Narrative review of single ventricle: where are we after 40 years?

Abstract

Background and objective: Key medical and surgical advances have been made in the longitudinal management of patients with "functionally" single ventricle physiology, with the principles of Fontan circulation applied to other complex congenital heart defects. The purpose of this article is to review all of the innovations, starting from fetal life, that led to a change of strategy for single ventricle.

Methods: Our literature review included all full articles published in English language on the Cochrane, MedLine, and Embase with references to "single ventricle" and "univentricular hearts", including the initial history of the treatments for this congenital heart defects as well as the innovations reported within the last decades.

Key content and findings: All innovations introduced have been analyzed, including: (I) fetal diagnosis and interventions, in particular to prevent or reduce brain damages; (II) neonatal care; (III) post-natal diagnosis; (IV) interventional cardiology procedures; (V) surgical procedures, including neonatal palliations, hybrid procedures, bidirectional Glenn and variations, Fontan completion, biventricular repair; (VI) peri-operative management; (VII) Fontan failure, with Fontan take-down and conversion, and mechanical circulatory support; (VIII) transplantation, including heart, heart and lung, heart and liver; (IX) exercise; (X) pregnancy; (XI) adolescents and adults without Fontan completion; (XII) future studies, including experimental studies on animals, computational studies, genetics, stem cells and bioengineering.

Conclusions: These last 40 years have certainly changed the course of natural history for children born with any form of "functionally" single ventricle, thanks to the improvement in diagnostic and treatment techniques, and particularly to the increased knowledge of the morphology and function of these complex hearts, from fetal to adult life. There is still much left unexplored and room for improvement, and all efforts should be concentrated in collaborations among different institutions and specialties, focused on the same matter.

Keywords: Congenital heart defects; Fontan procedure; congenital heart surgery; single ventricle; univentricular heart.