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C O N C E P T S O N T H E V E R G E O F T R A N S L A T I O N i C o n c e p t s
Great Vessel and Coronary Artery Anatomy inTransposition and Other Coronary AnomaliesA Universal Descriptive and Alphanumerical Sequential Classification
Sasi Sithamparanathan, MBBS,* Simon P. G. Padley, MBBS,† Michael B. Rubens, MBBS,†Michael A. Gatzoulis, PHD,‡ Siew Yen Ho, PHD,‡ Edward D. Nicol, MD, MBA†‡
Surrey, London, United Kingdom
In patients with transposition of the great arteries, the identification of coronary anatomy is fundamental
to optimal surgical outcome. A number of classifications describing the coronary vessels’ origin and course
in transposition of the great arteries have been published. However, all are limited to operative or
pathological case series. They are often alphanumeric classifications that do not lend themselves to clinical
practice; they do not consider certain important anatomical variations that may increase surgical morbid-
ity and mortality, nor do they fully delineate coronary anatomy or define the relationship to adjacent
structures seen with cardiovascular computed tomography. Using cardiovascular computed tomography
for illustrative purposes, we propose and validate a universal sequential descriptive classification and an
associated alphanumeric classification that may be used for all coronary anomalies with or without
Coronary computed tomography (CT) angiog-raphy allows for a complete visualization of theorigin and course of the coronary arteries, incontext with the surrounding cardiovascular anat-omy. Although of great potential for the analysisof anomalous coronary anatomy, this leads to therequirement of a comprehensive descriptiveframework for the coronary arteries and greatvessels to allow cardiologists, radiologists, andsurgeons alike to accurately describe and classifycoronary and cardiovascular anatomy. Existingalphanumeric classifications of coronaryanatomy, though useful in the research andtaxonomy settings are of limited value withinclinical settings where they do not cover all
From the *Department of Cardiology, Surrey and Sussex NationalKingdom; †Department of Radiology, Royal Brompton Hospital aand the ‡Department of Cardiology, Royal Brompton Hospital anThe authors have reported that they have no relationships relevant
Manuscript received April 30, 2012; revised manuscript received Septe
coronary variants and where their use re-quires a complete understanding of the al-phanumeric code by all clinicians. Whereas asequential descriptive classification exists foratrioventricular and ventriculo-arterial con-nections, there is currently a lack of a uni-versal, systematic descriptive classificationfor coronary and great vessel anatomy.
Clinically, coronary anomalies matter. Inpatients with transposition of the great arteries(TGA), the identification of coronary anatomyis fundamental to optimal surgical outcome (1).At the more benign end of the spectrum thismay include 3 separate coronary ostia (Fig. 1),whereas a single coronary ostium (Fig. 2)
lth Service (NHS) Trust, Redhill, Surrey, Unitedarefield NHS Trust, London, United Kingdom;arefield NHS Trust, London, United Kingdom.
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confers a 3-fold mortality increase, a “malignant”intramural/interarterial coronary artery (Fig. 3) isassociated with 6-fold increase in mortality,whereas overall mortality in those patients withabnormal anatomy is nearly double (1). (We use“malignant course” to describe both interarterial[major epicardial vessel running between the rightventricular outflow tract and the aortic root] andintramural [coronary arteries additionally residewithin the aortic wall for a variable duration of theirinterarterial course]. The use of multidetector CTto differentiate between these 2 types of malignantcourses is both unproven and challenging; however,both are associated with poorer prognosis.) As aresult of the association of coronary anomalies withadverse outcomes in TGA, the classification ofcoronary anatomy in TGA has been attempted byseveral investigators (Table 1). However, all previ-ous classifications are incomplete as they are basedon relatively small surgical, pathological, or echo-cardiographic series and, therefore, are limited tothese case series and cannot be applied to otheranomalies. No previous classification comprehen-sively covers important anatomical variations thathave been demonstrated to, or have the potential to,increase surgical morbidity and mortality. Finally,they cannot be used to describe isolated coronaryanomalies that may predispose to sudden cardiacdeath.
Partial classifications do exist for certain coronaryanomalies (such as Lipton’s classification of isolatedsingle coronary artery patterns and Angelini’s pro-posed descriptive approach to coronary anatomy atangiography [2]), but again these are limited, forexample, to invasive angiography and only applica-ble to patients without congenital heart disease(CHD). Additionally, they are not transferable foruse with other imaging modalities.
