Double Outlet Right Ventricle: Opinions Regarding ManagementFrank Cetta, MD*

Umar S. Boston, MDJoseph A. Dearani, MDDonald J. Hagler, MD

Address*Divisions of Pediatric Cardiology, Cardiovascular Diseases and Cardiovascular Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.E-mail: cetta.frank@mayo.edu

Current Treatment Options in Cardiovascular Medicine 2005, 7:385–390Current Science Inc. ISSN 1092-8464Copyright © 2005 by Current Science Inc.

IntroductionDouble outlet right ventricle (DORV) is a congenitalcardiac lesion that encompasses a large spectrum ofcongenital cardiac anatomy and physiology. From apurely anatomic perspective, the terminology “DORV”

indicates that greater than 50% of each great arteryarises from the morphologic right ventricle (Fig. 1) [1].The frequency of this lesion has been reported as0.09 cases per 1000 live births and represents 1.0% to

Opinion statementIn the current era of superb surgical results for congenital heart disease, several management options are available for patients born with double outlet right ventricle (DORV). The surgical repair of DORV is tailored to address the variety of abnormalities associated with this lesion. The treatment strategies are dependent upon the anatomy and relationship of the ventricular septal defect (VSD) and the great arteries. For patients with subaortic or doubly committed VSDs, without right ventricular outflow tract obstruction, the usual repair is an intraventricular tunnel from the VSD to the aorta. If right ventricular outflow tract obstruction exists, then augmentation of the right ventricular outflow tract or conduit placement from the right ventricle to the pulmonary artery is necessary. For the “Taussig-Bing anomaly” (subpulmonary VSD) an arterial switch operation is indicated with tunneling of the VSD to the neoaorta. For patients with a remote VSD, complex atrioventricular valve abnormalities, or unbalanced ventricles, a staged palliative approach is warranted. This approach will result in the patient having “single ventricle” physiology, and “Fontan anatomy” after the staging surgeries. Outcomes are determined by the surgery performed. Patients who require conduit placement from right ventricle to pulmonary artery will need subsequent surgery for replacement of the conduit. Complex intraventricular tunnels are at risk for develop-ing subaortic obstruction. Patients who had arterial switch operations have thus far had excellent results. However, these patients may be at risk for development of neoaortic valve regurgitation requiring subsequent reoperation. Complex biventricular intracardiac repairs have been associated with a higher risk of reoperation. In the past 10 to 15 years, patients undergoing Fontan operations have had improved early and late survival. However, long-term problems after the Fontan operation include arrhythmia and development of protein-losing enteropathy.

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1.5% of patients with congenital heart disease. DORVhas no gender or ethnic predilection.

Determining treatment options for patients withDORV depends on several important anatomic features:1) The relationship of the ventricular septal defect(VSD) to the great arteries; 2) the size of the VSD;3) the orientation of the great arteries to one another;and 4) the status of the atrioventricular (AV) valves.The physiology of DORV varies from cyanosis similar totetralogy of Fallot, to significant volume overloadsimilar to a large VSD shunt. The surgical managementof this lesion depends on the anatomic featuresdescribed earlier and the physiologic consequences ofthese anatomic features.

DORV was first repaired at the Mayo Clinic in 1957by Kirklin [2]. The anatomic features of DORV havebeen delineated by several pathologists [3,4]. Theseauthors define DORV when one arterial trunk and atleast 50% of the other arterial trunk emerge from themorphologic right ventricle. Other authors have addedmore rigorous criteria to the anatomic definition ofDORV and relied on the finding of both subaorticand subpulmonary conus tissue [5]. The conus tissueprovides discontinuity between the mitral valve andthe nearby semilunar valve and may be an importantdiagnostic marker for DORV (Fig. 2). However, notall patients with DORV have this anatomic substrate.More complex forms of DORV may be associatedwith hypoplasia or atresia of one of the AV valves ormultiple muscular VSDs. These patients have singleventricle physiology.

