Repair of Double Outlet Right Ventricle

The Arterial Switch Operation for Double Outlet Right Ventricle.

The arterial switch operation may be used for double outlet right ventricle along the d-TGA spectrum is the preferred operative approach. This is treated more fully in the arterial switch operation section.

Rastelli repair and reparation a l’étage ventriculaire (REV operation)

When the pulmonary valve is so close to the tricuspid valve such that there is a significant risk that subaortic stenosis may be created within a tunnel repair, it is necessary to place the baffle over both the pulmonary and aortic valves, as described by Rastelli for transposition of the great arteries with a ventricular septal defect and pulmonary stenosis. The main pulmonary artery should be divided (not ligated) and may be connected to the right ventricle using either a pulmonary or aortic allograft conduit.

An alternative to the use of an allograft or synthetic conduit for the Rastelli type of repair is wide mobilization of the pulmonary arteries, as for the arterial switch repair, followed by direct suture of the main pulmonary artery to the right ventriculotomy. This technique was first described by the French group from Hospital Laennec, Paris, and has been termed Reparation a l’étage ventriculaire (REV operation). Anteriorly the repair is completed by placement of a generous patch of pericardium. To achieve the Lecompte maneuver as part of the REV repair, it is necessary to divide the ascending aorta. The aorta is reconstituted by direct anastomosis with continuous absorbable sutures. When the great arteries are related directly anterior and posterior, it is useful to bring both pulmonary artery branches anterior to the aorta, as described by Lecompte et al. If this is not done, either one of the branch pulmonary arteries must traverse an excessively long course around the aorta, depending on whether the main pulmonary artery is brought around the left side or the right side of the aorta once the aorta has been moved posteriorly. The advantage of the Lecompte maneuver - less distance that the pulmonary artery branch must reach - is considerable for anteroposterior great arteries, being at least ( /2 x aortic diameter). When the great vessels take up a more side-by-side relationship (as one moves from the transposition end of the double outlet right ventricle spectrum toward the tetralogy end), the advantage of the Lecompte maneuver decreases, but it is probably still useful until the aorta lies in a plane posterior to the main pulmonary artery. It is not possible to establish a rule as to when to apply the Lecompte maneuver, because not only are the pulmonary arteries being translocated in an anteroposterior direction, but there is also translocation in a superoinferior plane onto the anterior right ventricular free wall. The amount of superoinferior movement necessary will be determined by the development of the right ventricular infundibulum, as well as the distribution of the coronary arteries, which will determine the location of the right ventriculotomy. In addition, careful consideration must be given to the relationship of the anterior coronary artery (usually the right coronary artery as it arises from the aorta) to the main pulmonary artery. Because the pulmonary artery will be under some degree of tension, it must not lie directly on the coronary artery, as this may cause unacceptable compression.

Coronary Artery Anterior to the Infundibulum. If the anterior descending coronary artery passes across the infundibulum at its narrowest point, this may also present a contraindication to the standard intraventricular repair without a conduit. The right ventricular incision must be placed lower in the right ventricular free wall. Continuity between the right ventricle and the pulmonary arteries is generally established by the placement of a conduit - preferably an aortic allograft, as a pulmonary allograft is unlikely to be sufficiently long. The REV procedure usually is not feasible in this setting because of the long distance separating the ventriculotomy from the pulmonary arteries, although the pulmonary translocation operation is not precluded. In addition the severe tension that would result from the distance required for translocation might cause serious compression of the anteriorly placed coronary.

Aortic translocation (Nikaidoh procedure)

An operation described in the setting of double outlet right ventricle or transposition with pulmonary stenosis, including pulmonary annular hypoplasia, is aortic translocation with reconstruction of the right ventricular outflow tract[54]. The aortic root, including the aortic valve, is excised from the right ventricular outflow tract in a manner analogous to that applied for the pulmonary autograft operation. In addition, it is necessary to mobilize the coronary arteries, as is done for an arterial switch procedure. The pulmonary root is divided at the level of the pulmonary valve, which is excised. The outlet septum is excised, thereby removing the superior margin of the ventricular septal defect. The aortic root is translocated posteriorly so that it lies primarily over the left ventricle. The ventricular septal defect is closed with a patch, which is anchored to the aortic root at its superior margin. The pulmonary artery is connected to the right ventriculotomy with an anterior patch of pericardium. No large series using this procedure have been reported, so its practicability remains to be determined. Nevertheless, with increasing experience with the arterial switch and the pulmonary autograft aortic root operations, the necessary steps w-ill be familiar to surgeons who contemplate using this innovative procedure.

