High patency rates with early cannulation graft with bioactive surface

Results of vascular access using a new ePTFE graft show “satisfactory” primary patency rates at one year, and are similar to those achieved with an autogenous access. In the experience, conducted in one centre in Italy, the graft also demonstrated a low thrombosis rate.

Vascular surgeon Matteo Tozzi, Department of Surgery and Morphological Sciences, University of Insubria School of Medicine, Circolo University Teaching Hospital, Varese, Italy, presented the results with the Gore Acuseal (Gore) for prosthetic vascular access at the Society for Vascular Surgery Annual Meeting (5–7 June, Boston, USA).

Tozzi explained that the structure of the new graft has been specifically created to reduce the complications seen with previous ePTFE grafts for vascular access, but most importantly to allow a rapid cannulation. He said that with this device, cannulation can be carried out in the first 48 hours from the graft implantation.

The Acuseal graft is composed of three layers: the external layer consists of ePTFE; the middle layer is an elastomeric membrane that allows the sealing during anastomosis and cannulation; and the internal layer consists of ePTFE with Carmeda BioActive Surface (CBAS Surface) on the luminar surface. This surface is thromboresistant due to the heparin covalent bond to ePTFE (Fig1).

“Autogenous vascular access is the gold standard in patients with end-stage renal disease, due to long-term patency and lower frequency of complications such as stenosis and thrombosis. The disadvantages are the long maturation time of autogenous vascular access, of around 2–3 weeks before usage, and the fact that 10–24% thrombose directly after operation or fail to mature,” he said. “Prosthetic vascular access is an alternative in case of autogenous vascular access failure or when the native vessels are poor.”

Tozzi noted that from 2011 to 2014 his group performed early cannulation with the Acuseal prosthetic graft in 60 patients (mean age 63.6 years; range 34–85 years, 39 men and 21 women). The most frequent causes for prosthetic vascular access was autogenous vascular access failure (42.6%) and malfunction of central venous catheter (22%). All patients had an average of at least 2.2 previous autogenous vascular accesses and the mean interval time from the start of haemodialysis and prosthetic vascular access was 28.4 months.

“We prefer the loop configuration of vascular access in the upper arm. The most common procedure is the radio-basilic/axillary vein vascular access. We have also performed straight configuration in the upper arm and loops in the lower limb (Fig 2–3),” Tozzi said.

He further commented: “The Kaplan-Meier analysis showed unexpectedly favourable results. In fact, the graft freedom from thrombosis at one year was 83% with a secondary patency of 93.5% at one year. However, the mean follow-up is still short at 10.7 months. The mortality rate was 6.7% but the deaths were not related to our intervention.”

After surgical treatment the patients were treated with dual antiplatelet therapy: clopidogrel (75mg) and acetylsalicylic acid (100mg) and also with fish oil capsules (4000mg) for three months after surgery and with clopidogrel only thereafter.

Tozzi concluded that his group’s preliminary experience with Acuseal for prosthetic vascular access was satisfactory—the graft proved to be safe and effective in patients with end-stage renal disease undergoing haemodialysis.

“Primary patency rates were satisfactory ranging up to 70% at 12 months, similar to those of an autogenous vascular access. The low thrombosis rate of this new graft could be related to the heparin bonding on the endoluminal surface, a characteristic that might help restoration of the graft as documented by the overall high secondary patency rate of 90%,” he said.