I was about a month for an elbow AVF. Infiltrated once but that was at three months and more a technician problem than an AVF issue. They started with a larger gauge needle but migrated within a week.
«Maturation mostly occurs 4 to 6 weeks after the initial fistula surgery but that timeframe can vary with the average time ranging from 1 to 4 months. » • https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5989091/
I believe they did a second vein mapping (dynamic ultrasound of the blood flow) that needed to reach a particular flow rate and possibly diameter before approving use.
Something like «The Rules of 6 (flow volume >600 mL/min, vein diameter >6 mm, vein depth <6 mm) » • https://pubmed.ncbi.nlm.nih.gov/35227801/
Presumably if it failed to mature sufficiently they would follow up in another month or so.
