Selected
Clinical Topics
in Urology
This presentation was created with
funding from Pfizer Inc.
Erectile Dysfunction
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological
Association Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28:
853-870
Erectile Dysfunction
 Normal
Sexual Function
 Erectile
Dysfunction (ED): General
Considerations
 Evaluation
 ED
of a Man Presenting with ED
Treatments
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological
Association Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28:
853-870
Erectile Dysfunction
Normal Sexual Function
Neuroanatomic considerations
 Sexual
activity is initiated in the central
nervous system



The brain is the most poorly understood
component of the sexual response, but is of great
importance
Some important areas that are known to
contribute to sexual response include the medial
preoptic nucleus and paraventricular nucleus,
which reside near the hypothalamus
The exact function and interaction of these
structures are not known
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Neuroanatomic considerations
 The
most common sexual adverse effect of
the frequently prescribed selective
serotonin reuptake inhibitors (SSRIs) is
anorgasmia

although decreased libido and isolated erectile
dysfunction may also occur
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Neuroanatomic considerations
 Descending
neural pathways controlling
erection exit the brain and travel in the
spinal cord to the level of S2-4, where they
exit as peripheral parasympathetic nerves



Activation of these parasympathetic nerves
causes vascular changes that lead to erection
The detumescence mechanism is under control of
the sympathetic nervous system
Ejaculation is a completely different neurological
event from penile erection
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Neuroanatomic considerations
 The
locations of the sympathetic chain just
lateral to the aorta and of the hypogastric
plexus anterior to the aorta make these
structures prone to surgical injury from aortic
surgery or retroperitoneal
lymphadenectomy for testis cancer
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Penile anatomy and vascular supply



A. Penile arterial
supply
B. Venous drainage
C. Cross section of
penis showing
corpora cavernosa,
corpus spongiosum
and their
relationship to the
vascular supply
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Penile anatomy and vascular supply
 The
penile deep structures consist of 3
erectile bodies, 2 corpora cavernosa and
a single corpus spongiosum
 Surrounding
the entire package of erectile
bodies is Buck’s fascia
 All
3 bodies contain erectile tissue
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Penile anatomy and vascular supply
 The
corpus spongiosum surrounds the
urethra and distally enlarges to become
the glans penis
 Although
the corpus spongiosum becomes
engorged during sexual stimulation, it does
not contain a tough fascial covering and
thus cannot become rigid
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Penile anatomy and vascular supply
 The
arterial blood supply to the penis is
from the common iliac internal iliac
(hypogastric) internal pudendal
common penile artery
 Normal blood flow on one side is usually
enough to keep things functioning
properly

However, there can be individual variation in the
anatomy
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Penile anatomy and vascular supply
 In
some men, only one side provides the
majority of dorsal arteries may provide
intracavernosal flow via perforating vessels
more distally than normal
 This
anatomic variation may have
importance in planning Peyronie’s disease
surgery, in which the neurovascular bundle
is elevated blood
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Penile anatomy and vascular supply
 The
venous drainage of the penis is
redundant and plentiful
 The
largest vein is the deep dorsal,
originating at the glans and running deep
to Buck’s fascia
 Circumflex
veins coming up from the side
and a few direct cavernosal perforators join
the deep dorsal vein in its proximal course
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Neurovascular changes of erection




In the flaccid state, there is very little blood flow
into the penis
The predominant basic neural tone is
sympathetic
The smooth muscle surrounding the lacunar
spaces are held in a state of contraction from
this sympathetic tone, and therefore, as each
unit of space holds less blood, the penis as a
whole contains less blood volume and is smaller
The baseline sympathetic tone also keeps the
blood supply in a vasoconstricted state
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Neurovascular changes of erection

Blood flow increases 20-40 fold through the
cavernosal arteries

Smooth muscle relaxation of the cavernosal
smooth muscle surrounding the lacunar spaces
also occurs, creating a permissive increase in
blood volume stored in each space

