Transcript Erect1 - Urology Information Site

Erectile Dysfunction - A rising problem
Mr C Dawson MS FRCS
Consultant Urologist
Edith Cavell Hospital
Peterborough
Prevalence and significance of E.D.
• Exact incidence unknown
• May affect 1 in 10 men
• Affects 10 million men in
US alone, 400,000 OPD
visits and 30,000 hospital
admissions (1992 figs)
• Significance to Urologists Increased public
awareness of new
treatments has resulted in
increase in referrals
Definition of Erectile Dysfunction
• “Inability to achieve and maintain an erection
sufficient to allow penetrative sexual
intercourse to occur (.... with satisfaction to
the patient and his partner)”
Myths surrounding E.D.
• “Nothing can be done”
• “It’s to be expected at my age, isn’t it?”
• “Do you think it’s all in my mind doctor?”
Erectile Dysfunction and ageing
• Testosterone levels decline with age
• Effects of testosterone on erectile capacity is
not clear
• Wide variation in “normal” levels of
testosterone
• Therefore, ageing and reduced testosterone
may be independently associated with E.D.
Psychological cause?
• Careful history will usually determine those
patients with a psychological element to their
E.D.
• Persistent E.D., especially of insidious onset
is more likely to have an organic cause
• More than 90% of cases of E.D. have an
organic basis
Mechanism of erection
Depends on integrated processes of :
– increased arterial inflow to penis
– filling of sinusoids of the corpora cavernosa,
aided by relaxation of cavernosal smooth
muscle
– passive occlusion of the venous plexus
provides increased resistance to outflow and
aids rigidity
Mechanism of erection
The role of chemical mediators
• Previously suggested that erection under
parasympathetic, and detumescence under
sympathetic, control - over simplified view
• Non-adrenergic non-cholinergic (NANC)
mechanisms now believed to be important
The role of chemical mediators
• Nitric oxide (NO) now appears to be the final
element in the NANC pathway and may be
derived from nerve endings
• NO raises cyclic GMP levels leading to penile
smooth muscle relaxation
Pathophysiology of E.D.
Robert Krane, BAUS 1996
• Arterial insufficiency in E.D. may lead to
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hypoxia of the corpora
Imbalance between PGE1 and TGF-B1
Excess Collagen Deposition
Fibrosis of the corpora cavernosa
Dysfunction of the veno-occlusive mechanism
Pathophysiology of E.D.
• Flaccid state
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Hypoxia, increased TGF-B1, and fibrosis
• Asleep
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Nocturnal penile tumescence 3-5x per night, 40
mins per time. Normoxic episodes increase
PGE1, decrease collagen, and decrease TGF
• Established E.D.
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Hypoxia all the time; don’t get the benefit of NPT
episodes
Pathophysiology of E.D.
Use it or lose it!
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More erections = increased normoxia
Increased PGE and cAMP
Decreased TGF-B
?? decrease fibrosis already present
Assessment of the patient with E.D.
• Careful History
• Examination
• Further investigations
Points to note in the initial history
• Duration, ?insidious or acute onset
• Absence of erections or diminished quality
• Penetrative SI possible? Able to masturbate? Early
morning erections?
• Libido normal, or decreased
• Pain or curvature of erection (?Peyronie’s disease)
• Related psychosocial factors
Medical History
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Chronic systemic medical disease
Neurological Problems
Previous surgery
Vascular risk factors
Drug History
Physical examination
• Endocrine
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Assessment of secondary sexual characteristics
Examine neck for Thyroid
Gynaecomastia
Size and consistency of testes
• Neurological
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Sensory deficit in sacral dermatomes
• Vascular
BP, Carotid Bruits, AAA, Foot pulses
• Local - examine penis for plaques or fibrosis
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Laboratory Investigations
No single diagnostic test
• FBC, U+E, LFT - to screen systemic medical
disorders
Role of Hormone evaluation
• Testosterone affects secondary sex characteristics; effects on
erections unclear - If libido is reduced, testosterone should be
measured
• If Testosterone repeatedly low check LH
– Low Testosterone and Low LH may indicate hypothalamic or
pituitary defect (CT advised)
– Low Testosterone and High LH suggests testicular failure
• Hyperprolactinaemia inhibits LHRH pulse
• Abnormal thyroid function may cause E.D.
Further Management of E.D.
• Pragmatic approach best, based upon available
treatments
• Diagnostic intracavernosal injection
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Normal erection suggests normal vascular dynamics,
and precludes further investigation
Poor, or absent, erectile response may be followed by
investigations in certain circumstances
Further Management of E.D.
• Medical therapy
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“Magic Pill” still sought
Yohimbine - may improve erectile capacity in
some men
Intracavernosal Pharmacotherapy
• Papaverine +/Phentolamine
• Prostaglandin E1
(Caverject)
• Combination therapies
• Requires trained
supervision until patient
competent to give injection
Results of intracavernosal therapy
• Papaverine alone -30% success rate
• PGE1 alone - 70% success rate
• Combination therapies may have success
rates of 85-90%
• Priapism less with PGE1 (0.4% vs 6% for
Papaverine
• Early drop-out rate as high as 50%
Vacuum device
• Less invasive than
intracavernous injection
• Results good - up to 92%
success in some series
• Bruising reported so
contraindicated in bleeding
diathesis or anticoagulant
treatment
• Expensive for patient to
purchase
Penile Prosthesis
• Usually tried only after injections and vacuum
device have failed, or for E.D. associated with
Peyronie’s disease
• Rigid, or inflatable types
• Insertion requires strict asepsis under GA
• Infection is the most important complication,
necessitating removal
• Erosion of one or both cylinders may occur
The Future
• Better understanding of chemical mediators may
lead to pharmacological treatments? - e.g.
Sildenafil
Conclusions
• Media attention and public awareness has led to
increased referrals
• Better understanding of mechanism of erection,
and pathophysiology of E.D. has rationalised
investigation and treatment
Conclusions
• Current management relies on pragmatic
approach, and response to intracavernosal
injection of PGE
• Good success rates with either injections or
vacuum device. Prosthesis rarely required
• Future developments likely to radically alter
management of this condition