anatomically corrected malposition great arteriesrected malposition irrespective of the presence or...

British HeartJournal, I975, 373 993-IOI3.

Anatomically corrected malposition of great arteries

Robert H. Anderson, Anton E. Becker, Tom G. Losekoot, and Leon M. GerlisFrom the Department of Paediatrics, Cardiothoracic Institute, Brompton Hospital, London; Departments ofPathology and Paediatrics, University of Amsterdam, The Netherlands; and the Department of Pathology,Grimsby General Hospital

Four anomalous hearts are described in which the great arteries arise in unusualfashion from their morpho-logically appropriate ventricles. This malformation, previously termed anatomically corrected transposition,is now termed anatomically corrected malposition. This is because, following the precedent of Van Praagh andhis associates, we now reserve the term 'transposition' to describe the situation in which both great arteriesarise from separate morphologically inappropriate ventricles. All the hearts examined exhibited atrioven-tricular concordance, i with viscero-atrial situs inversus, and 3 with situs solitus. However, there were con-siderable variations in ventricular morphology between the cases. Thus, 2 cases exhibited atresia of the rightatrioventricular valve, and in the remaining 2 cases right and left ventricular sinuses were both identified. Twoofthe cases also hadpulmonary atresia, and coronary artery anomalies were present in all 4. The cases emphasizethe fact that the term anatomically corrected malposition describes not a discrete anomaly but only a ven-triculo-arterial relation, which is one of ventriculo-arterial concordance. Doubt has previously been cast uponthe existence of this as an anatomical entity. It is concluded that the relation does indeed exist, andfurther-more can coexist with all varieties of atrioventricular relations. It is suggested that the differing atrio-ventricular relations can be distinguished by usage of the terms 'concordant' or 'discordant' anatomicallycorrected malposition. Finally, it is emphasized that it is necessary to distinguish this anomaly, which in mostcases presents with left-sided anterior aorta,from the left-sided anterior aorta morefrequently encountered in'classically corrected transposition'.

In recent years it has become evident that the term'transposition' is used to describe a great variety ofrelations of the great arteries, and hence has becomea non-specific term. This lack of specificity washighlighted by Van Praagh and his colleagues(1971) who suggested that it would be better if theterm were used as initially intended (Farre, I8I4),to describe the situation in which both great arterieswere placed across the ventricular septum so as toarise independently from morphologically inap-propriate ventricles (Fig. iB and C). They furtherindicated that it was necessary to introduce anadditional term to describe arteries which werethen neither transposed nor normally related. Theytherefore introduced the term malposition. Thisterm itself was subdivided into malpositions inwhich only one artery is placed across the septum

Received 7 April I975.1R.HJA. was a MRC Travelling Fellow at the University ofAmsterdam during the time of this investigation. He is now aBritish Heart Foundation Senior Research Fellow. Presentaddress: Cardiothoracic Institute, London.

so that both arteries then arise from the sameventricle, be it left or right (double outlet situations,Fig. iD and E), and the situation in which botharteries are abnormally related to their appropriateventricles. The latter variety was termed 'anatomi-cally corrected malposition' (Fig. IF).This form of ventriculo-arterial relation had been

previously referred to as anatomically correctedtransposition (Harris and Farber, 1939). Someauthorities (Van Mierop and Wiglesworth, I963)had doubted the existence of the malformation onembryological premises, despite the fact that it hadbeen described by distinguished morphologistssuch as Rokitansky (I875), Lewis and Abbott(I9I5), Cams, Ritchie, and Musser (1941),and Doerr (I939). Van Praagh and Van Praagh(I967) indicated that they too had doubted itspedigree before studying three specimens whichprovided incontrovertible proof of its existence.Raghib, Anderson, and Edwards (I966) had de-scribed an example at much the same time, but hadtermed it 'isolated bulbar inversion'. Since then

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994 Anderson, Becker, Losekoot, and Gerlis

A. Normal heart

D. DORVwth d-malposition E. DORVwith L-malposition F. Anatoinicall corrected malposition

FIG . i Diagrams which illustrate the concept of transposition and malposition as espousedby Van Praagh and his colleagues (1971). Fig. iA shows the normal relation of the greatarteries. The aorta is to the right of, and posterior to, the pulmonary artery. Fig. iB and C areboth transpositions. The arteries are placed across the septum so as to arise from inappropriateventricles. When associated with atrioventricular concordance (iB) the circulation is trans-posed (complete transposition). When associated with atrioventricular discordance (iC) thecirculation is corrected (corrected transposition). Fig. iD-F show malpositions. Fig. iD and xErepresent double outlet ventricle situations in which only one great artery (in the case of the rightventricle, the aorta; in the case of the left ventricle, the pulmonary artery) is placed across theseptum. Double outlet right ventricle is illustrated. In this situation the aorta can be either tothe right of the pulmonary artery (d-malposition) or to its left (1-malposition). Fig. IF showsthe situation in which both arteries arise from appropriate ventricles, but are abnormallyrelated. The aorta is to the left of, and in approximately the samefrontalplane as, thepulmonaryartery. In this report we have adopted the nomenclature of Van Praagh et al. (197I) andreferred to this anomaly as 'anatomically corrected malposition'.

further descriptions have attested to the existenceof this type of ventriculo-arterial relation (Anderson,Arnold, and Jones, I972; Freedom and Harrington,1974) while others have described repair of itsassociated cardiac defects (Sunada et al., I967;Kirklin et al., 1973).However, while these reports attest to the exis-

tence of the malformation, they contribute furtherto the disagreements which surround it. ThusKirklin et al. (I973) defined 'anatomically correctedmalposition' when observed in association with

atrioventricular concordance as a particular varietyof ventriculo-arterial concordance, yet defined thesame ventriculo-arterial relation as 'isolated ven-tricular inversion' when it was associated with dis-cordant atria and ventricles. Furthermore, thoughKirklin et al. (I973) have defined anatomicallycorrected malposition as a concordant relation be-tween ventricles and arteries because pulmonaryvenous blood reaches the aorta, de la Cruz et al.(I974) define the same flow situation as a discordantarterio-ventricular relation if the pulmonary artery



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does not 'point' to the morphological right ven-tricle. A similar contrast is found concerningnomenclature of an anterior, left-sided aorta whicharises from the left ventricle in some cases of tri-cuspid atresia with situs solitus. Freedom andHarrington (1974) referred to this arrangement asanother example of anatomically corrected mal-position. Tandon and Edwards (I974) on the otherhand described the arteries when thus arranged asexhibiting i-transposition. The latter usage is par-ticularly confusing since the term 'tricuspid atresiawith i-transposition' is also used to describe theanomaly in which atresia of the left-sided atrioven-tricular valve occurs in hearts with solitus atrialchambers, atrioventricular discordance, and i-trans-position (classically corrected transposition).