The surgical approach to DORV is quite varied andneeds to be customized for the individual patient.Surgical approaches include an arterial switch operationfor patients with a large subpulmonary VSD (alsoknown as the Taussig-Bing anomaly) [3]. Conversely,surgical repair may be similar to repair of tetralogy ofFallot if there is a large subaortic VSD and subpulmo-nary outflow obstruction. The repair may be as simpleas closure of a large subarterial VSD, and as complexas the sequence of surgeries required for patients withsingle ventricle physiology if there are anatomic issueswith the AV valves.

ANATOMIC VARIABILITY OF DORVRelationship of the great arteries Four types of greatartery relationships have been described in DORV [6,7]:1) Right posterior aorta. The aortic valve and ascendingaorta originate from the right ventricle at a locationposterior and to the right of the pulmonary valve.2) Right lateral aorta (side-by-side relationship). Theaorta is to the right of the pulmonary artery and thesemilunar valves lie in the same transverse and coronalplanes. This is the classically described great arteryrelationship in DORV. 3) Right anterior aorta. The aorta

is located to the right and anterior of the pulmonaryartery. This grouping also includes some cases where theaorta is directly anterior of the pulmonary artery. 4) Leftanterior aorta. The aorta is leftward and anterior of thepulmonary artery. This group includes rare cases wherethe aorta is nearly entirely to the left of the pulmonaryartery in a side-by-side relationship or “left lateral.”

Position of the VSD Four positions have classicallybeen defined for the location of the VSD in DORV[3,6,7]: 1) Subaortic type. The VSD is located anatomi-cally closer to the aortic valve than to the pulmonaryvalve. 2) Subpulmonary type. The VSD is locatedcloser to the pulmonary valve than to the aortic valve.When this defect is supracristal it is located above theseptal limb of the crista supra ventricularis. This typeof VSD relationship in DORV is also described as the“Taussig-Bing complex.” 3) Doubly committed type.The VSD is very large and it is closely related to boththe aortic and pulmonary valves. 4) Remote type. TheVSD is distant from both semilunar valves and mayrepresent a posterior VSD, AV canal-type defect, or anisolated muscular VSD.

Based on the orientation of the great arteries andthe VSD, 16 possible assortments of DORV have beenidentified. In addition, cases involving situs abnormali-ties, AV discordance, and unbalanced ventricles havebeen described. Rarely, the ventricular septum is intactin DORV. In the Mayo Clinic series, the side-by-sidegreat artery orientation with a subaortic VSD was mostcommon (46% of cases) [6,7].

Figure 1. Pathologic specimen of double outlet right ventricle demonstrating origin of the aorta (Ao) and pulmonary artery (PA) from the right ventricle (RV). (From Edwards [1]; with permission.)

Double Outlet Right Ventricle: Opinions Regarding Management Cetta et al. 387

Conduction system orientation The AV node in DORV isoriented in its normal posterior position penetratingthe right side of the central fiberous body. The bundlebranches have been noted to lie inferiorly and posteri-orly along the rims of the VSD. Variation in the site ofthe AV node and the course of the bundle branchesmay depend on the exact location and size of the VSD.Dual AV nodes have been described as well.

Coronary artery anatomy There are three types of coro-nary artery patterns that have been described in DORV:1) normal; 2) abnormal: similar to what is typicallyseen in patients with tetralogy of Fallot; and 3) abnor-mal: similar to anomalies described in patients withtransposition of the great arteries. In the tetralogy ofFallot type of DORV, anomalous origin of the leftanterior descending coronary artery from the right coro-nary artery has been described. In the transposition type

of DORV, origin of the right coronary artery fromthe right posterior aortic cusp and origin of the leftcoronary artery from the left posterior cusp have beendescribed. Origin of the circumflex coronary arteryfrom the right coronary artery also occurs. Rarely,anomalous origin of a coronary artery from the pulmo-nary artery has been described in the Taussig-Bingform of DORV [8].

