DISCUSSION
The Congenital Aorto-Right Ventricle Fistula is a defect on the wall of
the aorta and, although there is no definitive etiology for this
anomaly, it is probably caused by its weakness throughout the
development. The abnormalities of the Sinus of Valsalva are
characterized into three different groups: (1) unruptured aneurysm of
the Sinus of Valsalva, (2) aneurysm of the Sinus of Valsalva with
intracardiac or extracardiac rupture, and (3) intracardiac or
extracardiac fistula of the Sinus of
Valsalva[1,5].
Meyer and colleagues[1] made a survey about the
procedures realized at the Texas Heart institute from April, 1956, to
September, 1973. They found 45 patients with aneurysm and/or fistula of
the Sinus of Valsalva, representing 0.43% of all procedures which were
required cardiopulmonary bypass. Of the 45 patients in the group, 22 had
an unruptured aneurysm, whereas 10 and 13 had a ruptured aneurysm and a
simple fistulous communication, respectively. On the other hand,
according to Walpot and contributors[6] and Nishi
et al.[5], the major cause of an aorto-cardiac
fistula is a rupture of an aortic sinus aneurysm, accounting for 76% of
the cases.
Many patients can be asymptomatic, but the typical symptoms are like
Congestive Heart Failure (CHF). A pain in the chest and a sudden onset
of the symptoms point to a ruptured aneurysm. It is possible to hear a
“to-and-fro” murmur on cardiac auscultation with a systolic and
diastolic thrill. The diagnosis is usually taken by transthoracic or
transesophageal echocardiography, cardiac catheterization with
aortography, computed tomography or magnetic resonance imaging (MRI),
revealing a left-to-right shunt.
It is important to differentiate the ARVF from the Aorto-Right
Ventricular Tunnel (ARVT). This condition, as the first, communicates
the aorta to the right ventricle, however the second one’s perforation
arises above the sinutubular junction instead. In the ARVF, the
communication is localized below the sinutubular
structure.[8] Most part of the aorto-ventricle
tunnel communicates the aorta to the left ventricle (90%), and just a
small part of the cases do to the right
ventricle[9].
The surgical correction is the treatment of choice. If promptly
diagnosed and treated, it is possible to avoid major morbidity resulting
from CHF caused by left-to-right shunt[2]. Even in
asymptomatic patients, closure of the fistula is recommended in low
surgical risk person due to the low rate of procedure complications and
the risk of heart failure, bacterial endocarditis, pulmonary vascular
disease, aneurysm formation and spontaneous
rupture[3]. Currently, an alternative of treatment
is transcatheter closure, but it is required more studies to analyze the
optimal management[2,5].