The increase in penile size is checked by the
limitation of stretch of the tunica albuginia
surrounding the corpus cavernosum
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Neurovascular changes of erection
 The
smooth muscle relaxation is controlled
by well known neurochemical cascades
 The
major control system is the nitric
oxide/cyclic GMP (NO/cGMP) system
 NO
is released by nitrergic end-neurons and
endothelial cells in the cavernosal tissue in
response to sexual stimulation
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Neurovascular changes of erection
 Production
of NO causes the conversion of
GTP into cGMP by the action of guanylate
cyclase
 Interaction
of cGMP with protein kinase G
causes calcium shifts and resultant smooth
muscle relaxation
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Neurovascular changes of erection
 Cyclic
nucleotides of all types are broken
down by phophodiesterases (PDEs) in the
body
 The
most important PDE in the penile tissue
is PDE5, which is present in high
concentration, is specific for cGMP and
plays a central role in inactivation of the
NO/ cGMP pathway
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Neurovascular changes of erection
 Although
PDE5 is clearly the predominant
PDE in the penis, and its relative importance
in the penis compared to the rest of the
body is substantial

allowing an oral agent to be given to get an
effect in the penis without exaggerated systemic
adverse events
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Neurovascular changes of erection
 Although
less important than the cGMP
system, a parallel cAMP systemis present in
the penile tissue, as well. cAMP is degraded
by several cAMP specific PDEs (not PDE5,
which is cGMP-specific)
 When
present, cAMP also causes smooth
muscle relaxation via protein kinase A and
calciumflux in much the same way as
cGMP
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Neurovascular changes of erection

Both cyclic nucleotide systems can be
manipulated by non-specific PDE inhibitors,
such as papaverine

Injection of this drug into the penis causes
prolonged smooth muscle relaxation by
preventing the degradation of both cGMP
and cAMP

However, oral administration cannot achieve
a targeted response in the penis without
insurmountable systemic adverse effects of
PDE inhibition
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Neurovascular changes of erection
 Following
sexual activity, activation of the
sympathetic supply to the penis results in
arterial vasoconstriction, contraction of
lacunar smooth muscle, defeat of the
venoocclusive mechanism as intrapenile
pressure decreases, and reversal of the
changes mentioned above
 This
results in return to the baseline flaccid
state
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Physiology of ejaculation

After a period of sexual stimulation,
coordination of psychic and physical
stimulation results in climax and ejaculation

The brain component of this stimulation is
poorly understood

Sensory input into the reflex is mostly from the
glans and is carried via the dorsal nerves of
the penis, which enter the cord at levels S2-4
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Physiology of ejaculation

Sacral input into the reflex causes contraction of
the periurethral muscles and proprioception from
these muscles may give further to promote
reaching climax

Following high pressure contraction of the
pelvic/periurethral muscles, ascending pathways
meet those descending from the brain at the
thoracolumbar junction at levels T10-L

From there, sympathetic nerves exit the cord and
course via the route above, culminating in the
ejaculatory organs
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Normal Sexual Function
Physiology of ejaculation
 Since
ejaculation is a separate
neurological event from penile erection,
climax and ejaculation can occur in the
absence of an erection
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Erectile Dysfunction (ED): General Considerations
Epidemiology of ED
 ED
should be defined as: “Inability of the
male to attain and maintain erection of
the penis to permit satisfactory sexual
intercourse
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Erectile Dysfunction (ED): General Considerations
Epidemiology of ED

