A personal experience:
YOU HAVE TO WORK TO REVERSE IT
I have not reacted in the Circle [mailing list], but would like to provide some input.
I had a radical prostectomy in December 1996 in Southampton UK, and in January 1997 commenced on Zoladex with a 28 day course of Casodex. Prior to the RP I was not specifically made aware that there would be a "shrinkage" of my penis, but being in the Coroners profession, I was very much aware of the procedure that is necessary to carry out a radical prostectomy.
As I was placed on Zoladex immediately the catheter was removed, and the subsequent interference with my hormones, I was not really aware of the "shortage." I was not advised by the medical profession of the necessity to engorge the penis, and believe it or not, Viagra was not then available in UK, and even when it did become available, it took several private prescriptions for me to obtain it, until the government made up it's mind to fund it for certain "categories" of which, thankfully, RRP become one of them.
It was in the Circle that I read a comment about VEDs etc., (and I think it was Wendy) who mentioned it and I took it up with the surgeon, you see, because of the Zoladex, I was not getting any erections at all. I had to purchase a VED, not available in the UK on prescription! I then commenced to use it, once or twice a week just to engorge, as I had absolutely no inclination for sex. A total opposite of pre-RRP and Zoladex. (And I mean total.)
Logically it makes sense that when the sewing together of the urethra is done by the surgeon then he has to pull two ends together, the least "anchored" of the two ends is in the penis side, so it gives and thus you end up with this "shrinkage."
Now with a VED and Viagra, four years post RRP (and off Zoladex too) it is back to pre-RRP, but you have to work at it to get it there, and it does, at times get painful, not hurting more of an "ache," as what you are doing is stretching it. If you keep it erect too long, especially in the early post-RRP days, then it is almost like the pain you experience after the initial shock of being struck in the testicles (kicked in the balls/dropping onto the cross bar of the bike), is the best way that I can describe it.
I think it is the least of the "worries" when you are taking the decision about which route to take for the treatment, but I don't think it is something that many surgeons actually tell the men. It is just assumed that when explaining the procedure that they would grasp this. I often wonder how many men actually are aware of the actual procedure.
Anyway, if this is of some help then please advertise it on your site.