Erectile dysfunction
Introduction
Definition and overview:
Erectile dysfunction is the continuously inability to achieve or maintain penial
erection necessary for sex performance.
Historical context:
The history of erectile dysfunction (ED)
extends for many centuries. With the
improvement of different theories and
methods, the very first recorded treatment was
from 8th century BC in India. It was believed
that sex with undesirable women causes ED,
leading to treatments involves herbal
medicines with animal-derived additives.
However, in the beginning of the 20th century,
John R. Brinkley controversially promoted
goat testicle transplant as an ED treatment,
which led to canceling his medical license. By
the 1970s, penile implants and vacuum pumps became common, with Geddings
Osbon's "youth equivalence device" paving the way for modern penis vacuum
devices. In the 1980s, Dr. Giles Brindley's research on vasodilators laid the base
for medicinal treatments. The big discovery came in the beginnings of the 1990s
with the discovery of sildenafil (Viagra), which was initially developed as a heart
medication. Pfizer launched Viagra in 1998, revolutionizing the treatment of ED
and making it widely available, including over the counter and online options.
Epidemiology:
Erectile dysfunction effects nearly 10% of men whose age is between 40 to 70
years, in addition, 25% of them experiencing moderate or alternating difficulties.
ED spreads increasingly with age, rising from 22% at age 40 to 49% at age 70.
Despite it is less common in younger men, it stills affect 5% to 10% of those who
are younger than 40.
Etiology
Causes and risk factors:
There are many causes and risk factors for ED. But the
most significant are the following: prostate problems, type
2 diabetes, high blood pressure, vascular disease/surgery,
high levels of cholesterol, sleep disorders, drugs,
neurogenic disorders, depression, alcoholism, and
smoking.
Genetic and environmental influences:
Genetically, variation and mutation in some genes may incline people to ED.
Natural environments don’t have many influences on ED but some lifestyle
choices like smoking, alcohol, and chronic and psychological factors can have a
strong impact on ED.
Clinical Features
Signs and symptoms:
The symptoms of ED are neither much nor complicated, and they are the
following: disability of getting an erection, keeping it, and reduced sexual desire.
Disease stages and progression:
ED passes through various stages from weak to dangerous. At first, it may appear
as random difficulty achieving an erection. As the state gets worse, these events
become more frequent and constant, often related to health conditions like
cardiovascular disease or diabetes. In many cases, individuals may experience a
complete inability to achieve an erection.
Complications:
Some of the complications of the ED are the following: stress and anxiety, low
self-esteem, fertility issues, relationships problems, and depression.
Diagnosis
Diagnostic criteria:
Diagnostic criteria of ED involve reviewing ED symptoms, any medical
conditions, medications/ drugs, and psychological factors.
Diagnostic tests and procedures:
Laboratory examinations like diabetes blood tests, testosterone levels…etc. In
addition to some specialized tests like penile Doppler ultrasound or nocturnal
penile tumescence.
Differential diagnosis:
Differential diagnosis for ED includes but is not limited to the following:
psychological disorders, cardiovascular conditions, endocrine and urological
disorders, neurological conditions, medication side effects, bad lifestyle effects,
and aging.
Pathophysiology
Mechanisms of disease development:
ED can develop by many ways, some of them are the following:
- Atherosclerosis, endothelial dysfunction, and hypertension reduce blood flow to
the penis.
- Nerve damage or peripheral neuropathy impairs signal transmission for erections.
- Low testosterone and thyroid disorders affect libido and erectile function.
- Stress, anxiety, and depression interfere with the psychological arousal needed
for an erection.
- Substance abuse and smoking impair sexual function.
- Natural age-related changes in vascular, neurological, and hormonal systems can
contribute to ED.
Cellular and molecular changes:
ED can cause some changes in the human body like: blood flow issues, vascular
problems, muscle problems, hormonal changes, and inflammation.
Impact on body systems:
ED impacts many body systems. Cardiovascular: it can indicate cardiovascular
issues due to impaired blood flow. Hormonal: hormonal imbalances, such as low
testosterone, can worsen ED. Nervous: Nerve damage from conditions like
diabetes affects sexual arousal. Psychological: ED can lead to psychological issues
such as stress, anxiety, and depression. Reproductive: ED directly impacts sexual
function and intimacy. Musculoskeletal: ED potentially reducing physical activity
and fitness.
Management and Treatment
Medical and surgical treatments:
Medical treatments include oral medications like sildenafil and tadalafil, hormone
therapy, intraurethral suppositories, vacuum erection devices, and psychological
counseling. Surgical treatments involve penile implants (inflatable or malleable)
and vascular surgery (bypass or revascularization) to improve blood flow and
achieve erections.
Pharmacological therapies:
Pharmacological therapies for erectile dysfunction (ED) include:
Phosphodiesterase Type 5 Inhibitors (PDE5i): Medications like sildenafil (Viagra),
tadalafil (Cialis), vardenafil (Levitra), and avanafil (Stendra) improve blood flow
to the penis.
