Early Cannulation ePTFE Arteriovenous Access Grafts are Associated with a Low Incidence of Pseudoaneurysm Formation

Abstract

Pseudoaneurysm formation is common in standard thin-walled polytetrafluoroethylene (sPTFE) grafts, occurring in up to 10% of grafts, and is reported as the most common cause of graft loss for grafts more than 2years old. The Gore® Acuseal™ graft is an early cannulation graft, needled before incorporation, and thus may be especially prone to pseudoaneurysm formation. In addition, as this is a relatively new product, there are limited data on long-term outcomes such as pseudoaneurysm. We report one center's experience of the incidence and etiological factors associated with pseudoaneurysm formation over 5years and 265 grafts. A total of 265 Acuseal grafts were placed in the last 5years. All patients had prospective data entered into an electronic searchable patient record. Surveillance was performed with 3 monthly imaging (digital subtraction angiography or ultrasound), clinical examination, and hemodynamic performance. Data examined included the incidence, causative factors, and outcomes of pseudoaneurysm. Eleven grafts (4.15%) developed a pseudoaneurysm, with 2 patients developing significant hemorrhage. The median time to development of a pseudoaneurysm was 25months interquartile range (IQR, 20-28months). Several common etiological factors were identified. All but one patient had overuse of needling sites (n=10; 90.9%). Other factors associated with pseudoaneurysm formation were inadequate surveillance (n=9; 81.8%), venous outflow stenosis (n=9; 81.8%), and anticoagulation/dual antiplatelet therapy (n=7; 63.6%). Management included observation and needle rotation (n=5; 45.5%), stent grafting (n=3; 27.3%), or excision (n=1; 9.1%) of the pseudoaneurysm. Surgical or endovascular augmentation of the venous outflow was required in 9 patients (81.8%). Graft ligation and explantation were required in 5 patients (45.5%) with graft preservation achieved in 6/11 patients (54.5%). Pseudoaneurysm formation occurs less frequently in Acuseal grafts compared with historical data for standard PTFE grafts. Pseudoaneurysm formation did not occur in any graft within the first 13months after implantation, suggesting early cannulation before incorporation is not by itself a risk factor for pseudoaneurysm development. Poor needling, venous stenosis, inadequate surveillance, and anticoagulation/dual antiplatelet therapy are remediable factors, and graft preservation is possible. Acuseal is a robust graft with lower rates of pseudoaneurysm formation on long-term follow-up than standard PTFE grafts.