Do you need a kidney transplant?
Have you discussed this with your nephrologist?
At 88, any major and complicated operation carries a very large risk and are usually avoided unless there is no other way.
In my country (The Netherlands) there is no age limit for a kidney transplant, but a lot of consideration is put in operation risk and chances of a good recovery in older patients. Which means that a transplant is rare at almost 90 years old.
The decision is com[plex in the UK. The NHS uses a number of standards to judge whether any surgical procedure is justified or justtifiable. One is the "Quality Adjusted Life Year" (QALY). Basically this is a way of trying to assess whether a procedure might be worth carrying out, based on the number of years of improved life the patient might potentially benefit from if the procedure was carried out. This obviously favours interventions for children and young people generally. It takes into account the seriousness/complexity of the procedure and the time it might take to recover, as well as the cost in terms of clinical staff time - ie if they're doing X it means they're not free to do Y or Z.
So for those of us clocking up the years it becomes generally less likely that a given procedure would pass that test, simply because we're not expected to live long enough to benefit sufficiently. Less likely, but far from impossible.
I have no idea and wouldn't even begin to guess what any decision might be in any specific case such as yours. You would have to talk to your doctor about that.