Rear Tip Extenders and Penile Prosthesis Rigidity: A Laboratory Study of Coloplast Prostheses.

The final frontier. Deciding when, if and how.
thereishope
Posts: 190
Joined: Sat Oct 27, 2018 3:22 am

Rear Tip Extenders and Penile Prosthesis Rigidity: A Laboratory Study of Coloplast Prostheses.

Postby thereishope » Wed Apr 22, 2020 3:40 pm

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6358419/

"
Conclusions

Rear tip extenders are one of many components developed over the evolution of inflatable penile prostheses. Our data indicate that minimizing their use and maximizing the inflatable portion of the device may more closely approximate natural erection. Further work is needed to fully validate and confirm these findings both in the lab and in patients, if possible. Future advances in penile prosthetic technology should focus on maximizing rigidity by minimizing the length of the fixed portion of the cylinders.


Safe to say that people on this board advocating for going to doctors that try their best at avoiding RTE's when it's possible to install an implant in the same size have been right all this time?

Lost Sheep
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Re: Rear Tip Extenders and Penile Prosthesis Rigidity: A Laboratory Study of Coloplast Prostheses.

Postby Lost Sheep » Wed Apr 22, 2020 7:46 pm

Yes, there is a dearth of studies on the effect of RTEs on angle of erection, stability of erection ("hinge effect") and patient/partner satisfaction.

The studies I have seen have one glaring flaw. None are in-vivo, but study the implant alone - not installed in a penis. This is a lot easier to do, but leaves out a number of variables. Principally, I think, how the rear of the implant fits in the man's crus. Of course, including more variables, especially in-vivo, makes it VERY difficult to control for those variables.
Lost Sheep
AMS LGX 18+3 Nov 6, 2017
Prostate Cancer 2023
READ OLD THREADS-ask better questions -better understand answers
Be part of your medical team
Document pre-op size-photos and written records
Pre-op VED therapy helps. Post-op is another matter

oldbeek
Posts: 2460
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Location: Los Angeles area

Re: Rear Tip Extenders and Penile Prosthesis Rigidity: A Laboratory Study of Coloplast Prostheses.

Postby oldbeek » Wed Apr 22, 2020 8:55 pm

I have a 15cm 700x with 5cm rte. I only had ed 9 for months right after an RP surgery. My dick sticks straight out and I can hang a hand towel on it. When deflated the 15cm hangs down off the RTE which ends just under my pubic bone. I don't see a problem with a RTE.
82, good health, RP 7-2017, all nerves taken , PSA 0.05, 4-18,, .07 1/19,.05 4/19, .03 11-21, .04 11-23, implanted 4-1-18, Infra-pubic, AMS lgx 15 cm with 5cm rte. Implant at USC Keck. Dr Boyd and Dr Loh Doyle 6.5 x 5, 800 AUS 7-21-20

thereishope
Posts: 190
Joined: Sat Oct 27, 2018 3:22 am

Re: Rear Tip Extenders and Penile Prosthesis Rigidity: A Laboratory Study of Coloplast Prostheses.

Postby thereishope » Thu Apr 23, 2020 2:43 pm

oldbeek wrote:I have a 15cm 700x with 5cm rte. I only had ed 9 for months right after an RP surgery. My dick sticks straight out and I can hang a hand towel on it. When deflated the 15cm hangs down off the RTE which ends just under my pubic bone. I don't see a problem with a RTE.


As the paper shows, that is a questionable claim. I would love to see photos to back these statements up. For the sake of transparency?

merrix
Posts: 1187
Joined: Tue Oct 27, 2015 1:08 am

Re: Rear Tip Extenders and Penile Prosthesis Rigidity: A Laboratory Study of Coloplast Prostheses.

Postby merrix » Sat Apr 25, 2020 7:32 pm

Lost Sheep wrote:Yes, there is a dearth of studies on the effect of RTEs on angle of erection, stability of erection ("hinge effect") and patient/partner satisfaction.

