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Ann Thorac Surg 2000;69:S249-S263
© 2000 The Society of Thoracic Surgeons
a Department of Surgery, Wayne State University School of Medicine, Children’s Hospital of Michigan, Detroit, Michigan, USA
b Department of Surgery, Northwestern University School of Medicine, Children’s Memorial Hospital, Chicago, Illinois, USA
c Department of Surgery, McGill University, The Montreal Children’s Hospital, Montreal, Quebec, Canada
d Department of Surgery, University of South Florida School of Medicine, All Children’s Hospital, St. Petersburg, Florida, USA
e Department of Surgery, Marie Lannelongue Hospital, Paris, France
f Department of Surgery, Hanneman University School of Medicine, St. Christopher’s Children’s Hospital, Philadelphia, Pennsylvania, USA
Address reprint requests to Dr Walters, Department of Cardiovascular Surgery, Children’s Hospital of Michigan, 3901 Beaubien Blvd, Detroit, MI 48201
e-mail: halwalters{at}aol.com
Presented at the International Nomenclature Conferences for Pediatric Cardiac Surgery, 1998–1999.
Abstract
Double outlet right ventricle (DORV) is a type of ventriculoarterial connection in which both great vessels arise entirely or predominantly from the right ventricle. Although the presence of aortic-mitral discontinuity and bilateral coni are important descriptors, they should not serve as absolute prerequisites for the diagnosis of DORV. The morphology of DORV is encompassed by a careful description of the ventricular septal defect (VSD) with its relationship to the semilunar valves, the great artery relationships to each other, the coronary artery anatomy, the presence or absence of pulmonary outflow tract obstruction (POTO) and aortic outflow tract obstruction (AOTO), the tricuspid-pulmonary annular distance, and the presence or absence of associated cardiac lesions. The preferred surgical treatment involves the connection of the left ventricle to the systemic circulation by an intraventricular tunnel repair connecting the VSD to the systemic semilunar valve. This ideal surgical therapy is not always possible due to the presence of confounding anatomical barriers. A multitude of alternative surgical procedures has been devised to accommodate these more complex situations. A framework for the development of the DORV module for a pediatric cardiac surgical database is proposed.
I. Background
Double outlet right ventricle (DORV) is a fascinating cardiac malformation encompassing a wide spectrum of anatomic arrangements and pathophysiologic disturbances. At one end of the spectrum, it mimics tetralogy of Fallot (TOF) in the presence of pulmonary stenosis, or a large ventricular septal defect (VSD) in the absence of such stenosis. At the other end of the spectrum, it behaves like transposition of the great arteries with a VSD. This extreme heterogeneity has led to a number of controversies over the years with respect to definition, classification type, and timing of surgical repair.
The purpose of this review is to discuss the historical aspects, the currently used nomenclature, the definition, the morphology, and the surgical treatment of DORV. A synthesis of this discussion has led us to an outline that will facilitate the creation of a pediatric cardiac surgery database. The database scheme is organized into a hierarchical form at the end of this article. Hierarchy levels 1 and 2 constitute a minimum data set. Data beyond these hierarchies constitute a more comprehensive data set.
Historical aspects and review of nomenclature
Until the second half of the 20th century, what we now call DORV was regarded as a type of transposition of the great arteries (TGA) [1]. In 1898, Vierordt used the term partial transposition for what we now call DORV, meaning that only one great artery was transposed (the aorta over the right ventricle) [2]. This was in distinction to complete transposition. In 1923, Spitzer reclassified transposition into 4 types. Type II is what he called simple transposition, which today is called DORV [3]. In 1939, Harris and Farber rejected what today is known as DORV from their reclassification of transposition [4]. In 1949, Taussig and Bing described a case of complete transposition of the aorta and levoposition of the pulmonary artery [5]. In 1950, Lev and Volk published a similar case calling the anomaly "the Taussig-Bing heart" [6]. All previously known cases of partial transposition had a subaortic VSD, with either pulmonary outflow tract obstruction (Fallot type) or without (Eisenmenger type). The Taussig-Bing heart had a subpulmonary VSD; thus, a newly recognized type of partial transposition was recognized. In 1952, Braun and associates reported a case of DORV with pulmonary stenosis and used the term double outlet ventricle [7]. However in 1957, it was Witham who introduced the term double outlet right ventricle as it is known today [8]. A factor contributing to the decline and abandonment of the term partial transposition in favor of DORV, was the discovery of double outlet left ventricle (DOLV) by Sakakibara and associates in 1967 [9], and its confirmation by Paul and associates in 1970 [10].
When the first repair of DORV with subaortic VSD, was confirmed by Kirklin and associates in 1957 at the Mayo Clinic, the diagnosis was only made at operation, and an intraventricular tunnel repair was performed. The term "origin of both great vessels from the right ventricle" was used and the surgical repair was described by McGoon in 1961 [11] and by Kirklin and associates in 1964 [12]. Early reports of successful surgical repair of the Taussig-Bing heart were by Daicoff and Kirklin in 1967 [13], by Patrick and McGoon in 1969 [14] and by Kawashima and associates in 1971 [15].
The earliest classification of DORV by Neufeld and associates [16, 17] was based on three considerations: (1) the relationship of the VSD to the crista supraventricularis; (2) the relationship of the VSD to the great arteries; and (3) the presence or absence of pulmonary stenosis; and is as follows:
In 1972, Lev and associates described DORV according to the relational anatomy between the VSD and the great arteries and this forms the basis of the most widely used classification of DORV today [18]:
Although this classification is useful, with physiological and surgical implications, it also has a number of important limitations. As pointed out by Lecompte and associates [19], Kirklin and Barratt-Boyes [20], and Castaneda and associates [21], there is no absolute correlation between the type of commitment of the VSD to the great arteries and the surgical option.