It is, therefore, evident that, though severalinvestigators have already adopted the terminologyof Van Praagh et al. (I971), usage of the term'anatomically corrected malposition' is by no meansgenerally accepted or agreed upon. For this reasonwe are now describing an additional 4 examples ofthe malformation. Though the hearts exhibit con-siderable variations in the morphology of their atrialand ventricular chambers, they all have the sameventriculo-arterial relation. We will indicate whywe believe the term 'anatomically corrected mal-position' provides the best description of thisrelation. We will then indicate how the term can beused in conjunction with descriptions of atrioven-tricular relations and anomalies. Finally, we willdemonstrate how, when interpreted in the settingof the conal maldevelopment hypothesis, this ven-triculo-arterial relation should no longer be con-sidered an embryological impossibility.

Definition of termsAs we have indicated in the introduction, we shallemploy the definition of Van Praagh et al. (I971) fortransposed and malposed great arteries. In allsituations, unless stated otherwise, we shall referto the relative positions of the aorta and pulmonaryartery at their valve rings, and will describe thesesimply as 'aorta' and 'pulmonary artery'.

Transposition of the great arteries will, there-fore, describe only that situation in which the aortaarises from the morphologically right ventricle andthe pulmonary artery from the morphologically leftventricle (Fig. 2B).

Malposition of the great arteries will describetwo situations. Firstly, that in which both arteriesarise from the same ventricle, be it right or leftventricle (Fig. iD, E). When the aorta in this situa-tion is to the right, it will be described as being

d-malposed with relation to the pulmonary artery;similarly when the aorta is to the left, it will bedescribed as being l-malposed. The second cate-gory of malposition will describe the anomaly inwhich both great arteries arise from their approp-riate ventricles (or their embryological anlagen) butin which either one or both arteries are abnormallyrelated to their ventricles. This category will betermed 'anatomically corrected malposition' (Fig.iF). Arteries arising in normal fashion from theirappropriate ventricles will be described as beingnormally related. This arrangement of great arteriesfor a d-bulboventricular loop is for the aorta, thougharising from the morphological left ventricle, to beposterior and right-sided with relation to the pul-monary artery, and for the adjoining portions of itsnon-coronary and left coronary cusps to be infibrous continuity with the mitral valve (Fig. 2A).In an l-bulboventricular loop, the normally relatedaorta, arising from the right-sided morphologicallyleft ventricle would be left-sided and posterior,with fibrous continuity between the right-sidedmitral valve and the adjoining portions of the rightand non-coronary aortic cusps (Fig. 2D). It, there-fore, follows that the situation in which a left-sidedaorta arose from a left-sided morphological leftventricle would be considered as anatomically cor-rected malposition irrespective of the presence orabsence of mitral-aortic valvar continuity. Simi-larly, if in the presence of an l-loop the aorta wasright-sided and in fibrous continuity with the right-sided mitral valve, this would be described asanatomically corrected malposition. We are awarethat Van Praagh and Van Praagh (I966) have de-scribed such a situation as a variant of normal, or'isolated ventricular inversion'. As we shall indicatesubsequently, we do not consider this justified be-cause the great arteries are not normally related totheir appropriate ventricles, but are malposed. Thedefinition of 'anatomically corrected malposition'presently employed is, therefore, that situation inwhich both great arteries arise from their approp-riate ventricles but in which either is abnormallyrelated to its ventricle.

Chamber designationWe shall refer to the cardiac chambers in terms oftheir morphological characteristics irrespective oftheir positions relative to the right and left sides ofthe body (Lev and Rowlatt, I96I). Thus the mor-phologically right atrium will refer to the chamberwith the anatomical characteristics of the normalsystemic venous atrium, and the morphologicallyright and left ventricles will refer to the normalvenous and arterial ventricles, respectively. How-ever, wherever a chamber does not correspond to



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A. Normally related B. Transposition

X ~ ~~~~RC

C. Malposition D. Normally related(L-loop)Right Conus septum Left

Conoventricular flange

FIG . 2 Diagrams illustrating in greater detail the relation of the arteries to the underlyingventricles in A) and D) normal hearts, B) transposition, and C) anatomically corrected malposi-tion. In the normal heart, following absorption of the conoventricular flange, the aorta is trans-ferred to the left ventricle. Aortic-mitral valvular continuity is present between the mitral valveand the adjacentparts of the non-coronary (NC) and left coronary (LC) cusps of the aortic valve.The aorta is posterior to and to the right of the pulmonary artery. In the mirror image normalheart (Fig. 2D) the relations are reversed with respect to the right-left axis. Thus the aorta isto the left of and posterior to the pulmonary artery, and continuity is made between the adjacentparts of the right coronary (RC) and non-coronary cusps and the mitral valve. The relationshould be considered as the normal relation with regard to an 1-bulboventricular loop irrespectiveof the atrial situs. Fig. 2B shows the usual relation in complete transposition (see Fig. I). Theaorta is placed across the septum to arise anteriorly from its inappropriate ventricle, the right.The pulmonary artery arises posteriorly from the left ventricle, and pulmonary-mitral valvularcontinuity is usually present. Fig. 2C represents the usual arrangement in 'anatomically cor-rected malposition' with solitus atria and atrioventricular concordance. The great arteries arisefrom their appropriate ventricles, but are in approximately the same frontal plane. Neithersemilunar valve is usually in fibrous contact with an atrioventricular valve (bilateral conus).The aorta is to the left of the pulmonary artery.

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its usual position, we shall continue to adopt theprecedent of Lev and Rowlatt (I96I) and refer alsoto its position; thus we would describe a 'mor-phologically right atrium (left-sided)', when thischamber is in inverted position.

Conus septum will be used to describe the mus-cular septum which separates that part of the ven-tricular outflow tracts derived from the embryonicbulbus (Anderson et al., I974c).

