Family doctor

Overview:

• Benign prostatic hyperplasia is a growth of the prostate tissue
• It occurs in most men as they grow older
• About 20 to 30 percent of men will require treatment
• The condition causes problems with urination such as increased frequency
• Diagnosis includes examination, blood tests, urine flow tests, and ultrasound
• Treatment involves drug treatment or prostate surgery
• There is a small chance of erectile dysfunction following prostate surgery

What is BPH?

This is also often referred to as benign prostatic hypertrophy.

This is a nodular growth of the peri-urethral prostatic tissue. It eventually occurs in most men to varying degrees. The location of the prostatic growth may result in urethral compression, and cause a group of symptoms often referred to as "prostatism". This term is slowly being replaced with "LUTS" (lower urinary tract symptoms), as other causes of bladder outflow obstruction that don't involve the prostate, for example urethral strictures and bladder dysfunction, may cause the same symptoms.

Estimates of the prevalence of symptomatic BPH vary significantly, as there is no standard definition for BPH on the basis of symptoms. It is estimated that 20-30% of men require some type of treatment for symptomatic BPH in their lifetime.

At present there are no known risk factors for BPH other than age and the presence of testes. This includes race, nationality, sexual history, diet, or other diseases or medications.

The prostate normally weighs approximately 20 grams at age 20-30. From around the age of 40 the prostate often increases in size, to an average of 40-50 grams at age 80.

The prostate can get extremely large, and weights upwards of 500 grams have been reported. The size of the prostate has a poor correlation to the severity of symptoms, and also to bladder outflow obstruction.

It is now generally agreed that there are 2 elements to obstruction from the prostate - a "static" component, referring to mechanical obstruction of the prostatic urethra, caused by the enlarging prostate tissue, and there is also evidence that smooth muscle growth ("hypertrophy") occurs in BPH. This may cause increased muscle tone - the so-called "dynamic" part of the obstruction. Recognition of this dynamic component is responsible for the variation in symptoms that occurs with many patients over time, and possibly in response to certain dietary factors, stress, change in temperature etc.

Symptoms

These have classically been categorised as "obstructive" or irritating, however these classifications are slowly changing, as we are becoming more "urodynamically" orientated. We can now classify symptoms into "filling" and "voiding".

A) "filling" or "irritative" symptoms include nocturia (getting up at night to urinate), day-time frequency, urgency, at times progressing to urge incontinence. These symptoms are generally thought to result from the effects of obstruction on the bladder, which may cause an irritated (unstable) hyperactive bladder, often causing it to contract at relatively low bladder volumes. Sometimes these symptoms are a result of a reduced functional capacity of the bladder, as patients with obstruction may leave a large amount of residual urine in the bladder following urination.

B) "obstructive" or "voiding" symptoms include difficulty initiating urine flow, often hesitancy, a delay in initiating urination, and a slow urinary flow. The flow may be intermittent, and may be followed with a sensation of incomplete bladder emptying and terminal dribbling of the urine flow.

It is important to remember that these symptoms are not specific for prostate disease, i.e. other conditions can cause the same symptoms.

Various scoring indexes have been used in an attempt to quantitate symptoms.

These symptom scores may be useful for measuring the severity of symptoms, and are used as a guide for reviewing patients and assessing response to treatment. Probably the most important part of these symptom scores is the "bothersome" score, which reflects the impact of these symptoms on the individual patient.

Other symptoms:

BPH can affect bladder function, giving rise to a thickened bladder wall, trabeculation, instability (involuntary bladder contractions, causing urgency or urge incontinence). If there is a large amount of residual urine left in the bladder, bladder stones can occur, and chronic retention of urine, with a grossly enlarged bladder can occur sometimes with very little in the way of symptoms. Occasionally upper urinary tract dilatation from "back pressure" from a chronically distended bladder can occur, and result in renal failure. Patients with large residual urine volumes are also at risk of urinary tract infections.

Either microscopic (not visible) or macroscopic (visible) "haematuria" (blood in the urine) can occur with an enlarged, vascular prostate, but other causes for bleeding need to be excluded.

Signs of BPH:

1. Physical examination (i.e. digital rectal examination) may reveal an enlarged prostate, however the degree of enlargement is not proportional to the severity of symptoms or the degree of obstruction.

2. Abdominal examination may reveal an enlarged bladder.

3. Tests that may be needed: Following a history and rectal examination of the prostate and examination of the abdomen, a urine flow test is obtained. This records the strength of urine flow, which is very useful to assess the likelihood of obstruction.

Optional tests include a urinary tract ultrasound scan, which is useful for detecting the amount of residual urine, and detecting other anatomical abnormalities in the urinary tract. Occasionally cystourethroscopy (looking in the bladder with a telescope) may be important, particularly to rule out other causes of obstruction: urethral strictures etc.

Renal (kidney) function is generally measured with a blood test (serum creatinine), and a urinalysis (urine test) to rule out urinary infection and haematuria are standard.

Treatment options:

There are generally 3 major treatment options.

These include "wait and watch", medical treatment, or surgical treatment.

Recently a number of alternative technologies have been used. The place of these treatments has not yet been well established. They are often more effective than medical treatment, although most are not as effective as surgical treatment (prostatectomy).

Before deciding on treatment it is important to understand the "natural history" of BPH.

Many patients have fluctuating symptoms, and in nearly half of patients symptoms remain static for many years. Over half of patients will experience a gradual deterioration in symptoms, although only a small percentage of patients each year will experience acute urinary retention (complete "blockage", requiring the insertion of a catheter).

There is a large "placebo effect" in treating lower urinary tract symptoms - at least 30% of patients experience a significant improvement in symptoms, at least in the short term, regardless of which medication or vitamin tablets etc are taken for this.

