A data extraction form was created to extract the following characteristics: Author, Year, Country, Study Type, Arterial and/or Venous Mapping Pre-Op US criteria, Fistula used for dialysis with Ultrasound, Fistula succesfully used for dialysis with Physical Examination Only, Statistically Significant Ultrasound Parameters, DUS Criteria, Outcome Follow Up, Success Rate, Failure Rate, Maturation Rate, Primary Patency, Primary-Assisted Patency, Secondary Patency. This form was evaluated for suitability in two randomly selected studies by all study’s authors. After finalizing the form, two of the authors independently extracted the data from each study.