LAUSR

OBJECTIVE To evaluate the impact of initial aneurysmal sac reduction after endovascular aneurysm repair (EVAR) on the evolution of aneurysmal sac over follow-up. MATERIAL AND METHODS A retrospective cohort study was made of patients subjected to elective treatment between January 2005 and December 2014, with a minimum follow-up of 18 months. An analysis was made of the evolution of the aneurysmal sac according to its condition one year after surgery, defining of two groups: A (sac reduction) and B (stable sac). Follow-up by CT angiography was made after one month and then every 6 months or annually, depending on the presence of endoleak. RESULTS A total of 128 patients were included. Fifty-one patients (39.8%) showed a significant decrease in diameter during the first year (group A) while 77 patients (60.2%) showed no initial decrease (group B). Preoperative CT angiography showed the patients in group A to have larger aneurysms (63.5 mm vs 59.25; p = 0.048), a greater presence of posterior thrombus (68.6% vs 30.7%; p<0.001), and fewer patent lumbar vessels (56.9% vs 83.1%; p = 0.001). The prevalence of endoleak at some point during follow-up was lower in group A (31.4% vs 74% in group B; p<0.001), and 100% of all aneurysmal growths were associated to the presence of endoleak. After 5 years, significant differences were observed in the growth-free rate (96.9% in group A vs 85.2% in group B; HR 4.8 [1.1-21.4; p = 0.036]) and in the reintervention-free rate (95,7% vs 84.6%; HR 6.6 [0.8-52.4; p = 0.07]). No reoperation in group A was due to type II endoleak. CONCLUSIONS The aneurysmal sac can be expected to take a favorable course in those cases characterized by initial aneurysmal sac reduction. These findings may imply a change in the follow-up protocol, even in cases with type II endoleak.