Conoventricular flange will be used to describethe muscular tissue intervening in the specimensdescribed between the semilunar and the atrioven-tricular valves. It represents the inner curvature ofthe primitive heart tube and can also be consideredas conal musculature. We have previously referredto this structure in embryological terms as thebulboatrioventricular ledge (Anderson et al., I974c,d). When it is absorbed then semilunar-atrioven-tricular valvular fibrous contmuity occurs.

Description of specimensCase IThis heart was from a male infant who died at the age of4 months. Only the heart and lungs were available forexamination but the hospital records indicated that aspleen had been observed at necropsy. Though bothlungs were bilobed, and no eparterial bronchus could beidentified, the atrial chambers were arranged as for thesitus solitus visceral arrangement. Thus the right-sidedatrium received a small right superior vena cava and alarge dilated left superior vena cava which drained to theatrium via a coronary sinus. The chamber also receivedthe inferior vena cava and was in communication withthe left atrium via a secundum type of atrial septaldefect (Fig. 3B). There was partial juxtaposition of theright auricle. A blunt pouch extended to the right and alonger appendage passed posterior to the great arteriesto lie alongside the left auricle (Fig. 3A). This auriclewas more reminiscent of the normal left auricle thanthat normally arising from the right atrium. The left-sided atrium received 4 pulmonary veins and gave riseto a typical left auricle. Atrioventricular concordancewas present. Thus the right atrium drained to the mor-phologically right ventricle (right-sided) via a valvewith the characteristics of the tricuspid valve. However,the sinus of this ventricle was small and muscle bound,containing multiple posterior papillary muscles (Fig.3C). The left atrium opened to the left ventricle througha mitral valve, and the sinus of this ventricle was wellformed (Fig. 3D). The great arteries arose from theventricles in a side-by-side position, with the pulmonaryartery to the right of the aorta (Fig. 3A). Both arterieswere separated from the atrioventricular valves by largesegments of conoventricular flange, so that a bilateralconus was present (Fig. 3C and D). The two conuseswere in continuity through a large anterior ventricular

septal defect. The tricuspid and mitral valves were incontinuity in the posterior edge of this defect (Fig. 3Cand D). The roof of the defect was formed by a promi-nent conus septum, while its floor was the anteriorventricular septum (Fig. 3D). The anterior portion ofthe right-sided ventricle was coarsely trabeculated andcontained a well-formed trabecula septomarginalis onits septal aspect. The latter structure gave rise inferiorlyto the anterior papillary muscle of the tricuspid valveand superiorly to the conal papillary muscle (Fig. 3C).Such structures were lacking from the anterior portionof the left-sided ventricle and the septal aspect of thisventricle was smooth (Fig. 3D). However, a prominenttrabecula was present posteriorly in the left ventricle. Alarge coronary artery arose from the right septal aorticsinus which gave rise to right, left circumflex, andanterior descending coronary arteries. A very small cor-onary artery arose from the left septal aortic sinus andpassed into the atrioventricular groove. The aortic archwas right-sided and a right-sided persistent ductusarteriosus was identified.The diagnosis of anatomically corrected malposition

with atrioventricular concordance {S,D,L} was made.Though the atria were identified in the solitus arrange-ment, the position of the auricular appendages and thepresence of two lungs with characteristics of left lungspresented the possibility that the case may have beenassociated with the polysplenia syndrome. However, thehospital records had indicated that the abdominalorgans were normally arranged. The malformation wasadditionally complicated by the presence of a secundwnatrial septal defect, a ventricular septal defect, hypoplasiaof the right ventricular sinus, a right-sided aortic arch withpersistent right-sided ductus arteriosus and coronary arteryabnormalities.

Case 2The specimen was from a male neonate dying at the ageof 3 days. At necropsy, the thoraco-abdominal organswere found to be arranged as in situs inversus totalis.The spleen was identified on the right side, and wassingle. Other findings were confined to the heart, whichwas situated in the left hemithorax (laevocardia withsitus inversus). The atrial chambers were inverted. Theright-sided left atrium received 4 pulmonary veins, andpossessed a typical left auricle (Fig. 4B). The morpho-logically right atrium (left-sided) received a left superiorvena cava, inferior vena cava, and a small coronary sinus.Its auricle was typical of the morphologically rightatrium. The two atria were in communication througha secundum type of atrial septal defect which waspartially guarded by a filigreed septum primum (Fig.4C). The right-sided left atrium drained to the morpho-logically left ventricle (right-sided) (Fig. 4C). Theventricle contained a typical mitral valve with twoprominent papillary muscles in anterior and posteriorpositions. The surface of the ventricular septum wassmooth in this ventricle. The left-sided right atriumdrained to the morphologically right ventricle (left-sided)and its orifice was guarded by a morphologically tricus-pid valve (Fig. 5). Multiple posterior papillary muscles



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were present together with a large anterior papillarymuscle which took origin from a well-formed left-sidedinfundibulum, and the conal papillary muscle arosefrom this structure (Fig. 5). The aorta and pulmonaryartery arose in the same frontal plane, but the pulmonaryartery was atretic (Fig. 4A). When observed from theventricular aspect, the aorta straddled a large anteriorseptal defect, and was separated from the right-sidedmitral valve by the prominent conoventricular flange(Fig. 4C). It was judged that the greater part of theaorta arose from the left ventricle (right-sided). Thoughthe pulmonary artery was atretic, its conal origin couldbe identified. This slit-like structure was separated fromthe aortic orifice by the conus septum and from thetricuspid valve ring (left-sided) by the left extremityof the conoventricular flange. The septal defect wasstraddled superiorly by the aortic valve ring. Its floorwas the anterior portion of the ventricular septum, andthe atrioventricular valve rings were fused in the pos-terior aspect. The aorta ascended to the right of thepulmonary artery (Fig. 4A) and the aortic arch was right-sided. The pulmonary arteries were filled via a right-sided persistent ductus arteriosus. A single coronaryartery was present arising from the right septal aorticsinus which gave rise to the right circumflex, left, andanterior descending coronary arteries.The diagnosis was made of anatomically corrected

malposition in situs inversus with atrioventricular con-cordance {I,L,D}. Additional malformations weresecundum atrial septal defect, pulmonary atresia, ven-tricular septal defect, hypoplasia of the sinus of the mor-phologically right ventricle, persistent ductus arteriosus,and single coronary artery.

