Conformability of the GORE EXCLUDER iliac branch endoprosthesis is associated with freedom from adverse iliac events.

OBJECTIVE

The GORE EXCLUDER iliac branch endoprosthesis (IBE; W.L. Gore & Associates, Flagstaff, Ariz) is designed to preserve internal iliac artery (IIA) patency during endovascular treatment of aneurysms involving the common iliac artery. The device is intended to conform to iliac tortuosity, which may decrease adverse iliac events (AIE). The objective of this study was to evaluate risk factors for AIE after IBE implantation.

METHODS

This was a post hoc analysis of the prospective, multicenter GORE 12-04 IBE pivotal trial. Patients with preoperative and postoperative axial imaging were included, with analysis based on each treated iliac system. An independent core laboratory performed all scan measurements, including iliac diameters, lengths, and tortuosity. Conformability was analyzed by the changes in tortuosity after IBE deployment, with less change indicating greater conformation. The end point was AIE, defined as ipsilateral radiographic or clinical complications. Critical nonconformation was defined as a threshold change in tortuosity associated with a significant increase in AIE.

RESULTS

We included 98 patients with 101 treated iliac systems. There were eight AIE (8%; six IIA component occlusions, one iliac branch component occlusion, and one EIA dissection requiring reintervention). Patients with AIE had smaller IIA diameters and less IBE conformability. After multivariable logistic regression analysis, an IIA diameter of less than 10 mm and a change in total iliac tortuosity beyond -15% were independently associated with AIE (odds ratio, 12 [interquartile range, 1.4-110] and odds ratio, 8.2 [interquartile range, 1.5-46], respectively), and the latter was used to define critical nonconformation. Critical nonconformation occurred in 11% of treated systems, and was associated with a high rate of AIE (36% vs 4%; P = .004).

CONCLUSIONS

Endograft conformation is a novel device property and technical outcome that, along with a larger IIA diameter, is associated with freedom from AIE after IBE deployment. An evaluation of these risk factors may better inform the management of patients with iliac aneurysmal disease. Further research on endograft conformation and patient outcomes is warranted, particularly for those with challenging anatomy undergoing complex procedures.