Mechanical Methods: Vacuum Devices and Penile Rings
Vacuum device is a pump machine consists of a plastic cylinder with an aperture at one end that is placed over the penile shaft, the other end is a pump mechanism that is used to generate negative pressure within the cylinder to draw venous and arterial blood into the erectile tissue. The erection is maintained by placing a constricting ring around the base of the penis and can slow down the speed at which blood leaves the penis.The constriction ring should not remain on for more than 30 – 45 minutes.
| Author Year; Country Score Research Design Total Sample Size |
Methods | Outcome |
|---|---|---|
| Moemen et al. 2008; Egypt Pre-post Level 4 N=60 |
Population: 60 men with SCI and erectile dysfunction, at least 6 months post-injury, randomized into 3 groups of 20 (A, B, C) Treatment: Group A took sildenafil 50mg before sexual activity for 1 month; Group B were given intracorporal injection (ICI, 10 mg/ml prostaglandin E1 or 0.5 ml trimix) for 1 month and then took sildenafil for 1 month; Group C used vacuum constriction device (VCD) for 1 month and sildenafil for 1 month Outcome Measures: International Index of Erectile Function – erectile function domain (IIEF-EF); Global Efficacy Assessment Questionnaire (GAQ); Hormonal Profile |
1. 90% of people in all groups showed improvement of erection as measured by IIEF-EF after sildenafil. 90% showed improvement in Group B after ICI, and 70% in Group C after VCD. 2. Improvement in erection reached 100% in all groups according to the GAQ, but ability to penetrate reached 90% after sildenafil, 90% after ICI, and 70% after VCD. 3. There was a significant increase in testosterone in all groups after sildenafil treatment. 4. Participants in Group B reported that ICI resulted in more rigid erections than sildenafil, but 14 participants preferred sildenafil due to easier administration; no participants in Group C was satisfied with VCD and preferred either ICI or sildenafil. |
| Denil et al. 1996; USA Post-test Level 4 N=20 |
Population: 20 men with SCI; Age range 20-50 yrs: 13 complete, 7 incomplete. Treatment: Vacuum erection device (VED). Outcome Measures: Safety and efficacy of vacuum erection device, patient & partner satisfaction. |
1. At 3 months, 93% of the men and 83% of the women reported rigidity sufficient for vaginal penetration. 2. At 6 months, 14 couples were regularly using device at least 1/wk. 3. At 6 months, 41% of the men and 45% of the women were satisfied with the device. 4. 60% of men and 42% of women indicated an improvement of the sexual relationship. |
| Chancellor et al. 1994; USA Post-test Level 4 N=18 |
Population: 18 men; Age: range 19-65 yrs; Level of injury: C7-L3, 15 thoracic. Treatment: Minoxidil spray, papaverine injection, or vacuum constriction device (VCD). Outcome Measures: Erectile response. |
1. Vacuum constriction device changed rigidity a median range of 57% range (30-80%). 2. No difference between vacuum constriction device and papaverine. 3. Patient subjective rating scale was significantly lower for minoxidil than vacuum constriction device or papaverine. 4. Physician subjective ratings (from 0 to 10) were significantly lower for minoxidil than other treatments on erectile response. |
| Heller et al. 1992; Israel Pre-post Level 4 N=30 |
Population: 30 men with neurological impairment, 10 paraplegia, 2 tetraplegia, 7 paraparesis, 7 hemiplegia, 2 multiple sclerosis, 2 autonomic neuropathy. Treatment: Vacuum tumescence constriction therapy (VTCT). Outcome Measures: Device usage, frequency of coitus. |
1. 17 (57%) of 30 patients bought vacuum tumescence constriction therapy device. 2. 83% very satisfied at follow-up. 3. 53% using device at follow-up. |
| Zasler & Katz 1989; USA Post-test Level 4 N=20 |
Population: 20 men with SCI; Age: range 21-65 yrs; Level of injury: C4-L2. Treatment: Each patient was custom fitted for the synergist erection system. Outcome Measures: Efficacy of the synergist erection system. |
1. Snap-gauge (a device used to measure circumferential penile expansion and rigidity) assessment correlated significantly with subjective reports of erectile capability. 2. 15 men and 14 women rated the quality of coitus as very good to excellent compared to previous best since injury. |
Discussion
There are no RCT studies in this area, but level 4 pre-post studies noted that the vacuum constriction device (VCD) is an acceptable alternative for ED therapy in men with SCI who may not tolerate other methods and whose hand function can warrant its use (unless a partner applies it). Premature loss of rigidity, petechiae and penile skin edema, lack of spontaneity, uncomfortable erections and a ‘cold penis” were cited as unwanted side effects. For safe practice, it is recommended that the maximum vacuum pressure should not exceed 250 mmHg (to prevent petechiae and ecchymosis) and the penile ring placed at the base of the penis to trap blood does not remain on for more than 30-45 minutes. An alternative vacuum device (Synergist) is a vacuum device within a silicone sheath that remains on the penis that can be used for longer periods of time due to the absence of constricting bands and a much lower vacuum pressure (8-20 mmHg), and which most patients found satisfying. Denil et al. (1996) reported on 20 couples where 93% of men with SCI and 83% of their female partners reported sufficient penile rigidity for intercourse obtained by the use of a vacuum device after 3 months, but by 6 months less than half the couples were satisfied with the device. Most side effects were temporary and minor. In the Moemen et al. (2008) study, while vacuum device therapy was the least favored option as opposed to ICI or PDE5i, 70% had a normal IIEF-EF score with its use. The authors suggested that the range in variation in patient response to this option might be related to acceptability of the vacuum device by the patient or his partner.
Conclusion
There is level 4 evidence (Moemen et al. 2008; Denil et al. 1996; Chancellor et al. 1994; Heller et al. 1992; Zasler and Katz 1989) that supports the use of medically sanctioned vacuum constriction devices and penile rings as treatment for erectile dysfunction in men with SCI.