Other associated lesions At the Mayo Clinic from 1972to 1992, 179 patients were operated on for completerepair of DORV. The following associated lesions wereobserved: atrial septal defect (55%), persistent leftsuperior vena cava (19%), coronary artery anomalies(19%), situs inversus (10%), patent ductus arteriosus(10%), right aortic arch (9%), AV (3%), coarctation ofthe aorta (3%), and anomalous pulmonary venousconnections (2%) [9].

Treatment

• Optimal surgical approach is tailored to each patient’s specific anatomic anomaly. The overall goal is for complete anatomic repair. This is usually feasible in the more common forms of DORV, which have been described in this article. Complete anatomic repair includes establishing 1) continu-ity of the left ventricle with the systemic circulation; 2) continuity of the right ventricle with the pulmonary circulation; and 3) closure (in some manner) of the VSD. Frequently, patients with DORV require a prior palliative surgery [10,11,12•]. In these series, anywhere from 42% to 75% of patients required a prior surgery. This illustrates the complexity and variety of DORV. Prior to contemplating the specific type of repair, it is

Figure 2. A and B, Echocardiographs from the subcostal sagittal projection demonstrating a direct anterior/posterior orientation of the great arteries in double outlet right ventricle. The image on the right indicates the conus tissue (arrow) below both semilunar valves. Ao—aorta; PA—pulmonary artery; RV—right ventricle.

Surgical management of DORV

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essential for the surgeon to categorize the form of DORV that a particular patient may have. Surgical management is guided by the anatomic and physiologic types of DORV that are present. These are summarized below:

– Subaortic or doubly committed VSD and right ventricular outflow tract obstruction (tetralogy of Fallot physiology)

– Subpulmonary VSD (transposition of the great arteries physiology)– Subaortic or doubly committed VSD without right ventricular out-

flow tract obstruction (large VSD physiology)– Noncommitted or remote VSD with or without right ventricular

outflow tract obstruction– Complex forms of DORV involving situs abnormalities, AV valve

hypoplasia or atresia, and unbalanced ventricular chamber sizes (one diminutive ventricle; single ventricle physiology)

Subaortic or doubly committed VSD with right ventricular outflow tract obstruction (tetralogy of Fallot physiology)The repair of this anomaly is similar to that for traditional tetralogy of Fallot. The VSD may be exposed via a transatrial approach. The infundibulum is resected to enlarge the right ventricular outflow tract. The VSD is closed using a tunnel technique. The right ventriculotomy is closed with a patch technique to prevent recurrence of right ventricular outflow tract obstruction. Anomalies of the right coronary artery across the right ventricular outflow tract can cause technical problems with this type of repair, resulting in inadequate relief of right ventricular outflow tract obstruction. In this situation a valved extracardiac conduit may need to be inserted from the right ventricle to the pulmonary artery. In the current era, most centers perform repair of this anomaly during the first year of life. Alterna-tively, palliation with a systemic to pulmonary artery shunt may be performed in the newborn period and “complete repair” deferred for several months. Insertion of a systemic to pulmonary artery shunt would occur in situations when significant cyanosis is present early in life.

Subpulmonary VSD (Taussig-Bing type of anomaly; transposition of the great arteries physiology)The operation of choice for DORV with subpulmonary VSD and no obstruction to right ventricular outflow tract flow is the arterial switch operation with patch closure of the VSD. This procedure directs blood flow from the left ventricle to the pulmonary (neoaortic) valve. This surgical technique is similar to that for repair of transposition of the great arteries. Closure of the VSD is approached either from the right atrium, right ventricle, or aortic root depending on its location. Results for the arterial switch operation have been excellent and mortality has decreased significantly in recent years [13]. If aortic arch hypoplasia is present with this type of defect, a single stage repair is usually unlikely. An additional operation requiring reconstruction of the aortic arch would be necessary.

