Date Published: February 9, 2017
Publisher: Public Library of Science
Author(s): Qiang Guo, Xiaojiong Du, Jichun Zhao, Yukui Ma, Bin Huang, Ding Yuan, Yi Yang, Guojun Zeng, Fei Xiong, Rudolf Kirchmair.
This systematic review and meta-analysis aims to determine the current evidence on risk factors for type II endoleaks after endovascular aneurysm repair (EVAR).
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.
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. 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.
Endovascular aneurysm repair (EVAR) has become the primary choice of treatment for abdominal aortic aneurysms (AAAs) in suitable patients . EVAR always has better short-term outcomes compared with open repair [2,3]. Aortic endograft occlusion, migration, and endoleaks are known complications after EVAR , 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 . 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 .
Endoleaks are specific complications of EVAR. Type II endoleaks are the most common type of endoleaks, occurring in approximately 10% of patients after EVAR . Although Type II endoleaks are less likely to require secondary reintervention than type I or III endoleaks because of the possibility of arterial rupture , type II endoleaks are a risk factor for aneurysm sac growth, and ruptures occur in approximately 1% of patients with type II endoleaks after EVAR . Thus, patients need continuous surveillance after EVAR to detect aneurysm growth and endoleaks. Previous studies explored risk factors for type II endoleaks after EVAR [9–11]. However, controversies have been found between these studies. These discrepancies may be attributed to the insufficient statistical power of individual studies and the inability to perform separate analyses. Therefore, we conducted a systematic review and meta-analysis to identify the risk factors for type II endoleaks after EVAR. Furthermore, the pooled prevalence of type II endoleaks must be updated on the basis of the latest evidence.