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BENIGN PROSTATIC HYPERPLASIA - a patient's guide
Dr Michael Mackey - Urologist
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).
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