Custom testicle implants have become popular for a variety of reasons, some recognized and others not. The most obvious reason for their use is that they provide sizes that are not available with the use of standard testicles implants which stop at 5.0cm sizes. They can also be made in various 3D dimensions that go beyond the traditional 2D 0.7:1 width to length ratio.
Another benefit they have is that the durometer or softness of the implant material can be adjusted as needed. Almost all custom testicle implants are made of an XXS (extra extra soft) silicone material as no patient has ever said that their testicle implant was too soft.
But as implant sizes become bigger this means more material. As a result even an XXS implant can feel firmer than one would like in very large sizes. A method I have developed to make even the largest testicle implant soft is to design it with a hollow inner chamber. This is done by creating in the implant a small entrance on one end which leads to a small central chamber. By reducing the amount of material inside the implant it will collapse or be easier to compress. (i.e., feel softer)
One other benefit of an internal chamber with an entrance way is that it can have antibiotic solutions or powder put inside the implant. This would then be released after implantation as an extra guard against infection prevention.
Despite the entrance into the implant it is not big enough to allow any significant tissue ingrowth, thus avoiding a source of implant fixation/adhesion.
Dr. Barry Eppley
World-Renowned Plastic Surgeon