Results Presented for Vascular Flow Technologies' Spiral Flow AV Graft

April 16, 2015—Vascular Flow Technologies (VFT) announced that midterm results for its Spiral Flow arteriovenous (AV) graft were presented at the 9th Congress of the Vascular Access Society held April 15–18 in Barcelona, Spain. Investigator Wolfgang Hofmann, MD, presented the data from the first series of European patients in the independent study of the device for hemodialysis. 

According to the company, the independent study results in the first European series of patients demonstrated substantially better primary patency rates for the company’s Spiral Flow AV graft than for a polytetrafluoroethylene (PTFE) graft.

The Spiral Flow device uses the company’s Spiral Laminar Flow (SLF) technology to replicate natural blood flow for enhanced patient outcomes. The SLF technology is designed to reduce turbulence at the distal (venous) end of the graft, thereby reducing shear stress, endothelial activation, and platelet activation that precede thrombus formation at the distal anastomosis. The study used duplex mapping to confirm the presence of spiral flow in the grafts.

VFT stated that the study compared primary patency rates for 15 patients receiving Spiral Flow AV grafts with a consecutive series of 87 patients receiving PTFE grafts. Spiral Flow AV grafts were only used if, according to preoperative duplex mapping, patients were not suitable for any type of autologous fistula. Follow-up consisted of duplex mapping every 3 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, of which two were managed by thrombectomy. 

Primary patency at 18 months for Spiral Flow AV grafts was 72%, calculated by Kaplan-Meier, compared to 36.7% for PTFE grafts. Secondary patency for the Spiral Flow device was 85.5%.

In VFT’s press release, Dr. Hofmann commented, “The results are more than satisfactory, particularly as the patients receiving Spiral Flow grafts were negatively selected.” He added, “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.” Dr. Hofmann is from the Department of Vascular Surgery at Feldkirch General Hospital in Feldkirch, Austria.

VFT’s Spiral Flow peripheral bypass graft and the Spiral Flow AV access graft have received CE Mark and FDA approval and are commercially available in Europe and the United States. The SLF technology is used to create a longer-lasting graft or stent, reducing vascular complications and improving longevity of the implant, advised the company.