Subaortic or doubly committed VSD without right ventricular outflow tract obstruction (large VSD physiology)The VSD is approached either through a right ventriculotomy or from a right atrial approach. The diameter of the VSD must be at least the diameter of the aortic annu-lus in order to prevent recurrence of outflow obstruction. If the VSD is restrictive, it needs to be enlarged in an anterior and superior direction. Obstructing muscle bundles in the right ventricular outflow tract may frequently need to be resected. The VSD patch is sewn so as to channel the flow of blood from the left ventricle through the hole toward the aortic annulus. Care must be exercised during this surgery to avoid injury to the conduction tissue, especially when resection of the septum is performed to enlarge the VSD or when the patch is being sewn in. Complete intraventricular tunnel repair is performed within the first 6 months of life in order to decrease the chance of the patient developing significant pulmonary vascular obstructive disease. Initial palliation for this lesion with a pulmonary artery band to “protect” the distal pulmonary vascular bed is rarely used.

Double Outlet Right Ventricle: Opinions Regarding Management Cetta et al. 389

Noncommitted or remote VSD with or without right ventricular outflow tract obstructionSurgical repair of this lesion is complex and challenging. Many of these patients need to follow a single ventricle pathway that requires a series of operations. This series would include an initial palliative operation in the newborn period to either decrease or augment pulmonary blood flow depending on the clinical situation. This is followed by a bidirectional cavopulmonary connection performed at 4 to 9 months of age. Finally, permanent palliation is achieved with a Fontan operation that would typically be performed between ages 2 and 4 years. Patients with straddling AV valves, AV canal-type VSDs, hypoplasia of one ventricle, or multiple VSDs may need to be addressed in this manner. Operative mortality for the Fontan operation in these patients has decreased significantly in recent years [12•,14,15].

• Early mortality for repair of DORV has been reported to range from 2% to 9% [11,12•,16,17]. In general, late outcome is determined by the original anatomy and complications of the initial repair. Patients who had place-ment of a right ventricle to pulmonary artery conduit require subsequent replacement of that conduit. Subaortic obstruction is a complication observed in the immediate postoperative period and during late follow-up in certain patients. This complication is a result of the intracardiac tunnel-ing of the VSD to the aorta. Late development of subaortic obstruction results from protrusion of the inferior rim of the tunnel into the left ventricular outflow tract or from fibrous tissue development below the aortic valve. This complication has been reported in 5% to 50% of patients who underwent repair of DORV [11,18]. Brown et al. [12•] reported a 20-year experience in 124 patients having repair of DORV. Fifteen-year survival was 96% for patients who required “simple” intracardiac repairs, 90% for subpulmonary VSDs, and 90% for patients with straddling AV valves or hypoplastic ventricles. Freedom from reoperation after 15 years was 87% for “simple” intracardiac repairs, 72% for subpulmonary VSDs, and 100% for those with more complex intracardiac anatomy who underwent an arterial switch operation and VSD closure. Patients with single ventricle physiology and managed with a Fontan operation have long-term risks of supraventricular arrhythmia (occurs in most patients 20 to 30 years after Fontan operation) and development of protein-losing enteropathy (occurs in 15% of patients after Fontan operation) [19–21].

• With rare exception, most patients with repaired DORV will require life-long endocarditis prophylaxis. One exception may be a patient with a repaired subaortic VSD, no right ventricular outflow obstruction, no residual shunt, and no aortic regurgitation. Repaired patients with DORV and good postoperative hemodynamics are encouraged to participate in aerobic physical activities. Exercise programs should be tailored to each individual’s anatomy and physiology.

References and Recommended ReadingPapers of particular interest, published recently, have been highlighted as:• Of importance•• Of major importance

1. Edwards WE: Classification and terminology of cardio-vascular anomalies. In Moss and Adams’ Heart Disease in Infants, Children, and Adults, Including the Fetus and Young Adult, edn 6. Edited by Allen HD, et al. Philadelphia: Lippincott, Williams & Wilkins; 2001:118–142.

2. Kirklin J, Barratt-Boyes B, eds: Double outlet right ventricle. In Cardiac Surgery, edn 2. New York: Churchill-Livingstone; 1993:1469–1509.

