Fate of Pure Type II Endoleaks Following Endovascular Aneurysm Repair

PURPOSE: Type II endoleaks (T2ELs) are the most common type of endoleaks observed after endovascular aneurysm repair (EVAR). However, whether T2ELs should be treated remains debatable. In the present study, we aimed to describe the natural course of T2ELs and suggest the direction of their management. MATERIALS AND METHODS: We reviewed the data of 383 patients who underwent EVAR between 2007 and 2016. Data, including demographic and anatomical details, were collected, and patients with T2ELs were compared to those without them. Patients with T2ELs were categorized into subgroups according to changes in sac size and treatment requirement. RESULTS: We found patent lumbar artery count and lesser thickness of mural thrombi to be significant risk factors for T2ELs. Among the 383 patients, 85 (22.2%) patients were diagnosed with pure T2ELs. Among these 85 patients, the sac size increased in 29 (34.1%) patients, showed no significant change in 39 (45.9%) patients, and decreased in 17 (20.0%) patients. Fifteen (17.6%) patients, among 85 with initial pure T2ELs, showed spontaneous resolution. Five (5.9%) patients among 29, in whom the sac size increased, developed combined-type endoleaks. No sac ruptures were noted among the patients with T2ELs. CONCLUSION: T2ELs with sac expansion potentially contribute to other types of endoleaks. Therefore, periodic screening is important for these patients, particularly for those showing an increasing sac size. In addition, intervention should be considered when other types of endoleaks occur.