The dysfunction should be recurrent or
persistent

The ability either to obtain and/ or maintain
an erection may be affected

It is important that sexual function and
expectation is not homogeneous across a
patient population, so the definition of
dysfunction must add in an element of
patient expectation/satisfaction
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Erectile Dysfunction (ED): General Considerations
Epidemiology of ED
 Sexual
dysfunction was positively
correlated (Selvin study) with age,
hypertension and presence of preexisting
cardiovascular disease
 Diabetics
have a particularly high rate of
problems with a crude incidence rate of
> 50%
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Erectile Dysfunction (ED): General Considerations
Epidemiology of ED
 Men
with ED are also at risk for
developing manifestations of
cardiovascular disease when followed
over time, suggesting that ED represents
the first manifestation of the generalized
condition
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Erectile Dysfunction (ED): General Considerations
General types of ED
 Arteriogenic:
 If
one cannot increase blood flow the 2040 fold that is necessary to fill the penis,
inadequate blood supply will be the
cause of ED
 This can be due to atherosclerotic
disease, diabetic small vessel disease, or
trauma, which may either be a major
pelvic injury or chronic compression, such
as that seen in bicycle riders
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Erectile Dysfunction (ED): General Considerations
General types of ED
 Veno-occlusive
dysfunction:
 Blood trapping is an essential part of the
erectile process
 Lack of smooth muscle relaxation in the
cavernosal bodies, due to tissue
degeneration from ischemia, trauma,
inadequate neurotransmitter release
(diabetic microneuropathy), or Peyronie’s
Disease can cause ED, even in the face
of normal arterial inflow
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Erectile Dysfunction (ED): General Considerations
General types of ED
 Neurogenic:
 Conditions
such as diabetic or alcoholic
neuropathy, multiple sclerosis, spinal cord
injury, or radical prostatectomy can lead
to a situation where the signal to cause
vascular changes never gets to the
penile tissues
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Erectile Dysfunction (ED): General Considerations
General types of ED
 Hormonal:
 Testosterone
deficiency has been shown
in multiple animal models to result in
decreased production of nitric oxide
synthase, NO and cGMP production, and
worsened erectile function

It is clear now that in addition to effects on
libido, testosterone deficiency may result in an
unfavorable change in penile tissue function
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Erectile Dysfunction (ED): General Considerations
General types of ED
 Anatomic:
 Peyronie’s
Disease can lead to sexual
difficulty due to deformity, decreased
flexibility of the penile tissue or from the
development of venoocclusive
dysfunction
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Erectile Dysfunction (ED): General Considerations
General types of ED
 Drug-induced:
 Many
drugs can lead to erectile
dysfunction, and the list is too long to print
here
 The most commonly implicated drugs are
antihypertensives and antidepressants,
due to the CNS effects
CNS: Central Nervous System
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Erectile Dysfunction (ED): General Considerations
General types of ED
 Psychogenic:
 Although
with our current understanding
of ED we believe that 90% of cases have
a predominantly organic cause, there
remains a large subset of patients with a
psychogenic source
 Differentiation of these cases is usually by
history, but other testing may be
necessary
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
 The
evaluation of a man with ED follows
the typical model for most medical
evaluations, history, physical examination,
basic lab tests, specialized testing, and
finally, treatment
 The goal-oriented approach to erectile
dysfunction treatment is a widely
accepted concept

One must remember that consensus panels on
the definition of ED have focused on putting
the definition in terms of “satisfactory” sexual
activity, and the goal-oriented treatment
approach follows along that same line
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
History
 The
history is essential in determining
whether the ED appears predominantly
organic or psychogenic
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
History

Components of the ED history that would
support the diagnosis of organic ED include







Older age
Presence of organic risk factors, such as diabetes
or hypertension
Gradual onset and progressive worsening
Pelvic or retroperitoneal surgery, such as radical
prostatectomy
Consistent dysfunction—no difference between
intercourse and masturbation
Sleep erections and morning erections are absent
or significantly diminished in quality
Orgasm present, even without penile tumescence
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
History
 Conversely,
components of the history that
should make the clinician suspect
psychogenic source include:






