UK-based medical device firm Vascular Flow Technologies (VFT) has reported independent study results showing substantially better primary patency rates for its Spiral Flow arteriovenous (AV) graft compared to a polytetrafluoroethylene (PTFE) graft.

The company uses Spiral Laminar Flow (SLF) technology to replicate natural blood flow for improved patient outcomes.

Spiral Flow grafts are designed to encourage a spiral laminar flow within the graft, which replicates natural blood flow.

Mid-term results of the first European series showed 18-month primary patency rates of 72% for Spiral Flow AV graft, compared to 36.7% for PTFE grafts, which are the current standard of care.

Austria-based Feldkirch General Hospital investigator of the Department of Vascular Surgery Dr Wolfgang Hofmann presented the results at the Vascular Access Society meeting in Barcelona, Spain.

"The company uses Spiral Laminar Flow (SLF) technology to replicate natural blood flow for improved patient outcomes."

Dr Hofmann said: "The results are more than satisfactory, particularly as the patients receiving Spiral Flow grafts were negatively selected."

In the trial, primary patency rates for 15 patients receiving Spiral Flow AV grafts were compared with a consecutive series of 87 patients receiving PTFE grafts.

According to pre-operative duplex mapping, Spiral Flow AV grafts were only used if patients were not suitable for any type of autologous fistula.

The company said that follow-up included duplex mapping every three months, and additional duplex scanning if there was suspicion of impending shunt failure.

Of the 15 patients receiving Spiral Flow AV grafts, there were four shunt occlusions, out of which two were managed by thrombectomy.

Primary patency at 18 months for Spiral Flow AV grafts, which was calculated by Kaplan Meier, was 72%, secondary patency was 85.5%.

Dr Hofmann said: "We have long known that prosthetic graft failure is a normal tissue response to an abnormal flow environment.

"It was particularly gratifying to see that changing the flow pattern at the venous anastomosis improves the patency of the graft."

The company has two CE marked and FDA approved devices commercialised in Europe and the US, the Spiral Flow peripheral bypass (PV) graft and the Spiral Flow arteriovenous access (AV) graft.