Purpose: To compare the mid-term results following the use of bifurcated (ABIS) and aorto-uniiliac (AUIS) endovascular devices in the treatment of abdominal aortic aneurysms (AAA) in a population of patients deemed to be at high risk for open surgery.
Material and methods: Over a 4 year period (January 2003 to December 2007), 447 underwent elective endovascular aneurysm repair (EVAR) using ZENITH) stent-grafts. Group I comprised patients treated using the AUIS (n=124), and group II those receiving ABIS (n=323). Outcome measures included the assisted technical success rate, perioperative mortality, major complications, freedom from reintervention, and primary and secondary patencies. Factors associated with mid-term clinical failures were determined using univariate and multivariate analyses.
Results: The assisted primary technical success rate was 94% and 99% in groups I and II respectively (p=.002). Major perioperative complications occurred in 13 group I patients (10%) vs. 12 group II patients (4%) (p=.005). The 30-day mortality rate was 3.2% vs.1.5% (p=0.2). TASC C and D iliac lesions significantly increased the risk of major perioperative complications (35% vs. 3%; OR=14.94; 95% CI: 5.75 to 38.78; p<.0001). During the follow-up period (median 24 months), secondary procedures were required in 11% and 5% of group I and group II patients respectively (p=.01). Freedom from reintervention at 12, 24 and 36 months was 98%, 90%, and 85% in group I vs. 96%, 92%, and 92% in group II (P<0.005). The primary and secondary patency rates at 3 years were 92% vs. 98% (p=.003) and 97% vs. 99% (p=.04) for groups I and II respectively. In group I, the Crossover Femoro-Femoral Bypass (CFFB) was responsible for 3 major complications (2.4%) which occurred at 7, 12 and 57 months of follow-up. However, the use of AUIS with CFFB did not independently increase the risk of major complications during follow-up (HR=0.108; 95% CI: 0.007 to 1.637; p=.11, Cox proportion model). In both univariate and multivariate analysis, concomitant iliac arterial occlusive disease (IAOD) was the only significant predictor of clinical failure in study population as a whole (OR=3.996; 95% CI: 1.996 to 7.921; p<.0001).
Conclusion: This study demonstrates that ABIS is associated with better results than AUIS in the management of patients with AAA. Iliac artery occlusive disease was more frequently diagnosed in the AUIS group and this was significantly associated with a higher risk of complications, while the crossover graft itself was not. Nevertheless, the outcomes for both groups are encouraging in this high risk population.