Case 3A male infant died at the age of 51 months. The viscerawere arranged in solitus fashion. The atrial chambers

were concordant with visceral situs, but the right atriumpossessed no outlet other than through a secundumtype of atrial septal defect (Fig. 6B). The septumprimum was herniated into the left atrium (Fig. 6G). Thesuperior and inferior caval veins drained into the rightatrium. A coronary sinus was not identified, neitherwas there any evidence of a 'dimple' on the Iloor of thechamber (Fig. 6B). The left atrium was enlarged andreceived pulmonary blood via normal pulmonary veins,and right atrial blood through the foramen ovale. Amitral valve guarded the orifice from the left atrium to a' single' ventricular chamber (Fig. 6G). The valvepossessed cusps typical of the mitral valve, and theposterior papillary muscle was of mitral pattern. Thelarge anterior papillary muscle arose from the ventricularwall, and in addition from a large trabecula whichextended from the ventricular apex to the underside ofthe conus septum (Fig. 6D). The great arteries aroseanteriorly from the 'single' ventricular chamber, and thetrabecula produced some separation between the twooutflow tracts. The aorta was to the left of the pul-monary artery (Fig. 6A). The pulmonary artery wassmall, and its outflow tract was stenosed. Both semi-lunar valves were separated from the mitral valve by apersistent conoventricular flange (Fig. 6D). There wasadditional dome-shaped stenosis of the pulmonary valve.There was no evidence of either right or left bulbo-ventricular ridges within the 'single' ventricular cham-ber. The aortic arch was left-sided, and the ductusarteriosus was patent. A single coronary artery arose fromthe right septal aortic sinus (Fig. 6A) and gave rise to aright circumflex, a right marginal, and left circumflexbranches. The latter branch ran to the left, posteriorlyto the great arteries.The diagnosis was made of tricuspid atresia with single

ventricle. The 'single' ventricle was considered torepresent an unseptated bulboventricular loop, with

FIG. 3 Photographs illustrating the pertinent features of Case i. Fig. 3A shows the anteriorview of the heart. The aorta (Ao) is to the left of the pulmonary artery (PA). Both greatarteries are deviated rightwards, and there is partial juxtaposition of the atrial appendages(RAA, LAA). The large persistent left superior vena cava is seen (LSVC). Fig. 3B shows theright-sided chambers of the heart. A typical right atrium receiving the right superior vena cava(RSVC), left superior vena cava via the coronary sinus (CS), and the inferior vena cava,drains through a morphologically tricuspid valve (TV) to the morphologically right ventricle.The opening of the juxtaposed portion of the auricle (RAA) is seen. The right ventricular sinus(RVS) is poorly formed and muscle bound. The pulmonary veins (RPV, LPV) are visibleentering the left atrium. Fig. 3C illustrates the pulmonary artery (PA) arising anteriorly fromthe right ventricle. It is separated from the tricuspid valve by the right margin of the conoven-tricular flange (RCVF). The anterior papillary muscle (APM) and ventricular septal defect(VSD) are both seen. Fig. 3D shows the abnormal origin of the aorta (Ao) from the leftventricle. The large conus septum (CoS) separates the aorta from the pulmonary artery. Itforms the roof of the anterior septal defect, and is continuous posteriorly with the left margin ofthe conoventricular flange (LCVF) which separates the aortic and mitral (MV) valves. Notethat the mitral and tricuspid valves are in fibrous continuity in the posterior margin of thedefect. Note also the typical features of the morphologically left ventricle (LV).



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the mitral valve entering the ventricular component andthe arteries arising from the bulbar component. In rela-tion to this d-loop the arteries were considered toexhibit the relation of anatomically corrected malposition{S,D,L}. An alternative description of this relationwould be double outlet bulbus with l-malposition. Assoc-iated anomalies were persistent ductus arteriosus, patentformen ovale, and single coronary artery.

Case 4The specimen was from a male neonate dying at 2days of age. Visceroatrial situs solitus was present and anormal spleen was observed. The cardiac apex wasdirected to the right and the heart was centrally posi-tioned in the thorax (Fig. 7A). The right atrium re-ceived a right superior vena cava, a left superior venacava via a coronary sinus, and an inferior vena cava.The chamber was blind-ending, and the only egress forright atrial blood was through a secundum atrial septaldefect. A dimple was not identified in the chamber floor.The right auricle was juxtaposed to the left of the greatarteries (Fig. 7A and B). The left atrium received 4pulmonary veins, together with the systemic venousreturn via the secundum defect. It drained through avalve with morphological characteristics of a mitralvalve to a main ventricular chamber (Fig. 7G). Theaorta arose anteriorly from this chamber, and its pos-terior cusp was in tenuous fibrous continuity with themitral valve via the central fibrous body (Fig. 7C). Ahypoplastic outlet chamber was situated on the rightanterior shoulder of the main chamber, and a fair sizedbulboventricular foramen connected the two (Fig. 7D).The aorta overrode the bulboventricular septum byapproximately IO per cent. The cavity of the hypoplasticoutlet chamber was barely recognizable, and the pul-monary artery arising from the chamber was atretic(Fig. 7B). The pulmonary artery arose in the same frontalplane as, and to the right of, the aorta (Fig. 7A, B). Asingle coronary artery arose from the right anterior aorticsinus, immediately dividing to give right and left cir-cumflex branches. A large right anterior descendingbranch was present. The ductus arteriosus was patent.

The diagnosis was made of tricuspid atresia. Theventricular morphology was typical of that seen in theanomaly of single ventricle with outlet chamber, exceptthat the right atrioventricular valve was absent. Theventricles were arranged in d-bulboventricular looppattern. In relation to this loop, the arteries exhibited therelation of anatomically corrected malposition {S,D,L).Associated anomalies were persistent ductus arteriosus,pulmonary atresia, ventricular septal defect, persistent leftsuperior vena cava, laevo juxtaposition of the auricles, andsingle coronary artery.

