Endovascular grafting of complex aortic aneurysms with a modular side branch stent-graft system in a porcine model

Objectives. To evaluate and refine a stent-graft system with side branches for treatment of aneurysms with essential branch arteries. Methods. In a porcine model (n = 4) supra- and juxta-renal aortic aneurysms were created by suturing an artificial patch onto an anterior aortotomy. Angiography was performed to determine the exact location of the renal arteries. Accordingly, fenestrations were created in an appropriately sized aortic stent-graft. Initial deployment of the aortic graft is partial, whereby the top stent is secured in a cap and distal stents are being restrained, thus ensuring longitudinal and rotational manoeuvrability during alignment of the branch arteries. Separate branch grafts with silicone flanges for connection with the main stent-graft are subsequently placed in the renal arteries followed by full deployment of the main stent-graft. Outcome was evaluated by postoperative angiography and autopsy results and by measuring operating time, blood loss and use of contrast agent. Results. Branched grafts were placed successfully in all trials. The median endovascular procedure time was 126 min (90-160), with 575 ml (400-800) blood loss and 65 ml (50-80) contrast agent use. Angiographically, all aneurysms were excluded without signs of endoleak and all renal arteries were patent. At autopsy, the main stent-graft and all side branches were adequately placed with intact connections between main stent-graft and branch grafts. Conclusions. In this model, endovascular repair of complex aneurysms using a modular branch graft system is feasible in a reliable, predictable and timely fashion.