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With all the understandable fear of tip erosion that has been expressed in this forum, it got me wondering why are the distal tips (and even more so the proximal tips in the crus) so pointed in the inflatable implants?

The only reason I can think of for this shape is to allow the implant cylinders to be pulled through the corpus cavernosum more easily.

However, my engineering training and experience tells me that this shape is the worst one that is capable of withstanding the point load caused by the axial force during thrusting.

Some members(sic) talk of the more comfortable round tips of malleable implants, a shape that I would have thought is the optimum design to reduce the likelihood of tip erosion and pain since the load is spread over a much larger area of tissue.

Has anyone any information on the reason for this design or experience with a IPP followed by a MPP?

For what it's worth, my surgeon Laurence Levine has said that the IPP and MPP have essentially the same rate of erosion, and that success depends on the surgeon's technique and not so much on the device itself. But yes, I've wondered the same thing. Seems like a lot of people on this forum feel they're experts in physics, prosthetic urology, and engineering without really addressing the basics, or the recent literature. There is going to be pressure inside the tissues no matter what device you have, simply because you have something inside your corpora.

Also, per Coloplast's own data: around 80% of Titan patients are diabetic. Failures due to erosion or infection have a lot to do with diabetic symptoms.

The dumbest design ever

Doggedly_positive wrote:The only reason I can think of for this shape is to allow the implant cylinders to be pulled through the corpus cavernosum more easily.

But also, both the distal and proximal ends of the corpora cavernosa are narrower at the ends. The shape of the implant cylinders are manufactured to be close to the same length and shape as the corpora, since the intent is to implant cylinders that are the same length as the corpora, but not oversized.

The distal and proximal ends of the AMS implants are somewhat more rounded than the Coloplast cylinders. But from what I've read elsewhere on this site, the risk of erosion at the distal end of the cylinders seems to be related to an implant cylinder that was oversized rather than the shape of the distal end of the cylinders. Maybe guys on FT who have had both an AMS and Coloplast implant can opine as to whether one brand's cylinder tips are more comfortable or functional than the other.

Someone posted an MRI of a floppy glans penis once.
The distal ends of the corporas were shaped exactly the same as the implant cylinders. Just 2 cms short.

For the Coloplast Genesis MPP, their marketing messages highlight these reasons:

1) Fits small corporotomies
2) Offers a better fit
3) Provides a natural aesthetic result
4) Ensures glans support

What strikes me is that they focus on aesthetics and fit rather than patient comfort. Well, no one wants floppy glans either, so it's a toss!

not going to lie, when i first started pumping damn those tips hurt

Implant2025 wrote:

Doggedly_positive wrote:The only reason I can think of for this shape is to allow the implant cylinders to be pulled through the corpus cavernosum more easily.

But also, both the distal and proximal ends of the corpora cavernosa are narrower at the ends. The shape of the implant cylinders are manufactured to be close to the same length and shape as the corpora, since the intent is to implant cylinders that are the same length as the corpora, but not oversized.

The distal and proximal ends of the AMS implants are somewhat more rounded than the Coloplast cylinders. But from what I've read elsewhere on this site, the risk of erosion at the distal end of the cylinders seems to be related to an implant cylinder that was oversized rather than the shape of the distal end of the cylinders. Maybe guys on FT who have had both an AMS and Coloplast implant can opine as to whether one brand's cylinder tips are more comfortable or functional than the other.

I would imagine that those same same ends of the corpora are softer and more flexible than the implant cylinder tips, which leads me to believe that they would easily adapt to rounder tips.

In any case, once erosion has started, the corpora tip shape surely becomes irrelevant as the cylinder has now escaped that intended location, so would the best shape to slow further erosion not be one that spreads the load over a wider area?