through the prostate gland to the penis.

Benign prostatic hypertrophy (BPH) is a non-cancerous enlargement of the prostate gland, commonly found in men over the age of 50.

Benign Prostatic Hyperplasia (BPH)

What is benign prostatic hyperplasia (BPH)?

BPH (also referred to as benign prostatic hypertrophy) is a condition in which the prostate gland becomes very enlarged and may cause problems associated with urination. BPH can raise PSA

(prostate-specific antigen) levels two to three times higher than the normal level. An increased

PSA level does not indicate cancer, but the higher the PSA level, the higher the chance of having cancer.

Some of the signs of BPH and prostate cancer are the same, however, having BPH does not seem to increase the chances of developing prostate cancer. A man who has BPH may also have undetected prostate cancer at the same time or may develop prostate cancer in the future.

Therefore, the National Cancer Institute and the American Cancer Society recommend that all men over 50 consult their physicians about having a digital rectal and PSA examination once a year to screen for prostate cancer.

How does BPH occur?

The prostate goes through two main periods of growth. In early puberty, the prostate doubles in size. Then, around age 25, the prostate begins to grow again and continues to grow throughout most of a man’s life.

The continuing enlargement of the prostate does not usually cause problems until later in life.

However, the second period of growth may, many years later, result in BPH. According to the

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK):

BPH rarely causes symptoms before age 40.

More than half of men in their 60s have some symptoms of BPH.

As many as 90 percent of men in their 70s and 80s have some symptoms of BPH.

What happens when the prostate enlarges?

As the prostate enlarges, it presses against the urethra and interferes with urination. At the same time, the bladder wall becomes thicker and irritated, and begins to contract - even when it contains small amounts of urine - which causes more frequent urination. And, as the bladder continues to weaken, it may not empty completely and leave some urine behind.

Blocking or narrowing of the urethra by the prostate, and partial emptying of the bladder, cause many of the problems associated with BPH.

What are symptoms of BPH?

The following are the most common symptoms of benign prostatic hyperplasia. However, each individual may experience symptoms differently. Symptoms may include:

 leaking or dribbling of urine more frequent urination, especially at night

 urgency to urinate

 urine retention - inability to urinate.

 a hesitant, interrupted, weak stream of urine

These problems may lead to one/more of the following:

 incontinence

 kidney damage

 bladder damage

 urinary tract infections bladder stones

The symptoms of benign prostatic hyperplasia may resemble other conditions or medical problems. Always consult your physician for a diagnosis.

How is BPH diagnosed?

Diagnosing BPH in its earlier stages can lower the risk of developing such complications. Delay can cause permanent bladder damage for which BPH treatment may be ineffective. In addition to a complete medical history and physical examination, diagnostic procedures for BPH may include the following:

 digital rectal exam (DRE) - a procedure in which the physician inserts a gloved finger into the rectum to examine the rectum and the prostate gland for signs of cancer.

 renal ultrasound - a non-invasive test in which a transducer is passed over the kidney producing sound waves which bounce off of the kidney, transmitting a picture of the organ on a video screen. The test is used to determine the size and shape of the kidney, and to detect a mass, kidney stone, cyst, or other obstruction or abnormalities.

 intravenous pyelogram (IVP) - a series of x-rays of the kidney, ureters, and bladder with the injection of a contrast dye into the vein - to detect tumors, abnormalities, kidney stones, or any obstructions, and to assess renal blood flow.

 cystoscopy (Also called cystourethroscopy.) - an examination in which a scope, a flexible tube and viewing device, is inserted through the urethra to examine the bladder and urinary tract for structural abnormalities or obstructions, such as tumors or stones.

 urine flow study - a test in which the patient urinates into a special device that measures how quickly the urine is flowing. A reduced flow may suggest benign prostatic hyperplasia

(BPH).

Treatment for BPH:

Specific treatment for BPH will be determined by your physician based on:

 your age, overall health, and medical history

 extent of the disease

 your tolerance for specific medications, procedures, or therapies

 expectations for the course of the disease

 your opinion or preference

Eventually, BPH symptoms usually require some kind of treatment. When the gland is just mildly enlarged, treatment may not be needed, as research has shown that some of the symptoms of

BPH clear up without treatment in some mild cases. This determination can only be made by your physician after careful evaluation of your individual condition. Regular checkups are important, however, to watch for developing problems.

Treatment for BPH may include:

 Surgery to remove only the enlarged tissue that is pressing against the urethra, with the rest of the inside tissue and the outside capsule left intact. Types of surgery often include the following: o transurethral surgery - no external incision is needed. The surgeon reaches the prostate by inserting an instrument through the urethra.

 transurethral resection of the prostate (TURP) - a resectoscope - an instrument that 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 - is inserted through the penis. 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 flushed out at the end of the operation.

 transurethral incision of the prostate (TUIP) - a procedure that widens the urethra by making some small cuts in the bladder neck, where the urethra joins the bladder, and in the prostate gland itself. o laser surgery - using laser instruments to vaporize obstructing prostate tissue. o open surgery - surgery that requires an external incision; often done when the gland is very enlarged, when there are complicating factors, or when the bladder has been damaged and needs to be repaired.

 Nonsurgical treatments may include: o balloon urethroplasty - a thin tube with a balloon is inserted into the opening of the penis and guided to the narrowed portion of the urethra, where the balloon is inflated to widen the urethra and ease the flow of urine. o transurethral microwave thermotherapy (TUMT) - a device called a Prostatron uses microwaves to heat and destroy excess prostate tissue to reduce urinary frequency and urgency. o medications (to shrink or at least stop the growth of the prostate without using surgery) o transurethral hyperthermia - an investigative procedure that uses heat, usually provided by microwaves, to shrink the prostate. o prostatic stents - investigative procedure using stents, inserted through the urethra to the narrowed area, which are allowed to expand, like a spring, and push back the prostatic tissue and widen the urethra. o Lifestyle management for BPH may include:

 dietary factors

Increasing your intake of soy and drinking green tea may benefit the prostate, although this is not yet proven. Also, avoiding or decreasing your intake of alcohol, coffee, and other fluids, particularly after dinner, is often helpful. A higher risk for BPH has been found in association with a diet high in zinc, butter, and margarine, while individuals who eat lots of fruits are thought to have a lower risk for BPH.

 medications that worsen symptoms

Decongestants and antihistamines can slow urine flow in some men with BPH.

Some antidepressants and diuretics can also aggravate symptoms of BPH.

Consult your physician if you are taking any of these medications to discuss changing dosages or switching medications, if possible.

Kegel exercises

Repeatedly tightening and releasing the pelvic muscle, also known as "Kegel exercises," is helpful in preventing urine leakage. Physicians recommend practicing this exercise while urinating in order to isolate the specific muscle: contract the muscle until the flow of urine decreases or stops, and then release the muscle. It is recommended that men with BPH repeat five to 15 contractions, holding each for 10 seconds, three to five times a day. Consult your physician for more information

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