Double Outlet Right Ventricle Surgery Treatment & Management

Updated: Jan 30, 2015
  • Author: Abdullah A Alghamdi, MD, FRCSC; Chief Editor: Jonah Odim, MD, PhD, MBA  more...
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Treatment

Medical Therapy

Medical management in the treatment of double outlet right ventricle (DORV) is based on the combination of anatomical lesions and the underlying physiology. A spectrum of presentations is possible with double outlet right ventricle, ranging from inadequate pulmonary blood flow with associated cyanosis to excessive pulmonary blood flow with congestive heart failure. However, double outlet right ventricle is a disorder that cannot spontaneously resolve, and the diagnosis alone is a sufficient indication for surgery.

In the setting of inadequate blood pulmonary blood flow, preserving ductal (ie, patent ductus arteriosus) blood flow is vital. An infusion of prostaglandin E (ie, alprostadil) is the standard of care until repair can take place. When the contrary clinical picture of congestive heart failure is present, careful dieresis, digoxin, inotropic support, and control of pulmonary blood flow by means of intubation and manipulation of blood gases may be indicated.

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Surgical Therapy

When double outlet right ventricle repair is planned, several anatomic and physiologic factors are reviewed. The location of the ventriculoseptal defect (VSD) and its size are critical to the repair. [7, 8, 9]

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Preoperative Details

Preoperative studies should be used to accurately determine the surgically relevant features, including the following:

  • Separation of the pulmonary valve from the tricuspid valve relative to the diameter of the aortic valve annulus

  • Location of the VSD, including degree of involvement of the conal septum

  • Chordal attachments to the conal septum, VSD ridge, and presence of straddling chordae

  • Degree of subpulmonary stenosis and whether it is fixed or dynamic

  • Degree of pulmonary valvar stenosis

  • Coronary anatomy

  • Relative size of the great vessels and their relationship

  • The aortic arch and the presence of coarctation

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Intraoperative Details

Repair of double outlet right ventricle with subaortic ventriculoseptal defect

Repair of double outlet right ventricle with a subaortic VSD is accomplished by creating an intraventricular tunnel that channels left ventricular blood through the VSD to the aorta. This is facilitated by the use of a patch (eg, polytetrafluoroethylene [PTFE]) that corresponds to the circumference of the aorta.

After cardiopulmonary bypass with bicaval cannulation and cardioplegic arrest is established by routine means, the intracardiac anatomy is carefully inspected through a right atriotomy. The VSD is visualized through the tricuspid valve, and its relationship to the aorta is confirmed. If the VSD is suspected to be smaller than the aorta before or during surgery, the VSD is enlarged. The VSD is enlarged superiorly and anteriorly; thus, some of the infundibular septum is resected. The conduction tissue runs inferiorly and is avoided.

The patch is oriented along its longitudinal axis corresponding to an imaginary line from the anterior most portion of the aorta to the anterior-inferior limit of the VSD.

The VSD can be closed by using interrupted pledgetted sutures or a continuous-suture technique. If the intraventricular tunnel appears to be bulging into the right ventricular outflow tract, the right ventriculotomy is closed with a patch (eg, autologous pericardium) to prevent right ventricular outflow tract obstruction.

In patients who have double outlet right ventricle with subaortic VSD and pulmonary stenosis, the general approach is similar to those with tetralogy of Fallot (TOF). Identifying the coronary arteries and marking the planned right ventriculotomy incision (if needed) before cardioplegic arrest is effected is important. The obstructive right ventricular muscle bundles are divided. The VSD is enlarged if restrictive.

Intraventricular tunnel repair of the VSD is similar to that used for patients who have double outlet right ventricle and subaortic VSD without pulmonary stenosis. The pulmonary valve, main pulmonary artery, and branch pulmonary artery are inspected and are patched as needed to eliminate obstruction. If an important coronary artery crosses the right ventricular outflow tract, a conduit may be added as an additional outflow path from the right ventricle. In patients with crossing coronary arteries, palliative surgery may result in 2 right ventricular outflow tracts: through the native pulmonary valve, and, if necessary, through the right ventricle to pulmonary artery conduit.

Anatomic repair of double outlet right ventricle with subpulmonary ventriculoseptal defect

The preferred surgical repair of double outlet right ventricle with subpulmonary VSD (ie, the Taussig-Bing heart) is anatomic repair (ie, the arterial switch operation). Because coarctation of the aorta is commonly observed in this situation, patients may have undergone coarctation repair with a pulmonary artery band, although single-stage repair of the coarctation and double outlet right ventricle can be accomplished. Atrial septectomy is performed if the atrial septum is restrictive. The subsequent procedure is a single stage complete repair with VSD enlargement if restrictive, repair of the VSD to direct the left ventricular blood to the pulmonary artery, followed by an arterial switch procedure. When an aortic arch obstruction is also associated, it is repaired at the same time under hypothermic circulatory arrest.

Repair of double outlet right ventricle with doubly committed ventriculoseptal defect

Surgical correction of double outlet right ventricle with a doubly committed VSD (an uncommon variant of this disorder) is performed in a fashion similar to that described above for double outlet right ventricle with subaortic VSD. The VSD, which is typically large, usually does not create difficulty in channeling left ventricular blood to the aorta with an intraventricular tunnel. Concurrent pulmonary stenosis or obstruction of the right ventricular outflow tract due to the tunnel may necessitate the creation of a right ventricle outflow patch or even a right ventricle–to–pulmonary artery conduit.

