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

Purpose: As a minimally invasive strategy for the treatment of patients wit h abdominal aortic aneurysm (AAA), endovascular repair has been embraced wi th enthusiasm because of the promise of achieving a durable result with a r educed risk of perioperative morbidity and mortality. Our mid-term experien ce with endovascular AAA repair was assessed by examining early and late cl inical outcome in concurrent cohorts of patients stratified either as low-r isk or as at increased-risk for intervention. Methods: From April 1994 to December 1999, endovascular AAA repair was perf ormed in 104 patients with commercially available systems. A subset of pati ents considered at increased risk for intervention (n = 51) were categorize d as such based on a pre-existing history of ischemic coronary artery disea se (73%), with documentation of myocardial infarction (57%) or congestive h eart failure (29%), or because of the presence of chronic obstructive pulmo nary 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 mi nutes), blood loss (437 +/- 402 mL vs 331 +/- 238 mL), postoperative hospit al stay (4.4 +/- 2.7 days vs 4.2 +/- 2.5 days), or days in the intensive ca re 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 m m 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-r isk and low-risk groups at 3.9% and 5.7%, respectively. The initial endolea k 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 ri sk have been monitored for 14.6 +/- 12.4 months, and patients at low risk h ave been monitored for 17.7 +/- 15.0 months. Kaplan-Meier analysis for cumu lative patient survival demonstrated a reduced probability of survival amon g those patients initially classified as at increased risk for intervention (P < .05, Mantel-Cox test). Both cohorts had similar 2-year clinical succe ss rates of approximately 75%. Conclusion: Despite the use of an endovascular approach for aneurysm treatm ent, the risk of perioperative death and morbidity remains present for all patients including those who have no significant medical comorbidity. Moreo ver, although clinical success rates are comparable in both patient groups, 2 years after endovascular repair was performed, at least one in four pati ents was classified as a clinical failure. Given the continued uncertainty associated with clinical outcome and the need for dose life-long surveillan ce, caution is dictated in advocating endovascular treatment for the patien t who is otherwise considered an ideal candidate for standard open surgical repair.