Younger age
Absence of risk factors
Abrupt onset, especially in relation to a
psychologically traumatic event
Inconsistent and varying dysfunction, with
differences between sexual situations
Sleep and morning erections present
Orgasm absent
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
History
 Individuals
with psychogenic ED should be
identified in the history, so that they may
receive proper psychological treatment
 Drug
interactions are possible with ED
treatments, and it is important to have a
complete list of patient medications
 Previous
surgeries, such as prostatectomy,
can lead to ED
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
History

Evaluation of the person’s cardiovascular risk
and risk reduction program is important

The other cardiac history that is necessary in the
urologist’s office is whether the patient can
tolerate the physical rigors of sexual activity


If he is then given a method to have an erection, he
may be at risk for a cardiac event during sex.
Questions regarding ability to successfully perform
activities of about 3-5 MET will predict success with
sexual activity
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
History
 The
Princeton Guidelines is a good reference
that allows the stratification of men into
certain cardiac risk classes
 When
a man presents with ED, a clinical
assessment of risk factors allows him to be
placed into low, intermediate and high risk
groups
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
History

Princeton Guidelines algorithm for interaction between erectile
dysfunction treatment and cardiac risk
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
History
 The
history should include queries about
what the patient’s goals are in treatment of
erectile dysfunction
 This
may change the choice of treatment
plan
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
Physical examination

The degree of virilization should be noted, and if
abnormal, may make the clinician suspect
hypogonadism

Peripheral pulses should be palpated

If abnormal, there may an increased likelihood of vasculogenic
ED

Neurological examination can tip off CNS disease or
peripheral neuropathies that may be the cause of the
dysfunction

Detailed examination of the penis for hypospadias,
disproportion of the corporal bodies, and plaque is
performed
CNS: Central Nervous System
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
Basic laboratory testing
A
testosterone level should be performed in
all men presenting with ED

because of the potential effects on libido and also
penile tissue function
 Whether
or not to obtain a total testosterone
(low cost) or free testosterone (more
accurate) is controversial

It is probably best to obtain the level in the morning,
especially if the patient is a younger man, as there
is a diurnal variation with peaks in the morning
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
Basic laboratory testing
 In
men with hypogonadism on initial testing,
further evaluation should include a prolactin
level, and LH
 In
men without good prior medical care,
assessment for cardiovascular risk factors
with blood testing is recommended

These include lipid profile and assessment for
diabetes with either fasting blood glucose or
hemoglobin A1C
LH: Luteinizing Hormone
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
Specialized testing

Nocturnal penile tumescence (NPT) monitoring:

Men will have several erections during sleep



This is related to sleep pattern, and not to sexual stimulation
Because men with a psychogenic source of ED will
continue to have such sleep pattern-related erections,
this test represents an opportunity to differentiate men
with organic from those with predominantly
psychogenic problems
The men with organic ED will have poor responses
noted during sleep, in concert with their organic
dysfunction

Men with psychogenic problems will have a discrepancy
between sleep and conscious erections
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
Specialized testing




NPT testing can be done in a supervised sleep
laboratory or in an ambulatory setting
The disadvantages of the laboratory setting are
cost and difficulty sleeping in a strange
surrounding
The advantage of the lab is the ability to monitor
for rapid eye movement (REM) sleep by lab
personnel
Absence of such sleep may lead to false positive
testing
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
Specialized testing

Many urologists utilize the RigiScan ambulatory
NPT monitor

Advantages include low cost and the ability of
patient to sleep in his own surroundings

Another advantage is the ability of the machine to
measure penile rigidity
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
Specialized testing

REM sleep is not measured in the ambulatory
setting and false positive tests may be
encountered

There are many standards for what constitutes a normal
test, but most would consider 2-3 erectile events per night,
duration of >15 minutes per event and rigidity of 50%-60%
a normal test
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
Specialized testing

A. Normal Rigiscan
study showing several
episodes of prolonged
tumescence during a
night of sleep

B. Abnormal Rigiscan
study with short-lived
episodes of
tumescence; the tip
does not have
adequate rigidity
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
Specialized testing



