Download Asymptomatic dissecting aortic aneurysm in a young adult: a case

Asymptomatic dissecting aortic aneurysm in a young adult: a case report
Ehab M Esheiba, Mais Mamoon
ABSTRACT
Aortic dissection is a rare condition, yet it is potentially fatal. We report here a case of a 37-year old asymptomatic
male who came for a cardiology checkup as he was concerned that seven of his family members had been
diagnosed with aortic aneurysm and some of them had progressed to aortic dissection. He had a history of
hypertension that was controlled with medications. Although the patient was entirely asymptomatic, the diagnosis
of a dissecting aortic aneurysm was confirmed. The aneurysm was confined entirely to the ascending thoracic aorta.
The clinical presentation, diagnosis and management of ascending aortic dissection were reviewed. It has to be
noted that early and accurate diagnosis and treatment of such a potentially lethal condition are essential for survival.
Long term follow up is also required as there is always a risk of recurrence.
Key words: aneurysm, familial, CT aortogram, transesophageal echocardiography, dissection
Citation
Esheiba EM, Mamoon M. Asymptomatic dissecting aortic aneurysm in a young adult: a case report. Gulf Medical
Journal. 2013;2(1):32-35.
INTRODUCTION
Thoracic Aortic Aneurysms leading to acute
dissection (TAAD) are responsible for significant
premature mortality and are associated with a wide
range of underlying conditions including
hypertension, bicuspid aortic valve, and syndromic
conditions such as Marfan syndrome (MFS) or
Loeys-Dietz syndrome1. In the absence of a
syndromic cause, it has been estimated that 19 to
20% of TAAD cases have a genetic component
leading to familial TAAD (FTAAD). These
conditions display interfamilial variability as well as
variable penetrance and severity2,3.
Whereas familial thoracic aortic aneurysms are
less common than many other cardiovascular
conditions, the fact that they can be lifethreatening and that even large aneurysms may not
produce symptoms makes it all the more
important for clinicians to be vigilant in their
evaluation of patients at risk. Screening of first
degree relatives with Familial Thoracic Aortic
Aneurysm (FTAA) and FTAAD is essential.
Department of Cardiology, Gulf Medical College Hospital, Ajman,
UAE.
Correspondence: Dr. Ehab M Esheiba, Specialist A and Lecturer,
Department of Cardiology, Gulf Medical College Hospital, P.O. Box
1484, Ajman, UAE.
email: [email protected]
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FTAA and FTAAD could be detected during
routine evaluation for non-cardiac reasons or
during evaluation of aortic regurgitation murmur.
CASE REPORT
A 37 year-old male patient apparently healthy,
reported for routine checkup and evaluation. He
had a history of hypertension and family history of
ischemic heart disease, diabetes mellitus and
hypertension. He was asymptomatic on
presentation. He stated that he had seven of his
family members (both males and females)
diagnosed with aortic aneurysm, and some had
progressed into aortic dissection.
Clinical examination revealed a regular pulse
rate at 67 beats per minute and a blood pressure
160/75mm Hg that was equal bilaterally.
Peripheral pulses were all felt equally bilaterally.
On auscultation, there was an early diastolic
murmur at the base of the heart consistent with
aortic regurgitation (AR). There were no signs of
Marfan syndrome or other connective tissue
diseases. 12-lead surface electrocardiogram (ECG)
showed high-voltage criteria for left ventricular
hypertrophy (LVH). Chest X–Ray revealed normal
cardiac size and clear lung fields, but there was
wide mediastinum. Transthoracic echocardiography (TTE) revealed proximal aortic aneurysm
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and there was a suspicion of the presence of an
intimal flap. Moderate AR was detected. CT
aortography was performed for full evaluation of
thoracic and abdominal aorta. It revealed that the
ascending aorta was dilated at its origin (5.3cm)
with a suspicious flap-like shadow at its posterior
aspect warranting further evaluation (Figure 1).
replaced with a prosthetic graft and the coronary
arteries were re-implanted. We are still following
up the patient for more than two years after
surgery. He is asymptomatic and all the secondary
preventive measures are being followed. In this
case, timely referral for early surgical correction
saved the life of the patient without complications.
DISCUSSION
Figure 1. CT Aortogram showing the aneurysmal dilatation of the
proximal aorta. The dissecting flap is seen.
The aortic arch and descending aorta were of
normal diameter down to the aortic bifurcation.
