Sac hygroma after endovascular abdominal aortic aneurysm repair: successful treatment with endograft relining.

Aneurysm sac expansion following endovascular abdominal aortic aneurysm repair (EVAR) is typically associated with endoleaks that can be readily diagnosed on computed tomographic angiography (CTA), ultrasound, or catheter-directed arteriography. Sac hygromas are a cause of sac expansion without apparent endoleak and are presumed to be a result of ultrafiltration of serum manifested by accumulation of fibrinous, gelatinous material within the aneurysm sac following EVAR. Although there are no reported associated ruptures, sac expansion is nevertheless disconcerting and intervention is presumably indicated. We report a case of an expanding aneurysm after EVAR secondary to sac hygroma that was successfully treated with relining of the existing, original endograft.