Prevalence and risk factors of type II endoleaks after endovascular aneurysm repair: A meta-analysis

February Prevalence and risk factors of type II endoleaks after endovascular aneurysm repair: A meta-analysis Qiang Guo☯ 0 1 Xiaojiong Du☯ 0 1 Jichun Zhao 0 1 Yukui Ma 0 1 Bin Huang 0 1 Ding Yuan 0 1 Yi Yang 0 1 Guojun Zeng 0 1 Fei Xiong 0 1 0 Department of Vascular Surgery, West China Hospital, Sichuan University , Chengdu, Sichuan Province , China 1 Editor: Rudolf Kirchmair, Medical University Innsbruck , AUSTRIA - Data availability statement: All relevant data are within the paper and its Supporting Information files. Funding: The authors received no specific funding for this work. Competing interests: The authors have declared that no competing interests exist. Objectives This systematic review and meta-analysis aims to determine the current evidence on risk factors for type II endoleaks after endovascular aneurysm repair (EVAR). Materials and methods A systematic literature search was carried out for studies that evaluated the association of demographic, co-morbidity, and other patient-determined factors with the onset of type II endoleaks. Pooled prevalence of type II endoleaks after EVAR was updated. Results Among the 504 studies screened, 45 studies with a total of 36,588 participants were included in this review. The pooled prevalence of type II endoleaks after EVAR was 22% [95% confidence interval (CI), 19%±25%]. The main factors consistently associated with type II endoleaks included age [pooled odds ratio (OR), 0.37; 95% CI, 0.31±0.43; P<0.001], smoking (pooled OR, 0.71; 95% CI, 0.55±0.92; P<0.001), patent inferior mesenteric artery (pooled OR, 1.98; 95% CI, 1.06±3.71; P = 0.012), maximum aneurysm diameter (pooled OR, 0.23; 95% CI, 0.17±0.30; P<0.001), and number of patent lumbar arteries (pooled OR, 3.07; 95% CI, 2.81±3.33; P<0.001). Sex, diabetes, hypertension, anticoagulants, antiplatelet, hyperlipidemia, chronic renal insufficiency, types of graft material, and chronic obstructive pulmonary diseases (COPD) did not show any association with the onset of type II endoleaks. Conclusions Clinicians can use the identified risk factors to detect and manage patients at risk of developing type II endoleaks after EVAR. However, further studies are needed to analyze a number of potential risk factors. Introduction Endovascular aneurysm repair (EVAR) has become the primary choice of treatment for abdominal aortic aneurysms (AAAs) in suitable patients [ 1 ]. EVAR always has better shortterm outcomes compared with open repair [ 2,3 ]. Aortic endograft occlusion, migration, and endoleaks are known complications after EVAR [4], among which endoleaks are the most frequent. Types I and III endoleaks require urgent intervention to relieve aneurysm re-pressurization [ 5,6 ]. Type II endoleaks are caused by backflow of collateral arteries into the aneurysm sac, with an occurrence rate of 10.2% after EVAR [7]. Type II endoleaks do not exert any immediate adverse effects. However, persistent type II endoleaks are believed to be associated with increased sac pressure and cause adverse outcomes and even aneurysm rupture [ 8 ]. Various studies assessed risk factors for type II endoleaks following EVAR [9±11]. Potential correlations may exist between preoperative characteristics and development of type II endoleaks [ 9 ]. A patent inferior mesenteric artery (IMA) and the number of patent lumbar arteries have been investigated as risk factors for type II endoleaks [ 10,11 ]. However, no previous systematic review has concentrated on this topic. Hence, the primary objective of the present systematic review and meta-analysis was to determine the current evidence on risk factors for the onset of type II endoleaks. This review concentrated on nonclinical risk factors, such as sex and age, preoperative comorbidities, and aortic anatomy. Moreover, we intended to report the updated pooled prevalence of type II endoleaks after EVAR. Methods Search strategy and study selection Relevant publications were identified by searching the following database: MEDLINE (from Jan 1, 1950, to June 30, 2016) (S1 File), Scopus (from 1966 to June 30, 2016), and EMBASE (from 1966 to June 30, 2016). The terms ªtype II endoleakº or ªtype 2 endoleak,º ªendovascular,º and ªaneurysmº were searched. The references cited in published original and review articles were searched to identify additional studies. The search was limited to human adults and publications in English. Subsequently, two authors (Q.G. and X.D.) independently reviewed the title and abstract of the studies identified in the search to exclude those that did not answer the research question of interest in accordance with prespecified inclusion and exclusion criteria. Records extracted by the initial search were screened, and potentially relevant papers were retrieved and examined in detail. Duplicate publications and case reports were also excluded. Whenever publications of overlapping populations were available, the publication with the most complete a (...truncated)