Mid-term results after endovascular repair of the abdominal aortic aneurysm.

PURPOSE: As a minimally invasive strategy for the treatment of patients with abdominal aortic aneurysm (AAA), endovascular repair has been embraced with enthusiasm because of the promise of achieving a durable result with a reduced risk of perioperative morbidity and mortality. Our mid-term experience with endovascular AAA repair was assessed by examining early and late clinical outcome in concurrent cohorts of patients stratified either as low-risk or as at increased-risk for intervention.
METHODS: From April 1994 to December 1999, endovascular AAA repair was performed in 104 patients with commercially available systems. A subset of patients considered at increased risk for intervention (n = 51) were categorized as such based on a pre-existing history of ischemic coronary artery disease (73%), with documentation of myocardial infarction (57%) or congestive heart failure (29%), or because of the presence of chronic obstructive pulmonary disease, liver disease, or malignancy.
RESULTS: The perioperative mortality rate (30-day) was 7.8% for patients at increased risk compared with 1.9% among those classified as low-risk (P = NS). There was no difference between groups in age (72 +/- 7 years vs 74 +/- 7 years; mean +/- SD), surgical time (221 +/- 90 minutes vs 192 +/- 68 minutes), blood loss (437 +/- 402 mL vs 331 +/- 238 mL), postoperative hospital stay (4.4 +/- 2.7 days vs 4.2 +/- 2.5 days), or days in the intensive care unit (1.2 +/- 1.6 days vs 0.6 +/- 1.3 days). Patients at increased risk of intervention had larger aneurysms than patients at low risk (58 +/- 11 mm vs 52 +/- 12 mm; P < .05). Stent grafts were successfully implanted in 47 (92%) patients at increased risk versus 50 (94%) patients at low risk (P = NS). Conversion rates to open operative repair were similar in increased-risk and low-risk groups at 3.9% and 5.7%, respectively. The initial endoleak rate was 21% versus 18% based on the first computed tomography performed (either at discharge or 1 month; P = NS). To date, patients at increased risk have been monitored for 14.6 +/- 12.4 months, and patients at low risk have been monitored for 17.7 +/- 15.0 months. Kaplan-Meier analysis for cumulative patient survival demonstrated a reduced probability of survival among those patients initially classified as at increased risk for intervention (P < .05, Mantel-Cox test). Both cohorts had similar 2-year clinical success rates of approximately 75%.
CONCLUSION: Despite the use of an endovascular approach for aneurysm treatment, the risk of perioperative death and morbidity remains present for all patients including those who have no significant medical comorbidity. Moreover, although clinical success rates are comparable in both patient groups, 2 years after endovascular repair was performed, at least one in four patients was classified as a clinical failure. Given the continued uncertainty associated with clinical outcome and the need for close life-long surveillance, caution is dictated in advocating endovascular treatment for the patient who is otherwise considered an ideal candidate for standard open surgical repair.