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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 4, July/August 2017
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AFRICA
with chronic dissection and very high risk of rupture. Second,
despite previous reports on several patients with giant aneurysms
without rupture, to our knowledge, our patient represents the
first asymptomatic redo case of a giant dissecting ascending
aortic aneurysm occurring five years after BAV replacement.
Third, a surgical treatment of this giant dissecting ascending
aortic aneurysm was performed with moderate hypothermic
circulatory arrest without any subsequent neurological sequelae
in the face of a high risk of aortic injury during sternotomy due
to the close proximity to the sternum, caused by the previous
aortic valvular surgery.
Giant ascending aortic aneurysms may give rise to very severe
clinical complications, among which, dissection and rupture
are often fatal.
1
The risk of rupture is related to the dimensions
of the aneurysm and the expansion rate during follow up.
1
An
expansion rate exceeding 1 cm/year or an aneurysmal diameter
greater than 6 cm is associated with a dramatic increase in the
risk of rupture.
5,6
The risk of dissection in aortic aneurysms is proportional
to the increase in diameter, and nearly 25% of patients with
chronic aortic dissections may develop aneurysms.
7
Our patient
seemed to have an aortic aneurysm secondary to chronic aortic
dissection, based on the fact that the actual underlying pathology
was BAV, the aneurysmal expansion rate was high, and the
clinical course was of a chronic nature. The expansion rate and
risk of rupture in ascending aortic aneurysms in patients with
chronic aortic dissection is significantly higher compared to
aneurysms on the same site due to other conditions.
The average expansion rate of thoracic aortic aneurysms is
0.1 to 0.2 cm/year.
1
By contrast, in our patient the ascending
aortic diameter was 42 mm at the time of aortic replacement,
and this increased to 132.5 mm within a five-year period, which
corresponds to a significantly higher rate of expansion than
usually reported, namely 18.1 mm/year.
8
The probable cause
of this high rate of expansion was the dissection, which was a
complication of a BAV, and the subsequent rapid dilatation of
the aneurysm. The lifetime risk of aortic dissection in patients
with BAV disease is approximately 6.13%, which is nearly nine
times higher than in the normal population.
3
Conclusion
Despite the rare occurrence and a very high risk of rupture, giant
ascending aortic aneurysms may present with an asymptomatic
clinical course, as was the case in our patient, who had a giant
aneurysm of 13.25 cm. These challenging aneurysms are adjacent
to the sternal wall, require redo operation and are associated
with high mortality rates. Therefore adequate surgical planning
and expertise are prerequisites for their proper management.
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