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
Research Design
Total Sample Size
Methods Outcome
Moemen et al. 2008;
Level 4
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
3. There was a significant increase in
testosterone in all groups after sildenafil
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
Denil et al. 1996;
Level 4
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
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
4. 60% of men and 42% of women
indicated an improvement of the sexual
Chancellor et al. 1994;
Level 4
Population: 18 men; Age: range 19-65 yrs;
Level of injury: C7-L3, 15 thoracic.
Treatment: Minoxidil spray, papaverine
injection, or vacuum constriction device
Outcome Measures: Erectile response.
1. Vacuum constriction device changed
rigidity a median range of 57% range
2. No difference between vacuum
constriction device and papaverine.
3. Patient subjective rating scale was
significantly lower for minoxidil than
vacuum constriction device or
4. Physician subjective ratings (from 0 to
10) were significantly lower for minoxidil
than other treatments on erectile
Heller et al. 1992;
Level 4
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
2. 83% very satisfied at follow-up.
3. 53% using device at follow-up.
Zasler & Katz 1989;
Level 4
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.


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.


There is level 4 evidence (Moemen et al. 2008Denil et al. 1996Chancellor et al. 1994Heller et al. 1992Zasler 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.