Definition
DORV represents a complex spectrum of congenital cardiac malformations that morphologically lie between VSD with overriding aorta and transposition of the great arteries with VSD. We define DORV as a type of ventriculoarterial connection in which both great vessels arise entirely or predominantly from the right ventricle [22]. Hearts with DORV and subpulmonary VSD (Taussig-Bing malformation) are considered a subset of DORV until the pulmonary artery arises predominately from the left ventricle; they are then considered a subset of TGA with VSD [23, 24]. Occasionally, DORV is associated with discordant [25] or univentricular [20] atrioventricular (AV) connections, AV valve atresia, or atrial isomerism [26]. This review is limited to DORV with usual atrial arrangements and concordant AV connections, and normally or near-normally sized ventricles.
DORV associated with discordant atrioventricular connections is presented in the "Corrected (Discordant) Transposition of the Great Arteries (and related malformations)" article by Wilkinson and colleagues in this supplement. Their article discusses and classifies the following lesions:
DORV associated with univentricular atrioventricular connections, atrioventricular valve atresia, or atrial isomerism is presented in the "Single Ventricle" article by Jacobs and Mayer in this supplement. Their article discusses and classifies the following lesions:
The ventriculoarterial relationship known as DORV is distinguished from other lesions, such as simple VSD with overriding aorta, or from TOF, because the VSD, in DORV, forms an integral part of the left ventricular outflow tract (LVOT). Simple straight patch closure of the VSD results in either isolation of the left ventricle from the semilunar valves or, at the very least, results in an obstructed LVOT. In true DORV, an anatomic repair, by definition, requires deliberate tunneling of the VSD to the systemic semilunar valve to create a widely patent LVOT. This is a practical and consistent morphological characteristic of DORV that separates it from other lesions with which it can be confused.
GUEST EDITORS’ NOTE: One area of controversy centers on the differentiation between TOF and DORV. This issue is addressed in the TOF article by Marshall L. Jacobs in this supplement with the following discussion:
"The distinction between DORV and TOF is controversial. Some authors use the term DORV when the pulmonary artery arises from the right ventricle and more than 50% of the aorta arises from the right ventricle. Other authors only use the term DORV when the pulmonary artery arises from the right ventricle and 90% or more of the aorta arises from the right ventricle. Still others use the term DORV only when there is absence of fibrous continuity between the aortic and mitral valves. In the DORV article of this publication, DORV is defined as a type of ventriculoarterial connection in which both great vessels arise predominantly from the right ventricle. It is inescapable that some hearts will be called TOF at some centers and DORV at other centers."
Over the years there have been proponents of either the 50% or the 90% requirement of great vessel override over the right ventricle before the malformation is called DORV. In a survey of several recent well-recognized textbooks, all currently refer to the 50% override rule [20, 21, 27, 28]. Even if one is to accept this rule, it may be difficult from a practical point of view to decide whether the aortic override is 40% or 60%. The differentiation between TOF and DORV with subaortic VSD and POTO, may not be that obvious. Cases will be invariably assigned as TOF by some and as DORV by others.
The same difficulty exists when one is trying to differentiate between TGA-VSD and the Taussig-Bing heart. On the other hand, we believe that no one will disagree that if there is less than 50% override, the lesion is not a DORV.
Whether the definition of DORV should include the presence of aortic-mitral discontinuity is controversial. Lev and associates define DORV as "that condition in which both arterial trunks emerge almost completely or completely from the right ventricle, and there may or may not be aortic-mitral or pulmonic-mitral continuity" [18]. Though exclusion of cases with aortic-mitral and pulmonic-mitral continuity is semantically pure, and provides a sharp dividing point between cases of TOF and DORV with subaortic VSD plus pulmonary stenosis, this concept does not satisfy the pathological data. In the transition from TOF to DORV with subaortic VSD plus pulmonary stenosis, there is a gradual diminution in the extent of normal aortic-mitral continuity until it is completely lost. Also, the pathologist sees a gradual transition from the Taussig-Bing heart without any overriding of the pulmonary trunk over the interventricular septum to those cases in which: there is slight overriding of the pulmonary trunk into the left ventricle; the pulmonary trunk emerges equally from both ventricles; the pulmonary trunk arises more from the left ventricle; and, there is complete TGA with VSD. During this process there is a gradual development of pulmonic-mitral continuity.
Another related controversy is whether bilateral coni must be present to categorize a lesion as DORV. This issue may have arisen from the original description of the Taussig-Bing heart [5, 29], which did indeed have bilateral and well-developed subpulmonary and subaortic muscular coni. That may have encouraged the application of this criterion of bilateral coni to the definition of all hearts with DORV. This concept was supported by the radiographic studies of Baron [30] and Hallerman and associates [31]; they used the criteria of separation of the aortic and mitral valve leaflets to distinguish radiologically between DORV and TOF. Howell and his colleagues [32], in an analysis of a selected group of hearts with an unequivocally complete origin of both great arteries from the morphologic right ventricle, stated that only 37.5% exhibited complete muscular and bilateral coni. They concluded that this criterion was a useful morphologic descriptor but was not an absolute requirement for classification as DORV. For the purposes of this review, we recommend including the infundibular morphology as a descriptor of DORV rather than as a prerequisite for it.
Our efforts to propose a precise definition of DORV are based on the desire to have an accurate and reproducible pediatric cardiac surgery database with the greatest amount of consensus, resulting in reliable and meaningful outcome studies for the variety of surgical procedures available. We can either propose very stringent criteria such as the 90% rule with the presence of aortic-mitral discontinuity, and bilateral coni a very liberal requirement of the 50% rule with none of the other two requirements. After several debates of the STS Congenital Heart Surgery Nomenclature and Database Committee, a consensus was reached, which was previously stated, and is repeated for emphasis:
DORV is a type of ventriculoarterial connection in which both great vessels arise either entirely or predominantly from the right ventricle.
This definition is deliberately broad and leaves it to each individual to decide if the great vessels arise "predominantly" from the right ventricle. Within the context of this definition, DORV can exist either in biventricular or univentricular hearts, with any AV connection and type of atrial arrangement. As previously stated, this review is limited to DORV with usual atrial situs and AV concordance.
