Impact of Post-EVAR Graft Limb Kinking in EVAR Limb Occlusion: Aetiology, Early Diagnosis, and Management

Abstract

Endograft limb occlusion is a potential complication of endovascular aneurysm repair (EVAR), being one of the major causes of secondary interventions and rehospitalisation. The aim of this review is to report on the impact of endograft kinking in endograft limb occlusion, as well as on risk factors, prevention, early diagnosis, and management. A systematic review and meta-analysis was conducted according to the recommendations of the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) statement. After a MEDLINE and Scopus search, 55 articles (27,509 patients) were included in the qualitative analysis and eight in the quantitative analysis. In this meta-analysis, 179at risk limbs were treated by pre-emptive stenting, which significantly reduced the risk of limb occlusion: not pre-emptively stenting limbs at risk had a negative impact on graft limb patency (odds ratio 4.30, 95% confidence interval 1.45-12.78). Post-operatively, a kink was identified in 422 patients (1.5%), contributing to 42.8% of all limb occlusions. Relevant data support that completion angiography is an inadequate means of diagnosing high risk limbs, proposing cone beam computed tomography and intravascular ultrasound as adjuncts. The post-operative limb occlusion rate ranged from 0% to 10.6%, affecting 984 patients. Several risk factors for limb occlusion have been identified. Regarding treatment, most patients were submitted to femorofemoral bypass (52.3%) or to deployment of a bare metal stent, either alone or associated with catheter directed thrombolysis or mechanical thrombectomy (26.4%). Complications and outcome after re-intervention for limb occlusion are described infrequently in the literature, but single studies have reported on re-occlusion, major amputation, and limb occlusion related mortality rates. Pre-EVAR planning should focus on identification of risk factors for kinking. Adjunctive stenting is an effective prophylaxis for selected high risk limbs, yet intra-operative identification remains problematic. Also, it is noteworthy that most limb occlusions occur in the first year after EVAR, emphasising the importance of careful early follow up of high risk patients.