Introduction
Numerous studies have assessed the complexity and variability in origin
and course of the coronary arteries when discordant ventriculo-arterial
connections are found in the setting of concordant atrioventricular, the
arrangement usually described as transposition.1-12Prior to the introduction of the arterial switch procedure, such
variability was mainly of academic interest. Knowledge of the
variability is now of paramount surgical importance, with certain
variations presaging a poor outcome.8,12-14Understanding of the variations, and their significance, has been
complicated thus far by lack of uniform descriptions. Classifications
have tended either to be incomplete,8 or excessively
complex.4 The Leiden approach is most universally
applicable.8,9 The system does not, however, account
for all the potentially significant variables, such as
looping.12 The course of the artery to the sinus node
may also be of significance.3,15 Among the multiple
patterns, the presence of a solitary artery, the intramural variant, and
looping, have been associated with an increased risk of complications in
some surgical series, but not all.1-28 With this in
mind, we have evaluated the varied patterns relative to the early and
late outcomes of the arterial switch procedure.