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

Five-year outcomes for bell bottom, iliac branch endoprosthesis, and coil and cover approaches from the GREAT registry

OBJECTIVE

There are a variety of methods used today to treat common iliac aneurysms with endovascular techniques. Of these approaches, little is known about whether a particular limb strategy influences endoleak, reintervention, or aneurysm regression rates. We present 5-year data comparing endoleak, stent graft migration, fracture, aneurysm sac dynamics, and aortic rupture rates among patients treated with bell bottom limbs (BB), iliac branch endoprosthesis (IBE), and coil and cover (CC) approaches from the Global Registry for Endovascular Aortic Treatment registry. Secondary end points were all-cause mortality, stroke, reintervention, and paraplegia.

METHODS

Subjects from the GORE Global Registry for Endovascular Aortic Treatment were enrolled over a 5-year period from October 2017 to August 2022. We included 924 subjects in this study. Statistical data was generated on R software and limb groups were compared using the Pearson's χ2 test and the Kruskal-Wallis rank-sum test.

RESULTS

We found no statistical difference in endoleak rates, stent graft migration, fracture, or aortic rupture when stratified by limb strategy. There was no difference between limb approaches with regard to aneurysm sac dynamics among those with abdominal aortic aneurysms and common iliac aneurysms. Similarly, no statistical difference between limb strategies was found in all-cause mortality, stroke, paraplegia, or reintervention rates. Among patients that required an additional graft during reintervention, the highest rates were found within the IBE group 8.6%, compared with BB group 2.2% and CC group 1.3% (P = .006).

CONCLUSIONS

Overall, there was no difference among limb strategies in endoleak rates, stent graft migration, aneurysm sac dynamics, aortic rupture rates, or our secondary end points. Increased rates of reintervention requiring an additional graft within the IBE group is noteworthy and must be weighed against the adverse effects of hypogastric sacrifice with the CC approach or potentially less advantageous seal zones in the BB approach. This finding suggests that all limb approaches have equivalent effectiveness in managing the aneurysmal common iliac artery; thus, the choice of limb strategy should be individualized and remain at physician discretion. Future research should include a more robust sample size to reproduce these findings.

The Impact of Iliac Artery Anatomy on Distal Landing Zone After EVAR During the 12-Month Follow-Up

BACKGROUND

Proximal sealing zone has been the main interest in endovascular abdominal aortic aneurysm repair (EVAR), although the distal landing zone remodeling may also affect EVAR durability. The aim of this study was to assess iliac anatomy and its potential impact on distal landing zone adverse events after EVAR during the 12-month follow-up.

METHODS

A prospective data collection of patients treated with standard bifurcated EVAR devices for abdominal aortic aneurysm was undertaken between 2017 and 2019. Patients that received extension to the external iliac artery were excluded. Follow-up included computed tomography angiography (CTA) at the 1st and 12th month postoperatively. The common iliac artery (CIA) diameter was assessed in three levels: origin (just below the aortic bifurcation), distally (just above the iliac bifurcation) and the middle of the distance between these two landmarks. Iliac angle, tortuosity indexes, relining and oversizing were also analyzed. Distal landing zone-related adverse events were any limb related re-intervention, endoleak type Ib, graft migration, limb stenosis, or occlusion.

RESULTS

In total, 268 iliac limbs (134 patients) were included. In all three levels, the mean iliac artery diameters increased at 12-month follow-up. At the origin of the CIA, the diameter increased from 18.7 ± 10.5 mm to 19.9 ± 9.4 mm (P = 0.04), at the middle portion of the CIA, the diameter changed significantly from 15.5 ± 5.1 mm to 17.4 ± 5.4 mm (P < 0.001) and at the distal CIA, from 14.6 ± 3.3 mm to 15.1 ± 3.9 mm (P = 0.03). The iliac angle remained stable (P = 0.14) while the CIA index decreased significantly from 1.17 ± 0.13 to 1.11 ± 0.09 (P < 0.001). The mean value of oversizing was 21.5 ± 14.5% and affected distal iliac diameter increase (P < 0.001). The composite outcome of distal landing zone adverse events was not associated to diameter changes at any level. In 57 cases, a distal iliac diameter ≥18 mm was recorded. The estimated oversizing was lower (16.3 ± 11.8%) compared to <18 mm arteries (22.5 ± 14.9%, P = 0.01). At 12-month follow-up, iliac diameters remained stable in the ≥18 mm group. Endoleak type Ib was more common in iliac arteries ≥18 mm [3 (5.3%) vs. 1 (0.5%) (P = 0.04)] at 12-months.

CONCLUSIONS

Post-EVAR iliac artery dilation does not seem to have an impact on distal landing zone adverse events during the 12-month follow-up. Aggressive oversizing may be related to iliac dilation. EVAR patients with iliac arteries ≥18 mm are at higher risk for ET Ib.