Objective: To determine the utility of computed tomography (CT) ventricular volumes and morphometric parameters for deciding the treatment strategy in children with a hypoplastic left ventricle (LV).
Materials and methods: Ninety-four consecutive children were included in this study and divided into small LV single ventricle repair (SVR) (n = 28), small LV biventricular repair (BVR) (n = 6), disease-matched control (n = 19), and control (n = 41) groups. The CT-based indexed LV volumes, LV-to-right-ventricular (LV/RV) volume ratio, left-to-right atrioventricular valve (AVV) area ratio, left-to-right AVV diameter ratio, and LV/RV long dimension ratio were compared between groups. Proportions of preferred SVR in the small LV SVR group suggested by the parameters were evaluated.
Results: Indexed LV end-systolic (ES) and end-diastolic (ED) volumes in the small LV SVR group (6.3 ± 4.0 mL/m2 and 14.4 ± 10.2 mL/m2, respectively) were significantly smaller than those in the disease-matched control group (16.0 ± 4.7 mL/m2 and 37.7 ± 12.0 mL/m2, respectively; p < 0.001) and the control group (16.0 ± 5.5 mL/m2 and 46.3 ± 10.8 mL/m2, respectively; p < 0.001). These volumes were 8.3 ± 2.4 mL/m2 and 21.4 ± 5.3 mL/m2, respectively, in the small LV BVR group. ES and ED indexed LV volumes of < 7 mL/m2 and < 17 mL/m2, LV/RV volume ratios of < 0.22 and < 0.25, AVV area ratios of < 0.33 and < 0.24, and AVV diameter ratios of < 0.52 and < 0.46, respectively, enabled the differentiation of a subset of patients in the small LV SVR group from those in the two control groups. One patient in the small LV biventricular group died after BVR, indicating that this patient might not have been a good candidate based on the suggested cut-off values.
Conclusion: CT-based ventricular volumes and morphometric parameters can suggest cut-off values for SVR in children with a hypoplastic LV.
Keywords: Biventricular repair; Cardiac CT; Child; Hypoplastic left ventricle; Single ventricle repair; Threshold-based segmentation; Ventricular volume quantification.