Erectile Dysfunction - A rising problem

1. Erectile Dysfunction - A rising problem Mr C Dawson MS FRCS Consultant Urologist Edith Cavell Hospital Peterborough

2. 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 Prevalence and significance of E.D.

3. 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)”

4. 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?”

5. 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.

6. 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

7. 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

8. Mechanism of erection

9. 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

10. 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

11. Pathophysiology of E.D. Robert Krane, BAUS 1996 • Arterial insufficiency in E.D. may lead to • hypoxia of the corpora • Imbalance between PGE1 and TGF-B1 • Excess Collagen Deposition • Fibrosis of the corpora cavernosa • Dysfunction of the veno-occlusive mechanism

12. Pathophysiology of E.D. • Flaccid state • Hypoxia, increased TGF-B1, and fibrosis • Asleep • Nocturnal penile tumescence 3-5x per night, 40 mins per time. Normoxic episodes increase PGE1, decrease collagen, and decrease TGF • Established E.D. • Hypoxia all the time; don’t get the benefit of NPT episodes

13. Pathophysiology of E.D. Use it or lose it! • More erections = increased normoxia • Increased PGE and cAMP • Decreased TGF-B • ?? decrease fibrosis already present

14. Assessment of the patient with E.D. • Careful History • Examination • Further investigations

15. 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

16. Medical History • Chronic systemic medical disease • Neurological Problems • Previous surgery • Vascular risk factors • Drug History

17. Physical examination • Endocrine • Assessment of secondary sexual characteristics • Examine neck for Thyroid • Gynaecomastia • Size and consistency of testes • Neurological • Sensory deficit in sacral dermatomes • Vascular • BP, Carotid Bruits, AAA, Foot pulses • Local - examine penis for plaques or fibrosis

18. Laboratory Investigations No single diagnostic test • FBC, U+E, LFT - to screen systemic medical disorders

19. 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.

20. Further Management of E.D. • Pragmatic approach best, based upon available treatments • Diagnostic intracavernosal injection • Normal erection suggests normal vascular dynamics, and precludes further investigation • Poor, or absent, erectile response may be followed by investigations in certain circumstances

21. Further Management of E.D. • Medical therapy • “Magic Pill” still sought • Yohimbine - may improve erectile capacity in some men

22. Papaverine +/- Phentolamine Prostaglandin E1 (Caverject) Combination therapies Requires trained supervision until patient competent to give injection Intracavernosal Pharmacotherapy

23. 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%

24. 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 Vacuum device

25. 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

26. The Future • Better understanding of chemical mediators may lead to pharmacological treatments? - e.g. Sildenafil

27. 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

28. 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