Prevalence of thoracic ascending aortic aneurysm in adult patients with known abdominal aortic aneurysm: An echocardiographic study

Abstract

Aortic aneurysms (AAs) can develop in all parts of the aorta and a lot of them remain undetected unless incidentally discovered or until a lifethreatening complication occurs [1,2]. Thoracic aorta is usually studied with computed tomographic imaging (CT),magnetic resonance imaging and echocardiography [1,2]. Transthoracic echocardiography (TE) is commonly performed prior to abdominal AA (AAA) repair to evaluate the cardiac structure and function. In a recent paper, a highprevalence of thoracicAA(ATA) inpatientswithAAAassessedbyCThas been reported [3]. In our study we retrospectively enrolled 1942 patients in order to evaluate the prevalence of the ascending thoracic aortic and aortic arch dilatation/aneurysm in patients with AAA that underwent transthoracic echocardiography (TE) prior to surgery. The exclusion criteriawere: the presence of bicuspid aortic valve, previous aortic valve and/or ascending aortic surgery, genetic syndromes (Marfan syndrome, Ehlers–Danlos syndrome and others), and inflammatory and traumatic diseases. Thus, 1305 patients were considered eligible for the study. The aortic root and the proximal ascending aorta segments were visualized in the left and rightparasternal long-axis views. Inparasternal view the Valsalva sinuses and the proximal portion of the ascending aorta were measured. In the parasternal short axis bicuspid aortic valve was rule out. The aortic arch was evaluated by suprasternal view between the innominate and left carotid artery. Standardmeasurements were made by the leading edge-to-leading edge diameter in enddiastole taking care to obtain a true perpendicular dimension and appropriate gain settings [4]. Views used for measurements were those that showed the largest diameter of the aortic segment and in particular the maximum diameter measured perpendicular to the long axis of the vessel in that view. All the measurements were achieved in twodimensional mode. We used the absolute values as normal standard references of aortic sizes as follows: 1. Valsalva sinuses: 37 mm inmen and 33 inwomen; 2. Proximal ascending aorta: 34 mm inmen and 31 mm inwomen; and 3. Aortic arch: 32 mm in men and 29 mm in women. Sex-specific criteria wereused todefineanascendingaortic aneurysm:womenN42 mmand men N47 mm, and aortic arch aneurysm: women N32 mm and men N37 mm [5–7]. The study complies with the principles and guidelines of the Declaration of Helsinki. The clinical characteristics of the study population and the median diameters of the aorta are reported in Tables 1 and 2. 50% of the population had increased diameters of the Valsalva sinuses and proximal portion of ascending aorta, and 25% had the diameter of the aortic arch greater than normal range. Valsalva sinuses were increased in 25% of men and 75% of women. 50% of men and 75% of women had increased diameter of the proximal ascending aorta. The aortic arch diameter was above the normal range in 25% ofmen and 50% ofwomen. On the basis of sex-specific criteria for aneurysm4% of the patients had an ascending aortic aneurysm and 6.5% an aortic arch aneurysm. Furthermore, 2% men had an ascending aortic aneurysm compared with 25.8% of the women (p b 0.0001), and 6.6% men had an aortic arch aneurysm compared with 10.5% of the women (p b 0.4). Thus, we demonstrate a high prevalence of dilatation/aneurysm of the ascending aorta and the aortic arch in patients with AAA evaluated by TE during pre-operative risk stratification. Our study supports the common idea that ATA is commonly misdiagnosed because of its lack of symptoms. Itani et al. estimated the prevalence of asymptomatic ATA between 0.16 and 0.34% [8]. Larrson et al. evaluated the prevalence of ATA in AAA with CT scan, and they reported the presence of thoracic aorta dilatation in more than 25% of 422 patients [3]. Other retrospective studies had already assessed a higher incidence of thoracic aorta repair in patients that had previously undergone to abdominal aortic repair, although in their reports patients with connective disease were included as well. Alegret et al. stated that