Tis true for the reasons mentioned that a fistula is left in place post transplant. In my case it was fortunate as my transplant failed after getting swine flu. Going on dialysis again it was just a matter of showing up and starting up again. Not without serious disappointment of course.
Mind you they are recommending a fistula not for their health, but yours. Especially if you are having a translpant, you want to be as healthy as possible. Catheters are problem prone and patients with catheters are much more succeptable to both viral and bacterial infection. Not only for short term health but for long term health too.Higher Kt/V is obtainable with a fistula as opposed to a catheter. You want to minimize the damage kidney failure does to your body.
Also, anuerisms form due to a large number of factors. Improper cannulation is one of them, but so is scar tissue formation which occurs over time. It "could" likely be that your fistula may not even be noticable for months to a year or more.
The longevity of a transplanted kidney is a crap shoot. Just consider the contributors to the forums on this website and you will see wide variation. It's is for this reason that placement of a fistula serves as an excellent "insurance policy" in the event of transplant failure.
Generallly, when a transplant fails, it is a fairly quick process and not one that affords the time to get a fistula placed and have it mature in time for use in hemodialysis. Three months is the general rule of thumb for fistua maturity before use. The complications associated with venous catheters and grafts as well as the adequacy of dialysis, have made the arterio-venous fistula the "gold standard" of vascular access. There are kidney failure and transplant patients that have had fistulas in place for 25 years or more.
Proper care and maintenance will assure long trouble free functioning of an AV fistula. Individuals with poor circulation, e.g. diabetics, will be at far higher risk of other circulatory complications that include the effect of a fistula on heart function.