Morphology
Sakata and Lecompte and their colleagues state that the classification and terminology of this complex group of patients with disorders of ventriculoarterial connection is less important than a precise definition of the preoperative anatomic criteria that are useful in determining the best type of surgical repair [33, 34]. Nonetheless, efforts to accurately categorize patients with DORV are necessary to make valid inferences regarding the results of different surgical treatments for comparable anatomic subsets. Approximately 86% of surgical patients with DORV have concordant AV connections [35]. AV discordance is present in 11% [25]. There may be atrial situs solitus, situs inversus, or left/right atrial isomerism [36, 37]. Hearts with DORV may have a muscular conus located beneath each of the semilunar valves (bilateral conus), a single conus beneath one of the semilunar valves, or no conus at all. As stated above, this review concentrates upon DORV with usual atrial arrangements and concordant atrioventricular connections.
Characteristics of the VSD
The VSD, which is an integral part of the outflow tract from the morphologic left ventricle, is usually unrestrictive (diameter equal to or larger than the diameter of the aortic annulus). The VSD is restrictive in at least 10% of the cases although others have reported this important surgical finding in as many as 62% [38]. Very rarely, however is there no interventricular communication [39]. When there is no VSD, mitral valve and left ventricular hypoplasia usually coexist, and a small atrial septal defect serves as the only source of a left-to-right shunt. In 13% of all cases of DORV the VSDs are multiple [20].
Location of the VSD
The actual anatomic location of the VSD in DORV is fairly constant. Most of these defects are conoventricular; they lie nestled within the anterior and posterior limbs of the trabeculoseptomarginalis (TSM or septal band). These VSDs are not conoventricular when they are located in the inlet septum, the trabecular portion of the muscular interventricular septum or when a perimembranous VSD extends inferiorly to occupy the inlet septum. In these rare cases the VSD is typically noncommitted, difficult to repair with an intraventricular tunnel, and can be associated with any relationship of the great arteries.
Relationship of the VSD to the semilunar valves
The VSD in DORV is usually described in relational terms as subaortic, subpulmonary, doubly-committed, or noncommitted [18]. This relationship of the VSD to the semilunar valves has special surgical, rather than anatomic or embryological, significance. These terms do not imply that the VSD moves around within the interventricular septum. To the contrary, this important relationship of the VSD to the semilunar valves depends more upon the highly variable relationships of the great arteries to each other, and upon the orientation and size of the infundibular (conal) septum. In DORV the terms subaortic or subpulmonary do not necessarily imply that one of the borders of the VSD is formed by a semilunar valve (juxtaaortic, juxtapulmonary, or juxtaarterial). This distinction between the location of the VSD within the interventricular septum, and its relationship to the semilunar valves, is important to a complete understanding of this disorder.
Subaortic VSD
Subaortic VSDs are the most common type, and occur in approximately 50% of surgical patients with DORV [20]. They are located beneath the aortic valve and are separated from the valve by a variable distance, depending upon the presence and length of the subaortic conus. When a subaortic conus is absent (by definition aortic-mitral continuity is present), the left cusp of the aortic valve or the base of the anterior leaflet of the mitral valve forms the actual posterosuperior margin of the VSD (juxtaaortic) [20]. Typical subaortic VSDs in hearts with a right-sided aorta are located in the superior interventricular septum, posterior to the infundibular septum. VSDs are usually perimembranous. They reach the annulus of the tricuspid valve at its anteroseptal commissure and there is mitral-tricuspid continuity at the posteroinferior rim of the defect. Occasionally, the posterior margin of the VSD is separated from the base of the tricuspid valve by a rim of muscular tissue. This represents fusion of the ventriculoinfundibular fold and the posterior limb of the TSM. The VSD can extend inferiorly from the perimembranous region to lie partly beneath the base of the septal leaflet of the tricuspid valve [40]. In an autopsy series, 77% of patients with DORV and subaortic VSDs had a bilateral conus, and 23% had only a subpulmonary conus [20]. Most hearts with aortic-mitral valvar continuity will have subaortic or doubly committed VSDs, and most with pulmonic-mitral valvar continuity will have subpulmonary VSDs [32].
When DORV is associated with L-malposition of the aorta, the VSD is usually subaortic. Although still nestled within the limbs of the TSM, the VSD lies more anteriorly and superiorly within the muscular interventricular septum than it does when the aorta is in its usual position on the right side. Typically the superior border of the VSD is the aortic valve (juxtaaortic), and its inferior and posterior borders are formed by the anterior and posterior limbs of the TSM respectively. The VSD can extend to the annulus of the tricuspid valve posteriorly and be perimembranous. Rarely in DORV with L-malposition of the aorta, the VSD can be subpulmonary [41], noncommitted [42], or doubly committed [43].
Doubly-committed VSD
Doubly-committed VSDs occur in approximately 10% of DORV surgical series [44]. The VSD lies within the divisions of the TSM superiorly in the interventricular septum and immediately beneath the leaflets of the aortic and pulmonary valves (juxtaarterial). The pulmonary and aortic valves generally are contiguous, because the infundibular septum is deficient or absent. The semilunar valves form the superior border of this typically large VSD. The TSM, with its anterior and posterior divisions, make up its anterior, inferior, and posterior borders. There can be bilaterally deficient coni, combined with an absent or deficient infundibular septum, or a single conus may exist beneath the two semilunar valves [20].
