Rear Tip Extenders during Penile Implant – What are they used for?

I recently saw a well-educated, well-endowed patient interested in getting a Coloplast Titan implant, but worried about the feel of the implant in the flaccid state. He liked the idea of the AMS 700 series implant providing a more natural appearance but was concerned that a 24 cm implant (the largest inflatable implant) would be “too small.” This is in fact one of the most common questions, I get from patients interested in a penile implant - how long will my penis be?

There are two manufacturers of inflatable implants in the United States – Coloplast and AMS, differences which I’ve discussed in a prior post. He had watched several informative Youtube videos on rear tip extenders or RTEs (non-inflatable components that are attached to the deep portion of the implant for custom adjustment of size), and wanted to avoid these for his own reasons.

I find that there is quite a bit of misconceptions regarding the use of RTEs. RTEs are simply little spacers that can be attached to the proximal portion of the implant to increase the size. This enables your surgeon to provide a custom fit for your implant. You should have an understanding of the various sizes that are available for inflatable implants in the United States. For AMS, the implant comes in 15, 18, 21, 24 centimeter versions. For Coloplast, these include several more options including 14, 16, 18, 20, 22, 24, 26, 28 cm. This includes a “non-inflatable” solid silicone portion at the base that measures 5 cm on the Coloplast Titan and a slightly smaller portion on the AMS. This essentially means that even without any rear-tip extenders, the largest AMS implant is 21 cm of inflatable portion and Titan is 23 cm portion.

Although I do agree that it is important to try to maximize the size of the inflatable component of the implant to improve axial rigidity and minimize stacking RTEs, in reality each patient is different. The implant encompasses the entire length of the corpora, where 1/3 to a half is inside of the body. Here, having a non-inflatable component within the proximal base will not impact functional or cosmetic outcomes since its all inside of your body. Conversely, not using RTEs when they are needed can lead to short tubing going to the pump or what is referred to as “tail-pipe” penis, where the tubing exiting the corpora is very noticeable through the skin and you may also have a high-riding pump that impacts comfort during sexual activity. In some patients, I will appropriately use RTEs if necessary depending on their anatomy (length of corpora, proximal measurement, size of the scrotum). In others, I may use a slightly larger implant and even shave down that proximal silicone tip to get it to fit. For example in a man that measures 23 cm both proximal and distal, we can use a 24 cm implant and shave off the silicone part till it fits, essentially providing more inflatable size versus a 22 cm plus using a 1 cm RTE. 

I am very happy to offer both implants (Coloplast and AMS) and allow my patients to decide what makes the most sense for them. I do believe there are certain nuances to each implant, which may one a better option in one person, so the discussion needs to be individualized. I don’t feel that one is superior to other. I am grateful to be recognized as a Center of Excellence by Coloplast as well as a Center of Excellence by Boston Scientific/AMS and one of the few surgeons in the region with this dual designation.