DiscussionI) What is malposition?When Van Praagh and his colleagues (I97I) firstintroduced the concept of malposition of the twogreat arteries, they indicated that the term shoulddescribe all ventriculo-arterial relations which couldnot be considered as normal. Within this frameworkthey then defined the special category of transposi-tion. Great arteries were only considered to betransposed when both arose from separate mor-phologically inappropriate ventricles. However.having made this distinction, it now seems prefer-able to separate the two categories of transposed andmalposed arteries, so that the term malposition itselfbecomes more specific (R. Van Praagh, I974, per-sonal communication). If the term malposition is tobecome fully specific, it is necessary to distinguishthe malposition that occurs in double outlet situa-tions from the malposition that is anatomicallycorrected. The 'double outlet' type of malpositiondescribes the situation in which both great arteriesarise from the same ventricle, be it right or left.This is distinguished from transposition becauseonly one great artery is placed across the septum toproduce a double outlet ventricle. The significanceand usefulness of the malposition concept as applied

FIG. 4 Photographs to demonstrate the pertinent features of Case 2, which was associated withsitus inversus totalis. Fig. 4A shows the anterior view of the heart. The lungs (RL, LL) are in-verted. The aorta (Ao) arises anterior to and to the right of the pulmonary artery (not visible).Fig. 4B shows the posterior aspect. The atria are inverted, so that the morphologically leftatrium (MLA) is right-sided and receives the pulmonary veins (PV). The morphologically rightatrium (MRA) is left-sided and receives the systemic venous return. Fig. 4C shows the right-sided atrioventricular orifice. The morphologically left atrium drains to the morphologically leftventricle (MLV) through a mitral valve (MV). Note the filigreed valve of the foramen ovale(Fo). Fig. 4D illustrates the abnormal origin of the right-sided aorta from the morphologicallyleft ventricle (right-sided). Note the typical mitral valve and the fine trabeculae of the morpholo-gically left ventricle. The aortic valve is separatedfrom the mitral valve by the defect (VSD)but the aorta arose predominantly from the left ventricle (right-sided). The left-sided ventriclewas a typical morphological right ventricle and gave rise to an atretic pulmonary artery (seeFig. 5).



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I002 Anderson, Becker, Losekoot, and Gerlis

FIG. 5 Case 2. A) The left side of the heart. This is made up of the morphological rightatrinum (RA) which opens into the morphological right ventricle (RV). The opening of theinferior vena cava (IVC) and limbus fossae ovale (LFO) are both visible. The valve present isa morphologically tricuspid valve (TV) and the conspicuous anterior papillary muscle (APM)is seen arising from the trabeculun septomarginalis (TSM). The ventricular septal defect isvisible above the TSM (arrow) and the prominent conus septum (CS) is seen compressing thesht-like opening of the pulmonary artery (PA) which is atretic. B) The orientation of thegreat arteries. The aorta (Ao) arises anteriorly and to the right of the atretic pulmonary artery(PA). The pulmonary artery branches are fed by a persistent ductus arteriosus. As illustratedin Fig. 4 and Fig. 5A, the aorta arises from the inverted morphological left ventricle and theatretic opening of the pulmonary artery is related to the left-sided morphological right ventricte.



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to double outlet ventricles is that it convenientlyallows types of the anomalies to be distinguishedin which the aorta lies either to the right or to theleft of the pulmonary artery (d-malposition or1-malposition). However, it is also necessary to dis-tinguish double outlet malposition from the differentventriculo-arterial relation of anatomically cor-rected malposition.

2) What is anatomically corrected malposi-tion ?This term is used to describe the ventriculo-arterialrelation in which the great arteries arise from sep-arate ventricles, and are abnormally related to eachother, but in which, despite these features, the aortastill arises from the morphologically left ventricleand the pulmonary artery arises from the mor-phologically right ventricle. In terms of flow,therefore, the ventricles and arteries are normallyconnected since right ventricular blood will beconveyed to the lungs (in the absence of othercardiac defects). For this reason Kirklin and hiscolleagues (I973) have termed anatomically cor-rected malposition a concordant ventriculo-arterialrelation. Normally related great arteries are" simi-larly concordant with their ventricles; in contrastboth transpositions and double outlet situationsrepresent discordant arterio-ventricular relations.We consider that this concept, based on bothphysiological and anatomical criteria, is more usefuland less confusing than the concept of arterio-ventricular concordance and discordance recentlyproposed by de la Cruz et al. (I974).

Although the majority of cases of anatomicallycorrected malposition thus far described havepossessed a subaortic conus, it is our belief that theventriculo-arterial relation could exist in thepresence of aortic-mitral continuity. It is wellestablished that during normal development of theheart, subaortic conal musculature is absorbed toproduce normal aortic-mitral continuity (Pernkopfand Wirtinger, I933; Goor, Dische, and Lillehei,I972; Anderson et al., I974d). Similarly, when thepulmonary artery is transferred to the left ventriclein transposition, this can result in either presence orabsence of subpulmonary conal musculature(Anderson et al., 1974c). We would, therefore,contend that continued absorption of the subaorticconus during development of anatomically correctedmalposition could theoretically result in productionof a malposed aorta (not normally related) in fibrouscontinuity with the mitral valve. We would furthercontend that the 'normal' position of arteries de-scribed in a case reported by Van Praagh and VanPraagh (I966) is in fact a malposition since these

arteries cannot be considered as normal in positionin relation to the I-loop that was present in thisanomaly.We believe that nomenclature of ventriculo-

arterial relations would be simplified if confined tothe five'categories of a) normal relations; b) trans-position; c) double outlet malposition; d) anatomi-cally corrected malposition; and e) common truncus(Table).

3) How many varieties of anatomically cor-re'cted malposition are there?Since the term 'anatomically corrected malposition'.describes a ventriculo-arterial relation, it followsthat anatomically corrected malposition, like trans-position and double outlet ventricles, can coexistwith varying anomalies of the atrioventricular seg-ments of the heart tube. Thus, if we consider the 8varieties of 'transposition' postulated on theoreti-cal grounds by Geipel (1903) and by Harris andFarber (I939), in the setting of the transposition/malposition concept, then it becomes evident that4 of these varieties are transpositions and 4 areanatomically corrected malpositions (Fig. 8). Aswith transpositions, the most commonly reportedvariety of anatomically corrected malposition is thatassociated with solitus atrial chambers and atrio-ventricular concordance (Fig. 9A) (Raghib et al.,I966; Van Praagh and Van Praagh, I967; Sunadaet al., I967; Kirklin et al., 1973; Freedom andHarrington, I974; and 3 of the present cases). How-ever, the remaining 3 varieties of anatomically cor-rected malposition have all now received adequatedocumentation. Van Praagh and Van Praagh (I967)decribed the form in which anatomically correctedmalposition was associated with solitus atria andatrioventricular discordance' (Fig. 9C). Andersonet al. (I972) described an example of anatomicallycorrected malposition with inversus atria and atrio-ventricular discordance (Fig. 9D). There is somecontroversy concerning the existence of anatomicallycorrected malposition in situs inversus with atrio-ventricular concordance (Fig. 9B). Campbell andForgacs (I953) and Campbell and Deuchar (I965)described such cases in the material they studied atGuy's Hospital, and Shaher (I964) illustrated angio-grams from one of these cases. Despite these re-ports, both Kirklin et al. (I973) and Van Praaghet al. (I975) considered the variety still requiredadequate documentation. We submit that our Case2 provides necropsy evidence of the' existence of thisvariety of anatomically corrected malposition.Further examples of anatomically corrected malposi-tion can exist with the heterotaxia syndrome inwhich atrial situs cannot be determined. Freedom



