Expression of Plasma Levels of miRNA-181b and miRNA-21 in Patients With Abdominal Aortic Aneurysms and Their Effect on Clinical Outcome After Endovascular Treatment.

Introduction: Abdominal aortic aneurysms (AAA) are major causes of morbidity and mortality in the elderly population. Endovascular aneurysm repair (EVAR) is associated with lower complications rates than conventional treatment; however, rigorous follow-up with contrast imaging is required to confirm aneurysmal sac exclusion. The main objective of this study was to quantify and evaluate miRNA expression response to EVAR based on serum dosages at the 6-month follow-up.

Population And Method: 47 patients with indication for EVAR were recruited and 10 patients without comorbidities. miRNA-181b and miRNA-21 were selected for this study and their serum dosages were measured at two time points: preoperatively and after 6 months of follow-up, and only once in the control group. Demographic profiles, clinical follow-ups, and imaging examinations with angiotomography performed preoperatively and after 6 months were collected.

Results: Overexpression of miRNA-181b and miRNA-21 was observed in the whole blood of patients with AAA. EVAR of patients with AAA resulted in decreased expression of the studied miRNAs, indicating that exclusion of the aneurysmal sac alters the expression of these markers. In addition, the expressions of miRNAs did not correlate with endoleaks or the diameter of the aneurysm or with the different types of devices used for the EVAR.

Conclusions: The overexpression of miRNA-181b, miRNA-21 with its reduction after EVAR, may suggest the use of these molecules as potential biomarkers in the follow-up of these patients. However, miRNAs were not able to identify possible endoleaks or discriminate them into subtypes.

Clinical Impact: The clinical application of the use of biomarkers in other areas such as oncology is already well established. In endovascular surgery it is still incipient although with great potential in daily practice, in order to anticipate or schedule possible interventions in patients with endoleak. In addition, understand the mechanisms of action of miRNAs in Atherosclerotic diseases and aortic syndromes could provide a better understanding of the pathophysiology as well as pharmacological development for AAA prevention as well as remodeling of the aneurysm sac after EVAR.