Signs of impending rupture in abdominal aortic and iliac artery aneurysms by computed tomography: Outcomes in 41 patients

Bruno Fabricio Feio Antunes,Adriano Tachibana,Cynthia De Almeida Mendes,Lucas Lembrança,Marcela Juliano Silva,Marcelo Passos Teivelis,Nelson Wolosker

doi:10.6061/clinics/2021/e2455

Abstract

OBJECTIVES:This study aimed to determine the prevalence of signs of impending rupture (SIR) in asymptomatic patients with abdominal aortic and iliac artery aneurysms, and to evaluate whether these signs were associated with rupture in asymptomatic patients.METHODS:This was a retrospective study of patients with abdominal aortic and iliac artery aneurysms identified on computed tomography (CT) over a 10-year period in a single center. The CT scans were reviewed by two reviewers, and patients with SIR were assigned to one of three groups: (1) early symptomatic (ES), (2) late symptomatic (LS), and (3) always asymptomatic (AA). The four main SIR described in the literature were investigated: 1) crescent sign, 2) focal wall discontinuity of circumferential calcifications, 3) aortic bulges or blebs, and 4) aortic draping.RESULTS:From a total of 759 aortic and iliac aneurysm reports on 2226 CT scans, we identified 41 patients with at least one SIR, and a prevalence of 4.14% in asymptomatic patients. Focal wall discontinuity of circumferential calcifications was the most common sign, and it was present in 46.3% of these patients (19/41); among these, 26 were repaired (ES: 9, LS: 2, AA: 15). Eleven asymptomatic patients underwent follow-up CT. The aneurysm increased in size in 6 of the 11 (54.5%) patients, and three ruptured (all with discontinuity of calcifications), one of which had no increase in diameter.CONCLUSIONS:The presence of focal wall discontinuity of circumferential calcifications was the most common SIR. There was a prevalence of all signs in less than 5% of asymptomatic patients. In unrepaired patients, the signs could be observed on follow-up CT scans with an increase in aneurysm size, indicating that the presence of SIR alone in the absence of other clinical factors or aneurysm characteristics is an insufficient indication for surgery.

Highlights

We performed a word search of our comprehensive computer database containing all reports of Computed tomography (CT) scans of the abdomen and pelvis performed in symptomatic and asymptomatic patients with aortic and/or iliac artery aneurysms at the Albert Einstein Jewish Hospital (HIAE), São Paulo, Brazil between October 2007 and October 2017 using the keyword ‘‘aneurysm.’’ All CT scan reports were evaluated for the presence of imaging features, which may herald instability in the aortoiliac axis
For the analysis of focal wall discontinuity of circumferential calcifications, CT scans were compared with previous imaging examinations that were available in our record retrieval system
We retrospectively reviewed 2226 CT scans performed between October 2007 and October 2017 with the word ‘‘aneurysm’’ included in the reports

Summary

Introduction

The rupture of an abdominal aortic aneurysm (AAA) is one of the most dramatic emergencies in medicine; only approximately 50% of patients with ruptured AAAs are alive by the time they reach the hospital, among whom, up to 50% do not survive repair [1]. No potential conflict of interest was reported. Received for publication on October 2, 2020. Imaging is essential for the early detection and size measurement of AAAs. Elective repair of the aneurysm is indicated for rapidly expanding aneurysms or for those that exceed 5.5 cm in diameter in men and 5.0 cm in women as prophylaxis against rupture; the 30-day mortality ranges from 0.9% to 4.8% depending on the type of repair and center experience [2]. Previous reports have concluded that screening for AAA reduces the incidence of aneurysm rupture and AAA-related mortality [3]

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