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Normal Sexual Function
There are four parts to normal sexual function in men - sex drive (also called
libido), erection, ejaculation (emission of fluid), and orgasm.
What causes sex drive?
At puberty, the brain increases production of hormones that stimulate greater production
of testosterone by the testicles. Testosterone is the main hormone responsible for the
development of male sex organs and sexual behaviour. When testosterone
levels drop, sex drive diminishes. This occurs naturally with aging, but may also
occur with illness, some commonly used medications and with hormone treatment
for prostate cancer.
What happens when you have an erection?
The penis contains nerves, smooth muscle and blood vessels in three spongy chambers,
also called sinusoids. When a man is sexually stimulated, the nerves release a
substance which causes the smooth muscle to relax. This causes the spongy
chambers to dilate and blood is pumped in. The penis elongates shutting off the
veins so that blood can’t leave the penis.
After ejaculation, the nerves stop releasing the muscle relaxing substance, blood flow
to the penis is reduced, blood flow out of it increases and the erection subsides.
It follows that both nerves and healthy blood vessels are important for erections.
The nerves necessary for erections are different to those involved in sensation
from the penis or for orgasm.
What happens during ejaculation?
Sperm mature and are stored in a structure close to the testes called the epididymis and
structures close to the bladder called the seminal vesicles. During ejaculation, semen,
which contains sperm and fluid from other sources (such as the prostate and
seminal vesicles), is propelled by muscular contractions along a tube into the
urethra (urine tube). During ejaculation, a muscular valve at the bladder outlet
closes, forcing semen out of the penis.
What happens during orgasm?
Orgasm mainly happens in the brain and has little to do with the prostate. As long
as normal sensation is intact, orgasm can occur even in the absence of an erection
and ejaculation. This is the key reason why satisfactory sexual function can be
restored to most men after prostate cancer treatment involving surgery or
radiotherapy. The common exception here is men receiving hormone therapy,
because this frequently causes loss of libido (sexual desire).
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Why are erections
affected by treatment to the prostate gland?
The prostate is not particularly important for normal sexual function. It adds
secretions to the ejaculate, which help the sperm to survive. However it doesn’t
control the ability to have an erection. Nevertheless, structures which are
important to erectile function are in close proximity to the prostate and can be
damaged when the prostate cancer is treated. A series of fine nerves which
assist in the ability to have an erection lie in bundles against the prostatic capsule.
During sexual arousal, blood fills the penis to create an erection, and small
blood vessels expand in order to deliver enough blood. Prostate treatment such as
radiotherapy and surgery can damage the nerves and the blood vessels.
Trans-urethral resection of the prostate gland
A trans-urethral resection of the prostate (TURP) is an operation to remove
prostate tissue through the urine outflow tube (the urethra). It can improve urine
flow when the tube is blocked by benign enlargement of the prostate, or by
prostate cancer. Only a part of the prostate is removed and so some men
call this a ‘rebore’.
During this operation, the constricting “valve” at the bladder
neck is often opened – so that during ejaculation (because there’s no barrier to
keep semen from going back into the bladder), semen is propelled into the
bladder rather than through the penis to the outside. This results in a ‘dry ejaculation’.
It is not painful nor dangerous and the semen is passed out when the bladder is
next emptied.
Radical prostatectomy
During this operation for cancer, the entire prostate and the seminal vesicles are removed.
After a radical prostatectomy the focus of attention is initially on the return of
urinary control (continence), as the nerves and muscles controlling urination
also lie close to the prostate area.
A man will normally lose the capacity to have erections immediately after the
operation, however with time, there is usually some return of erections. In part,
the return of erections depends on the extent to which the nerves which lie
close to the prostate could be spared during surgery. This is a choice that the
surgeon is only able to make at the time of surgery, since to spare the nerves and
also leave cancer behind would defeat the purpose of the operation. If it is
considered safe to do so, techniques are available to preserve these nerves.