Subpulmonary VSD (Taussig-Bing)
The overwhelming majority of hearts with DORV, with subpulmonary VSD, have no pulmonary stenosis (PS) and are of the Taussig-Bing type. Those very rare hearts with DORV, and subpulmonary VSD and PS are not of the Taussig-Bing type. Subpulmonary VSDs are present in approximately 30% of patients in surgical series of DORV [24, 44]. These VSDs are usually unrestrictive. They lie anteriorly and superiorly beneath the pulmonary valve in the interventricular septum and are cradled within the limbs of the TSM. This VSD position is similar to that described for DORV with L-malposition of the aorta. In the presence of a subpulmonary conus the VSD is separated from the pulmonary valve by a variable distance, and the conus forms the superior boundary of the VSD. If there is pulmonary-mitral continuity (no subpulmonary conus), the pulmonary valve will override the VSD to a variable extent and will form its superior border (juxtapulmonary). The infundibular (conal) septum is sagittally oriented, and extends from the interventricular septum to the anterior wall of the right ventricle. So oriented, the infundibular septum does not actually constitute part of the interventricular septum, but separates the VSD and subpulmonary region from the subaortic region. This commits the VSD to the pulmonary artery. Hypertrophy of the infundibular septum and the parietal band can cause varying degrees of subaortic obstruction. This may account for the relatively common occurrence of aortic arch obstruction in the Taussig-Bing malformation. Bilateral coni or a single, subaortic conus each occur in approximately 50% of hearts with the Taussig-Bing malformation [20]. The pulmonary artery typically arises biventricularly. The aorta is usually to the right, and is slightly anterior to, or side-by-side with the pulmonary artery. These two great vessels are usually parallel. They do not spiral around each other as in the normal heart.
Noncommitted (remote) VSD
Noncommitted (remote) VSDs occur in 10% to 20% of patients in surgical series [24, 44]. These defects are far removed from both the aortic and pulmonary valves, are not nestled within the limbs of the TSM, and are located within the inlet septum without perimembranous extension or trabecular interventricular septum [45, 46]. Many of these noncommitted (remote) VSDs are in fact in hearts with DORV and CAVC (complete atrioventricular septal defect or CAVSD).
Great artery relationships
There are two basic patterns of the relationship of the great arteries to each other in DORV, spiraling and parallel. In most cases the great arteries are normally related to one another. The aortic trunk is situated posteriorly and to the right of the pulmonary trunk, and the two great arteries spiral around each other as they leave the base of the heart. In this case, the VSD is almost always found in a subaortic position. In the second group the aorta and pulmonary artery are parallel to each other (do not spiral). When the great arteries are parallel to each other, there can be any degree of anteroposterior variation of the aorta around the pulmonary artery. The aorta can be rightward and side-by-side with the pulmonary artery, rightward and anterior to the pulmonary artery, directly anterior to the pulmonary artery and, finally, the aorta can be leftward and anterior to the pulmonary artery (L-malposition). The VSD is usually subpulmonary when the great vessels are parallel and side-by-side. L-malposition is the least common great vessel orientation [47, 48]. In this subset the VSD is usually subaortic. Pulmonary stenosis usually accompanies L-malposition, and is complicated by the tendency for the right coronary artery to cross the pulmonary outflow tract (POT) on its way to the right AV groove. Although the relationship of the VSD to the semilunar valves can often be predicted by the relationships of the great arteries to each other, these are only generalizations. In fact, this relational anatomy of the VSD in hearts with DORV is independent of the relationships of the great arteries to each other [27].
Pulmonary outflow tract obstruction
All of the variations of POTO that are present in hearts with TOF can be present in hearts with DORV. POTO is most common in hearts with subaortic or doubly committed VSDs. It is uncommon in patients with the Taussig-Bing malformation and in those with noncommitted defects. Although POTO is most often infundibular, it can also be purely valvular with or without a small pulmonary valve annulus and hypoplasia of the central pulmonary arteries. DORV can occur in association with pulmonary atresia.
Subaortic stenosis
Subaortic stenosis is an uncommon, but clinically important feature of DORV. It occurs most often in those patients with subpulmonary VSD; 35% of the Taussig-Bing hearts in Sondheimer’s series [35]. It is especially common in Taussig-Bing hearts with aortic arch obstruction [49]. In this setting, the subaortic stenosis is usually due to a hypoplastic left ventricular (aortic) outflow tract. Subaortic stenosis can also be caused by AV valve tissue, by accessory tissue tags or by hypertrophied muscle bundles. Aortic valvular stenosis or atresia can also be present.
Conduction system
In DORV with concordant AV connections, the AV node lies in the usual position in the muscular portion of the AV septum. The bundle of His penetrates the fibrous right trigone of the central fibrous body and lies along the posteroinferior margin of the VSD in lesions that are juxtatricuspid (perimembranous) whether the defect is subaortic, doubly committed, or subpulmonary. When muscle is interposed between the defect and the tricuspid valve, this muscle protects the bundle, which no longer runs along the posteroinferior free margin of the defect.
Coronary artery anatomy
In most cases of DORV, the coronary orifices are rotated clockwise as the observer looks from above. Hence, the left coronary artery arises more posteriorly and the right coronary artery (RCA) arises more anteriorly. With a right-sided and anterior aorta, the coronary artery pattern is similar to that seen in complete TGA. The right coronary artery arises from the posterior (facing) sinus (sinus 2) and the left coronary artery arises from the anterior (facing) sinus (sinus 1). Nineteen (30%) of Wilcox’s patients with DORV had coronary artery abnormalities [50]. Two (3%) patients had a single coronary artery, one arising from sinus 1 and one from sinus 2. The branching pattern of the coronary arteries is usually normal; however, in Wilcox’s series the left anterior descending coronary artery (LAD) arose from the RCA and ran anteriorly beneath the pulmonary valve across the right ventricular outflow tract in 16 (25%) patients. In all of the 3 (5%) hearts with L-malposition of the aorta in Wilcox’s series, the RCA crossed anteriorly beneath the pulmonary valve on its way to the right atrioventricular groove.
Associated cardiac abnormalities
Almost any anomaly of the atrioventricular valves can complicate DORV and, when severe, create formidable obstacles to the performance of an anatomic repair. Examples of such anomalies include AV valve stenosis and atresia, straddling, and complete AV canal defect [51, 52]. Coarctation of the aorta and other forms of aortic outflow tract obstruction (AOTO) are more common in hearts with the Taussig-Bing malformation [35]. Various other cardiac abnormalities including patent ductus arteriosus, ventricular hypoplasia (especially associated with AV valve abnormalities), unroofed coronary sinus syndrome, abnormalities of systemic venous return, juxtaposed atrial appendages, situs inversus totalis, dextrocardia, and atrial septal defect can occur.
