Transposition Physiology in the Setting of Concordant
Ventriculo-arterial Connections
Abstract
Background and Aim: To review the anatomical details,
diagnostic challenges, associated cardiovascular anomalies, and
techniques and outcomes of management, including re-interventions, for
the rare instances of transposition physiology with concordant
ventriculo-arterial connections. Methods: We reviewed clinical
and necropsy studies on diagnosis and surgical treatment of individuals
with transposition physiology and concordant ventriculo-arterial
connections, analyzing also individuals with comparable flow patterns in
the setting of isomerism. Results: Among reported cases, just
over two-thirds were diagnosed during surgery, after initial palliation,
or after necropsy. Of the patients, four-fifths presented in infancy
with either cyanosis or congestive cardiac failure, with complex
associated cardiac malformations. Nearly half had ventricular septal
defects, and one-fifth had abnormalities of the tricuspid valve,
including hypoplasia of the morphologically right ventricle. A small
minority had common atrioventricular junctions We included cases
reported with isomerism when the flow patterns were comparable, although
the atrioventricular connections are mixed in this setting. Management
mostly involved construction of intraatrial baffles, along with
correction of coexisting anomalies, either together or multi-staged.
Overall mortality was 25%, with one-fifth of patients requiring
pacemakers for surgically-induced heart block. The majority of survivors
were in good functional state. Conclusions: The flow patterns
produced by discordant atrioventricular and concordant
ventriculo-arterial connections remain an important, albeit rare,
indication for atrial redirection. The procedure recruits the
morphologically left ventricle in the systemic circuit, producing good
long-term functional results. The approach can also be used for those
with isomeric atrial appendages and comparable hemodynamic circuits.