Introduction
Described initially as “Ivemark syndrome”, there is still no agreement
as how best to segregate individuals with jumbled-up thoracic and
abdominal organs.1-4 Usually considered under the
overarching term “heterotaxy”, 2-7 two specific
subsets exist within the overall group.2-7 The
existence of an isomeric arrangement of the lungs and bronchial tree was
long since established as a discriminating feature, but arguments have
raged as to whether isomerism might exist within the
heart.5-15 It has now been shown that, when assessed
on the basis of the extent of the pectinate muscles relative within the
atrial appendages relative to the atrial vestibules, cardiac isomerism
is a real entity.13 The two subsets thus identified
encompass a wide range of anatomical variants, characterized by complex
systemic and pulmonary venous connections, and complicated intracardiac
anatomy. The strategies for treating these patients remain equally
complicated. To date, most publications assessing the significance of
the isomeric arrangements have been based on necropsy studies, case
reports, or small case series.8-13 Only limited large
scale clinical studies have emphasized the potential significance of the
isomeric features.14-22 With all of this in mind, we
have assessed the published clinical and necropsy data to determine the
influences of right as opposed left isomerism on the surgical outcomes,
including re-interventions.