The Effect of Compliance Versus Non-compliance to Standard Imaging After Endovascular Aneurysm Repair on Re-intervention Rate and Mortality: A Systematic Review and Meta-analysis

Abstract

Introduction - Yearly imaging surveillance is recommended for patients who have undergone endovascular aortic repair (EVAR) for infrarenal abdominal aortic aneurysms to detect complications requiring reintervention. However, this is also a burden to patients and the healthcare system. It is yet unknown whether yearly imaging surveillance actually detects additional complications requiring reintervention and decreases the mortality rate. We aimed to study the effect of imaging surveillance after EVAR on reintervention rate and mortality. Also, what percentage of complications requiring reinterventions is detected via imaging surveillance compared to patients presenting with symptoms. Methods - Systematic review of cohort studies that compared complications in patients compliant to imaging surveillance with non-compliant patients. Two review authors independently performed the inclusions, quality assessment and data extraction. Risk differences as to reintervention and mortality rates between compliant and non-compliant patients were meta-analysed. Results were presented as absolute risk differences (ARD) with 95% confidence intervals (CI). A Mantel&Haenszel fixed effect model was used, if statistical heterogeneity was limited, i.e. having an I2 <50,. A Dersimonian&Laird random effects model was used, if statistical heterogeneity was present, i.e. an I2 >50%, Results - We included 11 relevant publications. Studies differed in imaging surveillance protocols and definitions for compliance subgroup. Pooled absolute risk difference (ARD) for reintervention rate was 4% (95%CI[1 to 7%]) in favour of imperfect/non-compliance (NNT 25; 95%CI[14 to100]), while mortality showed a non-significant ARD of 12% (95%CI[-2 to 26%]) in favour of imperfect/non-compliance. Two studies reported that complications requiring reintervention detected via imaging surveillance ranged between 41% and 53%, compared to patients presenting with symptoms. Conclusion - Patients who are compliant to imaging surveillance undergo more reinterventions than those who are imperfectly or non-compliant. However, this does not necessarily protect against mortality. This suggests that the recommended yearly imaging surveillance may not be beneficial for all EVAR-patients.