Title: Preoperative Endoleak Type in Patients of Aneurysmal Sac Expansion After Endovascular Aneurysm Repair and Intraoperative Blood Loss in Aneurysmorrhaphy: Analysis of a Case Series of 18 Patients

Purpose: EVAR (endovascular aneurysm repair) has become a possible treatment option of abdominal aortic aneurysms, and endoleak is the most common complication after EVAR. The purpose of this study was to determine the difference of intraoperative blood loss in aneurysmorraphy for aneurysmal sac expansion after EVAR according to type of endoleak. Methods Perioperative data of 18 patients underwent aneurysmorrhaphy for aneurysmal sac expansion after EVAR from July 2010 to November 2017 at the Jikei University Hospital are collected. Patients were divided in two group, endoleak type II or type V (endotension) according to preoperative imaging. Patient demographic and quantitative data, including intraoperative blood loss and intraoperative red blood cell transfusion volume, were collected from electronic medical and anesthetic records. Intraoperative blood loss in aneurysmorrhaphy were compared between the two groups. Results In 18 patients, 13 patients were diagnosed type II endoleak, and 5 patients were diagnosed endotension. There were statistically differences in intraoperative blood loss and red cell transfusion volume between type II endoleak and endotension groups (P = 0.0016 and P = 0.018, respectively). Conclusion These results suggest that the type of endoleak after EVAR may be associated with intraoperative blood loss in aneurysmorrhaphy. Pre-operative estimation of intraoperative blood loss depending on endoleak type may be helpful for the decision making of anesthetic management in aneurysmorrhaphy.