Outcome and prognosis

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3. Lev M, Bharati S, Meng C, et al.: A concept of double outlet right ventricle. J Thorac Cardiovasc Surg 1972, 64:271–281.

4. Anderson R, Wilkinson J, Arnold R, et al.: Morphogenesis of bulboventricular malformations. Considerations of embryogenesis in the normal heart. Br Heart J 1974, 36:242–255.

5. Van Praagh S, Davidoff A, Chin A: Double-outlet right ventricle: anatomic types and developmental implica-tions based on a study of 101 cases. Coeur (Paris) 1982, 12:389–439.

6. Sridaromont S, Feldt R, Ritter D: Double-outlet right ventricle: Hemodynamic and anatomic correlations. Am J Cardiol 1976, 38:85–94.

7. Hagler D: Double-outlet right ventricle. In Moss and Adams’ Heart Disease in Infants, Children, and Adolescents, Including the Fetus and Young Adult, edn 5. Edited by Emmanouilides GC, et al. Phildelphia: Lippincott, Williams & Wilkins; 1995:1246–1270.

8. Eidem B, Cetta F, Fisher E, et al.: Anomalous right coro-nary artery from the pulmonary artery in Taussig-Bing anomaly. Ann Thorac Surg 1998, 66:1797–1798.

9. Boston U, Dearani J: Double outlet right ventricle. In The Johns Hopkins Manual of Cardiothoracic Surgery. Edited by Yuh et al. New York: McGraw-Hill; 2005, in press.

10. Kleinert S, Sano T, Weintraub R, et al.: Anatomic features of surgical strategies in double-outlet right ventricle at the Brompton Hospital, 1973 to 1986. Circulation 1997, 96:1233–1239.

11. Belli E, Serraf A, Lacour-Gayet F, et al.: Biventricular repair for double-outlet right ventricle: results and long-term follow-up. Circulation 1998, 98:360–365.

12.• Brown J, Ruzmetzov M, Okada Y, et al.: Surgical results in patients with double outlet right ventricle: a 20-year experience. Ann Thorac Surg 2001, 72:1630–1635.

Excellent review of long-term surgical experience with DORV.

13. Masuda M, Kado H, Shiokawa Y, et al.: Clinical results of arterial switch operation for double-outlet right ventricle with subpulmonary VSD. Eur J Cardiothorac Surg 1999, 15:283–288.

14. Driscoll D, Offord K, Feldt R, et al.: Five to fifteen year follow-up after Fontan operation. Circulation 1992, 85:469–496.

15. Cetta F, Feldt R, O'Leary P, et al.: Improved early morbid-ity and mortality after Fontan operation: the Mayo Clinic experience, 1987 to 1992. J Am Coll Cardiol 1996, 28:480–486.

16. Kirklin J, Harp R, McGoon D: Surgical treatment of origin of both arteries from right ventricle, including cases of pulmonary stenosis. J Thorac Cardiovasc Surg 1964, 48:1026–1036.

17. Takeuchi K, McGowan F, del Nido P, et al.: Surgical outcome of double-outlet right ventricle with sub-pulmonary VSD. Ann Thorac Surg 2001, 71:49–53.

18. Belli E, Serraf A, Lacour-Gayet F, et al.: Surgical treat-ment of subaortic stenosis after biventricular repair of double-outlet right ventricle. J Thorac Cardiovasc Surg 1996, 112:1570–1580.

19. Durongpisitkul K, Porter C, Cetta F, et al.: Predictors of early and late onset supraventricular tachyarrhyth-mias after Fontan operation. Circulation 1998, 98:1099–1107.

20. Feldt R, Driscoll D, Offord K, et al.: Protein-losing enteropathy after the Fontan operation. J Thorac Cardiovasc Surg 1996, 112:672–680.

21. Russo P, Danielson G, Puga F, et al.: Modified Fontan procedure for biventricular hearts with complex forms of double-outlet right ventricle. Circulation 1988, 78(5 Pt 2):III20–III25.