Database requirements for the morphologic description of DORV
The database requirements for the morphological description of DORV can be divided into the following headings: the VSD, the POT, the great artery relationships, the coronary artery anatomy, the conal anatomy, the aortic outflow tract (AOT), the tricuspid-pulmonary annular distance and all other associated cardiac abnormalities.
For the minimal data set, DORV is classified as VSD type (subaortic and doubly-committed VSDs without POTO), TOF type (subaortic and doubly committed VSDs with POTO), TGA type (subpulmonary VSDs-Taussig-Bing) and remote VSD type (noncommitted VSDs with or without POTO). This scheme was chosen for the minimal data set because, in a concise way, it conveys a broad sense of the VSD relational anatomy and also groups DORV patients according to the general approach to their surgical repair [53]. The relational anatomy of the VSD (subaortic, doubly-committed, subpulmonary, and noncommitted) is described in more detail in the second hierarchy along with the presence or absence of POTO. Whereas the relational VSD terms are widely accepted, the positional descriptors are more diverse and controversial. Positional descriptors of VSD location in DORV should be identical to the nomenclature adopted by the database committee for VSD not associated with DORV. These terms should be descriptive, anatomically precise, and universal. These positional descriptors of VSD location are presented in the "Ventricular Septal Defect" manuscript by Jacobs and colleagues in this supplement.
The coronary artery anatomy in DORV is best described along with an assignment of the great arteries to one of the five possible great artery relationships. Hence, the great arteries are described as spiraling around each other in the usual relationship, or they are described as being in a parallel configuration with any degree of anteroposterior variation: 1) parallel with the aorta rightward and side-by-side, 2) parallel with the aorta rightward and anterior, 3) parallel with the aorta directly anterior, or 4) parallel with the aorta leftward and anterior (L-malposition). These various configurations can be illustrated using a schematic diagram in the database.
The coronary artery anatomy is described according to the system adopted by the database committee for describing the coronary artery anatomy associated with TGA. This coronary anatomy nomenclature is discussed in the "Transposition of the Great Arteries" article by Jaggers and colleagues in this supplement.
The presence or absence of a conus (or coni), preoperative AOTO, the tricuspid-pulmonary annular distance, and the presence of associated cardiac abnormalities should be documented in the comprehensive database as additional, important preoperative morphologic variables.
Surgical treatment and results
DORV, VSD type (with subaortic or doubly-committed VSD without pulmonary stenosis)
An intraventricular tunnel repair, connecting the left ventricle to the aorta, is preferred. Rarely, in patients with refractory congestive heart failure, who are not thought to be immediate candidates for complete repair, a pulmonary artery banding is required. During an intraventricular tunnel repair, if the VSD appears to be restrictive (diameter less than that of the aortic valve), it is enlarged by making an incision anterosuperiorly or by resecting a wedge of the interventricular septum in this area. Prominent right ventricular muscle bundles can be resected if necessary. Occasionally, a portion of the infundibular septum must be resected to construct a straight tunnel between the VSD and the aorta. It is usually possible to construct a tunnel from the left ventricle to the aorta without obstructing the POT.
Complications after the intraventricular tunnel repair of DORV with subaortic or doubly-committed VSD without pulmonary stenosis are rare. Complete heart block is uncommon, and the functional status of at least 87% of the survivors is New York Heart Association class I. Complications requiring reoperation have included subaortic obstruction (tunnel related and nontunnel related), POTO and residual VSD [24, 54].
DORV, tetralogy type (with subaortic or doubly-committed VSD with pulmonary stenosis)
In the presence of pulmonary stenosis, the techniques of repair are similar to those described for repair of TOF, except the VSD is closed with the tunnel technique rather than with a straight patch. If the branch pulmonary arteries are severely hypoplastic or it is felt that an extracardiac conduit will be required for the final correction, a palliative systemic-to-pulmonary artery shunt may be preferred by some prior to performing the definitive repair later in life. In patients with an anomalous coronary artery crossing the right ventricular (pulmonary) outflow tract immediately beneath the pulmonary valve annulus and in older patients with long-standing systemic artery to pulmonary artery shunts accompanied by significant pulmonary vascular disease, it is necessary to place a valved, extracardiac conduit when endocardial resection alone will not relieve the right ventricular (pulmonary) outflow tract obstruction. Patients with pure valvular pulmonary stenosis and a normal pulmonary annulus and arterial tree, can undergo pulmonary valvotomy or valvectomy. Similar patients with mild to moderate pulmonary vascular disease may benefit from the orthotopic placement of a pulmonary valve prosthesis.
Database requirements for the surgical treatment of DORV, VSD type or tetralogy type (with subaortic or doubly-committed VSD with or without pulmonary stenosis)
Surgical treatment of DORV with subaortic or doubly-committed VSD, with or without pulmonary stenosis, may require any of a number of procedures as outlined in the foregoing discussion. These procedures are classified as palliative or biventricular.
DORV, TGA type (with subpulmonary VSD, Taussig-Bing malformation)
Many approaches to the repair of this complex subset of patients with DORV have been employed: (1) patch tunneling of the VSD to the pulmonary artery combined with an atrial switch procedure (Mustard or Senning) [23]; (2) tunneling of the VSD to the pulmonary artery, aortopulmonary connection (Damus-Kaye-Stansel procedure) and placement of a valved extracardiac conduit from the right ventricle to the distal pulmonary artery [55]; (3) direct tunneling of the VSD to the aorta [23]; (4) tunneling of the VSD to the pulmonary artery combined with an arterial switch procedure [56]; and, in selected situations; and (5) tunneling of the VSD to the aorta with translocation of the pulmonary artery (Reparation l’etage Ventriculaire—REV procedure of Lecompte) [57, 58].
