FT13. Aneurysm Sac Thrombus Volume Predicts Endoleak With Aneurysm Expansion After Endovascular Aneurysm Repair

Abstract

Several studies have analyzed risk factors that may influence the incidence of endoleak with sac expansion after endovascular aneurysm repair (EVAR). Previous studies demonstrated a quantitative protective effect of intraluminal thrombus for endoleak. However, they assessed the amount of intraluminal thrombus indirectly by thrombus thickness, percentage of circumferential luminal thrombus, thrombus area, and so on. Therefore, the correlation still has not been well demonstrated. The aim of this study was to examine the correlation of preoperative intraluminal thrombus, measured by thrombus volume, with the incidence of endoleak and late sac expansion. Between June 2007 and March 2014, there were 423 patients who underwent EVAR at our institution. Ruptured, inflammatory, and infected aneurysms were excluded; 214 patients who had preoperative and postoperative computed tomography angiography (CTA) and at least 3 years of follow-up were included in this study. Prospectively collected data were supplemented with a retrospective review of medical records and radiologic images. The demographic and clinical characteristic profiles were collected. CTA was evaluated with Aquarius iNtuition software (TeraRecon, Foster City, Calif) to obtain aneurysm sac, intraluminal thrombus volume, and other anatomic factors. Late endoleak was defined as a leak observed at 30 days. Significant abdominal aortic aneurysm sac expansion was defined as an increase of 5 mm. Logistic regression and Cox regression analysis were used to assess the association of each variable with the incidence of late endoleak and sac expansion. Of 214 patients, 49.1% (105 patients) had late endoleak and 19.6% (48 patients) had late endoleak with sac expansion on CTA. The mean follow-up duration was 53.4 months (range, 18.5-109.4 months). Univariate analysis demonstrated that number of total patent lumbar arteries (P = .011), a patent inferior mesenteric artery (IMA; P < .01), diameter of IMA (P < .01), Excluder (W. L. Gore & Associates, Flagstaff, Ariz) stent graft (P < .01), smoking history (P = .022), and preoperative intraluminal thrombus volume/sac volume (P = .018) are significant factors regarding the incidence of late endoleak . Logistic regression analysis showed that variables such as diameter of IMA (P = .006), Excluder stent graft use (P < .01), and preoperative intraluminal thrombus volume/sac volume (P = .026) are predictors of incidence of late type II endoleak. Cox regression analysis showed that the preoperative intraluminal thrombus volume/sac volume is the only significant predictor of incidence of late endoleak with sac expansion (P = .015). Preoperative aneurysm sac thrombus volume predicts incidence of endoleak with aneurysm expansion after EVAR.