Can a Penile Implant Stay Partially Inflated?

According to the 2025 EAU Guidelines, there are two main classes of penile implants available for treating erectile dysfunction: inflatable devices (two- and three-piece) and semi-rigid devices (malleable, mechanical, and soft flexible).¹ Each type offers different capabilities regarding partial inflation and rigidity adjustment. The three-piece inflatable prosthesis is the most versatile option, allowing patients to achieve various degrees of rigidity by controlling how much fluid is transferred from the reservoir to the cylinders.² This adjustability enables the device to remain in a partially inflated state if desired, providing a more natural appearance and feel. The guidelines note that patients often prefer three-piece inflatable devices precisely because they provide more “natural” erections with adjustable firmness.³ Two-piece inflatable prostheses can also maintain partial inflation, though with less adjustability than the three-piece models. These devices are recommended as viable options for patients at high risk of complications with reservoir placement, such as those with previous abdominal surgery.⁴ While they offer some degree of adjustability, the control is more limited compared to three-piece systems. Semi-rigid prostheses, by contrast, result in a permanently firm penis that can be manually positioned but cannot be truly “deflated.” These devices maintain a constant level of rigidity that can be manually placed in an erect or flaccid state.⁵ The guidelines point out that while semi-rigid implants offer the advantages of a simple implantation technique and easy use, they have the disadvantage of creating an unnatural, persistent erection with reduced concealability.⁶ They may be appropriate for men with limited manual dexterity who might struggle with the inflation/deflation mechanisms of inflatable devices. Patient satisfaction rates are remarkably high across all implant types (92-100% in patients and 91-95% in partners) when appropriate counseling is provided.⁷ However, mechanical failure and infection remain the two main complications. Modern three-piece prostheses have mechanical failure rates of less than 5% after 5 years of follow-up. ⁸ A meta-analysis showed implant durability rates of 93.3% at 1 year, 91.0% at 3 years, 87.2% at 5 years, decreasing to 52.9% at 20 years.⁹ The guidelines emphasize that there are currently no head-to-head studies comparing different manufacturers’ implants that demonstrate superiority of one implant type over another.¹⁰ The choice between partially inflatable versus fully inflatable or semi-rigid options should be made based on individual patient factors, including manual dexterity, anatomical considerations, previous surgeries, and personal preferences after thorough counseling about the benefits and limitations of each type.