Analysis of medical risk factors and outcomes in patients undergoing open versus endovascular abdominal aortic aneurysm repair

OBJECTIVE: The emergence of endovascular repair (ER) for infrarenal abdominal aortic aneurysm (AAA) has provided surgeons with a new technique that should ideally improve patient outcomes. To more accurately characterize the advantages of ER versus traditional/open AAA repair (TOR), we compared the preoperative medical risk factors (PMRFs) and perioperative outcomes (PO) of those patients undergoing elective treatment of infrarenal AAA with ER and TOR over a recent 18-month period at our center. METHODS: Through our institutional vascular surgery patient registry, all patients undergoing aortic aneurysm repair of any type between December 1999 and June 2001 were identified. Only those patients undergoing elective infrarenal AAA repair were analyzed. Hospital records were examined for all patients, and PMRF and PO were assessed via Society for Vascular Surgery/International Society for Cardiovascular Surgery reporting guidelines. Student t, chi(2), Fisher exact, or Wilcoxon rank sum tests were applied where appropriate to determine differences among PMRF and PO according to method of aneurysm repair. RESULTS: During the 18-month study period, a total of 199 aortic aneurysms were repaired at our institution. Ninety-nine elective infrarenal AAA repairs made up the study cohort (ER, n = 33; TOR, n = 66). When examined by method of aneurysm repair, no differences existed in demographics or AAA size. Patients undergoing ER had a significantly greater degree of preoperative pulmonary comorbidity than patients undergoing TOR (P <.001). However, no differences existed in terms of American Society of Anesthesiologists classification or cardiac (P =.52), cerebrovascular (P =.44), diabetic (P =.51), hypertensive (P =.90), hyperlipidemia (P =.91) or renal (P =.23) comorbidities between the two groups. Perioperative morbidity and mortality rates were also not significantly different by method of repair. ER was associated with shorter operative time, intensive care unit stay, and overall hospital length of stay (P <.0001). However, subsequent operative procedures related to the AAA repair were performed more frequently after ER (TOR = 1.5% versus ER = 15.2%; P = 0.015). CONCLUSION: These results suggest that ER offers improvements in hospital convalescent and operating room times but no beneficial impact on overall morbidity and mortality rates when similar PMRFs exist, especially when used at medical centers where low morbidity and mortality rates are already established for TOR. Other centers performing ER should undertake such an analysis to assess its impact on their patients.