- What is a Penile Triplex?
- When is a Penile Triplex performed?
- What preparation is needed for a Penile Triplex performed?
- How is a Penile Triplex performed?
- How are the results of a Penile Triplex interpreted?
Erection is a vascular phaenomenon during which sexual arousal increases penile blood flow through the arteries of the corpora cavernosa. At the same time there is a mechanism blocking the penile venous network; as a result, the blood gets trapped inside the penile body and thus erection is achieved. Vascular problems are the most common etiology for organic erectile dysfunction.
Penile Triplex is a diagnostic test aiming at investigating the condition of the penile vasculature. It is conducted by using an ultrasound device with a fixed special high frequency transducer (7,5 to 13,5MHz). To perform the Penile Triplex, erection has to be induced by infusing specific drugs with a small injection directly into the penil cavernous body.
Penile Triplex is performed in patients with:
- erectile dysfunction of suspected organic etiology. Triplex will investigate any potentially occurring vascular lesion and evaluate the severity of the problem.
- Peyronie’s disease (acquired penile bending due to formation of fibrous plaques inside the tissue). The aim is to evaluate whether the fibrous plaque affects penile vascularisation.
- penile injury during sexual intercourse.
- high-flow priapism. Priapism is a condition when the penis remains permanently in erection due to arterial rupture within penile corpora cavernosa.
No special preparation is needed. You should be aware that it is a procedure that takes about 1 hour (30'-120'), so make sure that you have enough time at your disposal.
You will be asked to lie on the examination bed. The physician will apply a gel on the penis and perform an ultrasonogram at rest. In this way it will identified whether there are any potentially occurring anatomic problems (e.g. fibrous plaque). Then, the physician will cleanse the penis with a special antiseptic fluid and inject a small amount of drug into the penis with a very fine needle (insulin needle). The injection instantly causes a slight disturbance. The drug causes vasodilation in penile vasculature and, as a result, erection is induced. The time needed for the achievement of erection depends on the patient’s vascular condition and potential anxiety. It usually takes 10-15 minutes after the drug administration to have erection. Should the result not be satisfactory, there may be need for repeated drug doses.
Following the injection, the physician uses the special transducer of the ultrasound device to observe the vascular response and measure blood flow within vessels. This is done at regular time intervals, about every 5', until a rigid erection is achieved.
Once the procedure completed, you will have to remain in the physician’s office until erection subsides. You should be aware that some risks may arise from the examination. Penile Triplex is considered to be safe as long as it is performed by an experienced physician who is able to cope with any complication that might potentially occur. Adverse events that may emerge are:
- Nausea, drop of blood pressure. The drugs that are used to induce erection cause vasodilation. Should the veno-occlusive mechanism present any disorder, the drug does not remain in the penis but passes into body circulation and blood pressure drops. Your physician will immediately cope with the problem by making the appropriate interventions.
- Hematoma of penile skin. Your physician usually has to aspirate blood from the penis to treat priapism. In very rare cases, small hematomas may appear at the puncture site. These hematomas fully subside with time.
- Priapism. It is rare but probably the most severe complication that may arise from Penile Triplex. Priapism is the condition when erection prolongs for over 4 hours and starts getting painful. Your physician will aspirate blood from the penis and, if necessary, infuse a specific drug which ‘neutralizes’ the action of previous drugs.
The procedure is dynamic and the physician’s experience is highly significant so as to avoid false results. The evaluation concerns:
- Anatomic problems. By examining the penis at rest, the physician is able to identify any occurring penile impairment.
- Arterial sufficiency. During the procedure, the blood flow within penile arteries is measured. Peak systolic velocity (PSV) is the parameter providing information for arterial sufficiency. Values above 35cm/sec are considered to be normal, whereas values below 25cm/sec indicate insufficient blood flow.
- Competence of veno-occlusive mechanism. Besides PSV, another significant parameter evaluated is the end-diastolic velocity (EDV). The resistance/persistence index (RI) of penile vessels is calculated by using the formula (PSV- EDV)/PSV. RI reflects the veno-occlusive mechanism. Values above 0,85 are considered to be normal.
Besides absolute measurements that will be recorded during the examination procedure, your physician will also take into account other parameters as well to provide the final report. Such factors are the drug dosage that was used, the time needed until erection achievement and the conditions under which the examination was carried out (e.g. patient’s anxiety).