Hormone Therapy: Testosterone replacement
for men with low testosterone levels.
Intracavernosal Injections: Drugs like
alprostadil injected directly into the penis to
enhance blood flow.
Intraurethral Therapy: Alprostadil suppositories
placed inside the urethra to induce an erection.
Lifestyle and dietary modifications:
Some of the lifestyle and dietary modifications for ED are the following: regular
exercise, weight management, quit smoking, limit alcohol drinking, managing
stress, suitable sleeping amount, include healthy fats in food, and continuous
hydration.
Rehabilitation and supportive care:
ED rehabilitation and supportive care involve a
comprehensive approach that includes medical
management with medications, hormonal therapy,
vacuum devices, or surgery, alongside psychological support through counseling
or sex therapy. Lifestyle changes such as improving diet, exercise, quitting
smoking, and reducing alcohol intake play a crucial role. Education about the
condition and open communication with a partner are essential, as well as
participating in support groups for additional emotional support and practical
advice.
Prevention and Control
Primary, secondary, and tertiary prevention strategies:
Primary prevention of ED includes building a healthy lifestyle and avoiding bad
habits. It also includes managing stress and regular check-ups. Secondary
prevention includes early detection, medical involvement, and psychological
support. Tertiary prevention focuses on managing existing ED with medical
treatments, continuous monitoring, and therapy.
Public health interventions:
Public health interventions for ED include educational
campaigns, improving healthcare access, developing
healthy lifestyles, adding mental health support,
training healthcare providers, and developing
community programs.
Vaccination and screening programs:
Currently, there are no vaccines for ED. Future research may discover vaccines for
basic causes. Screening programs for the people who have ED focuses on
evaluating risk factors, evaluating mental health, and increasing awareness.
Prognosis
Disease outcomes and survival rates:
A study involving 1,519 men with cardiovascular disease (CVD) from 13 countries
discovered that those with erectile dysfunction (ED) faced significantly higher
health risks compared to those without ED. Specifically, men with both CVD and
ED were found to be 1.9 times more likely to die from cardiovascular disease,
twice as likely to suffer a heart attack, 1.2 times more likely to be hospitalized for
heart failure, and 1.1 times more likely to experience a stroke. The study
highlighted that ED could be an indicator of early atherosclerosis.
Factors influencing prognosis:
There are many factors influencing ED some of them are the following: underlying
health conditions, lifestyle factors, psychological factors, age, medication and
drugs usage, hormonal imbalance, and sexual health.
Quality of life:
ED can affect the quality of life in a significant way by influencing emotional well-
being, social interactions, relationships, and self-confidence. ED can also lead to
stress and underlying health issues.
Current Research and Future Directions
Recent advances and discoveries:
1- Weak shockwave therapy, which is a therapy that transfers sound waves to the
penile tissue which leads to improving blood flow and erectile function.
2- Stem cell and platelet rich plasma therapy. These focus on repairing damaged
tissues and improving erectile function.
3- Gene therapy which divides into two parts. The first one is addressing the
underlying cause of ED. The second one is fixing specific genes to improve
erectile function.
Ongoing clinical trials:
In 2024, the University of Zagreb is working on a trial
to investigate the combination of low intensity
shockwave therapy and tadalafil for minor to
moderate vasculogenic ED. Other trials conducted by
the American Urological Association (AUA) and
other research institutions. These trials focus on
another area of study involving alternative therapies, including stem cells and
platelet-rich plasma (PRP).
Future research needs:
More research is needed to discover the link between ED and comorbid conditions
like cardiovascular disease and diabetes, as managing these conditions can lead to
improvements in ED symptoms. Longitudinal research is also needed for
understanding the development of ED and the long-term effects of various
treatments, providing a broader view of the condition and its management over
time. Finally, combining psychological therapies with medical treatments can
significantly improve outcomes for ED patients, particularly because psychological
factors often play a crucial role in the condition.
Case Studies
Example cases:
John, a 55-year-old man, had type 2 diabetes for over 15 years. Despite medical
advice, his diabetes was badly controlled, leading to complications such as
neuropathy and cardiovascular issues. John also had high blood pressure and
hyperlipidemia, and he was a regular smoker and drinker. Year by year, he noticed
a continuing decrease in his ability to achieve and maintain erections, which began
to strain his relationship with his partner.
John's case is a classic example of how chronic illnesses, such as diabetes, can lead
to ED. The high blood sugar levels associated with diabetes can damage blood
vessels and nerves, which are crucial for achieving an erection. Additionally,
John's lifestyle choices, like smoking and alcohol consumption, further worsened
his condition. His treatment involved lifestyle modifications, including quitting
smoking and reducing alcohol intake, alongside better management of his diabetes
and high blood pressure. John was also recommended a phosphodiesterase type 5
(PDE5) inhibitor, such as sildenafil, which helped improve his erectile function.
