External iliac artery extension causes greater aneurysm sac regression than the bell-bottom technique or iliac branch endoprosthesis for repair of concomitant infrarenal aortic and iliac artery aneurysm.

Objective: Aneurysmal extension of abdominal aortic aneurysms (AAAs) to the common iliac artery (CIA) presents a technical challenge to successful endovascular abdominal aortic aneurysm repair (EVAR). In the present study, we compared sac shrinkage and perioperative outcomes after the bell-bottom technique (BBT), internal iliac artery embolization and external iliac artery extension (EIE), and iliac branch endoprosthesis (IBE).

Methods: Using the Vascular Quality Initiative database, a retrospective analysis was conducted for patients who had undergone EVAR from 2013 to 2019. The demographic, anatomic, and perioperative data were analyzed. All patients with a proximal aortic neck length <10 mm and aortic graft diameter >32 mm were excluded from the analysis. The patients were subdivided into four groups according to the distal limb strategy: group 1, control group with a bilateral common iliac artery limb <20 mm; group 2, BBT with either a unilateral or bilateral limb >20 mm; group 3, EIE technique; and group 4, IBE. The primary endpoint was the maximal change in the aortic diameter during follow-up. The secondary endpoints included postoperative complications and the rate of endoleak.

Results: The records for 14,455 patients who had undergone EVAR were queried and 5788 met the anatomic criteria. The average age was 73 years, and 86.3% were men. The maximal change in the aortic diameter in the control, BBT, IBE, and EIE groups was -7.2 mm, -6.1 mm, -4.6 mm, and -6.8 mm, respectively (P = .06). The differences were not statistically significant on univariate analysis at an average follow-up of 405 days. However, on multivariable analysis (P = .01), compared with the control group, the BBT and IBE groups were 18.4% (odds ratio [OR], 0.816; 95% confidence interval [CI], 0.68-0.98) and 48.0% (OR, 0.52; 95% CI, 0.33-0.82) less likely to experience aneurysmal shrinkage, respectively. In contrast, the EIE group showed no significant difference in shrinkage compared with that in the control group. Multivariable analysis of the groups also revealed that compared directly with the BBT group, the EIE group was 69.5% more likely to have experienced shrinkage in the aortic aneurysmal diameter (OR, 1.70; 95% CI, 1.05-2.75). The BBT and IBE groups had a significantly higher rate of type II endoleaks (17.63% and 16.95%, respectively; P = .03). The EIE group had a higher rate of type Ib endoleaks (1.9%) compared with the BBT (1.1%), IBE (1.7%), and control (0.3%) groups (P = .01). No differences were found between the groups in terms of postoperative myocardial infarction (P = .47) or respiratory (P = .61) or intestinal (P = .71) complications. However, the rates of limb complications and reoperation were higher in the EIE group.

Conclusions: The present study revealed that the EIE technique was more likely to demonstrate shrinkage in the aortic aneurysmal diameter than were the BBT and IBE groups compared with the control group on multivariable analysis. The EIE technique was also more likely to result in aneurysmal sac shrinkage than was the BBT group, albeit with greater rates of limb-related complications.