Penile vibratory stimulation (PVS) is a first-line method for sperm retrieval in men with spinal cord injury (SCI) and inability to ejaculate. The penile vibratory stimulator (Pic. 1) is a plier-like device that is placed around glans penis to stimulate it by vibration. PVS is thought to cause ejaculation via stimulation of the dorsal penile nerve (Pic. 2). In order to achieve ejaculation, the penile vibrator must appropriately stimulate this nerve.
A wide variety of devices can be used to perform PVS, but the most effective are devices delivering at least 2.5 mm of amplitude.
Since it is a non-invasive method, the process can be used at home by the patient himself, with no need for medical assistance. Due to the low local tactile sensitivity, patients should be instructed towards intermittent and non-prolonged use to avoid penile damage.
Briefly, a vibrator is applied for 2-3 minutes or until antegrade ejaculation (i. e. forward) occurs. If no ejaculation occurs, stimulation is stopped for 1-2 minutes, and then resumed. These steps are repeated for up to 10 minutes of stimulation.
Penile vibratory stimulation should be integrated into current cognitive-behavioral sex therapy techniques to achieve maximal effectiveness and satisfaction in men who had a complete inability to achieve an orgasm during sexual relations.
Vibratory stimulation of the glans can induce ejaculation, this being how semen samples are collected from patients with spinal cord injury. The PVS shows better results in men with spinal cord lesion located above the thoracic-lumbar efferent center (T10-L2; Pic. 3); that is, when the ejaculatory reflex arc remains intact.
If the patient has a history of retrograde ejaculation (i. e. backward), it is necessary to prepare the bladder by emptying it and installing a buffer appropriate for spermatozoa washing before starting the procedure. Alkalinisation of the urine needs to start at least 48 hours before the PVS session. During the session it is important to monitor the patient’s blood pressure (BP) continuously and terminate the procedure if the BP rises to a dangerously high level.
Patients who cannot respond to PVS are often referred for electroejaculation (electrostimulation used to stimulate ejaculation), which must be administered by a physician trained in this procedure.
Autonomic dysreflexia is a potentially dangerous clinical syndrome that develops in individuals with spinal cord injury, resulting in acute, uncontrolled high blood pressure (hypertension). Blood pressure must be monitored continuously throughout the PVS procedure.
During any PVS procedure, care must be taken to manage adverse symptoms such as penile skin edema/abrasion which is wound consisting of superficial damage to the skin.
PVS can provoke autonomic dysreflexia, especially in patients whose level of injury is T6 (sixth thoracic spinal vertebrae) or rostral. Autonomic dysreflexia is caused by extensive sympathetic discharge due to a noxious stimulus originating below the level of injury. Autonomic dysreflexia can be managed by the administration of medications prior to the onset of PVS. A common medication for this purpose is nifedipine, administered sublingually in a dose of 20 mg, 15 minutes prior to PVS onset.
PVS is recommended as the first line of treatment for anejaculation in men with SCI because PVS is safe, reliable, and cost-effective and, compared to other methods, yields the highest number of total motile sperm in antegrade fractions.
Most patients (89%) who are responsive to PVS will ejaculate, however, within two minutes of stimulation onset.