Dr. Eid on RTEs (tip extenders)

[strongagain]

Thank you Tangerine, fantastic info.

[PFracture]

I second the information provided by tangerine! Freaking amazing information! My jaw just dropped! Thank you so much!

[alibaba]

good information! That last one with tips stacked like leggos is preposterous but we have all read or seen videos that some doctors do that.

[shooter1000]

I found myself wishing that I hadn't read this post right before I went to bed. I couldn't get it out of my mind. My first reaction was "Duh" well of course if you move to fulcrum closer to the weak point (solid section) it will bend easier. There is certainly some valuable information in the study, but the fact that the real world applications have so many more variables than the study can easily lead you to false conclusions about a particular application.

You can't just assume that because a particular patient has more or longer RTE's that his implant is more flexible because the depth of the Crus is a major contributing factor. The test uses the same simulated Crus depth for a all of the implants. If for example you made the Crus 2CM deeper for each 2CM RTE, the deflection would not change as the fulcrum would always be in the same place.

What is clear is that you want the inflatable portion of your implant well down in your Crus for best rigidity. If your Crus is 12 CM deep though, 4 CM of RTE's is not likely to be a problem. In my case I have a very shallow Crus at about 8 CM and I got 2CM RTE's leaving 6 CM buried.

It is also interesting to see how the stiffness changes in a Titan with the thicker wall associated with the longer cylinder. Questions that swirled in my mind were wondering if corresponding larger sizes have similar differences on AMS 700 cylinders, and how the non inflatable base of an AMS 700 compares the that part of a Titan.

It is a fascinating and complex subject. We are all fortunate the the developers of the current products did the job so well. As a manufacturer of orthopaedic implants, I also understand the need to control the amount of inventory and sizes required. It would be ideal to have cylinders sized in 1 CM increments, but in this very low volume market it would like raise costs prohibitively.

[ThePlumber1964]

Shooter,

As a person with science and manegerial background, I find your posting very thorough and very well presented. Your analysis is spot on, revealing areas that should have been explored during the testing execution. Just the important fact that the proximal depth is so variable, and it was not taken into consideration, may reveal a flaw during the design of the experiment phase.

I really enjoy it!

[Lost Sheep]

Shooter,

As a person with science and manegerial background, I find your posting very thorough and very well presented. Your analysis is spot on, revealing areas that should have been explored during the testing execution. Just the important fact that the proximal depth is so variable, and it was not taken into consideration, may reveal a flaw during the design of the experiment phase.

I really enjoy it!

Would you call it a flaw or simply a deficiency?

Allowing variation in the parameter for crus depth would have multiplied the size and complexity of the study, prpbably far beyond their funding. Limiting (simplifying) the scope made the study more likely to be read and understood, not to mention, published.

Thanks for reading. I do not mean to criticize , only to critique.

[ThePlumber1964]

I see it as an incomplete, flawed design of the experiment, in which by not taking into consideration such an important variable as the proximal lengths, produced scewed data that will inevitably alter and corrupt the conclusions. I think shooter nailed it in the head.

I do not know what the purpose or target audience of the experiment was, but I doubt that it could have been used for any kind of submission for FDA approval, again because of missing such an important variable is artificially forcing and/or creating an inherent bias into the conclusion. I am not saying that this was done on purpose to mislead people , just that it is flawed, hence the conclusion is debatable.

[shooter1000]

Thanks for the compliment and support Plumber. Like you I doubt that it was intended to mislead, But unfortunately I does just that. You are correct I'm sure about the FDA. The last product I had tested required 5,000,000 cycles in a carefully controlled independent lab. Not that these implants would need that kind of number but the point is the FDA is quite strict and extremely cautious when approving an implantable device.

Before my procedure, I read the applicable patents on the implants. They have covered their butts in every way you can dream of lol. I was hoping that with personal experience I could find a way to advance the prior art as my patent Atty would say. Frankly , they have done quite a good job at both major companies considering the volume of the market. It is likely that all of our three musketeers have consulting contracts with one or more of the majors. The companies would need their feedback as they likely do almost 2/3 or more of all the implants in the USA.

So for now it continues to come down to picking the best cutter (surgeon), and I believe that any of our three is likely to do a good job, and they obviously care about their craft and their patients.

I have never met a surgeon who would not like to redo his first 100 operations of any new device. At the volumes I guess are being done I imagine almost all other than our three pus a few others are in that category.

[rahod1]

Here is a quote from Dr Eid's web site on extenders that I don't think was addressed here:

"However using rear tip extenders will negatively impact the quality of the erection as the non-inflatable portion of the cylinders will dilate the pseudo-capsule over time and the base of the cylinders will not be held firmly to the patient's body. The erection will wobble and we recommend judicious use of rear tip extenders"

So DEPTH isn't the only consideration.

[Lost Sheep]

Interesting side note:
Female to male transgender persons who get penile prostheses (at least one model I have seen written up) have the proximal end attached with connectors right to the pelvc bone.