[home] [Personal Program] [Help]

---

Session: Vascular III
Session starts: Friday 27 January, 14:00
Presentation starts: 14:15
Room: Room 559

---

Nicholas White (TU Delft & LUMC)
Koen van der Bogt (LUMC)
Joris Rotmans (LUMC)
Tim Horeman (TU Delft)

Abstract:
End-stage renal disease (ESRD) is a long-term health problem in which the structure and function of the kidney is affected. Patients with ESRD are largely dependent on dialysis for survival, with 85% receiving haemodialysis. For chronic haemodialysis, an adequately functioning high-flow vascular access is required, usually achieved by surgical creation of an arteriovenous fistula (AVF) between a vein and artery in the arm. However, the durability of AVFs in providing high-flow vascular access is far from optimal, with ~40% requiring surgical intervention within 1 year. The primary limiting factor affecting durability of AVFs is occlusion induced by the constantly elevated flow. On the contrary, ~80% of patients with a well-functioning AVF eventually develop cardiac issues due to the constantly elevated cardiac output. The high flow caused by the AVF is always present, but only necessary during dialysis sessions, rarely exceeding 12 hrs/week. By enabling opening and closing of the AVF, the necessary high flow for dialysis will only present during the 12 hours of dialysis sessions per week. Circulation can return to normal outside these sessions, removing the core of the issue in vascular access: continuous high flow. Patient outcomes and quality of life should greatly improve, as well as greatly reducing costs of dialysis related issues. A novel implant to allow opening and closing of this AVF is being developed. Actuation occurs non-invasively through a magnetic drive placed subcutaneously in the upper arm. A set of magnets outside the skin can then be coupled to allow actuation of the shunt non-invasively and transcutaneously. The drive is connected through a flexible Bowden cable to a valve mechanism that manipulates the AVF. A functional prototype has been developed and recently implanted into a goat model for a duration of 13 weeks in a pilot study (n=2). Transcutaneous actuation of the drive remained possible throughout the study. However, excessive fibrosis formation appeared to be the limiting factor in enabling fully opening and closing the AVF. An upcoming second pilot with an improved design expected to solve this issue could provide first insights into the systemic effects of opening and closing an AVF.