SAN FRANCISCO – The presence of rupture and the emergent nature of the explantation are two key negative predictors of long-term survival in patients who require explantation of endovascular aneurysm repair endografts, results from a single-center study showed.
"EVAR is now the most common method for treating abdominal aortic aneurysms, and increasing numbers of patients are being observed in long-term follow-up," Dr. Eric J. Turney said at the Society for Vascular Surgery Annual Meeting. "In addition, treatment of patients with indications outside of instructions for use is common."
Dr. Turney and his associates in the vascular surgery department at the Cleveland Clinic set out to evaluate the medical center’s experience with EVAR explants between 1999 and 2012. They identified modes of failure as well as predictors of outcomes. "Furthermore, we examined modes of failure by time since EVAR was implanted: those failing in the first year, those failing within years 1-5, and those failing beyond 5 years," he said. Outcomes included 30-day mortality, cumulative survival, and complications.
He reported on results from explants in 100 patients, making this study the largest single-center study of its kind to date. The majority (91%) of patients were male, and their mean age was 75 years. Coronary artery disease was the most common comorbidity (65%), followed by chronic kidney disease (24%) and chronic obstructive pulmonary disease (COPD) (23%). Suprarenal fixation was present in 37% of patients.
The most common indication for explant was endoleak (82%), followed by infection (13%), acute thrombosis (3%), recurrent thrombosis (1%), and claudication (1%). Fewer than half of patients (40) had type I endoleak, 30 had type II, 22 had type III, none had type IV, 6 had type V, and 16 had multiple endoleaks at the time of explantation.
The majority of endografts (71%) were explanted in an elective setting, with 10% being urgent, 19% being emergent, and 9% with ruptures.
Endografts were excised after a median of 41 months. They failed in 23% of patients within the first year, in 55% of patients between 1 and 5 years, and in 22% of patients beyond 5 years. Overall 30-day mortality was 17%, and it differed by level of acuity. Specifically, 30-day mortality was 9.9% in the elective group, 37% in the emergent group, 38% in the infection group, 56% in the ruptured group, and 60% in the anastomotic fistula group.
Significant predictors of 30-day mortality included visceral revascularization (P = .036), supraceliac clamp (P = .001), emergent explantation (P = .015), the presence of infection (P = .038), and the presence of rupture (P = .006).
Similarly, the negative predictors of long-term survival that reached statistical significance were the presence of rupture (HR, 5.44), the emergent nature of the explantation (HR, 4.07), visceral revascularization (HR, 4.02), the presence of infection (HR, 3.27), the presence of COPD (HR, 2.19), preoperative elevated creatinine (HR, 2.1), and postoperative elevated creatinine (HR, 2.02).
Limitations of the study included its retrospective design "and the fact that it was performed at a single center," Dr. Turney said. "Multiple surgeons performed the explants, with varying preferences in approach. In addition, 61% [of cases] came from an outside facility without preimplant imaging available."
Dr. Turney said that had no relevant financial conflicts to disclose. Other coauthors disclosed receiving research funding or consulting fees from several device manufacturers.