VasQ External Support for Arteriovenous Fistula

Inclusion Criteria: 1. Main study cohort: Patients referred for creation of a new brachiocephalic fistula who consent to take part in the study and which are not indicated for a more distal fistula per treatment guidelines. Supplementary study cohort: Patients referred for creation of a new forearm fistula who consent to take part in the study. 2. Male and female participants. 3. Age 18-80 years. 4. Patients willing and able to attend follow up visits over a period of 24 months. Exclusion Criteria: 1. Patients with the planned index procedure being a revision surgery of an existing fistula. 2. Main study cohort: Target artery smaller than 2.5 mm or larger than 6 mm in inner diameter by preoperative ultrasound. Supplementary study cohort: Target artery smaller than 2 mm or larger than 4.1 mm in inner diameter by preoperative ultrasound. 3. Main study cohort: Target vein smaller than 2.5 mm in inner diameter by preoperative ultrasound. Supplementary study cohort: Target vein smaller than 2 mm in inner diameter by preoperative ultrasound. 4. Significantly stenotic target vein on the side of surgery (≥50%) as diagnosed on preoperative ultrasound. (Scan should include the area between the planned anastomosis site and the Axillary vein.) 5. Unusual anatomy or vessel dimensions (observed on pre-operative ultrasound or intraoperatively) and which preclude adequate fit of the VasQ. 6. Patients with central venous stenosis or obstruction on the side of surgery. 7. Depth of vein greater than 8 mm (on ultrasound) on side of surgery. 8. Known coagulation disorder. 9. Congestive heart failure NYHA class ≥ 3. 10. Prior steal on the side of surgery. 11. Known allergy to nitinol. 12. Life expectancy less than 30 months. 13. Patients expecting to undergo kidney transplant within 6 months of enrollment. 14. Women of child bearing age without documented current negative pregnancy test. 15. Inability to give consent and/or comply with the study follow up schedule.