Tunneling of VSD to pulmonary artery with atrial switch
Patch tunneling of the VSD to the pulmonary artery combined with an atrial switch procedure is a technique with little clinical application today.
Damus-Kaye-Stansel procedure, tunnel closure of VSD and right ventricle to pulmonary artery conduit
Tunneling of the VSD to the pulmonary artery, aortopulmonary connection with closure of the aortic valve and placement of a valved, extracardiac conduit from the right ventricle to the distal pulmonary artery [55, 59] was first described by Smith and colleagues [59] for the repair of DORV with subpulmonary VSD. There are few current applications for this procedure in the treatment of the Taussig-Bing malformation given the wide applicability of the tunnel procedure and the arterial switch procedure.
Total or partial intraventricular tunnel repairs for the Taussig-Bing malformation
The most attractive alternative for the repair of DORV with subpulmonary VSD is a totally intraventricular repair without the need for the arterial switch operation or for the use of an extracardiac conduit. This type of repair has been accomplished utilizing a number of techniques: (1) posterior, tubular conduit repair of Abe [60]; (2) anterior, tubular conduit method of Doty [61]; (3) anterior, spiral tunnel repair of Patrick and McGoon [62]; and (4) posterior, straight tunnel technique of Kawashima [63].
The Abe and Doty techniques
Two techniques, requiring the use of either a totally or partially tubular intraventricular conduit to tunnel the VSD directly to the aorta, have been described in the literature. Abe and colleagues [60] advocated the placement of a tubular, intraventricular conduit posterior to the pulmonary artery when the great arteries were side by side. For great arteries that are in a more anterior-posterior relationship, Doty reported the construction of a pathway from the VSD directly anteriorly, along the septum, to the free wall of the right ventricle. A tubular and partially intraventricular conduit is brought sharply back to the right and anterior to the pulmonary artery. It is then sutured directly to the subaortic conus [61]. The conduit is actually sutured within the anterior wall of the right ventricle, and thus serves as a right ventricular outflow patch. Because the native aortic valve is left in place, a valveless conduit is used. These techniques are no longer recommended for the repair of any of the subsets of the Taussig-Bing malformation.
The Patrick-McGoon techniques
Two techniques for the repair of DORV with subpulmonary VSD have been described using an intraventricular tunnel, the Patrick-McGoon method and the Kawashima operation. The technique of Patrick and McGoon [62] was developed to repair the subset of patients who have obliquely or anteroposteriorly-related great arteries. It involves the formation of a long and geometrically complex intraventricular tunnel. This tunnel courses to the left of, and anterior to, the pulmonary valve to connect the VSD directly to the aorta. Because of its leftward course around the pulmonary artery, the construction of this tunnel is not dependent upon the distance between the tricuspid and pulmonary valves. This technique often requires enlargement of the VSD, even when it is unrestrictive. The Patrick-McGoon repair has been replaced by the arterial switch operation, as the procedure of choice, in this subset of patients.
The Kawashima operation
When the great arteries are in a more or less side-by-side relationship with the aorta to the right of the pulmonary artery, the Kawashima [63] repair connects the left ventricle directly to the aorta with a tunnel that runs posterior to the pulmonary artery between the tricuspid and pulmonary valves. The infundibular (conal) septum must be resected in order to provide an unobstructed path for the tunnel. The VSD is enlarged only if it is restrictive. Because this tunnel courses between the pulmonary and tricuspid valve annuli, these two structures must be separated by a sufficient distance to make tunnel creation possible. The minimal distance between the tricuspid valve annulus and the pulmonary valve annulus must be equal to or greater than the diameter of the aortic valve annulus. Preoperatively, this distance can generally be estimated accurately with the subxiphoid view of the two-dimensional echocardiogram [33, 34]. Sometimes the dimensions of the right ventricular (pulmonary) outflow tract must be augmented with an outflow patch because of the production of right ventricular (pulmonary) outflow tract obstruction by the intraventricular tunnel. In patients with an oblique or anterior-posterior relationship of the great arteries, the tricuspid-pulmonary valve distance may not be great enough to allow the creation of this tunnel, and the arterial switch technique must be employed [64].
Arterial switch operation with tunnel closure of VSD
The most common approach to the repair of DORV with subpulmonary VSD, is the arterial switch procedure combined with tunnel closure of the VSD to the pulmonary artery [56]. This technique has been used successfully for the repair of Taussig-Bing hearts with any arrangement of the great arteries.
Reparation l’etage ventriculaire (REV)
The Lecompte (REV) intraventricular repair [33, 34, 57] is designed for patients with abnormalities of ventriculoarterial connection in whom a standard intraventricular tunnel repair can not be performed. It is also suitable for patients in whom an arterial switch procedure with tunneling of the VSD to the pulmonary artery can not be performed because of pulmonary (LVOT) stenosis. Because REV results in pulmonary regurgitation, its use may best be restricted to patients with preoperative pulmonary stenosis and associated low pulmonary artery pressure. These patients tolerate the absence of a pulmonary valve better than patients who have had unrestricted pulmonary blood flow preoperatively [34].
The initial stages of the REV procedure are the same as those used for the arterial switch procedure. A vertical right ventriculotomy is then performed. The VSD is then tunneled to the aorta. The pulmonary artery is translocated to the right ventricular outflow tract and the pulmonary artery orifice is closed. A vertical incision is made on the anterior aspect of the main pulmonary artery. The posterior margin of the pulmonary artery is sutured to the superior aspect of the vertical right ventriculotomy incision. A generous patch of autologous pericardium is used to close the inferior portion of the right ventriculotomy and the anterior portion of the pulmonary artery. A monocusp pericardial valve may be inserted extemporaneously to minimize postoperative pulmonary regurgitation [34].
The Nikaidoh procedure
The Nikaidoh aortic translocation and biventricular outflow tract reconstruction technique [65] could be applied to patients with DORV, or TGA with VSD, who are not candidates for the arterial switch procedure because of pulmonary (future LVOT) obstruction. The inspiration for this procedure was derived from the aortoventriculoplasty of the Konno procedure and the aortic translocation procedure described by Bex and his colleagues for the treatment of TGA with intact ventricular septum [66].