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Anatomically corrected malposition I005

TABLE Ventriculo-arterial relations

Category

i. Normal relations

2. Transposition

3. Anatomically correctedmalposition

4a. Double outlet rightventricle

4b. Double outlet left ventricle

5. Common truncus

Possible variations

a) With situs solitus, AV concordance

b) With situs solitus, AV discordance*

c) With situs inversus, AV concordance

d) With situs inversus, AV discordance*

a) With situs solitus, AV concordance

b) With situs solitus, AV discordance


d) With situs inversus, AV discordance

Ia) With situs solitus, AV concordance

b) With situs solitus, AV discordance


d) With situs inversus, AV discordance

{a) With situs solitus, AV concordance

b) With situs solitus, AV discordancec) With situs inversus, AV concordanced) With situs inversus, AV discordance

{a) With situs solitus, AV concordance

Possibilities b-d have yet to be reportedCan exist with all variations of atrio-

ventricular relations

Aortic position

From LV; right-sided, posterior, A-Mcontinuity

From LV; left-sided, posterior, A-Mcontinuity

From LV; left-sided, posterior, A-Mcontinuity

From LV; right-sided, posterior, A-Mcontinuity

From RV; anterior or posterior; right-sided or left-sided; usually with conus

From RV; as yet only described anterior,to left or right, and with conus

From RV; as yet only described anterior,to left, and with conus

From RV; as yet only described anterior,to right, and with conus

From LV; left-sided; usually has conusbut could have A-M continuity

From LV; right-sided; usually has conusbut could have A-M continuity

From LV; right-sided; usually has conusbut could have A-M continuity

From LV; left-sided; usually has conusbut could have A-M continuity

From RV; right-sided (d-malposition)or left-sided (I-malposition)

From RV; usually l-malpositionFrom RV; usually l-malpositionFrom RV; d-malposition would be

expectedFrom LV; l-malposition or d-malposition;

with or without conus

Common truncus can theoretically arisefrom right ventricle, left ventricle, or invarying degrees from both ventricles;origin of aorta and pulmonary arteriesfrom common truncus is also variable

* These anomalies have yet to be described.Abbreviations: AV, atrioventricular; LV, left ventricle; RV, right ventricle; A-M, aortic-mitral.

FIG. 6 Photographs illustrating the pertinent morphological features of Case 3. Fig. 6A showsthe relation of the great arteries. The aorta (Ao) arises anteriorly to and to the right of thepoorly formed pulmonary artery (PA). Note the single coronary artery (SCA) arising fromthe right septal aortic sinus. Fig. 6B shows the blind-ending right atrium. The atrium has beenopened, and also dissected along its floor. Note that it overlies the right atrioventricular groove,and that there is no evidence of a 'dimple'. It receives the superior vena cava (SVC) andinferior vena cava (IVC) but the coronary sinus is lacking. Its only exit is via a patentforamenovale (Fo). Fig. 6C shows the left atrium (LA) cotmnunicating with a single 'ventricular'chamber ('SV') via a morphologically mitral valve (MV). The herniated floor of the fossaovalis (Fo) is seen in the left atrium. Note the anterior papillary muscle of the mitral valve,and that some chordae take origin from a prominent trabecula which partially separates theventricular chamber. Note also the pulmonary artery arising posteriorly to and to the right ofthe aorta. Fig. 6D shows the origin ofthe great arteriesfrom the anterior portion ofthe ventricularchamber, considered by us to be the bulbus. The aortic orifice is to the left of the stenosedpulmonary orifice, and the two are separated by the conus septum (CoS). The conoventricularflange (CVF) separates both semilunar valves from the mitral valve. Note the prominenttrabecula (T) which extends to the underside of the conus septum and gives some chords to themitral valve.



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FIG. 8 Diagram illustrating how the 8 forms of 'transposition' catalogued by Geipel (I903)can be rearranged within the transposition/malposition concept of Van Praagh et al. (I97I).Note that the 8 varieties are divisible into 4 mirror-image pairs, one of each pair being associatedwith situs solitus (S), the other with situs inversus (I). Of these 4 pairs, 2 are associated with thegreat arteries arising from inappropriate ventricles (transposition, Fig. 8A-D). The other 2pairs have the arteries arising unusually from appropriate ventricles (malpositions, Fig. 8E-H).The state of the circulation, being either corrected (physiol. correct) or transposed (physiol. com-plete), is dependent upon the presence of atrioventricular concordance or discordance. In the caseof the transpositions, discordance produces physiological correction (Fig. 8A, B) and concordanceproduces transposition (Fig. 8C, D). In the case of the malpositions, concordance produces physio-logical correction (Fig. 8E, F) and discordance produces physiological transposition (Fig. 8G, H).

FIG. 7 Photographs illustrating the pertinent morphologicalfeatures of Case 4. Fig. 7A showsthe anterior view of the heart. The aorta (Ao) is to the left of the pulmonary artery (PA) whichis atretic. The right auricle (RAA) is juxtaposed to the left. The right-sided superior vena cavais seen (SVC). The so-called right ventricle ('RV') is an outlet chamber situated on the rightshoulder of the primitive ventricle ('LV'). Fig. 7B shows the blind ending right atrium (RA).The origin of the pulmonary artery from the outlet chamber is demonstrated. The main pulmon-ary arteries (RPA - right pulmonary artery) fill via a persistent ductus arteriosus. Fig. 7Cdemonstrates the origin of the aorta from the primitive ventricle. A mitral valve (MV) drainsthe left atrium (not shown) and mitral-aortic valvular continuity is demonstrated (arrow).Despite this, the great arteries are abnormally related to each other and their respective ven-tricles, and thus malposition is present. Fig. 7D shows the bulboventricular foramen (BVF)on the anterior aspect of the primitive ventricle. The outlet chamber is small and the pulmonaryartery arising from it (not shown) is atretic. The mitral-aortic valvular continuity is again seen(arrow).



