Abstract: TH-PO752

AFE System Treatment Rapidly Dilates Ovine Cephalic Veins before AVF Surgery

Session Information

Category: Dialysis

  • 603 Hemodialysis: Vascular Access


  • Franano, F. Nicholas, Flow Forward Medical, Inc., Olathe, Kansas, United States
  • Loree, Howard M., Flow Forward Medical, Inc., Olathe, Kansas, United States
  • Richardson, J. Scott, Flow Forward Medical, Inc., Olathe, Kansas, United States
  • Groth, Dale M., Dale Groth Preclinical Consulting, LLC, Forest Lake, Minnesota, United States
  • Taneja, Maneesh, Surpass, Inc., Osceola, Wisconsin, United States
  • Szenay, Lesley A., Surpass, Inc., Osceola, Wisconsin, United States
  • Hutto, Barrett S., CIRTEC Medical Systems LLC, Los Gatos, California, United States
  • Dixon, Bradley S., University of Iowa Hospital and Clinics, Iowa City, Iowa, United States

Suboptimal wall shear stress (WSS) and cyclic stretching may slow AVF outflow vein dilation and lead to maturation failure. The AFE System™ is a medical device that delivers non-pulsatile blood flow to a peripheral vein, stimulating vein dilation prior to AVF surgery. During treatment, blood flow can be adjusted to maintain a mean WSS dose of 4 Pa in the vein. Use of larger veins to make AVFs may result in greater eligibility for AVF surgery, faster maturation, reduced maturation failure, and better primary and secondary patency rates.


AFE System prototypes were used to treat five sheep (54-68 kg). The devices comprised an extracorporeal centrifugal blood pump, heparin-coated and cuffed inflow and outflow conduits, and a benchtop controller. The inflow conduit was inserted into an external jugular vein and the tip was positioned in the superior vena cava. The outflow conduit was connected to a cephalic vein. Three sheep were treated using a duckbill tip inflow conduit and an outflow conduit with a distal ePTFE segment sutured to the vein. Two sheep were treated using an inflow conduit with a duckbill tip surrounded by a nitinol cage to prevent vein wall suction and an outflow conduit with an intravascular connector inserted into the vein lumen.


Mean vein diameter increased significantly from 4.5 to 8.4 mm with 6-11 days of treatment (n=5, p=0.005). Variation in conduit designs had no effect on final vein diameter. The average rate of vein dilation was 0.51 mm/day. The intravascular connector simplified placement of the outflow conduit and the inflow conduit tip-protecting nitinol cage prevented low flow events. AVFs were made with the dilated veins in all animals.


This pilot study shows the feasibility of dilating peripheral veins with the AFE System prior to AVF surgery.


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