The incidence of abdominal aortic
aneurysm increases as the advances. As the life expectancy is increasing more
number of people are going to face the cardiovascular problems towards the
later part of their life. In Tromso study 1
(Norway) an aneurysm (>29 mm) was present in 8.9% men and 2.2% women (p
< 0.001) aged between 25-84 years of age. Aorta > 39 mm diameter was
in 2.3% of men 0.4% of women aged between 25 to 84 years. The prevalence of
abdominal aortic aneurysm increased with age. In India with one billion people,
we can assume that at least 10 million people will be at risk of aortic
aneurysm development. It is considered that operations for aortic aneurysms are
major and they are associated with high risk even in the best hospitals. The
recently introduced Endorepairs (very expensive) are less invasive and
considered to be associated with less pain, shorter hospital stay. But one
would still ask for some medicine which can avoid intervention or operation if
the aneurysms are detected early enough. So, this question of medical therapies
is more relevant to us in India. On theoretical grounds, multiple medications
can suppress AAA formation and subsequent expansion, reducing the risk of
rupture or the need for surgical correction. However, none have been
conclusively shown to reverse the pathology in the aortic wall or to have a
clinically beneficial effect on slowing AAA growth. Because of potential side
effects, many of these drugs remain of experimental interest only.
However, despite the paucity of
good clinical information, it would appear that there is sufficient
experimental and observational evidence to support using some of these
medications. It would seem appropriate to control elevations in blood pressure
with ACE inhibitors or ARBs. In patients who are normotensive, either ACE
inhibitors or ARBs could still be used in low doses provided patients can
tolerate these medications. Addition of vitamin E should not be harmful and can
be beneficial. COX-2 inhibitors in patients with concomitant arthritis or pain
syndromes can have an additive benefit by reducing aneurysm expansion.
Doxycycline is an inexpensive medication with few side effects. Statins should
be considered in all AAA patients irrespective of cholesterol levels because of
their pleiotropic effects, which might not only reduce AAA expansion but also
improve overall cardiovascular risk. They can also benefit operative outcomes
in patients who ultimately come to elective or emergency surgery.
Probably
we can also think in terms of some kind of vaccination to prevent the
progressive changes in the aortic diameter. It should become a mandatory thing
in all the people above 50 years of age without smoking, above 30 year of age
in case of smokers just like the vaccinations in paediatrics. The understanding
at the genetic and molecular level may help us to find out a way to revert the
aneurysmal changes in the aorta or its branches. It is important to invest
money in this direction while continuing to think and develop mechanical solutions
for the biological problems such as smooth muscle cell apoptosis, elastin
degradation, inflammatory cell infiltration, synthetic abnormalities of
collagen in the wall of the aorta. The proposed cost of treating the
cardiovascular disease and aneurysmal disease in our country with mechanical (repetitive)
means (stents and devices) is beyond imagination of the common man. So, there
should be adequate encouragement, planning and funding for the development of
such programs in Hospitals, Medical universities and other Educational institutions
which can prevent non communicable diseases (NCDs).
[1]
Reference: K Singh, KH Bonna, BK
Jacobsen et al. Prevalence of and risk
factors for abdominal aortic aneurysms in a population based study. Tromso
study.
Am J Epidemiol 2001; 154(3): 236-44