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E Morph. RV MJjMorph.LV Pulmonary A. * Aorta

FIG. 9 Diagram illustrating the four varieties ofanatomically corrected malposition (Fig. 8) in greaterdetail. The four varieties are composed of pairs, beingassociated with either solitus or inversus atrial cham-bers, and either AV concordance or AV discordance.The common feature of the 4 anomalies is the relationof the arteries to the underlying ventricles. This is'anatomically corrected malposition', and as such can

exist with varying malformations of the underlyingventricles. All 4 of these varieties have now receivedadequate documentation.

and Harrington (I974) described such a case inassociation with asplenia. Despite identification of a'spleen' in our Case i at the original necropsy thecardiac anatomy in this specimen makes us stronglysuspect that polysplenia may have been present.

4) How are varieties ofanatomically correctedmalposition to be distinguished ?Since we have indicated that anatomically correctedmalposition is only a description of a ventriculo-arterial relation, it follows that the term does notdescribe the complete heart. Indeed, it is evident

from the above discussion that though all 4 var-ieties of anatomically corrected malposition exhibitconcordance of ventricles and arteries, flow throughthese segments would be made unphysiological byaccompanying discordance between the atria andthe ventricles. It is important to be able to dis-tinguish those varieties of anatomically correctedmalposition in which flow is physiologically normalfrom those in which flow is physiologically trans-posed. Similar variations in transpositions areusually distinguished by using the adjective 'com-plete' to describe the physiologically transposedvarieties (Fig. 8C and D, {S,D,D} and {I,L,L})and 'corrected' to describe those varieties withnormal flow patterns (Fig. 8A and B, {S,L,L} and{I,D,D}). It is possible that the terms 'complete'and 'corrected' could be used to distinguish thetypes of anatomically corrected malposition, butconfusion might be produced if the term 'correctedanatomically corrected malposition' were used. Itwould be preferable to discard the 'anatomicallycorrected' and refer simply to 'corrected malposi-tion' to describe the varieties with normal flowpatterns, and 'complete malposition' for those withtransposed flow. However, this could producefurther confusion with the double outlet varietiesof malposition and such a nomenclature demandsconsiderable initial knowledge. We would, there-fore, suggest that the hearts be described in theirfull segmental arrangement (Anderson, Shine-bourne, and Gerlis, I974b). The heart illustrated inFig. 8E would, therefore, be described as solitusatria, concordant atrioventricular relation, andanatomically corrected malposition. The nomen-clature for all four varieties can then easily beshortened to the term 'concordant anatomicallycorrected malposition', for the two varieties withnormal circulatory patterns ({S,D,L} and {I,L,D},Fig. 8E and F), and the term 'discordant anatomi-cally corrected malposition' for the two varietieswith physiologically transposed circulatory pat-terns ({S,L,D} and {I,D,L}, Fig. 8G and H). It willbe noted that since anatomically corrected malposi-tion is a concordant ventriculo-arterial relation, adiscordance at atrioventricular level producesphysiological transposition. In contrast, transposi-tion of the great arteries is already an example ofventriculo-arterial discordance, therefore a seconddiscordance at atrioventricular level serves to'correct' the circulation.

5) Can anatomically corrected malpositioncoexist with single (or primLitive) ventricle ?In Cases 3 and 4 we have designated the ventriculo-arterial relation as 'anatomically corrected malposi-



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tion', though right and left ventricular sinuses arenot identifiable as such. Both cases have coexistingtricuspid atresia, and the association of tricuspidatresia and anatomically corrected malposition iswell established (Freedom and Harrington, I974).Thus, the apparent absence of a right ventricularsinus is not contraindicative of anatomically cor-rected malposition. We have recently studied 75examples of tricuspid atresia (unpublished observa-tions), and it is our belief that the right ventricularsinus in this anomaly is part of the so-called 'leftventricle', and that the so-called 'right ventricle'is the bulbus or outlet chamber. Tricuspid atresiais, therefore, usually a variant of 'primitive ven-tricle with outlet chamber'. In Case 4 presentlydescribed, the pulmonary artery arises from thebulbus, and the aorta is left-sided, arising from theprimitive ventricle. Thus, though the great arteriesarise from their appropriate embryological prim-ordia, they are not normally related to these cham-bers. We, therefore, contend that this ventriculo-

Classically corrected TRANSposition{S,L,L}

arterial relation is one of anatomically correctedmalposition. In Case 3 the situation is complicatedsince an outlet chamber is not present. We considerthe ventricular morphology to represent 'primitiveventricle without outlet chamber', and we wouldsubmit that the right side of the ventricular mass ismade up of the unexpanded right ventricular sinus.We further contend that the pulmonary arteryarises from the bulbus and is related to this unex-panded right ventricular sinus while the left-sidedaorta is related to the left ventricular sinus, bothsinuses being derived from the primitive ventricle.It is therefore our belief that, as in Case 4, the greatarteries are abnormally related to their appropriateventricular primordia and that once again the ven-triculo-arterial relation is that of anatomically cor-rected malposition. It follows from the above dis-cussion that we would also consider it possible tofind anatomically corrected malposition in associa-tion with the anomaly of primitive (or 'single')ventricle either with or without outlet chamber

Anatomically corrected MALposition(S,D,L)

FIG. IO Diagram to compare the course of the cardiac conducting tissues in classically cor-rected transposition and anatomically corrected malposition. In classicdlly corrected transposi-tion the conducting tissue has been demonstrated to pass anterosuperiorly to accompanying septaldefects, and to encircle the lateral quadrants of the pulmonary valve (Anderson et al., 1973,I974a). In anatomically corrected malposition, in contrast, the conducting tissue is posterior toseptal defects, arising from a normally situated node (Anderson et al., I972). Note also thatwith solitus atrial chambers, corrected transposition is characterized by atrioventricular discord-ance (left ventricle (MLV) together with left bundle-branch (LBB) on right), whereas cor-rected malposition is characterized by atrioventricular concordance (right ventricle (MRV) andright bundle-branch (RBB) on right). Other abbreviations asfor Fig. 3-7.



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when both atrioventricular valves are present andempty into the primitive ventricle.