More recently some surgeons have been reconstructing the pathway
by grafting nerves into the area. Nevertheless, although the nerves are
important they are not essential. After a radical prostatectomy, approximately
20% of men who did not have nerves spared have return of erections.You may be advised by your doctor to
‘give it time’. After surgery your body needs time to heal. The erection you may
have 4 months after surgery is not necessarily the same one you’ll have 2
years later. Many men experience improved natural erections over time; with
continued improvement reported for up to 4 years postoperatively! Erections may
return gradually. Aids to assist with an erection after surgery may improve your
long-term function and so you may consider these only a few weeks after
your operation.
After a radical prostatectomy, the stimuli that cause an erection need to be altered.
Visual stimulation may not be as important as direct stimulation of the
penis. No damage can be done through experimenting with your sexual activity.
If you have a partial erection, go ahead and attempt intercourse - vaginal
stimulation will encourage further and better quality erections. Continue with
sexual relations even though erections may not occur and don’t wait until the
time when they ‘just happen.’ Soon after surgery traditional vaginal
penetration may not be easy. Some men have found that if they attempt sexual
activity standing up, they can achieve a much firmer erection. Sexual activity can
continue either while a man remains standing, or while he’s kneeling. Lubrications
such as K-Y jelly may also help.
Radiotherapy
After radiotherapy to the prostate sexual function is not usually affected in
the short to medium term. Several years after radiotherapy erectile function
declines gradually. This is thought to be due to the progressive damage to the
nerves and small blood vessels near the prostate that are important for erections.
It often stated that brachytherapy (interstitial radiotherapy) to control prostate cancer
will reduce the risk of erectile dysfunction in comparison to radiotherapy delivered
by external beam; however, further research is needed. Conformal radiotherapy and intensity modulated radiotherapy are newer
delivery techniques that may reduce damage to healthy tissues adjacent to the prostate.
Remember also that aging itself has an effect on sexual function!
Hormone Treatment
Control of prostate cancer using hormone therapy usually results in
the reduction of testosterone, and sex drive will be diminished for most men. However, continuation of simple
physical expressions of love and concern between you and your partner can be
very important in the ensuing years.
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What you can do
Medications
Viagra TM (sildenafil) first became available in Australia in 1998 and is not currently
subsidized by the Governmental Pharmaceutical Benefits Scheme (PBS).
It is a tablet that can assist some men to achieve an erection or a better quality
erection. Perhaps 3 in every 10 men who have had a radical prostatectomy can
achieve a satisfactory erection with Viagra TM. The recommended strength of tablet
initially is 50 mg, increasing to 100 mg if unsuccessful.
Viagra TM is not an aphrodisiac (ie does not increase sex drive) and typically
direct penile stimulation is required to achieve an erection. Loss of an erection
(detumescence) occurs after orgasm in a man taking Viagra TM , as would normally
be expected. The medication needs to be taken 30-60 minutes before attempting
intercourse, but may remain active in the circulation for up to 12 hours (some men
have noticed “spontaneous” erections the
following morning).
Men who take nitrate medication (eg anginine) for a heart condition must not
mix Viagra TM as the risk of low blood pressure and sudden death is increased.
Your doctor will advise you on your risk or may seek advice from a cardiologist (heart specialist).
Bear in mind that sexual activity is indeed exercise, and heart attacks are
more likely to occur during exercise than otherwise. Known side effects of taking
Viagra TM include headache (15%), facial flushing (11%), indigestion (6%), visual
disturbance (3%). Current cost is about
$55 for 4 tablets, regardless of tablet strength.If the medication doesn’t work at the first
attempt, it may be worthwhile retrying some months later.
Viagra TM
may help some men taking hormone therapy, but sexual desire is usually low. Other tablet medications for male
ED are being assessed in clinical trials in Australia and these may provide improved choices in the future.
Injection therapy
Direct penile injections are the most effective form of therapy to achieve erections after a radical prostatectomy.
