Techniques and systems for determining an arteriovenous (AV) fistula maturation in a patient may include detecting a first series of oxygen saturation levels of the patient at a central venous catheter (CVC) associated with a first series of hemodialysis treatments prior to the AV fistula implantation are described. The AV fistula may then be implanted in the patient. A second series of oxygen saturation levels of the patient at the CVC associated with a second series of hemodialysis treatments may be detected. The second series of oxygen saturation levels may be compared to a stable threshold mature AV fistula oxygen saturation level. Among other determinations from the comparison, in response to one or more of the second series of oxygen saturation levels meeting or exceeding the stable threshold mature AV fistula oxygen saturation level, determining the AV fistula is mature. Other embodiments are described.