Concurrent comparison of endoluminal repair vs. no treatment for small abdominal aortic aneurysms

Endoluminal repair of abdominal aortic aneurysms (AAA) requires the aneurysm to have a proximal neck of at least 1.5 cm between the renal arteries and the aneurysm. Therefore, there may be advantages in performing endoluminal repair in the early stages of aneurysm development. However, the results of endoluminal repair performed in patients with small aneurysms with favourable morphology are not known. The aim of this study was to determine whether a randomised trial of endoluminal repair vs. no treatment for small aneurysms would be justified by using a concurrent comparison of endoluminal repair vs. no treatment for AAA 5 cm or less in diameter in patients presenting to the same centre during a 4-year period.

Data on 117 patients presenting with AAA 5 cm or less in diameter were entered into a registry. The decision to perform endoluminal repair vs. no treatment was based on the patient's preference following surgical consultation and investigation by computed tomography. This study reports the mortality, morbidity and survival of patients presenting between June 1992 and August 1996. During this time 43 patients had endoluminal repair and 67 patients had no treatment for small AAA. Seven patients were unfit for any intervention. Despite patient selection for different management in each group, close analysis revealed that the groups were similar with regard to co-morbidities and risk factors, as well as age, sex, and size of aneurysm. Follow-up was by progress CT scanning and ranged from 1 to 51 months (mean 18 months (NT) and 22 months (ER)).

Endoluminal repair failed in six of 43 patients (14%) and resulted in 11 (25%) local vascular complications. There were two perioperative deaths and one late death in this group. Twenty-one of 67 AAA (31%) patients in the no treatment group enlarged beyond 5 cm in diameter during the study period. There was one death from aneurysm rupture and one death from myocardial infarction in this group.

The patients in the endoluminal repair group have gained an asset in having their aneurysms repaired at a cost of early morbidity following operation. These results suggest that a randomised trial of endoluminal repair vs. no treatment will become justified in the subset of patients with small AAA 5 cm or less, if the incidence of complications can be reduced by further improvements in endoluminal technology.