Outcomes in the short and long term
Despite the advances made in diagnosis and surgical treatment, the
overall prognosis remains less than satisfactory in either the long or
the short term.14-22 To an extent, this is hardly
surprising, since right isomerism has long been recognized as one of the
worst forms of congenital heart disease. The malformations in right
isomerism, for the most part, preclude biventricular
repair.15,18,19,21-23,41,43-47 Reported mortalities
range between one-third and one-half for construction of a
systemic-to-pulmonary arterial shunt and repair of totally anomalous
pulmonary venous connection repair, while comparable mortalities have
ranged between one-third and three-quarters for functionally
univentricular repair.15-23,46 Of those in whom a
superior cavopulmonary connection had been constructed, up to
one-quarter proceeded to completion of the Fontan circulation, but even
in this group there was reported mortality of
one-fifth.15-23,42 Totally anomalous pulmonary venous
connection was identified as a poor prognostic indicator, associated
with a median age at death of of 3 months, with the addition of
pulmonary atresia resulting in a median age at death of 1
month.9 But, since totally anomalous pulmonary venous
connection is universally present in those with right isomerism, it is
likely the combination with pulmonary atresia that is the straw that
breaks the back of the camel.
Reported mortalities for those with left isomerism and functionally
univentricular repair range between one-fifth and one-third, but for
those suitable for biventricular repair, mortality has been reported
between zero and one-quarter.16,17 Of those undergoing
univentricular palliation, however, only seven-tenths are in NYHA class
I, as opposed to almost all of those suitable for biventricular
repair.15-23,55 Longer term prognosis at present is
equally depressing. At one year, 85% of those with right isomerism are
dead, along with more than half of those with left
isomerism.15-23,55 The situation, of course, is
further tilted against those with right isomerism, since in absence of
the spleen they have an increased risk of
sepsis.15-23,55-57 In most reported series,
unsurprisingly, survival is better when the lesions permit biventricular
repair.14-23,55-58 Such biventricular repair has been
reported in a small proportion of patients with right
isomerism.15,18,19,21-23,41,43,47-49 And for those not
receiving surgical intervention, death is
inevitable.28 Incremental risk factors for death have
been identified as obstructed totally anomalous pulmonary venous
connection, restenosis of pulmonary veins, and pulmonary atresia.