Visceral stent patency after fenestrated endovascular aneurysm repair using bare-metal stent extensions versus covered stents only

Fenestrated endovascular aneurysm repair (FEVAR) is an alternative to treat complex abdominal aortic aneurysms. Patency of visceral vessels remains high when covered stents are used. The use of distal uncovered stents to prevent kinking has been associated with loss of branch patency. The aim of this study was to evaluate branch-related outcomes of FEVAR using covered stents only vs the use of uncovered stents distal to covered stents. During a 4-year period, 142 patients underwent FEVAR. Patients with suprarenal, juxtarenal, and type IV thoracoabdominal aneurysms were included. Patients treated with side branch devices were excluded. Covered iCAST (Maquet, Hudson, NH) stents were used as bridging stents in all cases. The primary end point was primary patency, defined as the absence of stenosis or occlusion that required intervention. Secondary end points included secondary patency, branch-related outcomes (kidney injury and gastrointestinal complications), branch instability, and mortality rates. A total of 442 target vessels were incorporated (49 scallops and 393 fenestrations). Uncovered stents were used in 38 (9.6%) visceral vessels. Median follow-up time was 11 (interquartile range, 6-13) months. Overall, visceral vessel primary patency was 91% at 12 and 24 months. The overall primary patency rate was 86% in the distal extension group vs 93% when only covered stents were used at 12 and 24 months (P = .8). Similarly, the rate of branch-related reinterventions at 12 months was 9% and 15% for each group, respectively, and 22% vs 32% at 24 months, respectively (P = .5). Overall, freedom from branch instability was 87% at 12 months and 81% at 24 months. Freedom from branch instability in the distal extension group was 82% at 12 and 24 months vs 89% at 12 months and 81% at 24 months when only covered stents were used (P =. 08). Mortality rate at 24 months was 15% for the bare-metal stent extension group vs 14% for the covered stent only group (P = .4). We found no statistical difference in acute kidney injury at any Kidney Disease: Improving Global Outcomes stage (P = 1.0) or gastrointestinal complications (P = 1.0) between the groups. The use of distal uncovered stents to prevent kinks was not associated with decreased early branch patency. The long-term outcomes of bare-metal stents remain to be determined. For now, the use of uncovered stents distal to covered stents may be considered to prevent kinks in complex anatomy.