Aortic dissection in Turner syndrome

Abstract

Purpose of review: Turner syndrome is a relatively common disorder of female development with cardinal features of short stature and congenital cardiovascular defects (CHD). Turner syndrome is the most common established cause of aortic dissection in young women, but has received little attention outside pediatric literature. This review focuses on emerging knowledge of the characteristics of aortic disease in Turner syndrome in comparison with Marfan-like syndromes and isolated aortic valve disease.

Recent findings: The incidence of aortic dissection is significantly increased in individuals with Turner syndrome at all ages, highest during young adult years and in pregnancy. Pediatric patients with dissection have known congenital cardiovascular defects (CHD), but adults often have aortic valve and arch abnormalities detected only by screening cardiac magnetic resonance. Thoracic aortic dilation in Turner syndrome must be evaluated in relation to body surface area. Dilation is most prominent at the ascending aorta, similar to the pattern seen in nonsyndromic bicuspid aortic valve, is equally prevalent (20-30%) in children and adults, and does not seem to be rapidly progressive. Cardiovascular anomalies and risk for aortic dissection in Turner syndrome are strongly linked to a history of fetal lymphedema, evidenced by the presence of neck webbing and shield chest.

Summary: Risk for acute aortic dissection is increased by more than 100-fold in young and middle-aged women with Turner syndrome. Monitoring frequency and treatment modalities are decided on an individual basis until more information on outcomes becomes available.

Fig. 1. Elongated transverse arch of the aorta (ETA) and associated anomalies in a woman with TS revealed by Gd-enhanced 3D MRA

(A) demonstrates flat and elongated transverse arch (large arrow) with characteristic kink in lesser curvature (small arrow). This same woman had aberrant origins of both right and left carotids at the greater curvature (A) and both subclavian arteries off a common, dilated vessel at the lesser curvature (A&B). This type of kinking at the usual coarctation site has been termed “pseudocoarctation” in other studies. Subject also had persistent LSVC as seen on reformatted coronal (C) and axial (D) postcontrast fat-suppressed spoiled gradient echo images. From Ho et al.[14].

Fig. 2

Fetal nuchal cystic hygroma result in neck webbing. A) Fetal ultrasound showing massively dilated jugular lymphatic sacs (arrows). B) Symmetric neck webbing in a 12 yo girl with TS, who has bicuspid aortic valve and aortic coarctation. Neck webbing or pterygium colli, defined as redundant skin folds extending from mastoid to acromion, result from tenting of the fetal skin over the dilated lymphatics, and is usually associated with low posterior hairline and shield chest.

Fig. 3

Incidence of aortic dissection in Turner syndrome by age group. This is a summary of epidemiological data reported by Gravholt et al[7]. The frequency of aortic dissection is greater in females with TS at all ages compared to the general population, with the highest incidence in young adults.

Fig. 4

Ascending aortic diameter normalized for BSA in 160 adults with TS and age-matched control women. This normalization termed aortic size index or ASI, showed that mean ascending aortic diameter is significantly increased in TS, and that a group of women with TS have extremely elevated values. Outcomes for these cases are illustrated in Fig. 5 Data extracted from Matura et al. [8].

Fig. 5

Outcomes among 158 women followed at the NIH for an average of 3 years according to baseline ASI. A – All undergoing regular monitoring for aortic diameters; those with ASI>2 are informed about the risk, aware of potential symptoms and need for urgent care, and wear medic alert ids B – Aortic valve replacement for valvular dysfunction was accompanied by proximal aortic graft C – Acute aortic dissection treated with emergent surgical intervention (an additional patient since recent Matura et al paper) D – Died from acute aortic dissection/rupture NV – ASI data for 37 age-matched female volunteers