Fistula Complications

Dear All,
Mom suffers from kidney failure. According to her physicians, she is at a terminal phase (less than 15-10% kidney functionality) and dialysis is the only chance to help her body sustain some of the damage.
She had one week ago an arteriovenous fistula created in her left arm. My father used to check its thrill at least twice a day to ensure its functionning, although the sound it makes is quite weak as of now.
This afternoon, my mother noticed that it ceased functionning as she could not hear its thrill. Back at home, my father checked again and nothing.
Is there a way to restaure its functionning at this stage or is it too late? Blood results are getting worse day by day and my mother cannot endure a neck ponction for the dialysis. Can it be a thrombosis at such an early stage? Or is it something else?

[jollyman069]

they can go in and put a stint in it if it is clogged so she needs to call her dr right away

[Verbatim700]

Thank you for the comment. Actually, she went to see her doctor and it was already over. They made another one in her arm (few centimeters away from the first) but they had to start dialysis. So, she had her first session today (1h30min) and they had to ponction at the level of the neck.
The doctor said that it was a problem of low blood pressure, so now she has to stop almost all meds she was taling for blood pressure in order to preserve her fistula.