Early experience with the SLF (Spiral Laminar Flow) AV Access Graft
Arteriovenous grafts for dialysis are associated with a high incidence of outflow stenosis requiring re-intervention and increased risk of failure. Pathological flow patterns promote neointimal hyperplasia in the outflow vein and attempts to improve graft outcomes have resulted in innovative graft technologies.
One such strategy involves the generation of spiral laminar outflow from the graft and the SLF AV graft (Vascular Flow Technologies, Dundee) is designed to recreate normal patterns of blood flow to reduce outflow stenosis. The aims of this study were to audit the early clinical outcomes of SLF grafts in a patient series from two European units.
Materials and Methods
A prospective series of implants was been collated from two surgeons series. The decision to use an SLF was based on surgeon preference and the site of implant based on clinical parameters. Flow was determined using Doppler ultrasound. For clinical outcomes data was collected prospectively with a standardized data collection tool at set time points post surgery.
Since September 2010 twelve SLF-AV Access grafts were implanted. All grafts were used in patients with complex access histories (median of 6 previous AV access procedures). One graft failed immediately, the cause attributed to poor inflow (small diseased high bifurcation brachial artery and hypotension). Of the eleven with immediate function two failed (56 days and 58 days). Thrombectomy was performed and no outflow stenosis was demonstrated in either. Despite this both grafts re-clotted within 24 hours. Primary patency in the series is 75% at a mean time point of 188 days (range 0 to 448). One superficial wound infection occurred which required surgical intervention. No graft infections occurred requiring graft intervention.
Whilst this represents a small series with limited follow up this early experience of the SLF AV is encouraging. Doppler studies support the SLF generating spiral flow at the distal (graft to vein) outflow and the short term data herein supports a low incidence of outflow stenosis with excellent primary patency to date.