Outcome of endovascular abdominal aortic aneurysm repair in patients with conditions considered unfit for an open procedure: a report on the EUROSTAR experience.

OBJECTIVE: Endovascular abdominal aortic aneurysm repair (EAR) can be performed in patients whose conditions were previously considered unfit for conventional treatment of the aneurysm. However, because the life span in this category of patients often is limited because of serious comorbidity, the efficacy of EAR in prolonging life expectancy remains uncertain. This study involves the evaluation of preoperative risk classification and an assessment of the outcome of interventions.
METHODS: The data of 3075 patients, who underwent operation in 101 European institutions that collaborated in the EUROSTAR Registry, were assessed. Only the patients who had been prospectively enrolled in the registry were used for this analysis. Patient characteristics, operative risk factors, procedural details, and types of devices were correlated with preoperative estimates of operative risk, early and late mortality, complications, and primary and secondary outcome success rates. In addition, the intermediate-term survival rates in patients with unfit conditions with EAR (observed series) and with conservative approaches of the aneurysms (rupture rates as derived from the literature) were compared in a mathematical model.
RESULTS: Of the overall study group, 2525 patients were at "normal" risk for a surgical procedure (group A), 399 patients had conditions that were considered unfit for open surgery (group B), and 151 patients had conditions that were unfit for general anesthesia (group C). Both unfit categories had significantly more comorbid factors and larger aneurysms than did the patients in good medical condition. Differences were observed in comorbidities between the two high-risk categories, groups B and C. Factors that influenced the abdominal approach (previous laparotomies, hostile abdomen, and obesity) and local anatomic factors (eg, retroperitoneal fibrosis, inflammatory aneurysm, dissections, and enterostomy) were present in 19% of the patients with conditions that were unfit for open surgery and in only 1% of the category unfit for anesthesia. In contrast, severe pulmonary disease was present in 33% of the patients with conditions that were unfit for anesthesia as opposed to 11% of the patients with conditions that were unfit for open surgery. The early and late mortality rates were significantly higher in the unfit categories (groups B and C). Life table results showed a 3-year survival rate of 83% in patients at normal operative risk and of 68% in patients with unfit conditions (P =.0001). An independent correlation with late death was shown for the clinical classification into high-risk groups B and C, pulmonary disease, team experience of less than 60 procedures, and the diameter of the aneurysm. In groups B and C, aneurysms smaller than 6.0 cm were associated with a 2-year survival rate of 80% and larger aneurysms with a rate of 68% (P =.02). This difference was caused by an increased non-aneurysm-related mortality rate in the group with aneurysms of more than 6 cm. The mathematical model showed an advantage of EAR with regard to the reduction of the death rate in patients with unfit conditions as compared with no intervention after 1 year. The advantage of EAR was observed in patients with AAAs between 5 and 6 cm and with larger aneurysms.
CONCLUSION: Early and late mortality rates were increased in patients with the preoperative clinical diagnosis "unfit for open surgery and general anesthesia" as compared with patients at "normal" operative risk. EAR appeared of potential benefit in patients with unfit conditions, regardless of the aneurysm diameter. The life expectancy of patients at high risk who are considered for EAR should be longer than 1 year before any realistic gain in life span can be anticipated.