Endovascular abdominal aortic aneurysm (AAA) repair since the FDA approval. Are we going too far?

ABSTRACT

BACKGROUND: Since the FDA approval of endovascular devices for abdominal aortic aneurysm (AAA) repair, clinicians have been relaxing the strict inclusion criteria of the clinical trials. We have reviewed our experience during and after the clinical trials to examine changes in patient selection, technical aspects of the procedure, and outcome. METHODS: A review of a prospectively compiled database of all endovascular AAA repairs performed at our institution was performed. RESULTS: Endovascular AAA repair was attempted in 130 patients 46 (35.4%) as a part of clinical trials (Group I), and 84 (64.6%) since the FDA approval of the devices (Group II). Significant differences in patient selection included a higher proportion of short (<15 mm) proximal necks in Group II (28.6 vs 0.0%, p<0.001), and a higher proportion of iliac occlusive disease in Group II (48.8 vs 15.4%, p=0.001). Additional trends suggested that Group II AAA's were more complex, including increased proximal neck angulation, increased proximal calcification, increased presence of proximal thrombus, and increased iliac tortuosity. Significant differences in technical aspects of the procedure included increased usage of iliac angioplasty (46.4 vs 13.3%, p<0.001), iliac stenting (31 vs 8.9%, p<0.01), and conduit access to the external iliac artery (10.7 vs 0%, p=0.03) in Group II. Analysis of outcome revealed a decreased incidence of the following in Group II cases conversions to open repair (2.4 vs 10.9%), lower extremity ischemia (3.6 vs 13.0%), and graft limb occlusion (2.4 vs 8.7%). Other major perioperative complications did not differ significantly between the 2 groups. However, although the overall rate of any endoleak noted in the postoperative course was decreased in Group II cases (26.2 vs 32.6%), the incidence of proximal or distal attachment site leaks has increased (11.9 vs 4.3%, p=0.14). Although this comparison did not reach statistical significance, the magnitude of the increase is concerning. CONCLUSIONS: Although we have been able to offer endovascular AAA repair to a larger number of patients since FDA approval, endovascular management of increasingly complex proximal necks and increased iliac artery disease appears to have increased the incidence of attachment site endoleaks. Although many of these leaks have been successfully managed with adjunctive endovascular procedures, their increasing incidence is worrisome and suggests that we may need to re-evaluate current inclusion criteria for using this technology. Although difficult access issues have been handled with adjunctive procedures, the presence of a short, angulated proximal neck may be difficult to overcome, and may not be well suited for endovascular repair with the currently available devices.