This placebo effect makes it difficult to tell how effective various medications are without properly conducted medical trials.

Medical treatment

Usually alpha-blockers are used to relax the smooth muscle within the prostate, thereby making it easier to push the prostatic urethra open - there are a wide variety of these, and some claim receptor selectivity. The most common ones used are:

• Terazosin (Hytrin)
• Doxazasin (Cardoxan)
• Alfuzacin
• Tamsulocin (Omnic)

These medications are all similar in their effectiveness, with a modest improvement in symptoms experienced in nearly half of patients, and a mild improvement in flow-rate experienced in approximately 1/3 of patients. They need to be taken daily, and the beneficial effect is only during the time the patients are on the medication.

Potential side-effects, experienced in 10-20% of patients are fatigue, dizziness, nasal stuffiness, and a small percentage of patients experience postural hypotension (lowering of blood pressure noticed when changing from a lying to standing position).

Another drug treatment is alpha reductase alpha inhibitors "Finastaride" (Proscar) - this medication does reduce prostate volume by about 20% over one year, however there are only modest improvements in symptoms and flow-rates, experienced by only approximately 20% of patients. Side effects are rare, with a three percent incidence of erectile dysfunction. The overall results have been disappointing, and in some countries this medication is not funded (New Zealand). Finasteride takes several months to work.

Surgical treatment - prostatectomy

Indications for surgical treatment:

Historically there have been certain absolute indications for surgery, which have included acute urinary retention, renal failure secondary to BPH, recurrent gross haematuria, recurrent bladder stones, a large residual urine, overflow incontinence, recurrent urinary tract infections.

Usually in these situations where medical treatment is not effective surgery is usually performed. Usually surgery is in the form of transurethral resection of the prostate, which is usually effective.

"Transurethral resection of the prostate" is an operation performed under spinal or general anaesthetic. An instrument ("resectoscope") is placed up the urethra into the bladder. The prostate is viewed through this instrument, and strips of prostate are cut away, with a heated wire loop. The pieces of tissue are irrigated from the bladder, and the blood vessels cauterised. A catheter tube is placed into the bladder, and this allows the urine and blood clots to leave the bladder. Patients generally need to stay in hospital for several days following prostatectomy. Very large prostates (generally bigger than 100 grams) are too large to safely perform transurethral prostatectomy, and an open retropubic prostatectomy may be required.

"Open retropubic prostatectomy". With this technique an incision is made in the lower abdomen, to expose the bladder and prostate. The outer capsule of the prostate is cut and the enlarged prostate gland is shelled out, by developing a plane between the enlarged prostate tissue and the capsule. The bleeding vessels are tied off and cauterised and a catheter tube is placed, and needs to remain in for at least a week, until the bladder and prostate capsule heal.

Following prostatectomy urination may be painful (dysuria), frequent and often blood stained. These symptoms generally last from several days to several weeks, and it is not uncommon to have minor temporary incontinence several days and sometimes weeks following the procedure.

The results from surgery are generally very good, with marked improvement in flow-rates and large improvement in symptoms in the majority of patients. Some of the bladder symptoms, particularly the urinary frequency and urgency can take several months to resolve, but do improve generally in over 80% of men.

Most men following prostatectomy will experience "retrograde ejaculation", where the ejaculate goes back into the bladder. This does not cause any harm. The ejaculate liquefies in the bladder, and is passed unnoticed with urination. In large series of transurethral resection of the prostate the incidence of blood transfusion has been between 2-20%, and the incidence of erectile dysfunction around 5-10%.

There is a wide array of alternative technologies to treat BPH. These include balloon dilation, urethral stents, transurethral needle ablation (TUNA), vaporisation and microwave treatment.

These technologies although generally less morbid than a TURP (transurethral resection of the prostate) have not been as effective in properly conducted trials, and the place of these remains uncertain.

Laser energy has been used to perform prostatectomy. Initially this was a neodinium "YAG" laser. Although there was very little bleeding with this technique, it did cause a lot of dysuria, and prolonged catheterisation in many patients.

A new technique which appears to have the same rate of effectiveness as TURP (tested in a FDA randomised controlled trial) is:

Holmium laser resection of the prostate:

The procedure is performed in a similar way to TURP, but instead of a wire loop a laser beam is used to cut away the tissue. The advantage of this technique is that the bleeding is significantly less, most patients only require a catheter overnight, and can get back to normal activities more quickly than TURP, with less chance of re-bleeding.

Commonly asked questions:

Q: Have I got prostate cancer?

A: Most patients with difficulty urinating do not have prostate cancer. A prostate examination and PSA will determine the risk of cancer, and whether other tests are needed.

Q: Do I need a prostate operation?

A: Many men have mild to moderate symptoms, and once prostate cancer has been ruled out do not necessarily require active treatment, as symptoms often remain relatively minor for many years. If symptoms are bothersome a prostate operation is optional if a flow test indicates that obstruction is present.

Q: Will a prostate operation make me impotent or incontinent?

A: Transurethral prostatectomy usually causes retrograde ejaculation (where the ejaculate goes back into the bladder and liquefies in the urine (so you don't see any ejaculate).

Erectile dysfunction is uncommon (5-10%) following prostatectomy (although many men are often having difficulty achieving an erection at the time of prostatectomy). A small number of men have improved potency following prostatectomy.

A change in continence is uncommon following prostatectomy, although can occur in the first few days or weeks following the operation. It is very rare for continence to be worse following the operation, and patients who have urgency and urge incontinence before the operation are usually improved by surgery (providing they were "obstructed" pre-operatively).