By Will Boggs MD
NEW YORK
(Reuters Health) Aug 04 - In aortic stenosis, replacing the aortic
valve can keep the descending aorta from becoming increasingly
dilated -- thereby sparing the vessel itself from replacement.
"Our
data simply confirm an intuitive concept: When the aortic
dilatation is a consequence of the hemodynamic derangement due to
flow through a stenotic aortic valve and not of a pathology of the
aortic wall, correction of the valvular stenosis is sufficient to
interrupt aortic dilatation," said lead author Dr. Mario Gaudino
from Catholic University in Rome, in an email to Reuters
Health.
"In the
past," he noted, "very few studies have tried to distinguish
between the different types of aneurysms in terms of evolution and
treatment."
This
week, he and his colleagues report on the evolution of aortic
dimensions after surgery in 93 patients with moderate post-stenotic
ascending aorta dilation (50 to 59 mm) who underwent aortic valve
replacement alone.
During
15 years of follow-up, there were 16 deaths, but in no case was
death attributed to an aortic event, according to a report
published August 2nd in the Journal of the American College of
Cardiology,
In fact,
no patient had an acute aortic event (rupture, dissection,
pseudoaneurysm) during follow-up, and there were no reoperations
for thoracic aortic pathology.
Aortic
dimension during the first 10 years after surgery did not change
appreciably. The mean aortic diameter grew by only 1 mm, and the
mean ascending aorta expansion rate was 0.3 mm per year.
"We are
aware of the fact that our data contradict the published guidelines
for the treatment of diseases of the ascending aorta," the
researchers write.
However,
they add, "these guidelines do not make specific recommendations
for the different subtypes of aortic dilations, although it seems
likely that the physiopathology, natural history, and treatment can
be different between degenerative or atherosclerotic and
post-stenotic aneurysms."
The
investigators suggest, "Ascending aorta replacement should be
considered only for very young patients with extremely long life
expectancy."
In his
email, Dr. Gaudino added, "We hope that our study can demonstrate
that the actual approach to ascending aorta aneurism is too
simplistic and underline the need of specific therapeutic
guidelines for the different types of aortic aneurysms."
In an
editorial, Dr. David D. Glower from Duke University Medical Center,
Durham, North Carolina writes, "Current American College of
Cardiology/American Heart Association guidelines recommend
replacing the ascending aorta at the time of aortic valve
replacement if the ascending aorta is more than 5.0 cm in any
patient or if the ascending aorta is more than 4.5 cm in bicuspid
patients. "
"Evidence supports the contention of Gaudino et al. that size alone
is not enough to indicate replacement of the ascending aorta in
many patients with aortas of less than 6.0 cm in diameter," Dr.
Glower notes. "Guidelines are just guidelines. Guidelines need to
be applied to individual patients by knowledgeable physicians."
SOURCE: http://bit.ly/nwfrB
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