Neurocognitive Outcomes for Children with Functional Single Ventricle Malformations

Only 25 years ago, the diagnosis of hypoplastic left heartsyndrome was associated with certain infant or neonatalmortality. During recent decades, exciting developments inperioperative care and surgical techniques have enabledvast improvements in early survival rates as high as80–90% [6, 9, 25]. With improved survival of even thishigh-risk patient group, it is now possible to focus onimprovements in quality of life outcomes including neu-rodevelopment. We are fortunate to have reached the era inwhich we can recognize that the best possible treatmentstrategies for children with congenital heart disease mustoptimize end organ function and not just survival rates.Functional single ventricle (FSV) is a term used in thisarticle to describe a broad category of heart malformationswith a single functioning pumping chamber. Althoughthere are a variety of diverse anatomies included (i.e.,hypoplastic left heart syndrome, tricuspid atresia, anddouble-inlet left ventricle), children with these malforma-tions are exposed to very similar physiologic states.Therefore, the issues related to neurological outcome forchildren with all types of FSVs are discussed in this review.The aims of this article are (1) to outline some of thedata measuring neurodevelopmental outcome for childrenfollowing the Fontan operation, (2) to review the knownand potential risks for abnormal neurodevelopment forthese children, and (3) to explore strategies that may con-tribute to improved neurodevelopmental outcomes forchildren with FSV abnormalities.Measurement of Neurodevelopment in Children withFSV AnatomyFaced with the information that their child has a complexcongenital heart abnormality, most parents want to know ifhe or she will be able to live a normal life, includingthriving in school and keeping up with peers. For theindividual, it is impossible to know deﬁnitively; however,we can begin to answer these questions more objectivelybecause some data now exist measuring neurodevelopmentfor children who have had the Fontan operation.During recent years, a number of centers have exploredneurodevelopment for children with FSV anatomy. The to-picwasintroducedtotheliteraturebyRogersandcolleagues.In 1995, this group described concerning outcomes forchildren with hypoplastic left heart syndrome. In this smallcohort, 7 of 11 patients were found to have signiﬁcant neu-rological insults [22]. These data, although disturbing, werelimited by the small sample size and did not represent theanecdotalobservationsatsomeothercenters.Thisstudywaslikely responsible for further efforts to measure the long-term neurodevelopmental outcome for children with hypo-plasticleftheartsyndromeandotherFSVanatomies,drivingother centers to objectively examine neurological outcomesfor this high-risk patient group.At the University of Michigan Congenital Heart Center,children between the ages of 3 and 8 years, who hadundergone the Fontan operation, were invited to return forneurodevelopmental follow-up. The testing included theWechsler Preschool and Primary Scales of Intelligence-Revised or the Wechsler Intelligence Scales for Children-III. These tests are composed of two portions, the verbalscale and the performance scale, which are combined toformulate the full scale IQ. The verbal scale focuses on