Meta-analysis and meta-regression analysis of iliac limb occlusion after endovascular aneurysm repair

Our objective was to investigate the incidence, interventions and outcomes of iliac limb occlusion after endovascular aneurysm repair (EVAR).

We performed a systematic review that conformed to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines using a registered protocol (CRD42017064375). We considered studies reporting patients with iliac limb occlusion after EVAR. We interrogated electronic information sources and bibliographic reference lists using a combination of free text and controlled vocabulary searches. We conducted a proportion meta-analysis of outcomes applying a random effects model. We used mixed effects (methods of moments) regression models to investigate whether the incidence of iliac limb occlusion changed over time.

We identified 13 studies reporting a total of 5454 patients who underwent EVAR from 1995 to 2014. The pooled incidence estimate of primary iliac limb occlusion was 5.6% (95% confidence interval [CI], 4.0-7.8). The incidence of iliac limb occlusion was more pronounced in old studies and declined in more recently published studies (slope P = .022; Q=5.279). Forty-four percent (95% CI, 36%-52%) had an acute presentation. One-half of the patients (48%; 95% CI, 41%-56%) presented within 30 days of EVAR. Seventeen percent (95% CI, 13%-23%) underwent endovascular treatment, 8% (95% CI, 5%-13%) received hybrid procedures, and 61% (95% CI, 54%-67%) had open surgery. The 30-day mortality was 0.036 (95% CI, 0.018-0.070; heterogeneity: P = .999, I² = 0%). The rate of limb loss within 30 days and during follow-up was 0.031 (95% CI, 0.015-0.063; heterogeneity: P = .999; I² = 0%) and 0.045 (95% CI, 0.024-0.083; heterogeneity: P = .978; I² = 0%), respectively. Reintervention was undertaken in 0.080 (95% CI, 0.048-0.130; heterogeneity P = .919; I² = 0%) over a follow-up ranging from 7 to 39 months. The mortality during follow-up was 0.056 (95% CI, 0.031-0.099; heterogeneity: P = .866; I² = 0%).

Iliac limb occlusion occurred in 5.6% of patients after EVAR. One-half of these patients presented early. Even though surgical treatment has been used more frequently, there is insufficient evidence to suggest its superiority over endovascular/hybrid repair. A considerable number of patients will require reintervention. Future research is needed in identifying patients at risk of iliac limb occlusion.