The studies I have seen have one glaring flaw. None are in-vivo, but study the implant alone - not installed in a penis. This is a lot easier to do, but leaves out a number of variables. Principally, I think, how the rear of the implant fits in the man's crus. Of course, including more variables, especially in-vivo, makes it VERY difficult to control for those variables.



Yep, the study linked does of course have the question of how these results transfer to real life hanging over it.
On the other hand, it means something. In real life, maybe results are less pronounced, or maybe more.

What you say though, about how the implant fits in the man's crus, is exactly what makes it even worse in real life. The RTEs deiamter is less than the cylinders' diameter. Hence, RTEs fits with less tightness and this is partly why the "wobbling" happens. Especially over time.

I talked to an implant surgeon who has done thousands of implants, and he said he was convinced about this effect. He had just seen it hundreds of times with his own eyes. People with long RTEs coming back after a few years with an erect angle far from what it was when th implant was new, complaining over that their implant "wobbles". A revision to a larger cylinder with no RTEs fixes the problem.

It is just quite obvious, isn't it? RTEs are there to make up for the size increments of cylinders. Not to make the cylinder longer. If that was the case, there would only be one size cylinders, and then docs just added RTEs to get to the right size.

And people on here saying they have foot-long RTEs and all works great, doen't really mean shit. There are alcoholics with great liver blood tests, smokers since 50 years with no lung cancer. Does that mean alcohol doesn't hurt the liver or tobacco doesn't damage lungs?
No it does not mean that. It means that there is random variation in everything.
But on average, alcohol is bad for your liver and tobacco is bad for your lungs.
And RTEs are bad for your angle and axial rigidity.
43 yo, ED forever from VL
Fit and active
Implanted December 2015
Titan XL 24 cm, no RTEs
Dr. Eid
Activated day 13
Sex after 3 weeks
Gained length and girth
So far It works perfectly
Only one advice: Find a world class surgeon

thereishope
Posts: 190
Joined: Sat Oct 27, 2018 3:22 am

Re: Rear Tip Extenders and Penile Prosthesis Rigidity: A Laboratory Study of Coloplast Prostheses.

Postby thereishope » Sat Apr 25, 2020 9:32 pm

merrix wrote:
Lost Sheep wrote:Yes, there is a dearth of studies on the effect of RTEs on angle of erection, stability of erection ("hinge effect") and patient/partner satisfaction.

The studies I have seen have one glaring flaw. None are in-vivo, but study the implant alone - not installed in a penis. This is a lot easier to do, but leaves out a number of variables. Principally, I think, how the rear of the implant fits in the man's crus. Of course, including more variables, especially in-vivo, makes it VERY difficult to control for those variables.



Yep, the study linked does of course have the question of how these results transfer to real life hanging over it.
On the other hand, it means something. In real life, maybe results are less pronounced, or maybe more.

What you say though, about how the implant fits in the man's crus, is exactly what makes it even worse in real life. The RTEs deiamter is less than the cylinders' diameter. Hence, RTEs fits with less tightness and this is partly why the "wobbling" happens. Especially over time.

I talked to an implant surgeon who has done thousands of implants, and he said he was convinced about this effect. He had just seen it hundreds of times with his own eyes. People with long RTEs coming back after a few years with an erect angle far from what it was when th implant was new, complaining over that their implant "wobbles". A revision to a larger cylinder with no RTEs fixes the problem.

It is just quite obvious, isn't it? RTEs are there to make up for the size increments of cylinders. Not to make the cylinder longer. If that was the case, there would only be one size cylinders, and then docs just added RTEs to get to the right size.

And people on here saying they have foot-long RTEs and all works great, doen't really mean shit. There are alcoholics with great liver blood tests, smokers since 50 years with no lung cancer. Does that mean alcohol doesn't hurt the liver or tobacco doesn't damage lungs?
No it does not mean that. It means that there is random variation in everything.
But on average, alcohol is bad for your liver and tobacco is bad for your lungs.
And RTEs are bad for your angle and axial rigidity.


the only thing i have to add here, is the lack of proof to back people's statements here. And that sucks...

