Hemodialysis Access Surveillance Evaluation Study

The purpose of the study is to learn if monitoring dialysis access blood flow during dialysis treatment with a transonic machine (an ultrasound technique) will prevent (or reduce) the development of dialysis access thrombosis (clotting). Investigators would like to study if monitoring with a specific technique called ultrasound dilution technique can help prevent problems with access when compared to what is the current standard of care for patients.