Clinically, Leiden’s classification is often used.However, this alphanumeric classification is com-plicated and may not fully describe coronaryanatomy, and the codex needs to be understoodby all clinicians to be of practical use. Thedescription of the aortic sinuses within the Le-iden classification is also confusing (Fig. 4), andthe relationship between the aortic root andpulmonary artery is not routinely described. TheLeiden classification cannot be used to describethe anatomy in congenitally corrected transposi-tion of the great arteries (ccTGA) where the“normal” variation of the coronary anatomy also
influences both natural history and prognosis nor
in isolated coronary anomalies that are increas-ingly recognized in patients.
We propose both a universal, descriptive, se-quential approach for use clinically and an alpha-numeric equivalent for the purposes of taxonomyand research where a shorthand description allowsfor a simple, universal, and standardized codex.Both classifications allow for the complete delinea-tion of great vessel and coronary anatomy, compre-hensively encompassing variations with significantmorbidity and mortality.Sequential descriptive and alphanumeric classificationof coronary anatomy. For the clinical setting, wedeveloped a descriptive approach to delineate thegreat vessel and coronary anatomy. However, wealso believed there was a value in an alphanumericsystem for taxonomy and research, and we recog-nized the potential to break down the descriptiveclassification into an alphanumeric classification.Therefore, we also present our descriptive classi-fication as an extended Leiden alphanu-meric classification that can be used inall CHD patients and isolated coronaryanomalies based on multidetector CT.
We describe the relationship of theaorta (Ao) to the pulmonary artery (PA)and then the coronary anatomy. In bothclassifications, we allow for additional os-tia to be described, describe which arteriessupply which ventricles in ccTGA, and, if
Ao � aorta; Cx � circumflex artery; LAD � left anterior descendingPA � pulmonary artery; RCA � right coronary artery; VR � volume
A B B
A N D
Ao �
ccTGA
transp
arteri
CHD �
CT �
PA �
TGA �
arteri
artery;
rendered.
R E V I A T I O N S
A C R O N YM S
aorta
� congenitally corrected
osition of the great
es
congenital heart disease
computed tomography
pulmonary artery
transposition of the great
pf
1
Abbrevia
AD � an
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present, denote an interarterial malignant course.We describe aortic sinuses as their morphologicalposition as related to the patient: anterior or pos-terior; right or left (Fig. 5). In the alphanumericclassification, we extend and modify the Leidenmethod to include the methodology described.These simple changes in the classification take intoaccount the important role of the coronary anatomyin the surgical outcome of CHD patients.Descriptive classification. The proposed new de-scriptive terminology is applied sequentially asfollows:
. VR Image Demonstrates a Single Coronary Ostium Supplyingronary Vessels
tions as in Figure 1.
. VR Image Shows a Malignant Interarterial Course of theCX Between Ao and PA
terior descending artery; other abbreviations as in Figure 1.
1. Use the axial views to describe the anatomicalrelationship of the aorta to the pulmonary artery(if present): Ao directly anterior to PA; Aodirectly posterior to PA; anterior right; anteriorleft; posterior right; posterior left; side-by-sideleft (Ao is left of PA); and side-by-side right(Ao is right of PA).
2. Describe the origin of the coronary arteries:describing the aortic sinuses as left or right,anterior or posterior with respect to the patientand stating the number of ostia present off eachsinus. If �1 ostium is present on a given sinus,the more anterior is described first, with subse-quent, more posterior ostia following in order.Bicuspid valves would be described as eitheranterior or posterior or left and right dependingon orientation (Fig. 5).
3. Describe the anterior descending artery accord-ing to cardiac morphology; that is, do notautomatically begin with the left anterior de-scending artery in TGA.
4. Describe clearly the high risk or malignantinterarterial/intramural coronary course be-tween Ao and PA.
5. Describe the coronary arterial supply to the leftor right ventricle for patients with ccTGA.
Alphanumeric classification. The proposed new al-hanumeric terminology is applied sequentially asollows:
. Use the axial view to describe the morphologicalrelationship of Ao to PA (if present): A � Aodirectly anterior to PA; P � Ao directly poste-rior to PA; AR � anterior right; AL � anteriorleft; PR � posterior right; PL � posterior left;SSL � side-by-side left (Ao is left of PA); andSSR � side-by-side right (Ao is right of PA).
2. Describe the origin of the coronary arteries:describing the aortic sinuses as left or right,anterior or posterior with respect to the patientand stating the number of ostia present off eachsinus. If �1 ostium is present on a given sinus,the more anterior is labeled i, with subsequent,more posterior sinuses labeled ii, iii, etc. Theuse of lowercase avoids confusion with coronarylabeling. a � anterior (if only 1 anterior sinus);ar � anterior right; al � anterior left; p �posterior (if only 1 posterior sinus); pr �posterior right; pl � posterior left. Bicuspidvalves would be a and p or l and r depending onorientation (Fig. 5). A semicolon is used toseparate the different aortic sinuses and if �1
Figure 2All 3 Co
Figure 3AD and
ostium is present in a given sinus.