NextStepImplant
Posts: 70
Joined: Fri May 17, 2019 6:22 am

Re: Rear Tip Extenders and Penile Prosthesis Rigidity: A Laboratory Study of Coloplast Prostheses.

Postby NextStepImplant » Sun Apr 26, 2020 2:18 am

supposedly the implant is more likely to bend where it meets the rte. Dr Eid told me this. Also the longer the implant is The more it will grow in length after two years. Titans increase in girth as they increase in length (20.22.24.26.28). the longer the implant installed is the more girth is has. If you are using more then 1cm of rte you are missing out on a implant that has more girth, more length and potential length after cycling, and possible increase chance of hinge effect. I got two charts that I think merrix supplied on a different post and is shows the size difference between titens. The 1st picture shows that there is a 5 cm non inflatable portion of every length of Implant. It all so shows a maximum growth factor that increases with length of implant. The last picture shows that the longer the implant is the wider it is. When you use more rte your missing out on girth and the length that comes with regular cycling. You may also be risking the hinge effect.
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oldbeek
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Re: Rear Tip Extenders and Penile Prosthesis Rigidity: A Laboratory Study of Coloplast Prostheses.

Postby oldbeek » Sun Apr 26, 2020 3:31 am

If you have a 5cm deep cruses, do the pressure tubes on a 20cm implant enter the cylinder down in your perineum area? Surely have to be a scrotal installation. Would the pressure tubing be inside the cruses area then run parallel to the inflatable till they exit into your scrotum. Mine was pubic entry and the tubes exit right at my pubic bone. Some body with a deep cruses and no RTE please enlighten me on how their tubing runs. Very curious.
82, good health, RP 7-2017, all nerves taken , PSA 0.05, 4-18,, .07 1/19,.05 4/19, .03 11-21, .04 11-23, implanted 4-1-18, Infra-pubic, AMS lgx 15 cm with 5cm rte. Implant at USC Keck. Dr Boyd and Dr Loh Doyle 6.5 x 5, 800 AUS 7-21-20

thereishope
Posts: 190
Joined: Sat Oct 27, 2018 3:22 am

Re: Rear Tip Extenders and Penile Prosthesis Rigidity: A Laboratory Study of Coloplast Prostheses.

Postby thereishope » Sun Apr 26, 2020 4:18 am

oldbeek wrote:If you have a 5cm deep cruses, do the pressure tubes on a 20cm implant enter the cylinder down in your perineum area? Surely have to be a scrotal installation. Would the pressure tubing be inside the cruses area then run parallel to the inflatable till they exit into your scrotum. Mine was pubic entry and the tubes exit right at my pubic bone. Some body with a deep cruses and no RTE please enlighten me on how their tubing runs. Very curious.


What does this even have to do with anything? As i expected, you totally disregarded my comment you hanging a towel on your penis and showing us factual proofof it .Kind of reminded me of other times in this board when we had a guy claiming that his stretching routine increased his penile size a great deal and when he was called out on it to show proof, he ran away from it for ages, eventually showing us nothing; (because there was nothing to begin with?)

Whilst i don't doubt your implant gets hard, and you can still have pleasure with it, claims like yours pass on the impression that RTE'S don't matter and don't affect the quality of the erection when that is actually not the case. Not only there is proof of it, as i have link here on the initial post, as there on the post that the images were linked, and here ( https://www.smsna.org/scottsdale2016/presentations/206.pdf. Also, i've spoken with guys that had AMS with RTE's and had revisions for Titan's with NO RTE's and they said that there is definitely a difference for the better in terms of stiffness.

This nonsense should be combated at all cost. Everybody should be informed of this, given that it may impact their doctor selection, since we all know, certain doctors care more about this particular item than others.

