Predictive Parameters of Type 1A Endoleak for Elective Endovascular Aortic Repair: A Single-Center Experience

Abstract

One of the most important factors that affects the success of Endovascular Aortic Repair (EVAR) treatment is the morphology of the neck of the aneurysm. Today, EVAR can be performed even in patients who do not meet the Instruction For Use criteria with hostile neck risk factors; thanks to the developing experience and technology. Our aim in this study was to determine risk factors for Type 1a endoleaks in patients who underwent EVAR and predictive factors for Type 1a endoleaks in patients with combinations of these risk factors. Patients who underwent elective EVAR for infrarenal abdominal aortic aneurysm in our medical center between July 2016 and January 2021 were enrolled. Of these 244 patients, 180 patients with documented preoperative and postoperative computed tomographic angiography results and a follow-up of at least 1year were included in the study. The Mann-Whitney U test and Student's t-test were used to assess the relationship between nominal data and numerical values, and the t-test and Wilcoxon test were used to compare dependent groups. Logistic regression analysis was performed to model risk factors associated with endoleaks. The results showed that a neck length less than 15mm increased the development of type 1a endoleak by 10.4 times (P<0.001). Furthermore, a neck diameter more than 28mm increased the development of type 1a endoleak by 21.9 times (P=0.04). A conical neck structure (gradual neck dilation > 2mm) increased the development of type 1a endoleaks 4.8 times (P=0.04). The presence of calcification (> 150 Hounsfield Unit and > 2mm) in the neck increased the risk of type 1a endoleaks fourfold (P=0.04). Hostile neck parameters were analyzed and patients with only 1 parameter (n=69) had a 7.2% type 1a endoleak rate, while patients with 2 parameters (n=15) had 26.6% and patients with more than 2 parameters (n=11) had 45.5% type 1a endoleak rate. Morphologic features of the neck structure of the aneurysm are among the most important parameters that affect the success of EVAR treatment. Alternative treatments should be considered in patients with more than 1 unfavorable neck parameter.