Aortic blisters: diagnosis and evolution.

In order to evaluate the incidence, the diagnostic modalities and significance of blisters of the abdominal aortic aneurysm wall, in a retrospective review, 14 patients (2.6%) having these lesions were identified between 1983 and 1995. At preoperative examination, aortography had less accuracy (1 case = 20%) than CT scan (3 cases = 27.2%) or MRI angiography (6 cases = 85.7%) to detect blisters; others were discovered intraoperatively in the remaining four patients. Most blisters were located on the anterior or antero-lateral wall of aneurysms; its area ranged from 0.8 to 2.6 cm2. One patient with a suspected blister diagnosed at aortography, during chest physiotherapy for his COPD, presented sudden abdominal pain: at urgent laparotomy, an acute contained rupture of a large blister, without extraluminal blood loss, was found. All patients underwent aneurysm repair, with no postoperative deaths. Occurrence of rupture in one patient clearly indicates the natural course of aortic blisters. MRI angiography may accurately detect these lesions; surgical treatment is necessary for preventing imminent rupture.