The Efficacy of a Protocol of Iliac Artery and Limb Treatment During EVAR in Minimising Early and Late Iliac Occlusion

Abstract

Iliac limb occlusion (ILO) is a complication of endovascular aortic repair (EVAR) and requires re-intervention in most cases. Attention to any intra-operative defect of iliac limbs and arteries may prevent ILO. The study aimed to analyse the long term effect of an intra-operative protocol of iliac limb treatment during EVAR on ILO. Patients treated from 2012 to 2017 for abdominal aortic aneurysm (AAA) with standard EVAR were collected prospectively. Pre-operative computed tomography angiography anatomical characteristics were evaluated. The protocol for intra-operative iliac limb management was: a. pre-EVAR angioplasty of common/external iliac artery stenosis; b. precise contralateral iliac limb deployment at the same level of the flow divider; c. iliac limb kissing ballooning with high pressure non-compliant balloons; d. iliac limb stenting for residual tortuosity/kink and adjunctive external iliac stenting for residual stenosis/dissection after EVAR. ILO was evaluated at 30 days and at follow up, which was performed by duplex ultrasonography before discharge, at three, six, and 12 months and yearly thereafter. Kaplan-Meier and Cox linear regression were used. Four hundred and forty-two patients and 884 iliac limbs were included in the study. Severe iliac tortuosity and calcification were present in 15% (132/884) and 8% (70/884), respectively. External iliac angioplasty and stenting of iliac limb were performed in 2% (18/884) and 9.5% (84/884) of limbs. The thirty day mortality was 1.6%, with no ILO. At a mean follow up of 33±12 months, ILO occurred in 7/884 (0.8%) limbs of six patients. Five ILO were treated by endovascular relining, two surgically: one by femorofemoral bypass and one by surgical explant. On univariable analysis, sac shrinkage was significantly associated with ILO (HR 1, 95% CI 0.8-2.5, p=.043). A protocol of aggressive iliac limb treatment in EVAR leads to a very low rate of late ILO. The role of sac shrinkage in ILO should be investigated further.