A drug is injected each time an erection is required - this occurs without any
direct sexual stimulation – it is a chemical response. Caverject TM (alprostadil) is
the most freely available and is supported by the PBS scheme.
It is important to start by injecting small doses (eg 5 micrograms) and
then gradually increase the dose until a satisfactory result is achieved.
This reduces the risk of one of the side effects - a painful prolonged erection,
called priapism. Any erection lasting more than 4 hours with this type of
medication requires urgent medical intervention. Typically blood is drained
from the penis and an “antidote” injected into the penis. Some doctors
prescribe a tablet to help deflate the erection should it last for 3 hrs or more,
eg pseudoephidrine 30 – 60 mg orally.
Most doctors recommend a maximum of 3 injections per week because more
frequent use carries with it a greater risk of permanent scarring within the penis. The correct
technique of injection therapy can be learned by most men, provided their
eyesight and dexterity are reasonable.
There are medications other than Caverject TM that have been used, some in
combination. As all rely on a relatively normal blood supply to the penis, injection
therapy can fail if this is inadequate. Caverject TM must be hard frozen
to maintain activity although a powder form that can be stored or transported at room temperature is
expected on the Australian market soon. Other agents usually require refrigeration to store.
Vacuum erection devices (VEDs)
An erection can be created by drawing blood into the penis by way of a vacuum
pump placed over the penis. Once the erection is created, a band is placed onto
the penile base close to the pubic bone to maintain the erection during sexual
activity. The band should be released within 30 minutes to avoid the risk of
damage to the penis itself. A VED is reusable. Education and personal
experience with these devices is very helpful and most companies make
available video tapes which demonstrate their use.
They are not available on the PBS and cost between $400 and $600 each.
Penile prostheses
Devices can be placed within the penis to create a mechanical erection. Such an
operation is normally not performed less than 2 years after radical prostatectomy
since recovery may occur naturally prior to this. The normal spongy penile structure
is destroyed to allow the device to be placed. Most of the cost of inserting
these devices is covered by private health funds.
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In conclusion
All men are able to enjoy a sexual relationship following surgery and
radiotherapy, since their sensation of arousal, excitement and orgasm is
typically unchanged. What is often lacking is the spontaneous event of a rigid penis.
A number of options for achieving an erection have been mentioned and one
or more of these is usually successful.
You can experiment also with other forms of sexual intimacy - there may be
new discoveries to be made!
Remember there is no potential for harm to your sexual partner from either the
cancer or from any potential urinary leakage during a sexual encounter.
Your partner, wherever possible should be included in discussions about your
sexuality and treatment choices.
Finally, it is important to keep in mind the larger picture! There is far more to
a fulfilling relationship than an erect penis, even though the latter often
becomes the focus of attention during consultations with treating doctors!
The purpose of your treatment is to rid you of a life threatening disease.
Check out these useful websites:
http://www.impotence.org
http://www.prostatehealth.org.au/PHIP
http://www.pslgroup.com/erectile.htm
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Initial contact with your urologist or
general practitioner is recommended.
Relationships Australia.
In your state Address the relationship aspects of erectile dysfunction. Call
the national office on 02 6285 4466 for local contact details.
Books
Men and Sex.
B. Zilbergeld, 1995.
Harper Collins. Also provides wider understand-ing of male sexuality.
The Sexual Male: Problems and Solutions.
R. Milsten and J. Slowinski, 1999. WW Norton. The authors are chief of Urology
at Underwood-Memorial Hospital in the US, and Assistant Professor in Psychiatry
at the University of Pennsylvania.
The Prostate.
P. Walsh and J. Worthington (one chapter), 1997. Warner Books, NY.
Dr. Walsh developed the 'nerce sparing radical prostatectomy'.
Your Prostate, Your Choices.
G. Hirst and S. Wilde (one chapter), 1999. Bantam Books,
Sydney. Clear, down-to-earth approach to problems with sex after treatment for
prostate disease.
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Information
Sheet 4: Monitoring After Treatment
Information
Sheet 6: Useful Resources 
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