Average Penile Size After Implant Placement

Penile prosthesis implantation is considered a third-line treatment option for erectile dysfunction when other treatments fail or based on patient preference.¹ The 2025 EAU Guidelines strongly recommend implanting a penile prosthesis in such cases, after fully informing patients about the benefits and potential complications associated with the procedure.² The guidelines identify two main types of penile implants: inflatable (three-piece and two-piece) and malleable (semi-rigid) prostheses.³ Three-piece inflatable devices consist of a pair of cylinders implanted in the corpora cavernosa, a pump placed in the scrotum, and a fluid reservoir positioned in the retropubic space. Two-piece inflatable prostheses have the fluid reservoir incorporated within the cylinders. Malleable prostheses are always rigid and can be bent manually into an erect or flaccid position.⁴ Regarding penile size outcomes after implantation, the 2025 EAU Guidelines clearly state that “penile prosthesis implantation is not effective in increasing penile length.”⁵ In a study cited by the guidelines, 72% of patients reported a subjective decrease in penile length following implantation, although no statistically significant difference was demonstrated in measured stretched penile length.⁶ This perception of penile shortening is an important consideration for patient counseling and setting realistic expectations. In specific cases where patients have Peyronie’s disease with minimal deformity (curvature< 30°) or severe penile fibrosis/scarring, some improvement in stretched penile length has been observed. One study using an expandable inflatable implant showed mean stretched penile length improved from 13.1 ± 1.2 cm to 13.7 ± 1.1 cm at 6 months and 14.2 ± 1.2 cm at 12 months post-implantation.⁷ However, this represents a special case and not the typical outcome for most implant recipients. The guidelines explicitly recommend against penile prosthesis implantation for patients specifically seeking penile lengthening options.⁸ This strong recommendation underscores that implants should be viewed primarily as a solution for erectile dysfunction rather than a means to increase penile dimensions. Patients should be counseled that the primary goal of penile prosthesis implantation is to restore erectile function and sexual activity, not to enhance penile size. Potential complications of penile prosthesis implantation include infection (requiring removal of the prosthesis and antibiotic administration), mechanical failure, impending implant erosion involving the distal corpora, urethra, or glans (occurring in 1-6% of cases), and non-infectious reservoir complications.⁹ Specific patient populations may have higher risk of complications, such as patients with diabetes, spinal cord injury (up to 16% infection rate), or those undergoing concomitant lengthening procedures.¹⁰