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Challenges for Off-the-Shelf Fenestrated Stent-Grafting

Fenestrated stent-grafts have found a major role in the treatment of short-necked infrarenal and juxtarenal aneurysms that are unsuitable for standard stent-graft implantation. However, there are many patients who currently are not suitable because of limitations of technology, including those who present urgently. Different strategies have been employed to solve the need for bespoke stentgraft manufacture, including in-situ fenestration techniques and off-the-shelf branched and fenestrated devices. This issue of JEVT contains 2 articles that assess challenges in the fenestrated stentgraft market, including the preliminary results of the off-the-shelf Ventana fenestrated stentgraft (Endologix, Inc, Irvine, CA, USA), and an article that examines the potential applicability of a prototype fenestrated device designed by Cook Medical (Bloomington, IN, USA). Both the Ventana device and the modification of Cook’s Zenith stent-graft allow implantation of an aortic endograft in patients previously thought unsuitable for standard fenestrated endovascular aneurysm repair (EVAR). While these devices are clearly needed, potentially allowing the treatment of more patients, there are many unanswered questions regarding their use. Possible solutions to create an off-the-shelf solution with existing fenestrated platforms have been mooted for some time. These efforts involve some compromise. Whether it is using dome-shaped fenestrations or movable, non-reinforced, 3-mm fenestrations that can be expanded to 10 mm in size to increase the morphological boundaries, we hope that the tolerances between the stent-grafts and the target vessels will increase, though we have yet to see any in vitro or clinical data that are reassuring. One drawback of these proposed technologies is the need to use 3 fenestrations and a scallop in every case. A proportion of cases would have previously required only a scallop for the superior mesenteric artery (SMA). The authors claim this approach is likely to result in a more durable repair (theoretically from a longer sealing zone in a disease-free segment). Lessons from current series would suggest that a greater number of fenestrations increases technical difficulties and perioperative morbidity. The long-term effects of covered stents in the SMA also remain to be determined. In the study by Sobocinski and colleagues, the authors attempted to quantify the proportion of patients who may benefit from a new off-the-shelf fenestrated aortic stent-graft. They suggest that over 70% of patients with juxtarenal aneurysms may be suitable for this new device. However, the answer may not be so simple. The patients examined in this study perhaps might be those who would benefit least from off-the-shelf technology, so the claim that 70% of juxtarenal aneurysms will be suitable for this new device may be too ambitious. Those included in the study were elective patients who had sufficient time to wait for manufacture of a custom-made device. The group of patients where this technology may have the greatest impact,