The aortic root is detached from its right ventricular origin. The main pulmonary artery is transected just above the pulmonary valve commissures and the pulmonary valve is excised. The pulmonary root is divided longitudinally through the interventricular septum and into the lumen of the VSD, to open the subpulmonary area. The aortic root is both translocated and sutured posteriorly in two layers to the widely opened native pulmonary annulus. The LVOT tract is reconstructed by closing the VSD to the anterior circumference of the posteriorly translocated aorta. The right ventricular outflow tract is reconstructed by suturing a patch to the ventriculotomy, extending it over the anterior aortic root and suturing it to the distal end of the transected main pulmonary artery trunk.
Database requirements for the surgical treatment of DORV, TGA type (with subpulmonic VSD, Taussig-Bing malformation)
In the following sections, all possible surgical procedures used in the treatment of DORV with subpulmonary VSD are categorized as either palliative or biventricular. Some of these procedures, as explained above, are primarily of historical significance. All of these procedures should be included in a comprehensive database to allow the enrollment of patients who have undergone these procedures in the past when they were more widely employed.
DORV, remote VSD type (with noncommitted VSD)
These patients often have an inlet (AV canal type) VSD. Although some can undergo an intraventricular tunnel repair [46], it is occasionally necessary to enlarge the VSD superiorly and anteriorly to make this possible. If the intraventricular tunnel obstructs the right ventricular outflow tract, it may be necessary to place a transannular patch or a valved, extracardiac conduit. If it is necessary to place the pulmonary artery on the left ventricular side of the patch, right ventriculoarterial continuity can be reestablished with the REV procedure or by placing a valved, extracardiac conduit. When the anatomy requires that the VSD be closed to the pulmonary artery, this can be performed in concert with an arterial switch procedure, if there is no associated pulmonary stenosis. Intraventricular tunnel repair is not possible when the tensor apparatus of the tricuspid valve spans the VSD, when the VSD is located in the trabecular septum, or when there are multiple VSDs. In this situation, if there is associated pulmonary stenosis, a systemic-to-pulmonary artery shunt may be necessary for clinically significant cyanosis. A bidirectional cavopulmonary anastomosis is performed at approximately 6 months of age, followed by a completion total cavopulmonary connection at 1 to 2 years of age. When there is no associated pulmonary stenosis, the pulmonary vasculature is protected by placing a pulmonary artery band as a neonate. At appropriate intervals, a bidirectional cavopulmonary anastomosis and a completion total cavopulmonary connection are performed, as described above.
Surgical series of DORV with noncommitted VSD are generally small [20, 24, 54]. In one study, the presence of a noncommitted VSD was found to be related to the need for reoperation. Reoperations were performed for AOTO, POTO, and residual VSD.
Database requirements for the surgical treatment of DORV, remote VSD type (with noncommitted VSD)
In the following sections, all possible surgical procedures used in the treatment of DORV with noncommitted VSD are categorized as either palliative or biventricular.
Database requirements for materials used in the surgical repair of DORV
A wide variety of materials can legitimately be used for the repair of DORV. These are listed in the following sections. A comprehensive database should contain a field for entry of the material used in all phases of any operation employed for the surgical treatment of all congenital cardiac malformations. This would allow for analyses of the effect of various materials on the results of the various surgical repairs.
Risk factors and outcome reports
The following section includes a list of risk factors and outcome reports that should be included in the database.
II. Analysis: a unified nomenclature system
DORV hierarchy level 1
DORV hierarchy level 2
DORV hierarhy level 3
DORV hierarchy level 4
Additional modifiers for DORV
Great artery relationships (GAR)
Although there can be a large number of great artery relationships in DORV, we have characterized five choices for this database.
Aortic outflow tract obstruction
Aortic outflow tract obstruction significantly affects outcome in patients with DORV. The obstruction can be subvalvar, valvar, or aortic arch related and these obstructions can be isolated or in various combinations.
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Aortic outflow obstruction is difficult to define in the presence of a ductal dependant circulation, even with a cardiac catheterization. In the most severe of Taussig-Bing hearts, there is panaortic outflow tract obstruction,which usually requires arch reconstruction and occasional right ventricular outflow tract reconstruction (with or without a homograft valved conduit), if an arterial switch operation is performed. Guidelines referable to left ventricular outflow tract obstruction, in neonates with normally related arteries and ventricles, should apply to evaluation of aortic outflow tract obstruction in these patients.
Conus
Tricuspid annulus-pulmonary annulus distance (TPAD)
Additional comments regarding DORV
Positional VSD anatomy
The positional anatomy of the VSD should be entered in the database according to the proposal outlined by Jacobs and colleagues in their "Ventricular Septal Defect" article in this supplement. The VSD type(s) in DORV can be coded in hierarchical detail utilizing the coding system presented in the VSD article of this publication. This hierarchical VSD coding can be entered into a comprehensive database as an additional or secondary diagnosis(es) under the primary DORV diagnosis.
Coronary artery anatomy
The coronary artery anatomy associated with DORV, TGA type should be entered according to the hierarchical database scheme presented by Jaggers and colleagues in their "Transposition of the Great Arteries" article included in this supplement. The coronary artery anatomy associated with DORV, TOF type however, can be coded in hierarchical detail utilizing the coding system presented by Dodge-Khatami and colleagues in their "Anomalies of the Coronary Arteries" article of this supplement. This hierarchical coronary artery anomalies coding can be entered into a comprehensive database as an additional or secondary diagnosis under the primary DORV diagnosis.
Other cardiac anomalies
Associated cardiac anomalies in patients with DORV are numerous. These associated defects are best coded as additional diagnoses in the appropriate section of the database. Examples of this are, patent ductus arteriosus, coarctation of the aorta, interrupted aortic arch, juxtaposed atrial appendages, and anomalies of pulmonary and systemic venous connections, to name a few.
