If Viagra and injections fail (or if you are unwilling or unable to use either therapy), a vacuum constriction device could work. During this procedure, a cylinder is placed over the penis. The air is pumped out of the cylinder, which draws blood into the penis and causes an erection. The erection is maintained by slipping a band off the base of the cylinder and onto the base of the penis. The band can stay in place for up to 30 minutes. Although these devices can be effective, they generally have been less desirable for patients who have been treated with surgery. Many patients dislike having to use the band at the base of the penis and find it uncomfortable.