What can we learn from systematic segmental analysis of fetal heart by postmortem micro-CT: Is it time to change approach?

Abstract

Background: Postmortem analysis of fetal heart is crucial but challenging. Alternative techniques to autopsy have been studied. We investigate micro-CT diagnostic accuracy in the analysis of fetal heart coming from early and late termination of pregnancy.

Methods: Micro-CT and autopsy analyzed human fetal heart using twenty-six indices of cardiac anatomy derived from segmental approach. Sub-analysis of smaller specimens was performed. Primary outcome is the agreement between techniques. Secondary outcomes are sensitivity, specificity, positive and negative predictive value. Indices are defined "visible" or "non-visible" (primary end point) and "normal", "abnormal" or "non-diagnostic" (secondary end point).

Results: Fifty-five cases were included. Agreement was 74.5% and 65.2% for primary end point and 93.3% and 91.8% for secondary end point in general population and in the group of smaller specimens, respectively. Sensitivity, specificity, positive and negative predictive value were 92.8%, 51.8%, 67.1%, 87.2% in the general population and 92.8%, 47.8%, 54.3%, 90.9% in the subgroup of smaller specimens for primary end point. They were 97.3%, 68.3%, 95.1%, 80.0% in the general population and 95.7%, 75.6%, 94.2%, 81.0% in the subgroup of smaller specimens for secondary end point. 86.1% and 91.5% of indices defined as "non-diagnostic" at autopsy would be visible by micro-CT in the two studied populations.

Conclusion: Micro-CT represents a valid alternative to autopsy for postmortem evaluation of human fetal heart. We proposed to use micro-CT for initial analysis of fetal heart and to perform autopsy only in unsolved cases or if histological analysis is needed.

Keywords: Congenital heart disease; Fetal heart; Micro-CT; Postmortem study; Virtual autopsy.

Fig. 1

Case 19, normal heart, GA at TOP 12 ​+ ​6. A1: Normal four chamber view; A2: normal short axis view at the level of papillary muscles; B1: normal left ventricular outflow tract; B2: origin of the left coronary artery from aorta, note the dimension of the left main coronary artery (70 ​μm); C1: normal right ventricular outflow tract; C2: short axis view at the level of the great arteries, showing the bifurcation of the pulmonary trunk and the ascending aorta; D1 and D2: external view of the heart at macroscopic dissection. LV: left ventricle; RV: right ventricle; AO: aorta; LMCA: left main coronary artery; PA: pulmonary artery; Ant: anterior; Post: posterior; R: right; L: left.

Fig. 2

Case 10, atrioventricular septal defect, GA at TOP 13 ​+ ​4. A1: four chamber view showing balanced right and left ventricle and an atrioventricular septal defect; A2: short axis view at the level of atrioventricular valve showing balanced right and left ventricle, septal component of the atrioventricular septal defect and the leaflets of the common atrioventricular valve; A3: short axis view at the level of papillary muscles; B1: left ventricular outflow tract; B2: right ventricular outflow tract; B3: short axis view at the level of great arteries showing the bifurcation of the pulmonary artery and the aorta; C1: anterior view of the sample; C2: posterior view of the sample. AVSD: atrioventricular septal defect; LV: left ventricle; RV: right ventricle; AO: aorta; PA: pulmonary artery; Ant: anterior; Post: posterior; R: right; L: left.

Fig. 3

Case 5, hypoplastic left heart syndrome, GA at TOP 21 ​+ ​6. A1: four chamber view, note the hypoplastic left ventricle; A2: short axis view at the level of the ventricle, note the hypoplastic left ventricle; B1: left ventricular outflow tract, note developed ascending aorta and the hypoplastic aortic arch; C1 and C2: right ventricular outflow tract; C3: short axis view at the level of semilunar valve; C4: short axis view at the level of pulmonary artery bifurcation; D1: anterior view of the sample showing the normal right ventricle; D2: posterior view of the sample showing the hypoplastic left ventricle. LV: left ventricle; RA: right atrium; RV: right ventricle; AO: aorta; Asc AO: ascending aorta; PA: pulmonary artery; Ant: anterior; Post: posterior; R: right; L: left.

Fig. 4

case 40, tricuspid atresia (associated to ventricular septal defect and transposed great arteries), GA at TOP 18 ​+ ​4. A1: Four chamber view, note the hypoplastic right ventricle; A2 and A3: basal and apical short axis view, note the hypoplastic right ventricle; B1: outflow tracts view, note the outlet ventricular septal defect and the transposed great arteries; B2: outflow tract showing the transposed great arteries; B3: short axis view at the level of the great arteries showing the anterior aorta and the posterior pulmonary artery with its bifurcation; C1: short axis view at the level of great arteries; C2: note the origin of the left main coronary artery from the aorta; C3: hypoplastic aortic arch; D1: anterior view of the sample, note the prevalence of the left ventricle; D2: posterior view of the sample showing the left ventricle. LV: left ventricle; LA: left atrium; RV: right ventricle; AO: aorta; VSD: ventricular septal defect; PA: pulmonary artery; LMCA: left main coronary artery; Ant: anterior; Post: posterior; R: right; L: left.

Fig. 5

case 6, pulmonary atresia/ventricular septal defect, GA at TOP 16 ​+ ​3. A1: five chamber view showing the balanced ventricles, the ventricular septal defect and the overriding aorta; A2 and A3: apical and basal short axis view at the level of the ventricle; A4: short axis view under the origin of the great arteries showing the ventricular septal defect; B1: left ventricular outflow tract, note the rotation to the right of the aorta (that seems to originate from the right ventricle from this section) and the presence of a second anterior great artery; B2: short axis view at the level of the origin of the great arteries showing two great vessels in an antero-posterior orientation; B3: bifurcation of the pulmonary artery; C1:cutted sample across the left ventricular outflow tract showing the origin of the ascending aorta and the presence of a second anterior great artery. LV: left ventricle; RV: right ventricle; AO: aorta; VSD: ventricular septal defect; PA: pulmonary artery; LMCA: left main coronary artery; Ant: anterior; Post: posterior; R: right; L: left.