III. Nomenclature for treatment options
DORV treatment comprehensive hierarchical nomenclature
This section will synthesize a formal hierarchical nomenclature strategy for treatment options for DORV, consistent with that in other manuscripts. In addition to the basic treatment options for DORV, several other therapeutic issues must be addressed and coded in other areas of the database. First, a separate part of the database must allow for coding of incisions, for this and all other diagnoses (median sternotomy, submammary incision, right thoracotomy, left thoracotomy, minimally invasive incisions, including partial sternotomy, parasternal incision, and minithoracotomy, etc). Second, a separate part of the database must allow for coding of cardiac incisions for this and all other diagnoses, including aortotomy, pulmonary arteriotomy, right atriotomy, right ventriculotomy, left ventriculotomy, etc. Third, a separate module of the database must permit coding of patch materials conduit type, conduit materials, conduit size, and use of other biologic or prosthetic materials.
Procedures directed at associated lesions (thymectomy, closure of patent foramen ovale, closure of atrial septal defect, etc) can be coded as additional or secondary procedures under the primary DORV procedure.
Details regarding management of cardiopulmonary bypass, myocardial protection, and associated issues will be recorded in another related and linked module of the database.
Finally, the various modifications of the bidirectional cavopulmonary anastomosis, hemifontan, and Fontan procedures are described in detail in the "Single Ventricle" article of this publication by Jacobs and colleagues, and are not represented in detail in this article. Obviously, the hierarchical description of these procedures described in detail in the "Single Ventricle" article may be applied to certain forms of DORV.
DORV treatment hierarchy level 1
DORV, treatment hierarchy level 2
DORV, treatment hierarchy level 3
Comments on DORV, treatment hierarchy level 3
DORV repair, arterial switch operation with tunneling of VSD to neoaortic valve
urther coding to document the different VSD types, coronary artery anatomy, and operative characteristics concerning the arterial switch operation can be accomplished in the VSD and TGA sections of this database, respectively.
DORV repair, reparation l’etage ventriculaire (REV procedure)
A separate module of the database must permit coding of patch materials, conduit type, conduit materials, conduit size, and use of other biologic or prosthetic materials.
DORV repair, Rastelli procedure
A separate module of the database must permit coding of patch materials conduit type, conduit materials, conduit size, and use of other biologic or prosthetic materials.
DORV repair, Nikaidoh procedure
A separate module of the database must permit coding of patch materials, conduit type, conduit materials, conduit size, and use of other biological or prosthetic materials.
Additional comments regarding DORV therapeutics
There are a number of therapeutic choices in this hierarchical scheme that are rarely used nowadays. For instance, the intraventricular tunnel techniques of Abe, Doty, and Patrick and McGoon, are included largely for historical purposes. The same is true for VSD closure with atrial baffle and the Damus-Kaye-Stansel procedure. Users of the database may want to enter these operations from their historical files. Their inclusion in this database scheme will allow that possibility.
IV. Diagnosis and procedure short lists
V. Potential diagnostic related risk factors
VI. Database studies and outcome analysis
References
This article has been cited by other articles:
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  S. P. Goldberg, A. C. McCanta, D. N. Campbell, E. V. Carpenter, D. R. Clarke, E. da Cruz, D. D. Ivy, and F. G. Lacour-Gayet Implications of incising the ventricular septum in double outlet right ventricle and in the Ross-Konno operation Eur. J. Cardiothorac. Surg., April 1, 2009; 35(4): 589 - 593. [Abstract] [Full Text] [PDF]
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|
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B. Alsoufi, S. Cai, W. G. Williams, J. G. Coles, C. A. Caldarone, A. M. Redington, and G. S. Van Arsdell Improved results with single-stage total correction of Taussig-Bing anomaly Eur. J. Cardiothorac. Surg., February 1, 2008; 33(2): 244 - 250. [Abstract] [Full Text] [PDF]
|
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|
|
 |
|
 A. K. Dharmapuram, S. Sundararaghavan, S. K. Swain, N. Ramdoss, P. Reddy, V. Okwulehie, R. Agarwal, and K. S. Murthy Morphosurgical correlation of outcomes in complete double outlet right ventricle Interactive CardioVascular and Thoracic Surgery, October 1, 2006; 5(5): 566 - 569. [Abstract] [Full Text] [PDF]
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J. H. Artrip, H. Sauer, D. N. Campbell, M. B. Mitchell, C. Haun, M. C. Almodovar, V. Hraska, and F. Lacour-Gayet Biventricular repair in double outlet right ventricle: surgical results based on the STS-EACTS International Nomenclature classification. Eur. J. Cardiothorac. Surg., April 1, 2006; 29(4): 545 - 550. [Abstract] [Full Text] [PDF]
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|
 |
|
 R. P. Beekman, M. M. Bartelings, M. G. Hazekamp, A. C. Gittenberger-de Groot, and J. Ottenkamp The morphologic nature of noncommitted ventricular septal defects in specimens with double-outlet right ventricle J. Thorac. Cardiovasc. Surg., November 1, 2002; 124(5): 984 - 990. [Abstract] [Full Text] [PDF]
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F. Lacour-Gayet, C. Haun, K. Ntalakoura, E. Belli, L. Houyel, P. Marcsek, F. Wagner, and J. Weil Biventricular repair of double outlet right ventricle with non-committed ventricular septal defect (VSD) by VSD rerouting to the pulmonary artery and arterial switch Eur. J. Cardiothorac. Surg., June 1, 2002; 21(6): 1042 - 1048. [Abstract] [Full Text] [PDF]
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 |
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 J. D. Crispino, M. B. Lodish, B. L. Thurberg, S. H. Litovsky, T. Collins, J. D. Molkentin, and S. H. Orkin Proper coronary vascular development and heart morphogenesis depend on interaction of GATA-4 with FOG cofactors Genes & Dev., April 1, 2001; 15(7): 839 - 844. [Abstract] [Full Text]
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