Transesophageal echocardiography (TEE) was
performed, which confirmed the presence of a
dissecting aortic aneurysm that was confined to
the ascending aorta (Figure 2).
Aggressive blood pressure lowering with beta
blockers was initiated. The patient was advised to
proceed for surgical treatment at the earliest.
Within a few days, surgery was performed. The
aortic valve was repaired, the ascending aorta was
Figure 2. TEE long axis view through the ascending aorta demonstrates
a type proximal dissection. The flap in the ascending aorta is
clearly shown.
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Aneurysms of the ascending thoracic aorta most
often result from cystic medial degeneration
(CMD), which appears histologically as smooth
muscle cell dropout and elastic fiber degeneration.
CMD leads to weakening of the aortic wall, which
in turn results in aortic dilatation and aneurysm
formation. CMD occurs normally to some extent
with aging, but the process is accelerated by
hypertension4. CMD is also seen in patients with
ascending thoracic aortic aneurysms who do not
have overt connective-tissue disorders4. Moreover,
it is now recognized that although cases of
thoracic aortic aneurysms in the absence of overt
connective-tissue disorders may be sporadic, they
are often familial and are now referred to as the
Familial Thoracic Aortic Aneurysm (FTAA)
syndrome.
In an analysis of a large database of thoracic
aortic aneurysm patients, Coady and colleagues
found that at least 19% of patients had a family
history of a thoracic aortic aneurysm, and that they
tend to present at significantly younger ages than
those with sporadic aneurysms5. Most pedigrees
suggest an autosomal-dominant mode of
inheritance6, but there is marked variability in the
expression and penetrance of the disorder, such
that some inherit and pass on the gene but show
no manifestation of the disease2,3. Several
mutations have been identified. A mutation on
3p24.2–25 can cause both isolated and familial
thoracic aortic aneurysms, with histological
evidence of CMD2,7. Mutations have also been
mapped to two other chromosomal loci (5q13–14
and 11q23.2-q24)4,8. The extent of genetic
heterogeneity is likely to become more evident as
more families with thoracic aortic aneurysms are
studied. It was also suggested that this is actually a
polygenic condition, thus explaining the variable
expression and penetrance. Consequently, at
present, it is not possible to perform routine
genetic screenings for this syndrome9.
Most patients with thoracic aortic aneurysms
are asymptomatic at the time of diagnosis, and the
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aneurysms are typically discovered incidentally on
imaging studies (chest x-ray, CT scan or
echocardiography) ordered for other indications.
However, the typical manifestations of aneurysms
of the root or ascending aorta may include:
secondary AR (so a diastolic murmur may be
detected on physical examination or, less often,
patients present with congestive heart failure),
local mass effect (especially with large aneurysms)
such as compression of the trachea or main stem
bronchus (causing cough, dyspnea, wheezing or
recurrent pneumonitis), compression of esophagus
(causing dysphagia), or compression of the
recurrent laryngeal nerve (causing hoarseness of
voice). Rarely, chest or back pain may occur with
non-dissecting aneurysms as a result of direct
compression of other intrathoracic structures or
erosions into adjacent bones. The feared
consequence of thoracic aneurysm is aortic
dissection or rupture (often referred to as an acute
aortic syndrome), which is potentially lethal.
Typical symptoms of acute aortic syndrome
include the abrupt onset of severe pain in the
chest, neck, back, and/or abdomen 9.
The diagnosis of pre-aneurysmal dilatation of
the proximal aortic root or ascending aorta is
based on measurement of the dimensions of the
sinuses of Valsalva and ascending aorta using
imaging modalities such as 2D echocardiography,
CT scan, MRI, or angiography and comparison
with age-appropriate nomograms indexed for
body surface area (BSA)10.
The major diagnostic criteria for familial
thoracic aortic aneurysms and aortic dissections
are the following:
 Progressive enlargement of the ascending
thoracic aorta involving the sinuses of Valsalva,
the ascending aorta, or both6.
 Exclusion of Marfan syndrome, Loeys-Dietz
syndrome, Ehlers Danlos syndrome, vascular
type and other syndromic causes of TAAD11.
 A positive family history of TAAD 4.
