Worst-case scenario for a Permanent Foley Cathether left in too long??

[manamene]

Because of several great difficulties that i won't go into here, my very old father has been wearing the same Permanent Foley Cathether (silicone) for too many months. He is exceptionally healthy (needs no meds of any kind), but an enlarged prostate made permanent catheterization necessary. Because of his advanced age (100 years!) the tissue is very fragile. The first three or four  catheters that were inserted  were  painful and caused a lot of bleeding, making it necessary to change the catheters frequently because of blood clots, etc., and this was very traumatic for my dad.
We understand that the risk of infection  increases with the number of days the catheter is in place and yet,  amazingly, he has had absolutely no problems with it.  As he is so old I wish I could "leave well enough alone" but we understand that the catheter has been in way too long and I am now frightened.

After so long, will it be possible to remove the catheter without injury? Will there be adhesions in the urethra that will make normal removal impossible or dangerous, requiring surgery?