Duplex doppler ultrasonography:
This has uniformly replaced other gross screening
tests for penile blood flow used in the past, such as
determination of the penile brachial index
Advantages include



ability to visualize the artery being measured
identification of Peyronie’s plaques
and direct measurement of blood flow in response to
pharmacologic injection
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
Specialized testing

Injection of a vasoactive drug into the penis is
essential to glean useful information from the test

It is the increase in blood flow that needs to be
measured to assess for arteriogenic erectile
dysfunction

There are a wide number of protocols for type and dose of
injected medicines, including 10-40 micrograms of
prostaglandin E1, 30-60 mg of papaverine, and
combinations of papaverine, phentolamine and
prostaglandin E1
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
Specialized testing

If during such a test, the patient notes that the
erection obtained is much poorer than his normal
baseline erection, the test may be a false-positive

Epinephrine that is released in response to the
penile injection activates the detumescence
mechanism and may be the cause

A patient with sufficient anxiety can also create a
false-positive test
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
Specialized testing
 Cavernosometry/
cavernosography:
 The test is invasive, with 2 needles in the penis,
1 for infusion of medications and saline, and
the other for pressure measurements
 A pharmacologic agent is injected to
achieve full smooth muscle relaxation, and
saline infusion is begun
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
Specialized testing
 In
men whom veno-occlusive dysfunction is
suspected, this test can give more specific
information

but is rarely carried out, as specific treatment of such
dysfunction is rarely performed
 Poor
durability of the results
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
Evaluation of a Man Presenting with ED
Specialized testing
 Penile
arteriography:

Specific arteriography of the internal pudendal
system is reserved for those individuals in whom
penile revascularization is being considered

The arteriogram is performed under
pharmacologically stimulated erection

Penile arterial supply, as well as patency of
potential donor arteries (usually inferior epigastrics)
is carefully examined
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
Sex Therapy
 After
identification of a psychogenic source
for ED, referral to a therapist with expertise in
treating sexual dysfunction is in order
 Organic
treatments may be used in
conjunction with the therapist’s
recommendations, but they should have a
good safety profile, so as to not put the
patient at undue risk
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
Yohimbine
 Yohimbine
is a supplement that has a
historical place in the treatment of ED
 Its
proposed role in the treatment of ED is to
increase parasympathetic and decrease
sympathetic activity
 In
high enough doses it can lead to
diaphoresis, palpitations and elevated
heart rate
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
Yohimbine
 The
AUA does not recommend yohimbine
for the treatment of ED
 Patients
with a history suggestive of
cardiovascular disease should be cautioned
against these supplements
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
PDE5 inhibitors

This class of drug is considered first line therapy
for those men presenting with ED without a
contraindication to their administration


Administration results in inhibition of PDE throughout the
body, but due to the relative importance of the enzyme
in the penile tissue, a favorable environment in the penile
tissue of prolonged cGMP effect is seen without major
change in systemic homeostasis
This is due to direct inhibition of the breakdown of cGMP
produced by the NO/cGMP system
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
PDE5 inhibitors
 Drugs



available include
sildenafil citrate (25, 50 and 100 mg),
vardenafil hydrochloride (5, 10 and 20 mg)
and tadalafil (5, 10 and 20 mg for demand dosing,
and 2.5 or 5 mg for daily use)
 All
are highly specific for PDE5, and all are
efficacious in promoting penile erection
capability in men with ED
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
PDE5 inhibitors
 Success
rates for improvement of erection is
~ 70%-80%, and improvement to the point
where the drugs are suitability for
monotherapy of ED is seen in ~ 60% of cases