Presently, it is not possible to perform routine
genetic screening for this syndrome9. Medications
that reduce hemodynamic stress on the aorta, such
as beta adrenergic blocking agents, are recommended. Because of the high mortality rate
associated with acute ascending aortic dissection
(≈40 to 50%), it is crucial to not only identify
patients with enlarged ascending aortas and to
attempt to slow aortic growth using medical
treatments but also to intervene surgically in an
elective fashion before dissection occurs1. How,
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then, is the clinician to determine when to proceed
to surgery? Knowledge of the likely risk of
dissection for a given condition in an individual
patient and aortic diameter become of paramount
importance. Surgery is generally recommended in
cases in which the ascending diameter exceeds 5.0
to 5.5cm; however, a large proportion of
dissections occur at smaller diameters, and even in
patients with no visible enlargement12.
CONCLUSION
This case reports on the chance of incidental
detection of asymptomatic Thoracic Aortic
Aneurysm and Dissection. Diagnosed as being a
familial condition in our patient, screening in the
first degree relatives was advised. Low threshold
for referral for surgical correction saved the
patient’s life. Blood pressure control and
adherence to the cardiovascular risk factor
reduction strategies are an essential part of the
management plan, both before and after the
surgery.
References
1. Hiratzka LF, Bakris GL, Beckman JA, Bersin RM, Carr
VF, Casey DE, et al. Guidelines for the diagnosis and
management of patients with thoracic aortic disease:
executive summary: a report of the American College of
Cardiology Foundation/American Heart Association
Task Force on Practice Guidelines, American
Association for Thoracic Surgery, American College of
Radiology, American Stroke Association, Society of
Cardiovascular
Anesthesiologists,
Society
for
Cardiovascular Angiography and Interventions, Society
of Interventional Radiology, Society of Thoracic
Surgeons, and Society for Vascular Medicine.
Circulation. 2010;121:266-369.
2. Milewicz DM, Chen H, Park ES, Petty EM, Zaghi H,
Shashidhar G, et al. Reduced penetrance and variable
expressivity of familial thoracic aortic aneurysms/
dissections. Am J Cardiol. 1998;82:474-9.
3. Albornoz G, Coady MA, Roberts M, Davies RR,
Tranquilli M, Rizzo JA, et al. Familial thoracic aortic
aneurysms and dissections: incidence, modes of
inheritance, and phenotypic patterns. Ann Thorac Surg.
2006;82:1400-5.
4. Guo D, Hasham S, Kuang SQ, Vaughan CJ, Boerwinkle
E, Chen H, et al. Familial thoracic aortic aneurysms and
dissections. Circulation. 2001;103:2461-8.
5. Coady MA, Davies RR, Roberts M, Goldtein LJ,
Rogalski MJ, Rizzo JA, et al. Familial patterns of
thoracic aortic aneurysms. Arch Surg. 1999;134:361-7.
6. Hahn RT, Roman MJ, Mogtader AH, Devereux RB.
Association of aortic dilation with regurgitant, stenotic
and functionally normal bicuspid aortic valves. J Am
Coll Cardiol. 1992;19:283-8.
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7. Hasham SN, Willing MC, Guo DC, Muilenburg A, He
R, Tran VT, et al. Mapping a locus for familial thoracic
aortic aneurysms and dissections (TAAD2) to 3p24–25.
Circulation. 2003;107:3184-90.
8. Vaughan CJ, Casey M, He J, Veugelers M, Henderson
K, Guo D, et al. Identification of a chromosome
11q23.2–q24 locus for familial aortic aneurysm disease, a
genetically heterogeneous disorder. Circulation.
2001;103:2469-75.
9. Eric MI. Thoracic and Abdominal aortic aneurysms.
Contemporary review in cardiovascular medicine.
Circulation. 2005;111:816-28.
10. Roman MJ, Rosen SE, Kramer-Fox R, Devereux RB.
Prognostic significance of the pattern of aortic root
dilation in the Marfan syndrome. J Am Coll
Cardiol.1993;22:1470-6.
11. De Paepe A, Devereux RB, Dietz HC, Hennekam RC,
Pyeritz RE. Revised diagnostic criteria for the Marfan
syndrome. Am J Med Genet. 1996;62:417-26.
12. Pape LA, Tsai TT, Isselbacher EM, Oh JK, O’Gara PT,
Evangelista A, et al. Aortic diameter ≥5.5 cm is not a
good predictor of type A aortic dissection: observations
from the International Registry of Acute Aortic
Dissection (IRAD). Circulation. 2007;116:1120-7.
This study was presented at the 4th Annual Scientific Meeting of Gulf Medical University, held on 05 and
06 November, 2012.
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