Erectile Dysfunction (ED)
ED is defined as the persistent "inability to achieve or maintain an erection sufficient for satisfactory sexual performance." While ED is not life threatening, the condition may result in withdrawal from sexual intimacy and reduced quality of life.
The cause of erectile dysfunction is inadequate rigidity of the blood filled cylinders (corpora cavernosa) of the penis. This may be due to a lack of nerve signals initiating blood flow into the penis, impairment of the arteries filling the penis, ineffective closure of veins required for appropriate storage of blood within the erect penis, psychological factors, and hormonal deficiencies. A combination of physical and psychological factors is often present. Secondary problems related to erectile dysfunction can include loss of sexual desire (loss of libido), premature ejaculation, or inability to reach orgasm.
The physical causes of ED can be further divided into nervous system problems, artery and vein damage, and hormonal causes. Nervous system causes may be due to brain or spinal cord disease (e.g., spinal cord injury, multiple sclerosis) or due to injury to smaller peripheral nerves (e.g. previous pelvic surgery and diabetic nerve damage). Artery or vein damage may be related to the build-up of obstructive cholesterol deposits in arteries, high blood pressure, diabetes, smoking, or trauma. Low testosterone levels can interfere with normal erectile function however this is not considered to be a principal cause of ED in the majority of patients.
The prevalence and severity of ED increase with age. By the time men reach their seventies, 70% will have ED to some extent (Figure 1). Other risk factors include high blood pressure, diabetes, smoking, high cholesterol, vascular disease.
Treatment options for ED have increased over the past decade to include oral treatment, intracavernosal injection therapy, vacuum constriction devices, hormone replacement and surgery. The goal of treatment is to restore satisfactory erections with minimal adverse effects. Men have demonstrated a strong preference for oral treatments even if they have low efficacy.
Oral phosphodiesterase type-5 inhibitors (PDE5 inhibitors) such as Viagra, Cialis and Levitra are first line therapy for ED.
The efficacy of sildenafil (Viagra), vardenafil (Levitra), and tadalafil (Cialis) are very similar. Because efficacy is very similar amongst the three agents, side effects and time-to-onset will be the main distinguishing factors. Viagra and Levitra feature rapid-onset of action, whereas Cialis has a long window of opportunity for use. Maximum levels in the bloodstream are reached within 45 minutes with Levitra, an hour and 10 minutes with Viagral, and 2 hours with Cialis. Conversely, the half-life of Viagra is 4 hours, for vardenafil 4 to 5 hours, and for Cialis 17 to 21 hours.
Cardiovascular diseases may be a contraindication to treatment with these medicines. Severely impaired patients may run the risk of a cardiac complication related to vigorous sexual activity. Likewise, patients actively taking nitrates, including nitroglycerine and other agents, are contraindicated from receiving prescriptions for PDE5 inhibitors.
Visual disturbances can be seen with sildenafil (blue haze to the visual field; this effect is temporary and is not dangerous).
A very rare but more serious visual complication is shared by all PDE5 inhibitors. This is non-arteritic anterior ischemic optic neuropathy (NAION). A number of cases have been reported and generally risk factors for this very rare form of blindness are severe cardiovascular conditions.
Intra-cavernosal injection is the most effective non-surgical treatment for erectile dysfunction. Alprostadil (prostaglandin E-1) phentolamine and papavarine are the medications used in the injection.
ICI is a very effective way to generate an erection in the early post operative period following radical prostatectomy. Using ICI improves the rate of recovery of normal erectile function following prostate surgery.
Intracavernosal injection has the highest potential for priapism (prolonged painful erection). For this reason the initial trial dose of intra-cavernosal injection therapy is administered under the supervision of Catherine Acton, our erectile dysfunction nurse. An erection lasting more than four to five hours may lead to long term erectile problems and needs to be treated urgently. If an erection lasts for four hours then patients should initially try to repeat the ejaculation, take a cold shower and go for a brisk 15 minute walk; if these measures do not help then taking the tablets supplied is recommended. If the erection is still present at five hours then urgent medical treatment at a hospital is required. The erection may need to be surgically drained of blood.
