Erectile dysfunction - causes and diagnosis

1. Erectile Dysfunction
Causes & Diagnosis
- Dr. Abhishek Pandey

2. ERECTION
 Sinusoidal relaxation
 Arterial dilatation
 Venous compression
• Tunica stretch – Intracavernosal pressure 100mmHg
• Types –
1. Psychogenic – Audiovisual stimuli, Fantasy
2. Reflexogenic – Tactile stimulation
3. Nocturnal – REM sleep (Cholinergic activity ↑ed)

4. Erectile Dysfunction
• Impotence – replaced by Erectile Dysfunction (ED)
• ED inability to attain &/Or maintain erection sufficient
for satisfactory sexual intercourse.
• Prevalence 20% worldwide in >20yr males
• Incidence 25 cases/1000 man-years
• Age – important factor (>40yr)

5. Risk Factors

6. Classification
• ED is usually mixed condition
• Primary ED – lifelong inability to initiate &/or
maintain erections – psychogenic/maldevelopment

7. Functional Classification of ED

8. Psychogenic
• Mechanisms –
Direct inhibition of spinal erection center
Increased sympathetic outflow
Increased circulating catecholamines
1. Generalized – decline in arousability
2. Situational –
a) Partner-related –
b) Performance-related – anxiety, premature ejaculation
c) Psychological distress – depression, major-stress

9. Neurogenic
• 10-20% ED is neurogenic
1. Brain – stroke, trauma, tumor, encephalitis
 Parkinson’s disease – dopaminergic imbalance
 Dementias – Alzheimer disease
2. Spinal cord lesions –
 Upper cord – reflexogenic erections preserved in 95%
 Lower cord – 25%
3. Cavernous nerve – Iatrogenic injury – RP, Rectal Sx
 Pelvic fracture – nerve injury + vascular insufficiency

10. Endocrinologic
• Testosterone increases –
– Sexual interest & frequency of sexual acts
– Nocturnal erections (>200ng/dL)
• Hypogonadism – loss of libido & ED
– 15% prevalence – most are asymptomatic
• Hyperprolactinemia – loss of libido & ED
• Hypo- or Hyper-thyroidism

11. Arteriogenic
• Atherosclerotic > Traumatic arterial occlusive disease
→ decreased penile perfusion pressure & ED
• Risk Factors –
– HTN, CVD, CAD, PVD [Generalized Atherosclerosis]
– Obesity, Hyperlipidemia, Diabetes mellitus
– Cigarette smoking
– Blunt pelvic/perineal trauma
– Pelvic radiation

12. Mechanism of Vascular ED

13. Cavernous (Venogenic)
• Veno-occlusive dysfunction – impaired compression
of subtunical & emissary veins
• Degenerative tunical changes – Peyronie Dx, age, DM
• Trauma to tunica albuginea – Penile #
• Acquired venous shunts – Priapism Sx
• Insufficient trabecular smooth muscle relaxation –
anxiety, increased adrenergic tone

14. Drug induced

15. Systemic disease
• Diabetes mellitus – 30% prevalence, 1st symptom in 12%
– Neurogenic / Vasculogenic / Psycological (↓ well being)
• Metabolic syndrome – Obesity, HTN, dyslipidemia,
insulin resistance – 30% prevalence of ED
• CKD – Uremia induced hormonal disturbances & ↑ed
atherogenesis. 45% prevalence
• ED – 45% increased risk of cardiac event at 5yr f/u
80% subsequent increased risk of CAD at 10yr

16. Diagnostic evaluation

18. International Index of Erectile Function (IIEF) Questionnaire
• 15 questions / Items
• 5 domains – erectile funcion, orgasmic function, sexual
desire, intercourse satisfaction, overall satisfaction
• Do not distinguish etiological basis for ED
• IIEF-5 – validated abridged 5-item version of IIEF
– Scoring (1-25) – No ED (22-25), Mild (17-21), Mild-moderate
(12-16), Moderate (8-11), Severe (5-7)

19. IIEF-5 / SHIM score
• The Sexual Health Inventory for Men (SHIM)
• Evaluates sexual function over past 6 months
1. Confidence to get/keep an erection
2. How often were erections hard enough for penetration
3. How often were erections maintained after penetration
4. How difficult to maintain erection till completion
5. How often was sexual intercourse satisfactory

20. Cardiovascular risk assessment

21. Specialized
evaluation
Evidence-based
recommendations

22. Combined Intracavernosal Injection & Stimulation
• CIS test – 1st line evaluation of penile blood flow
• Intracavernosal injection of Vasodilator –
– Alprostadil (synthetic PGE1)
– Bimix – Papaverine (non-specific PDE-i) + Phentolamine
(non-specific α-antagonist)
– Trimix – Alprostadil + Papaverine + Phentolamine
• 27-29 gauge needle inserted at lateral base of penis
• Phenylephrine inj. if no detumescence in an hour

23. Duplex USG
• Duplex USG after pharmacostimulation / CIS – 2nd
line evaluation of penile blood flow
• 7.5-12MHz probe, color-pulsed doppler
• Flow at baseline → every 5min after inj. upto 20min

24. • Peak Systolic Velocity (PSV) – cut-off of 25cm/s for
cavernous arterial insufficiency (normal>35cm/s)
• Vascular collaterals
• Veno-occlusive dysfunction
– Persistent high PSV
– High End-Diastolic Velocity (EDV)
– Rapid detumescence
– Resistive Index (RI) = (PSV-EDV)/PSV; RI<0.75 a/w veno-
occlusive dysfunction (normal>0.9)

25. Dynamic Infusion Cavernosometry-Cavernosography
• DICC – Evaluation of penile venous outflow system
– Pelvic/perineal trauma – suspected site-specific leak
– Primary/Lifelong ED
• Intracavernosal inj. → 2 needles palced → simultaneous
saline infusion & intracavernosal pressure monitoring
• VOD – failure to increase intracavernosal pressure to
mean SBP or rapid drop in pressure on stopping infusion
• Cavernosography – to show site of venous leakage

26. Cavernosal artery flow – continous-wave doppler
Systemic brachial arterial pressure
Intracavernosal pressure; CASOP – Cavernosal
artery systemic occlusion presssure
Cavernosography
Cavernosometry

27. Penile Angiography
• Reserved for young patient with ED 2° to vascular
injury considered for re-vascularization

28. Nocturnal Penile Tumescence & Rigidity
• NPTR – Assessment of physiologic erectile ability.
• Nocturnal monitoring – number of erections, tumescence
(circumference change), maximal penile rigidity, duration
of erections
• Documentation of REM sleep is important
• Normal NPTR criteria – 4-5 erection/night, mean duration
>30min, increase in circumference >2cm at tip & >3cm at
base, maximal rigidity >70% at tip & base.

29. Home Nocturnal
Monitoring
2 well-sustained completely rigid
nocturnal erections
2 poorly sustained & poorly rigid
nocturnal erections

30. Thank You

31. A
• A