6) Is it of clinical significance to recognizeanatomically corrected malposition?Since both concordant anatomically corrected mal-position and classically corrected transposition pro-duce circulatory patterns which are potentiallynormal, and since both have left-sided aortae withsolitus atrial chambers ({S,D,L} and {S,L,L}, Fig.8E and A, respectively), one may wonder if it isnecessary to distinguish the two conditions ? Recentfindings regarding disposition of conducting tissuesin the two anomalies indicate that it is vital to dis-

tinguish them. In classically corrected transposi-tion (Fig. ioA), it has been shown that the atrio-ventricular bundle is situated anteriorly in theseptum, descends from an anterior node, and isrelated to the antero-superior quadrants of anyaccompanying ventricular septal defects (Anderson,Arnold, and Wilkinson, I973; Anderson et al.,1974a). In contrast, in anatomically corrected mal-position (Fig. ioB) the bundle should be expectedto occupy its more usual posterior position (Truexand Bishof, I958). This hypothesis was supportedby gross inspection of our Cases i and 2, but hasnot been proven histologically. However, in anexample of anatomically corrected malposition thatwas studied histologically, the bundle was observed

Left -

1. Normal 7. Intermediate (b)

2. Fallot's tetralogy 5. DORV-Subpul mon ary defect 8."Completetransposition

3. DORV-Suboortic defect 6. Intermediate

Posterior3Anterior Segments of musc. septum

>- < Bulboventricular (primory) foramen

e (a) 9.'Posterior"tronsposition

_2:: Septal 1}nsertions of conus septum1P arietaIJ

%M4 Atriovent-Semilunar continuity

FIG . II Diagram illustrating the spectrum of conal maldevelopment associated with solitusatrial chambers and atrioventricular concordance. The spectrum is explained on the basis of'lack of conal inversion', 'lack of conal absorption', and realigmnent of the anterior ventricularseptum. Reproduced with alterations from Anderson et al. (1974C).



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in a posterior position despite the presence of atrio-ventricular discordance (Anderson et al., I972).

7) Is anatomically corrected malposition anembryological impossibility?Since the ventriculo-arterial relation now describedas anatomically corrected malposition was not con-sidered to be possible embryogenetically, VanMierop and Wiglesworth (I963) doubted thevalidity of the so-called examples of the anomalypreviously described. Since it now seems likely thatall 4 examples of anatomically corrected malpositionpostulated by Geipel (1903) and Harris and Farber(1939) have received adequate documentation, it isevident that the anomaly can no longer be con-sidered an impossibility. How then is it formed ?Some authors have termed the condition 'isolatedbulbar inversion' (Raghib et al., I966; Tandon andEdwards, 1974). However, consideration of thestructures formed from the bulbus indicates that itis unlikely that isolated inversion of the bulbuswould produce the situation of anatomically cor-rected malposition. Though there is doubt as towhether the right ventricular sinus is of bulbarorigin (Pernkopf and Wirtinger, I933), Streeter(I942) clearly demonstrated that the trabeculated

A Ao PA C

RV

pouch of the right ventricle developed from thebulbus. In none ofthe reported examples ofanatom-ically corrected malposition was this structure in-verted, as would be expected if the developmentalmechanism was indeed isolated bulbar inversion.In a similar fashion, isolated ventricular inversionwould not produce inversion of the trabeculatedportion of the right ventricle. It would not, there-fore, produce discordant anatomically correctedmalposition, as is suggested by usage of the term todescribe this anomaly by Kirklin et al. (I973) andGoor and Edwards (I973). Goor and Edwards(I973) and Van Praagh and Van Praagh (I967) sug-gested that isolated conal inversion may produceanatomically corrected malposition. This is indeed apossible mechanism, and would imply inversion ofconal musculature together with the arteries. How-ever, this inversion would be in reverse direction tothat normally seen, and would occur in addition tothe initial 'lack of conal inversion' shown to pro-duce double outlet right ventricle (Goor et al.,1972; Anderson et al., I974d). This paradoxof inversion and 'lack of inversion' occurringtogether is possible because 'lack of inversion'can be considered as reverse inversion from thenormal position. If the additional reverse inversion

DORV with d-malposi tion{S,D,D)

Complete transposition Anatomically corrected Physioloqically correctedIS, D,D) MALposition{S,D,L) TRANSposition {S,L,L)

FIG. I2 Diagrams illustrating the mode of developmentof: A and B) 'complete' transpositionfrom double outlet right ventricle with d-malposition and subpulmonary defect; C and D) anatomi-cally corrected malposition from double outlet right ventricle with 1-malposition and subaorticdefect; and E and F) physiologically corrected transposition from DORV with atrioventriculardiscordance and 1-malposition. In each case, the great artery nearest to the left ventricle is takeninto the ventricle by a process of conal absorption and realignment of the anterior interventricularseptum. Note that the only major difference between A) and C) is reversal of the position of theaorta (see text for discussion).



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through i800 did indeed occur, it might be ex-pected to produce torsion in the great arteries, in a

manner analogous to that in which normal conalinversion produces the torsion observed in normallyrelated arteries. However, examination of specimensof anatomically corrected malposition fails to revealsuch torsion. A further possibility exists to explainthe morphogenesis. When considering the anomaly

of double outlet right ventricle (DORV), Lincolnet al. (I975) suggested that the transition fromDORV with d-malposition to DORV with 1-malposition might result from 'plugging-in' of theaorta and pulmonary artery in reverse, or in otherwords 'isolated truncal inversion'. If this occurredin the double outlet situation, then the anomaly ofanatomically corrected malposition could be pro-duced from DORV with l-malposition in exactlythe same way that complete transposition has beenshown to be linked to DORV with d-malposition(Lev et al., I972; Goor and Edwards, I973; Ander-son et al., I974c) (Fig. ii and I2). If this hypothesisis correct, then it indicates that anatomically cor-rected malposition could result from conal mal-development (Van Praagh, I973a, b) together withtruncal inversion. The latter could well be producedby formation of a 'straight septum' in reverse. It is,therefore, evident that though the 'straight septumhypothesis' (Van Mierop and Wiglesworth, I963)can no longer be considered to produce classicallycomplete transposition, it is possible that a variantof this mechanism may be involved in the produc-tion of anatomically corrected malposition.

We are indebted to Dr. Richard Van Praagh for his helpduring the preparation of this manuscript, and to Dr. J.Bliddal for bringing several of the earlier references toour attention.

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Requests for reprints to Dr. R. H. Anderson, Depart-ment of Paediatrics, Cardiothoracic Institute, Bromp-ton Hospital, Fulham Road, London SW3 6HP.



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