Pathophysiology of proximal perigraft endoleak following endovascular repair of abdominal aortic aneurysms: a study using a flow model

Objective: to design a flow model to determine whether and why increased pr oximal neck angulation correlates with increased risk of proximal perigraft endoleak (PPE) flow. Methods: a tapered stent-graft (Gianturco stent + Dacron) was deployed with proximal and distal necks made of silicone. The amount of PPE was measured over 30-s periods while the angulation of the proximal neck was increased. Results: PPE flow increased significantly for angulations greater than or e qual to 30 degrees. The graft was lifted off the neck wall and gaps between the stent-graft and the neck created. Conclusion: greater neck angulation increased PPE flow. The stent-graft was lifted off the neck and subsequent gaps created. This model could be used to compare available stent-grafts and to test new designs that would improv e the seal in angulated necks.