Page 15 - ANZCP Gazette AUG 2023

TETRALOGY OF FALLOT: 40 YEARS OF TRANSATRIAL REPAIR, HOW THINGS HAVE CHANGED.
Purpose:
The aim of this audit was to track changes in patient parameters and outcomes, and bypass parameters from 1982 when the transatrial approach was adopted as the sole operative technique for Tetralogy of Fallot (ToF) at the Royal Children’s Hospital. Rates of reintervention were also studied.
Methodology:
Data from bypass records and patient histories; where available, were collated on a year by year basis. Demographic and bypass data were analysed for changes in patient age, size, bypass time, cross clamp time, circulatory arrest time, prime volume, length of stay, mortality and rate of reoperation. Data from the Departments papers “Intersurgeon variability in long- term outcomes after transatrial repair in Tetralogy of Fallot: 25 years’ experience with 675 patients” JTCVS 2014. 147(3): 880-888 and “Low risk of pulmonary valve implantation after a policy of transatrial repair of tetralogy of Fallot delayed beyond the neonatal period: the Melbourne experience over 25 years. J Am Coll Cardiol 2014;63:563–8” were reanalyzed and follow-up was updated.
Results:
There have been changes in all measured parameters over the forty years. While patients have trended to being younger and smaller, bypass and cross clamp times have increased. Circulatory arrest has disappeared altogether. Length of Stay has increased while the Rate of Reoperation has fallen. There is some variation in the type of re-operation although this could be due to differences in the information available.
Conclusion:
Over 40 years the outlook for patients has improved. Changes in parameters measured, apart from the patient demographics, are due to a number of factors. The important changes are the elimination of circulatory arrest, minimisation of use of donor blood, and the possible reduction in reintervention.
Introduction:
There is a choice of two techniques for repair of tetralogy of Fallot: the transventricular (TV) and the transatrial
(TA) approach. In the TV, the ventricular septal defect (VSD) and the stenosed right ventricular outflow tract (RVOT) are approached through an incision in the right ventricular free wall, while in the TA, the VSD is closed transatrially and the RVOT is approached via both the atrial incision via the tricuspid valve and a separate incision of the main pulmonary artery extended to the right ventricular outflow tract. While long-term outcomes of the TV repair have been well documented, the outcomes of the TA repair are less well reported despite the technique being first described by Hudspeth et al in 19631. Once the restricted RVOT has been opened, the right ventricle has to sustain the long-term effects of chronic pulmonary regurgitation and may subsequently dilate. In the four decades following the repair, many patients will experience an ongoing decrease in exercise capacity, and could also experience symptoms of dyspnea and fatigue. After a TV repair, up to a third of the patients may either require a reintervention to implant a valved conduit between their right ventricle and their pulmonary arteries, or die suddenly of a lethal ventricular arrhythmia, and even, exceptionally, require heart transplantation.
It is not well documented whether the transtrial approach, by minimizing the incision to the right ventricular wall, offers better outcomes after Fallot repair.
Tetralogy of Fallot is one of the most common congenital heart lesions. It was suitable for this study as we have only used the transatrial repair since 1982, and this study includes those patients from 1980 and 1981 who had this surgical approach. There is some variation in technique depending on the severity of the lesion.
Methodology:
The need for consent was waived according to RCH Ethics Committee guidelines because of the retrospective nature of the study and de-identification of patient data.
The first TA repair of Tetralogy of Fallot was performed in 1980 in the Royal Children’s Hospital. During 1980 and 1981, 35 patients underwent a TV repair and 27 a TA repair. Thereafter, TA repair was the only technique used in our centre. The records of all patients undergoing a TA repair of Tetralogy of Fallot in our hospital from 1980 to 2021 were reviewed. In order to review the
Clarke Thuys CCP(ANZ) Department of Cardiac Surgery The Royal Children’s Hospital Parkville, Australia
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