Conformational changes associated with proximal seal zone failure in abdominal aortic endografts

Objective: Endovascular aneurysm repair (EVAR) has become a popular treatment for abdominal aortic aneurysm (AAA). This study examines conformational changes in the infrarenal aortas of patients in whom proximal seal zone failures (PSF) developed after EVAR. Methods. All 189 patients with aortic endograft underwent routine post-EVAR computed tomographic scan surveillance. Patients identified with proximal type I endoleaks, type III endoleaks, or proximal component separation without demonstrable endoleak underwent three-dimensional reconstruction of the computed tomographic scans from which measurements of the migration, length, volume, and angulation of the infrarenal aorta were made. Results. Five patients (3%) had PSF develop, four of whom had aortic extender cuffs. Although changes in the AAA volume and aortic neck angle were slight or variable, the mean AAA length increased 34 mm and the mean aortic body angulation increased 17 degrees (P = .03 and .01, respectively). Lengthening and migration caused proximal component separation in four patients, with concomitant migration in two patients. Two patients underwent endovascular repair, two patients needed explantation of the endograft, and one patient awaits endovascular repair. Proximal component separation and type III endoleak recurred in one patient and were repaired with a custom-fitted graft. Conclusion: PSF of aortic endografts is associated with proximal angulation and lengthening of the infrarenal aorta. These findings reinforce the importance of proper initial deployment to minimize the need for aortic extender cuffs, which pose a risk of late endoleak development.