Does a penile implant change penis size?
A penile implant can make the erect penis slightly shorter than an erection produced with medication before surgery. In one study the loss averaged 0.74 cm one year after surgery. Most men feel some shortening, but in another study measured length did not change significantly, and in some men with Peyronie's disease stretched length increased.
How much length do men lose or gain after an implant?
The European guideline finds that the literature fails to show a direct relationship between an implant and penile length in men without Peyronie's disease. In one study, 72% of men reported a shorter penis after surgery, yet there was no statistically significant difference in measured stretched length.
Where erect length has been measured against an erection produced by an injection before surgery, the decreases were small. One study found average losses of 0.83 cm at six weeks, 0.75 cm at six months and 0.74 cm at one year. Another found the median length fall from 14.25 cm before surgery to 13.5 cm after it, and a study cited by the American guideline found 13.2 cm before and 12.5 cm one year after.
In one study, 45 men with Peyronie's disease without major curvature or severe scarring received an inflatable implant. Their mean stretched length rose from 13.1 cm before surgery to 13.7 cm at six months and 14.2 cm at 12 months, and stretched flaccid length also differed significantly between six and 12 months.
This group differs from the general implant population, so the result does not show that every man gains length.
Why can the penis look shorter even when it is not?
Several studies report that some men perceive the penis as shorter when the implant is inflated than during a full erection before surgery, so the common reasons for this are discussed beforehand. Memories of penile size can be inaccurate when erectile dysfunction has been present for a long time, and tissue can lose elasticity after a long period without full erections. Weight gain over the pubic area can hide part of the penis, and the glans does not swell during an implant erection.
"It is imperative that clinicians discuss and document expectations of post-prosthesis penile length with men and their partners prior to surgery to ensure appropriately calibrated post-operative expectations." Source 2, p. 31
What affects length after implant surgery?
When the erectile tissue is scarred, men are told that an implant is unlikely to bring back the size they had before. Shortening is also more likely after a delayed replacement, which follows the removal of an infected device.
There is some evidence that surgeons who implant often use longer cylinders, by a median of 2 cm, than surgeons who implant less often. Several strategies before, during and after surgery have been examined to improve length and girth, but the data are insufficient to provide clinical guidance.