Detection of broken sutures and metal-ring fractures in AneuRx stent-grafts by using three-dimensional CT angiography after endovascular abdominal aortic aneurysm repair: association with late endoleak development and device migration.

PURPOSE: To determine the prevalence of demonstrable stent-graft degradation by using three-dimensional computed tomographic (CT) angiography to assess endoleak and stent-graft migration after endovascular aortic aneurysm repair (EVAR).
MATERIALS AND METHODS: The institutional review board approved this retrospective study. Sixty-two consecutive patients with abdominal aortic aneurysm treated with the AneuRx stent-graft (Medtronic, Santa Rosa, Calif) were assessed between 0.5 and 9.5 years after EVAR (median, 5.1 years) for the presence of broken attachment sutures and metal-ring fractures by using CT angiography. The relative risk (RR) of delayed endoleak formation and endograft migration was calculated relative to the presence of suture breaks and metal-ring fractures. A two-tailed Fisher exact test was used to assess significant differences.
RESULTS: Suture breaks were observed in 55 of 62 subjects (89%), including 37 minor breaks (60%) and 18 major breaks (29%). Metal-ring fractures were observed in 11 of 62 subjects (18%). Twenty-seven endoleaks were observed in 24 of 62 subjects (39%) and were categorized as type I in seven of 27 (11%), type II in 16 of 27 (26%), and type III in four of 27 (6%). Major suture breaks were associated with six of seven (86%) delayed type I endoleaks (RR = 19.4, P = .003), and metal-ring fractures were associated with four of seven (57%) delayed type I endoleaks (RR = 6.2, P = .015) and three of four (75%) type III endoleaks (RR = 13.9, P = 003). Migration was observed in 15 of 62 patients (24%) and was associated with major suture breaks in 10 of 15 patients (67%, RR = 4.5, P = .001) and with metal-ring fractures in five of 11 patients (45%, RR = 4.1, P = .003). Repeat interventions were performed in 15 patients.
CONCLUSION: Major suture breaks and metal-ring fractures are demonstrated with CT and are associated with delayed type I and III endoleaks and with stent-graft migration after EVAR. © RSNA, 2014.