Accuracy of different imaging modalities prior to biventricular repair in Tetralogy of Fallot
The aim of the present study was to determine the diagnostic accuracy of non-invasive tests in patients with Tetralogy of Fallot prior to biventricular repair, and the need of invasive angiocardiography in specific subgroups. A retrospective analysis was performed for paediatric patients with Tetralogy of Fallot who underwent biventricular repair in three consecutive months. Patients were divided into two groups according to their age: below and above 5 years. We compared the findings of different imaging modalities (e.g. echocardiography, multi-detector Computed Tomography (CT) and invasive angiocardiography) to intraoperative findings to determine their accuracies in different subgroups. Results showed that echocardiography is reliable for preoperative imaging, especially in younger children (sensitivity=71.43%) and its findings are ‘moderately’ concordant with intraoperative findings (kappa=0.439). For patients above 5 years of age, its sensitivity (29.41%) declines and findings are ‘poorly’ concordant with intraoperative findings (kappa=0.093). With addition of multi-detector CT, the findings of non-invasive means are ‘perfectly’ concordant with the intraoperative findings (kappa=1) in children below 5 years and ‘moderately’ concordant with those (kappa=0.4) in children above 5 years. The findings of CT are ‘moderately’ concordant with those of invasive angiocardiography (kappa=0.4). Tetralogy of Fallot patients below 5 years can directly be subjected to surgery with work-up including detailed echocardiography only. If anatomy is not clearly delineated, CT helps and invasive angiocardiography is not essential. In patients above 5 years, CT has an important role in defining anatomy. The need for catheterization is limited to hemodynamic evaluation of prior shunt and embolization of aorto-pulmonary collaterals.
KEY WORDS: Tetralogy of Fallot; Pulmonary artery; Aorto-pulmonary collaterals; Echocardiography; Computed Tomography; Invasive angiocardiography