Vacuum Constriction Devices
Nearly 95% of men with erectile dysfunction can obtain an erection sufficient for sexual satisfaction with a vacuum constriction device. Vacuum constriction devices can be a useful treatment option especially in the patient with a supportive partner in a stable relationship. Virtually all men of all ages and with all types of erectile dysfunction can have successful intercourse with a vacuum constriction device. The device uses either a hand or battery operated pump to develop a negative pressure around the penis and thus draw blood into the penis. Used regularly following radical prostatectomy, a vacuum constriction device can improve the rate of recovery of normal erectile function.
The technique of using the device is shown in figure 2.
Catherine Acton, erectile dysfunction nurse at Wellington Urology Associates will provide instruction in the correct use of the device and supply you with a trial device to take home and learn the technique prior to considering purchase.
When other treatment options are unsuccessful, penile implant surgery can provide excellent patient and partner satisfaction. Both malleable (bendable) and inflatable devices can be implanted to allow penile rigidity and satisfactory sexual intercourse. The patient considering prosthesis implantation and when possible his partner, should be aware of the different types of prosthesis, risks of infection and erosion, mechanical failure and resulting re-operations, differences from the normal flaccid and erect penis including the possibility of penile shortening, and the potential reduction in the effectiveness of other therapies if the device is subsequently removed.
Penile implant surgery can be very effective, provided that precautions are taken to avoid infection. Prosthesis surgery is contraindicated if systemic, skin, or urinary infection is present. Antibiotics should be provided pre-operatively, and the surgical site should be shaved immediately prior to surgery. Patients are hospitalized overnight and sent home on seven days of post-operative antibiotics. Using these and other precautions, the implant infection rate is less than 5%.
Prior to surgery for penile implantation, a careful history and physical examination are necessary.� This confirms the nature of the erectile dysfunction, and identifies any additional sexual dysfunction such as loss of desire, inability to ejaculate, or premature ejaculation.� Penile implant surgery will not affect these other aspects of sexual function.� Physical examination is focused on the genitalia in order to identify any skin or urinary infection which would be a contraindication to surgery.� Additional features include the length and stretchability of the penis, previous surgical scars, and any penile fibrosis or scarring which may complicate the implant surgery.� There are two main categories of penile implant.
Malleable and inflatable penile implants share many risks and benefits.� Below will be found brief descriptions of the two operations followed by shared risks and complications.
Malleable Penile Prosthesis
A malleable penile prosthesis is always the same length.� The largest and longest device which can be accommodated by a man�s penile dimensions will be inserted via a small incision at the base of the penis in the penis-scrotal junction.� Concealment is achieved by bending the rods downward.� Sexual intercourse is possible by bending the malleable rods in the desired direction.� Implantation requires one to one and a half hours of surgery.
Inflatable Penile Prosthesis
Figure 2. Inflatable Penile Prosthesis
Inflatable penile prostheses use fluid to achieve rigidity.� This fluid is shifted from a reservoir placed next to the bladder into two paired cylinders placed on either side of the penis through an incision at the base of the penis at the penis-scrotal junction.� Fluid movement is controlled by a pump, which is placed in the scrotum next to either the left or right testis.� The main advantage of the inflatable penile prosthesis is complete flaccidity and concealment when the device is deflated.� Additionally, when the device is inflated, excellent girth is achieved, with full rigidity and a sense of change in penile size similar to an erection.� Of note, the head of the penis may not become rigid with this device, as it is merely supported by the device.� Inflatable penile prosthesis implantation takes one and a half to two hours to insert, and generally patients remain in the hospital overnight with a small closed suction drain placed adjacent to the device.� This is removed the first day after surgery.
Risks and Complications
The most serious complication is infection of the penile implant.� This happens up to 5% of the time depending on the nature of the implant, previous surgical history, and other factors which can influence the rate of infection.� Bleeding is rare, but maybe manifest as haematoma or bruising of the scrotum.� Mechanical failure occurs in approximately 5% of cases within the first 5 years after surgery.� Ultimately, like any mechanical device, failure depends on the amount of use and wear-and-tear on the device.� The penis will never be longer than it was before surgery, and usually there is a mild amount of shortening.� Some inflatable devices may undergo temporary inflation, termed auto-inflation.� This usually only lasts for several months and eventually goes away.
This fact sheet complements the discussion during your consultation, which will apply your individual circumstances to the above facts.