The study ends like this, as you can see for yourself:

Conclusion:
•Greater bending deflection was associated with the use of greater RTE length
•Use of RTE decreases the inflatable portion of the cylinder that is supported by the crus
•This data supports the notion that minimizing RTEs improves cylinder stiffness and overall erectile rigidity dynamics
•Decreasing the length of the non inflatable proximal portion decreases the bending deflection
•These observations could possibly improve the design of the next generation of cylinders


I come back to edit this post, because as i was browsing through pubmed i came across this very informative paper:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7108986/

It is well established that surgical outcomes tend to improve as surgeon volume increases (13,14). In a simplistic sense, this may relate to an increasing expertise and efficiency on the part of the surgeon, but it is equally likely that improvements in systems (e.g., operating room staff that are knowledgeable about the procedure, established treatment pathways for surgical patients, etc.) also contribute to these superior outcomes (15). Penile implants are no exception to this general rule of surgical outcomes; ergo, it may be preferable that penile prosthesis surgery not be performed by “dabblers” but rather by individuals who have had intensive training and/or extensive experience with implant surgery. A greater depth of experience and knowledge enables the implant surgeon to recognize and manage problems and potential solutions. This “center of excellence” concept is well recognized in the realm of urologic oncology, but there is no reason it cannot be applied to benign urologic surgeries such as penile implant placement.

Crucially, the enhanced ability of an experienced surgeon to recognize and manage potential problems applies in terms of both pre-operative counseling and intraoperative management. Most experienced implant surgeons have cared for patients with unreasonable or unattainable expectations. Trost et al. summarized these sorts of patients in an excellent review paper using the acronym “CURSED Penis”, referring to patients with tendencies to be Compulsive/Obsessive, Unrealistic, requesting Revision, Shopping for numerous surgeons, Entitled, in Denial, or carrying a Psychiatric diagnosis (e.g., mood disorder, body dysmorphic disorder, substance abuse) (16). Standards of medical professionalism dictate that even patients with these disorders not necessarily be denied management of ED with a penile implant; however, when there is abundant evidence that the patient’s perceived outcomes are likely to be poor, the surgeon is best served to defer management until such time as reasonable expectations about post-operative functional status can be set with the patient. Pre-operative expectations are a very strong predictor of post-operative outcome (17); it is essential that the patient approach penile prosthetic surgery with a reasonable idea of what a penile implant can and cannot do.
Go to:

Trends in operative management


Interestingly, the measured length of penile corpora and implant length shows a trend towards slight but significant increase over time. These findings were obtained from manufacturer data so causality cannot be inferred; whether this represents (ranked of in order of decreasing likelihood based on our collective opinion) a trend towards more aggressive sizing on the part of surgeons, a trend towards greater desire for implants among patients with larger phallus size, or a shift in population penis size over a very short interval of time is unclear (18). Regardless of cause, there is obviously an upward limit on the size of implant that can be placed without major risk, so we do not foresee this as a trend that will continue indefinitely.

Increasing mean penile length also begs the question of how to size prostheses appropriately. Although clinical data are not conclusive, experimental data indicate that greater a utilization of rear tip extenders is associated with lower axial rigidity of the activated penile prosthetic, particularly in larger size implants (19,20). This may relate to instability at the interface between the inflatable and non-inflatable device components and/or the relatively smaller size of the inflatable device itself when rear tip extenders are used to constitute the corporal length. The benefits of minimizing rear tip extenders must be balanced against technical challenges accessing the proximal portions of the crura and/or burying implant tubing with the corpora itself. Optimal use of rear tip extenders in the future is likely to be driven largely by surgeon preference and patient factors.

Canuck67
Posts: 66
Joined: Sun Oct 20, 2019 11:05 pm

Re: Rear Tip Extenders and Penile Prosthesis Rigidity: A Laboratory Study of Coloplast Prostheses.

Postby Canuck67 » Sun Apr 26, 2020 10:29 am

Why would a doctor put more than 1cm RTE?

The only reason I can see is they are not high volume implanter and they dont have all the size on hand when they operate.

Thats the first time I read that the Titan gets bigger tube as it gets longer from the pics here. So would the base 20 cm be 22mm and longer implants are over 22mm that Titan advertise?
1967 model. Looking for futur options. Using Cialis or Viagra with Good/mix results with the bad side effects.


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