is no connection between right atrium and right ventricle because the
tricuspid valve did not developed. The right ventricle is consequently
Tricuspid atresia. Venous blood in right atrium passes compulsory in
left atrium through a atrial septum communication. The pulmonary flow
is mantain by the blood that passes through the ventricular septal defect
in the small right ventricle and then in pulmonary artery-.
venous blood coming from the vena cava in the right atrium flows through
the foramen ovale in left atrium where it mixes with oxygenated blood
coming from the lungs, and then in
left ventricle. From here blood is pumped in aorta and through a VSD
in the little right ventricle and in pulmonary artery which is also
hypoplastic. There is a severe cyanosis because the blood pumped in
aorta is a mixed of arteriosus and venous blood and the pulmonary blood
flow is reduced. Children with tricuspid atresia usually need palliative
surgery to increase pulmonary blood flow and mitigate cyanosis. The
definitive surgery is not a corrective surgery because it is not possible
to create a valve and the right ventricle is so little that it will
not be able to lead its function of pump for the pulmonary circulation.
The intervention is the Fontan procedure (fig. 6.8) which consist in
a total cavo-pulmonary connection. In some cases the VSD is very large
and the pulmonary artery well developed; the pulmonary blood is increased
and the children are not cyanotic and can have heart failure signs.
The palliative surgery in this cases consist in the pulmonary banding.
This allows an improvement of the clinical situation and to wait for
definitive Fontan surgery.