Repair of double outlet right ventricle with noncommitted ventriculoseptal defect

Of the types of double outlet right ventricle, the defect that requires repair of the noncommitted VSD is the most difficult to correct. Its correction is a high-risk procedure that often involves univentricular repair. However, biventricular repair of double outlet right ventricle with noncommitted VSD, based on specific anatomic features, is a challenging but achievable outcome.

The major feature of this anomaly is a persistent subaortic conus and a double infundibulum. The subaortic conus is in excess to essentially normal right ventricular structures. Therefore, this variation of double outlet right ventricle represents malposition of the aorta, with a normally positioned pulmonary artery and with the great vessels usually side by side. The VSD, usually perimembranous, often has inlet and/or trabecular extension and can be restrictive. Crucial to biventricular repair is the distance between the tricuspid and mitral annuli because the aortic tunnel is constructed in this area.

Variations without pulmonary stenosis first require palliation with pulmonary artery banding. Severe subaortic obstruction, restrictive VSD, or aortic arch obstruction requires palliation with the pulmonary artery banding. Variations with stenosis may be physiologically palliated, or a systemic-to-pulmonary shunt, such as a modified Blalock-Taussig shunt, may be required.

Contraindications to performing a biventricular repair include significant left ventricular hypoplasia, major overriding, or straddling of the atrioventricular valve

With the use of combined atrial and ventricular approaches, an intraventricular tunnel that connects the VSD to the aorta is the operation of choice. A right vertical infundibulotomy is performed through the subaortic infundibulum, and the abnormal subaortic band between the subaortic conus and conal septum is resected. The diameter of the VSD is measured through the tricuspid valve and compared with that of the aorta, and the distance between the tricuspid annulus and the ostium infundibulum is measured. This last measurement should allow for a patch or tunnel that is at least the diameter of the aorta. Tricuspid chordal attachments blocking the channel are detached and reimplanted on the patch, and the VSD is enlarged anteriorly by avoiding the conduction tissue.

Two groups of investigators reported a mortality rate of approximately 10%, but the incidence of late subaortic stenosis is reasonably high. [10, 11]

When the VSD is distant, tunnel repair is associated with clinically significant subaortic stenosis in the early postoperative phase due to geometric errors in the construction of the tunnel and in the late postoperative phase due to fibrous obstruction.

When the VSD is situated in the inlet septum, Lacour-Gayet advocates using a tunnel to connect the VSD to the ostium infundibuli, followed by an arterial switch procedure. [12] He notes that the perimembranous VSD is close and requires a smaller tunnel. Also, the creation of a tunnel to the pulmonary artery does not depend on the pulmonary-tricuspid distance and is usually not affected by the presence of conal tricuspid chordae located above the tunnel. The subaortic band is resected, an infundibulotomy is created on the subpulmonary infundibulum, and the VSD is expanded. Then, an arterial switch procedure is performed as described above. He reported excellent early results, with resolution of patients' New York Heart Association (NYHA) status.

A study by Li et al found an estimated overall 5-year survival rate of 87.1% following biventricular repair of double outlet right ventricle with noncommitted VSD. The study included 75 patients (mean age 2.2 years) with the condition, with five types of biventricular repair performed. Surgery involved rerouting the VSD to either the aorta (40 patients) or the pulmonary artery (35 patients), with tunnel obstructions occurring in 10 patients who underwent the VSD-to-aorta procedure, versus none of the other patients, during the mean 4.1-year follow-up. The investigators also found that patients who underwent a concomitant tricuspid procedure had a significantly reduced likelihood of intracardiac obstruction, with no tricuspid regurgitation or stenosis developing. [13]

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Postoperative Details

See Intraoperative Details for discussion.

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Follow-up

See Intraoperative Details for discussion.

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Complications

See Intraoperative Details for discussion.

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Outcome and Prognosis

In a large series analyzing outcomes in patients with double outlet right ventricle (DORV) from 1980-2000, Brown et al reported that the 15-year overall survival rate (including the patients who underwent no surgical intervention) is 56%. [14] Brown et al reported that 15-year survival rates after repair for noncomplex double outlet right ventricle and for Taussig-Bing anomaly were 95% and 89%, respectively.

Small left-sided structure, including left ventricle and mitral valve, structural abnormality of the mitral valve, and aortic arch obstruction, has been identified as a risk factor for death after repair.

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Future and Controversies

Consensus surgical therapeutic strategies are available for noncomplex tetralogy type double outlet right ventricle (DORV) and Taussig-Bing anomaly. Controversy remains as to whether or not the indication of biventricular repair should be extended to borderline anatomic subgroups, such as small left-sided structures (including mitral valve and left ventricle) or nonsubaortic ventricular septal defect (VSD). The subgroups of patients with these risk factors have suboptimal early and long-term outcomes. Furthermore, significant improvement of survival and quality of life in single ventricle palliation and subsequent Fontan completion makes this issue debatable.

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