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3. Label the anterior descending artery accordingto cardiac morphology; that is, do not automat-ically begin with the left anterior descendingartery in TGA.
4. Describe clearly the high risk or malignantinterarterial coronary course between the Aoand PA and annotate the alphanumeric classi-fication with aM notation.
. Denote the coronary arterial supply to the leftor right ventricle for patients with ccTGA (i.e.,supplying morphological left ventricle or rightventricle).
To demonstrate these new sequential classifica-ions, we illustrate several cases with CT angiogra-hy and compare the proposed new classificationith the previous Leiden terminology and other
lassifications where appropriate. We show stan-ard caudal-cranial multiplanar reformatted radio-
ogical views alongside the schematic diagrams. Inlinical practice, however, the craniocaudal volumeendered images are often the most useful for fullyelineating the coronary anatomy, and these arehown are separate color images (Figs. 6 to 9).Results and interobserver variability. To validate the
roposed classification and to test interobserverariability, 2 level-3 Society of Cardiovascularomputed Tomography operators (consultant car-iologist and consultant radiologist) tested the va-
idity of the classification on 50 standard CToronary angiograms, including those with aberrantnatomy, and 50 cases with CHD (including TGA,cTGA, and other simple and complex CHD).
Table 1. Previous Classifications of Coronary Anatomy in TGA
Authors (Year)
Surgical orPathological Series(Cases Examined)
Types of CoronaryPattern Identified
n
Shaher and Paddu (1966) Pathological (166) 9
Yacoub (1978) Surgical (18) 5
Quaegebeur (Leiden)(1986)
Surgical (66) N/A*
Gittenberg (1983) Surgical (103) 12
Pasquini (1987) Surgical (32) 5
*Able to classify all previous types and be used for all other variants within limitathe PA. In general terms, the coronary sinuses closest to the PA are describedsinus giving rise right coronary artery (Fig. 4). ‡They describe the position of th
Ao � aorta; PA � pulmonary artery; TGA � transposition of great arteries.
greement was achieved in all but 1 case, a case of
ingle coronary artery where the proximal, mid, andistal left anterior descending consisted of 3 indi-idual vessels arising from different locations.Applicability to other imaging modalities. We pro-
ose a clinically relevant, universal descriptive, se-uential, morphological approach consisting of de-cribing the relationship of the Ao to the PA, theumber of coronary ostia in each aortic sinus, andhe origin and course of each major epicardialoronary artery. The alphanumeric classificationroposed is difficult to use in clinical settingsecause both users and readers need to possess fullnowledge and understanding of the coding system.n the fields of taxonomy and research, however,his extended alphanumerical methodology pro-
Figure 4. Aortic Sinuses Labeled According to the Leiden Classi
oronaryOrigin Coronary Ostia
RelationshipBetweenAo/PA
OtherLim
Yes Number only No Not comprehenTGA only
Yes Number and orientation No Course, directioncoronary vessdescribed
Not comprehenTGA only
Yes Number and orientation† Yes‡ More compreheAlphanumericTGA only
Yes Described but not includedin classification
Yes‡ TGA only
Yes Number and orientationlimited to certain types
No EchocardiographTGA only
of codification. †Coronary anatomy is described as if looking from the noncoronare “facing sinuses,” with the left facing sinus usually giving rise to the left coronato PA, but this is not incorporated into their classification.
fication
, C Points anditations
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, and length of theels before branching
sive
nsive
ic study
tions y sinus of Valsalva towardas th ry artery and right facinge Ao
Abbreviations as in Figure 1.
win
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vides the flexibility to describe coronary anatomymore comprehensively, accurately, and reproduciblyin patients with and without CHD.
Figure 5. Schematic Diagram Demonstrating the MorphologicalAnterior or Posterior and Left or Right
(A) There are 2 anterior sinuses on the right (ar) and left (al) and 1sinuses on the right (pr) and left (pl), respectively, and 1 anterior sithe sinuses in anterior (a) and posterior (p) position and with D sho
Figure 6. Case of a TGA Patient
There is no previous classification (no Leiden method because thertion: the Ao is anterior and slightly to the right of the PA. The antethe second gives rise to the AD. The right sinus gives rise to the CXand to the right of PA (AR). The anterior left sinus has 2 ostia (denostium (ii) gives rise to AD (A). The posterior sinus gives rise to thenary angiogram; and (C) Schematic diagram (viewed in standard ra
transposition of the great arteries; other abbreviations as in Figures 1 a
The new classification takes into considerationthe increasing knowledge of coronary anatomy fol-lowing the advent of multidetector CT coronary
ationship of the Aortic Sinuses to the Patient in Terms of
terior sinus denoted with a single p. (B) There are 2 posteriordenoted a. Illustrations of bicuspid aortic valves, with C showingg the sinuses in the left (l) and right (r) positions.
