I am the guy that had been on 21 different catheters, the last one being with me for 51 weeks straight. Why do you need to be on a Foley Catheter for life? Usually, if you need to be on one long term, a person usually ends up with a suprapubic catheter, which is inserted via an operation, and exits below your belly button, most times to the left side. Foley's are not considered safe for real long term use, i.e.,months or years.
I finally (due to constant stricture problems and radiation damage to my bladder) had to have my bladder by-passed, and I urinate via an Urostomy, a stoma, that exits into a replacable device with an attached bag.
Going back to yoru question, the normal reason for leakage, is often the volume of water or saline in the balloon portion of the cath. Too much, is bad, as it will cause rubbing along the bladder walls where the inlet to the catheter is located. Too little, and in theory the cath can pull out, or get cocked at a bad angle in your bladder. With either of those situations, you can leak.
Have you learned or been taught how to irragate the catheter yourself, if it slows up or blocks up? Takes a little practice, but it can be helpful to know.
If you are going to be long term like I was, it pays to invest in these neat devices that holds the catheter to your leg, they have a joint built into them, and last well. With these devices, you never have to worry about the tube pulling on you as you walk, sit, bend, etc. I can get you the brand name and product number if you are interested. I used them all the time, and it helped a lot.
Bladder spasms can cause leakage too. Are they a big problem with you? They were with me, so the entire time I was on catheters, I was on the generic drug, Ditropan. It eased the pain level and the frequency of the spasms, but never really eliminated them.
Long term Foley use is unusual, because they can cause cancer in the long term, which is why suprapubic caths are usually ordered for long term use. With those, and assuming you don't have any other issues like I did, a person can change one out in a couple of minutes or less, and you aren't having to go through your urethra or taking the chance of damaging your bladder neck.
Good luck to you, sorry you have the need to go through what you are going through, but I understand first hand.
David in SC
If you have any other more detailed questions on long term catheter use, please feel free to e-mail me.