Dundee, UK, 20 January, 2015 – Vascular Flow Technologies, the medical device company using proprietary Spiral Laminar Flow (SLF) technology to replicate natural blood flow for enhanced patient outcomes, today announced the start of a randomized controlled clinical trial at St. Georges Hospital, London, UK.
The 189-patient trial is using current best practice as the comparator and is designed to test the hypothesis that restoring the natural spiral blood flow pattern will increase arteriovenous graft patency in patients undergoing haemodialysis, resulting in fewer interventions over a 24-month period.
The trial will assess graft patency measured as the interval between graft placement and access thrombosis, or interventions to maintain, assist or re-establish patency over the 24 month period. In addition this clinical measurement the trial will record the costs of interventions, producing data to support health economic evaluation of the Spiral Flow AV Graft.
Spiral Laminar Flow (SLF) technology has been available since 2008 and is the only graft technology that is proven to replicate natural blood flow by generating a spiral laminar flow within the graft, reducing turbulence at the point where the blood flows into the blood vessel.1,2 This limits changes to the blood vessel wall that may be precursors to thrombosis.3 The clinical effectiveness of SLF technology has been reported in a number of published studies, with high patency rates at 30 months in vascular reconstruction in the leg (81% above the knee, and 57-64% below the knee).4
The trial will involve patients with end stage renal disease (ESRD) requiring dialysis, who will be randomized to Spiral Flow™ AV Graft or a standard polytetrafluoroethylene (PTFE) bridge graft. The main complication for PTFE grafts used for haemodialysis is thrombosis, which is reported to contribute to 70% of failures5 and these grafts show patency rates in published literature of 41-68% at 1 year,5-9 and 25% at 2 years.10
Mr. Eric Chemla, Consultant Vascular Surgeon, St. George’s Hospital, London, UK and lead investigator for the study commented: “St. George’s Hospital has one of the largest dialysis units in the UK, with a team of experienced vascular access surgeons, and a high throughput of this type of procedure. We are excited to be the trial centre for this study, which will produce clinical and economic evidence on the utility of this potentially game-changing technology.”
The haemodialysis access study is supported in part by a Scottish Enterprise Grant awarded to Dundee-based Vascular Flow Technologies, who are gathering evidence to support wider applications of their proprietary SLF technology.
Bill Allan, CEO of Vascular Flow Technologies said: “We are truly delighted to announce the first patient into this trial. We are confident in our technology and are now pursuing trials that will consolidate the clinical evidence gained to date, and provide data for health economic appraisals.”
1. Stonebridge PA, Buckley C, Thompson A, Dick J, Hunter G, Chudek JA, Houston JG, Belch JJ. Non spiral and spiral (helical) flow patterns in stenosis. In vitro observations using spin and gradient echo magnetic resonance imaging (MRI) and computational fluid dynamic modelling. In Angiol 2004 Sep;23(3):276-83.
2. Kokkalis E, Hoskins P, Corner G, Stonebridge P, Doull A, Houston G. Secondary flow in peripheral vascular prosthetic grafts using vector Doppler imaging. Ultrasound in Med & Biol 2013;39(12):2295-2307.
3. El Sayed HF. Vascular Flow Technology: Another run of the mill graft or a breakthrough technology? US experience and perspective. Presented at the 8th International St George’s Vascular Access Meeting at the 35th Charing Cross international vascular and endovascular symposium, 7th April 2013, London.
4. Stonebridge PA, Vermassen F, Dick JB, Belch JJ, Houston JG. Spiral Laminar Flow Prosthetic Bypass Graft: Medium-term results from a first-in-man structured registry study. Ann Vasc Surg 2012;26:1093-1099
5. Hodges TC, et al. Longitudinal comparison of dialysis access methods: risk factors for failure. J Vasc Surg 1997;26:1009-1019.
6. Cinat ME, Kopkins J, Wilson SE. A prospective evaluation of PTFE graft patency and surveillance techniques in haemodialysis access. Ann Vasc Surg 1999;13:191-198.
7. Matsuura JH, et al. Transposed basilic vein versus polytetrafluoroethylene for brachialaxillary arteriovenous fistulas. Am J Surg 1998;176:219-221.
8. Taylor SM, et al. Results and complications of arteriovenous access dialysis grafts in the lower extremity: a five year review. Amer Surg 1996;62:188-191.
9. Kaufman JI, et al. A prospective comparison of two expanded polytetrafluoroethylene grafts for linear forearm haemodialysis access: does the manufacturer matter? J Am CoIl Surg 1997;185:74-79.
10. Gibson KD, et al. Vascular access survival and incidence of revision: A comparison of prosthetic grafts, simple autogenous fistulas, and venous transposition fistulas from the United States Renal Data System Dialysis Morbidity and Mortality Study. J Vaso Surg 2001;34(4):694-700.