Choice of agent must take into consideration the
sexual pattern of the patient, without the physician
making assumptions about such things
The advent of daily tadalafil presents the option for
continuous treatment for ED, equivalent to that of
other organic diseases, without suffering a decline
in erectile improvement due to the lower dose
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
PDE5 inhibitors
 Because
these agents inhibit the PDE5
systemically, it is essential they NOT be given
in conjunction with organic nitrates
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
PDE5 inhibitors
 Advantages
of PDE5 inhibitors include oral
administration, safety and effectiveness
 Disadvantages
include cost, systemic
administration as opposed to local effect,
potential for interaction with nitrates, and
poor efficacy in men with severe ED

Cost is becoming an issue as well, as some
insurance companies offer extremely limited
coverage for any ED medications
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
Penile injection therapy
 Many
vasoactive agents have been used for
ED therapy
 Only
alprostadil (PGE1) has been approved
by the FDA for this indication
 Alprostadil,
when introduced into the corpus
cavernosum, actives the cAMP system,
leading to calcium flux and smooth muscle
relaxation
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
Mechanical devices
 Mechanical
devices are similar to semirigids
in that they are in a fixed degree of penile
girth, so erection quality is a complaint of
these devices
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
Mechanical devices

Malleable penile
prosthesis
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
Mechanical devices

2-piece inflatable devices were designed To
meet the advantages of inflatables, as far as
girth expansion and rigidity, while allowing
flaccidity and concealment, while also
capitalizing on the advantages of semirigid—
lack of the need for a reservoir implantation


There is only one 2-piece inflatable available on the
market
It has 2 cylinders which are filled in the center, allowing
for fluid insertion just under the surface of the cylinders
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
Mechanical devices

2-piece inflatable
penile prosthesis
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
Mechanical devices
 3-piece
inflatable devices are most reported
in series in the literature

They consist of 2 cylinders, a reservoir in the pelvis
and a pump in the scrotum
 They
are the most complicated devices and
require a larger surgical procedure to
implant the device

However, they give the best flaccidity and the best
rigidity of all the devices available
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
Mechanical devices

3-piece inflatable
penile prosthesis
with paired
cylinders, reservoir
and scrotal pump
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
Surgical approaches for penile implants
 There
are a variety of ways to place a penile
prosthesis, but most surgeons utilize the
infrapubic or penoscrotal approaches
 Advantages of the infrapubic approach
include

avoidance of the urethra, and ability to directly
open the abdominal fascia for reservoir placement
 Disadvantages

include
longer operative time, abdominal fascial incision
pain, and possibility of dorsal neurovascular bundle
injury
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
Surgical approaches for penile implants
 Advantages
include

of the penoscrotal approach
decreased operative time, decreased
postoperative pain due to no fascial incision, and
better access to the corporal bodies for dilation
 Disadvantages

include
the possibility of bladder or vascular injury during
blind reservoir placement
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
Surgical approaches for penile implants
 Complications
include


of penile prosthesis surgery
infection, erosion and mechanical failure,
necessitating re-operation
Erosion is thought to be due to subclinical infection
in nearly all cases
 With
current improvement in coating of
prosthetic devices, the infection rate should
be <1%
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
Surgical approaches for penile implants
 One
can never be faulted for removing a
device to treat infection
 Fibrosis
and shrinkage seen following
explantation dictates that one considers a
salvage operation in such cases
 If
mechanical malfunction is seen in a
prosthesis, the entire device should be
replaced with a new one
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870
Erectile Dysfunction
ED Treatments
Penile Revascularization

Revascularization of the penis to correct erectile
difficulty is uncommonly performed



due to the stringent criteria for patient selection,
including a young age, a history of significant
pelvic/perineal trauma, and no preexisting erectile
complaints
Angiography is a prerequisite to the surgery
Because ED in older men coexists with other
comorbidities and involves some degree of
venous leak, revascularization is not an option
Ohl A. D, Quallich A. S, Sønksen J. Erectile Dysfunction. In: The American Urological Association
Educational Review Manual in Urology. 2nd Edition 2010; Chapter 28: 853-870