Late graft failure is rare after endovascular aneurysm repair using the Zenith stent graft in a cohort of high-risk patients

Abstract

ObjectiveDevice-specific data on the long-term efficacy of endovascular aneurysm repair (EVAR) are limited by the constant evolution of stent graft design. Whereas some modifications, such as barb-mediated fixation, probably enhance durability, others, such as thin-walled fabric, are of less certain benefit. The purpose of this study was to examine 15 years of a single-center experience of EVAR using the Zenith stent graft (Cook Medical, Bloomington, Ind). MethodsRetrospective analysis was conducted of 325 high-risk patients who underwent elective EVAR with Zenith stent grafts between October 1998 and December 2005 under a physician-sponsored investigational device exemption. Patients' charts and death registries were reviewed to identify late stent graft failures and causes of death. Late stent graft failures were defined as type I or type III endoleaks; enlarging aneurysm sac requiring revision; and limb kinking or occlusion, stent graft infection, renal artery occlusion, or aneurysm rupture occurring >30 days after the index procedure. ResultsThe mean age at treatment was 75.9 ± 7.4 years, and 300 of 325 (92%) were men. The mean aneurysm diameter was 60 ± 9 mm, and the median main body stent graft diameter was 28 mm (range, 22-32 mm). During a median follow-up time of 5.6 years (interquartile range, 2.6-8.7 years), there were six (2%) aneurysm-related deaths caused by the following: one stent graft infection, one infection of a femoral-femoral bypass graft placed after limb occlusion, one infection of a stent graft placed to treat a type IB endoleak, and three aneurysm ruptures. There were 19 (6%) late stent graft failures occurring at a median time of 4.0 years (range, 39 days-14.6 years) after the procedure. Patients with late stent graft failure were more likely to have had impaired renal function (creatinine concentration ≥2 mg/dL; 21% vs 6%; P = .03) and less likely to have had cardiac disease (42% vs 67%; P = .04) at the time of the index procedure. There was no significant association between late stent graft failure and age, sex, aneurysm size, stent graft diameter, diabetes, smoking, or lung disease. Kaplan-Meier estimated overall survival was 60% at 5 years, 29% at 10 years, and 12% at 15 years. Kaplan-Meier estimated freedom from aneurysm-related mortality was 98% at 5 years, 97% at 10 years, and 97% at 15 years. ConclusionsLate-occurring stent graft failures and aneurysm-related death are rare after EVAR using the Zenith stent graft, especially in high-risk patients whose comorbidities diminish life expectancy.