Anatomically corrected malposition of the great arteries. Report of 2 cases, one with congenital asplenia; frequent association with juxtaposition of atrial appendages.

Abstract

Anatomically corrected malpositions are uncommon cardiac anomalies in which the pulmonary artery originates above the morphological right ventricle, and the aorta above the morphological left ventricle. However, because of interposition of abnormal subaortic conal myocardium, there is absence of aortic valve-mitral valvefibrous continuity. The relation between the pulmonary artery and aorta is also abnormal because of the abnormal conal morphology.Two cases of anatomically corrected malposition of the great arteries are presented, one of which is the first reported in a patient with the congenital asplenia syndrome; in the other, there was left juxtaposition of the atrial appendages. Review of all known cases of anatomically corrected malposition reveals a significant association with juxtaposition of the atrial appendages and hence with hypoplasia of the right ventricle, subpulmonary and subaortic obstruction. Possible surgical implications of this association are discussed.Although Harris and Farber first suggested the concept of anatomically corrected transposition of the great arteries in I939, recognition and documentation of this unusual entity was first provided by Van Praagh and Van Praagh in I967. In anatomically corrected transposition of the great arteries, the aorta arises above the morphological left ventricle but with aortic-mitral discontinuity because of abnormal subaortic conus, and the pulmonary artery originates above the morphological right ventricle. Because of the abnormal conal morphology, abnormal relation between the aorta and atrioventricular valve, and abnormal relation between the great arteries, this entity was initially thought to be a form of transposition (Van Praagh and Van Praagh, I967

Atresia of the right atrioventricular orifice.

“…It is important to realise, therefore, that normal ventriculoarterial connections can exist with an anterior leftsided aorta. This relation is usually termed anatomically corrected malposition, and its association with right atrial orificial atresia has previously been stressed by Melhuish and Van Praagh (1968) and by Freedom and Harrington (1974). It must also be remembered that any possible ventriculoarterial connection can exist with right atrial orificial atresia.…”

Left juxtaposition of the auricles with l-position of the aorta. Report of 6 cases.

“…Anatomically corrected malposition is rare, and has not, as far as we are aware, been reported previously in association with a primitive ventricle. Freedom and Harrington (1974) (Van Praagh et al, 1975a, b), but the variations in anatomy at both ventricular and conal levels necessitate careful assessment of the intracardiac arrangements.…”

“…Anatomically corrected malposition is rare, and has not, as far as we are aware, been reported previously in association with a primitive ventricle. Freedom and Harrington (1974) reviewed 13 cases of anatomically corrected malposition of which 7 had left juxtaposition of the atrial appendages, and Anderson et al (1974b) described 4 cases, of which 2 had juxtaposition. Of these 4, 3 had a single coronary artery with identical distribution to that of the present case.…”

How to determine atrial situs? Considerations initiated by 3 cases of absent spleen with a discordant anatomy between bronchi and atria.

“…Indeed, in patients with a normal spleen only 2 exceptions to this rule have as yet been reported (Clarkson et al, 1972;Liberthson et al, 1973;Brandt and Calder, 1977). However, anatomical studies have disclosed several other exceptions to this 'rule' in the presence of splenic abnormalities, albeit that the various authors do not always emphasise the discrepancy (Freedom and Fellows, 1973;Liberthson et al, 1973;Freedom and Harrington, 1974;Anderson et al, 1976). These exceptions necessitate a reconsideration of the criteria that determine the classification of atrial situs.…”