Postimplantation syndrome in endovascular aortic aneurysm repair – a systematic review

Postimplantation syndrome (PIS) following endovascular aortic aneurysm repair (EVAR) is a poorly understood phenomenon occurring in the early post-operative course. The underlying aetiology, risk factors, clinical sequalae, and treatment options, are largely unknown. The lack of any standardised diagnostic criteria limits current research in this field. The MEDLINE database was interrogated using a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) search strategy. Five search terms were used; "postimplantation syndrome" AND "aneurysm", AND "infection", AND "complications", AND "biomarkers", AND "outcomes". 19 studies were included in the review process, reporting a 17.4%-39.0% incidence of PIS. IL-6 was the most commonly elevated biomarker in PIS vs. non-PIS patients. There was a higher incidence of PIS in patients who received polyester rather than expanded-polytetrafluoroethylene (ePTFE) grafts. There was a lower rate of type 2 endoleaks observed in patients who developed PIS. Early major adverse cardiovascular events (MACE) were higher in PIS patients, however there were no studies reporting long-term MACE. Length of stay was higher in PIS patients. Current data support the role of IL-6 as being key to the development of PIS following EVAR. Further work describing the effect that PIS has on long-term clinical outcomes is needed. Lack of standardised diagnostic criteria limit the reporting of PIS between centres, the criteria proposed by this review may resolve this.