P-009 - ILIAC ANATOMY AND DISTAL LANDING ZONE CONSEQUENCES AT 12-MONTH FOLLOW-UP AFTER EVAR

TOPIC:
Abdominal Aortic Aneurysms
AUTHORS:
Nana P. (Vascular Surgery Department, Larissa University Hospital ~ Larissa ~ Greece) , Spanos K. (Vascular Surgery Department, Larissa University Hospital ~ Larissa ~ Greece) , Kouvelos G. (Vascular Surgery Department, Larissa University Hospital ~ Larissa ~ Greece) , Dakis K. (Vascular Surgery Department, Larissa University Hospital ~ Larissa ~ Greece) , Batzalexis K. (Vascular Surgery Department, Larissa University Hospital ~ Larissa ~ Greece) , Arnaoutoglou E. (Anesthesiology Department, Larissa University Hospital ~ Larissa ~ Greece) , Giannoukas A. (Vascular Surgery Department, Larissa University Hospital ~ Larissa ~ Greece) , Matsagkas M. (Vascular Surgery Department, Larissa University Hospital ~ Larissa ~ Greece)
Introduction:
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 consecutive patients treated with standard EVAR for abdominal aortic aneurysm was undertaken between 2017 and 2019. Follow-up included computed tomography angiography (CTA) at the 1st and 12th month post-operatively. 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 (Figure 1). Iliac angle, tortuosity indexes, relining and oversizing were also analysed. Distal landing zone-related adverse events were any limb related re-intervention, endoleak type Ib, graft migration, limb stenosis or occlusion. The study was approved by the Institutional Review Board.
Results:
In total, 248 iliac limbs (124 patients) were included. In all three levels, the mean iliac artery diameters increased at 12-month follow-up. At the level of origin, the diameter increased from 18.9±10.8mm to 20.4±10.5mm (p=.02), at the middle portion, from 15.8±6.0mm to 17.5±6.3mm (p<.001) and at the distal CIA, from 14.6±4.2mm to 15.1±3.9mm (p=0.05). Iliac angle altered from 34.1±18.1 degrees to 32.2±16.2 degrees (p<.001). CIA index increased from 0.83±0.12 to 0.88±0.1 (p<.001). The mean value of oversizing was 19.7±13.3% and affected distal iliac diameter increase (p<.001). No patient was lost to follow-up while no death was recorded during the initial 12 months. In total, 28 limbs presented distal landing zone-related adverse events (11%); ten cases of limb occlusion (4%) and five cases of ET Ib (2%) were detected (Table 1). Sixteen patients underwent re-intervention (6.5%). In 65 cases, a distal iliac diameter >18mm was recorded. The estimated oversizing was lower (16.8±11.7%) compared to <18mm arteries (22.5±14.8%, p=.02). At 12-month follow-up, iliac diameters remained stable in the >18mm group. Endoleak type Ib was more common in iliac arteries >18mm [4 (6.0%) vs 1 (0.5%) (p=.004)] at 12-months. Limb stenosis or occlusion and graft migration were similar between groups.
Conclusion:
Post- EVAR iliac artery dilation does not seem to have an impact on distal landing zone adverse events during the 12-month follow-up, except iliac arteries >18mm, which are more prone to ET Ib evolution. Aggressive oversizing may be related to iliac dilation but may have a protective role on ET Ib formation in iliac arteries >18mm.
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