How Much Penile Size is Lost After a Penile Implant?

In men with erectile dysfunction (ED) unrelated to Peyronie’s Disease (PD), clinical studies indicate a modest decrease in erect penile length following prosthesis implantation. One prospective study reported an average reduction of 0.83 cm at 6 weeks, 0.75 cm at 6 months, and 0.74 cm at 12 months postoperatively [1]. Despite these minimal objective changes, a significant proportion of patients report a subjective perception of penile shortening, likely influenced by preoperative expectations and changes in penile sensation.

The literature fails to show a direct relationship between penile prosthesis implantation (PPI) and penile length in men with ED and no concomitant PD [2]. The prospective study described above excluded patients with PD and compared erect penile length after implant inflation with baseline erections induced by intracavernosal injection [1]. Another study that excluded patients with PD also found a small decrease, showing that median pre-operative pharmacologically induced length (14.25 ± 2 cm) was decreased to median post-prosthesis penile length (13.5 ± 2.13 cm) [3].

In patients with Peyronie’s Disease, penile implants are primarily used to restore functional rigidity rather than to increase length. Patients with PD undergoing penile prosthesis surgery must be counseled that the prostheses are not designed to restore the previous penile length [4]. However, in selected cases with PD, length improvements have been observed over time. In one study, 45 men, including some with PD, who had no deformity or a penile curvature of 30° or less and no severe penile fibrosis/scarring were implanted with a three-piece inflatable penile prosthesis with length-expanding cylinders [5]. The mean stretched penile length improved from 13.1 ± 1.2 cm to 13.7 ± 1.1 cm and 14.2 ± 1.2 cm at 6 and 12 months, respectively. A significant difference was also observed in the length of the stretched flaccid penis between 6 and 12 months [5].

Advanced reconstructive techniques for patients with severe penile shortening due to PD may be considered, but these involve increased surgical complexity and higher risk of complications. These techniques should be reserved for highly experienced surgeons and carefully selected patients [6].

In the setting of ischemic priapism, penile shortening due to fibrosis is common. For refractory priapism or episodes lasting more than 48 hours, the EAU Guidelines advocate immediate penile prosthesis implantation; early implantation is associated with less penile shortening (3% vs. 40%) than late insertion [7]. Prompt intervention helps preserve both penile length and girth and may lead to better long-term functional outcomes.

Ultimately, while modest reductions in penile length may occur following implant surgery, the functional benefits of restored sexual activity and erectile rigidity often outweigh cosmetic concerns. Preoperative counseling is essential to align expectations and improve postoperative satisfaction.