3 ostia) to describe the coronary anatomy. Descriptive classifica-left sinus has 2 ostia. The RCA arises from the first ostium andphanumerical classification: {AR[aliR;aliiA;pCx]}. The Ao is anteriori and ii). From the first ostium (i), the RCA arises and the second(Cx). (A) VR image viewed from cranial-caudal aspect; (B) CT coro-gical [caudocranial] aspect). CT � computed tomography; TGA �
Rel
posnus
e arerior. AlotedCXdiolo
nd 3.
tion
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anatomy and can be used in the reporting of cardiacCT. Importantly, both classifications describe the 2variants of coronary arteries associated with thehighest mortality in TGA patients: malignant in-terarterial courses; and arteries arising from a singleostium. It also provides a fundamental method ofcommunicating complex coronary anatomy withinclinical and academic settings.
The new classification has been designed usingCT angiography; however, it is transferrable to
Figure 7. Case of ccTGA
There is no previously described classification system for congenside by side and to the left of PA. The anterior right sinus has aventricle (LV) and right ventricle (RV) respectively. The posteriorventricle. Alphanumerical classification: {SSL[arR(LV)A(RV);pCx(RVcomes off the RCA arising from the anterior right sinus. The RCAsinus) supply the RV. (A) VR image viewed from cranial-caudal a(viewed in standard radiological [caudocranial] aspect). Abbrevia
Figure 8. An Example of Coronary Anomaly in a Patient Withou
There is no Leiden classification for isolated congenital coronary anof the PA. Three main arteries arise from the right aortic sinus. Theand circumflex arteries taking an interarterial course. Alphanumeric(PR). All 3 arteries arise from the anterior right aortic sinus (ar), witing an interarterial course (AMCxM). (A) VR image viewed from cran
gram (viewed in standard radiological [caudocranial] aspect). Abbreviat
other imaging modalities. It is best suited to cross-sectional techniques such as CT and cardiac mag-netic resonance; however, it is not always possible tovisualize the entire coronary tree using cardiacmagnetic resonance. It is possible to use the classi-fication with ICA so long as all branches arevisualized. The classification is also theoreticallyapplicable to other imaging modalities, even thoughtechniques such as transesophageal echocardiogra-phy and transthoracic echocardiography do not
y corrected TGA (ccTGA). Descriptive classification: the Ao isle ostium giving rise to the RCA and AD, which supply the lefts has a single ostium giving rise to the CX, supplying the rightThe Ao is side by side and to the left of PA (SSL). The AD (A)plies the LV (LV), whilst the AD and CX (from the posteriort; (B) CT coronary angiogram; and (C) schematic diagrams as in Figures 1, 3, and 6.
D (Left Main Coronary Artery Atresia)
ly. Descriptive classification: the Ao is posterior and to the rightan absent left main coronary artery with the anterior descendinglassification: {PR[arRAMCxM]}. Ao is posterior and right of the PAabsent left main coronary artery with the AD and CX arteries tak-audal aspect; (B) CT coronary angiogram; and (C) schematic dia-
itallsingsinu)]}.sup
spec
t CH
omare isal ch anial-c
ions as in Figures 1, 3, and 6.
RS
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usually visualize the coronary tree sufficiently wellfor diagnostic purposes.Summary. The new classification will potentiallyallow a more sophisticated analysis of coronaryanomalies and support further research into theeffect of specific abnormalities on both pre-surgical
Figure 9. Images From a TGA patient, With Yacoub Type A VariLeiden Classification of [1LCx;2R]
Descriptive classification: Ao is anterior and right of the PA. AD ancoronary from the posterior aortic sinus. Alphanumerical classificatand CX (Cx) arise from a single ostium in the anterior left sinus andfrom cranial-caudal aspect; (B) CT coronary angiogram; (C) schematAbbreviations as in Figures 1, 3, and 6.
tern and outcome of arterial switchoperation for transposition of the great
2
2002;29:279–89.
other coronary anomalies, both in isolation andwith associated CHD.
Reprint requests and correspondence: Dr. Edward Nicol,oyal Brompton Hospital and Harefield NHS Trust,ydney Street, London, SW3 6NP, United Kingdom.
, Shaher Type 1, Gittenberger AI, and
X arise from a single ostium in the anterior left sinus and right{AR[alACx;pR]}. Ao is anterior and right of the PA (AR). AD (A)ht coronary from the posterior aortic sinus. (A) VR image viewediagram (viewed in standard radiological [caudocranial] aspect).
and general prognosis in patients with TGA and E-mail: [email protected].