Atrial inversion procedures

In view of the almost constant association of double outlet right ventricle with a ventricular septal defect, as well as the known poor results of atrial inversion procedures such as the Senning and Mustard operations when combined with ventricular septal defect closure, it is highly unlikely that circumstances could arise in which an atrial inversion procedure would be indicated for the management of double outlet right ventricle. In contrast to the poor results achieved with atrial inversion procedures, excellent results have been achieved with the arterial switch procedure for double outlet right ventricle, although many institutions experienced a learning curve in translating this procedure to the specific anatomic requirements of double outlet right ventricle.

Kawashima’s intraventricular repair

The general setup and approach are the same as those used for tetralogy of Fallot. After a median sternotomy, a patch of anterior pericardium is harvested and treated with 0.6% glutaraldehyde solution for about 10 minutes. Either circulatory arrest or continuous bypass may be selected, although for more complex intraventricular baffles, it is generally wiser to use continuous bypass to avoid an excessively long period of circulatory arrest. The heart is arrested, and an infundibular incision is made. As in tetralogy, great care is taken to preserve as many coronary arteries as possible.

The relationship of the aortic annulus to the ventricular septal defect is carefully defined, and the length of the outlet septum is assessed with respect to both the aortic and pulmonary valves. The presence of tricuspid chordal attachments to the outlet septum is noted. The anatomy of the subpulmonary stenosis is also defined. Usually, excision of the outlet septum helps to relieve the subpulmonary stenosis to some degree. If there are chordal attachments, these may be reattached to the patch on the ventricular septal defect at a later time. Close to the tetralogy end of the spectrum, simple division of the septal and parietal extensions of the outlet septum will relieve subpulmonary stenosis when performed with subsequent placement of an infundibular outflow patch. Until reaching the mid-point of the double outlet right ventricle spectrum, there should be a sufficient distance separating the pulmonary and tricuspid valves to allow a tunnel repair to be constructed. Sutures are placed around the circumference of the baffle pathway using the standard pledgetted horizontal mattress technique. In older children the circumference of the baffle is so great that it is generally impractical to use all interrupted sutures, and a continuous suture technique is necessary. In infants the friability of the muscle may result in an unacceptable incidence of residual ventricular septal defect if a continuous suture technique is used and in any event, the circumference is very much shorter than in the older child. Although a flat patch of GoreTex is used when the ventricular septal defect is closely related to the aortic annulus, consideration should be give to the use of a tube graft rather than a flat patch on the part of the circumference where the patch becomes more of a tunnel. Particular care must be taken at the mid-point of the baffle tunnel to ensure that a "waist" is not created where the pulmonary valve begins to approach the tricuspid valve. Care must also be taken at the site of excision of the outlet septum, where lack of the endocardium may increase the risk that sutures will tear out of the raw muscle surface.

As is the case with closure of the anterior, malalignment ventricular septal defect of tetralogy, great care should be taken with the placement of sutures as one passes around the aortic annulus. Muscle trabeculations often extend up to the annulus, creating "ridges and valleys." Failure to place sutures virtually in the annulus (taking great care not to injure the leaflets) may result in a residual ventricular septal defect through the "valleys." Relief of subpulmonary stenosis is largely achieved by division of the septal and parietal extensions of the outlet septum with or without excision of the outlet septum itself. The ventricular incision should not be closed by direct suture, as such closure will necessarily impinge on the circumference of the right ventricular outflow tract. A patch of pericardium or GoreTex is used to close the incision, extending it through the pulmonary annulus as necessary according to the same decision process used for the tetralogy of Fallot.

Pulmonary translocation

The goal of pulmonary translocation for double outlet right ventricle is to achieve a biventricular repair without the use of a conduit. The essence of the operation is to place an intraventricular baffle from the ventricular septal defect to the aortic valve, but with translocation of the pulmonary artery and valve to a more anterior position on the right ventricle in order to allow for an unobstructed subaortic tunnel. It is especially suited for double outlet right ventricle with subaortic or doubly-committed ventricular septal defects, but can also be used in the presence of a subpulmonary ventricular septal defect. Pulmonary translocation can also be used for double outlet right ventricle with pulmonary stenosis, as transannular patching in not precluded.

• The operative approach is through a standard median sternotomy incision. A patch of pericardium is harvested (if available) and treated with 0.6% glutaraldehyde for about 10 minutes prior to heparinization.
• The right and left pulmonary arteries are mobilized as much as possible and encircled with snares. The arterial duct or ligament is controlled and divided.
• Cardiopulmonary bypass is established using bicaval cannulation and a single aortic cannulation. The left ventricle is vented via the right superior pulmonary vein. The heart is arrested with an infusion of cold-blood potassium cardioplegia.
• Completion of mobilization of the branch left and right pulmonary arteries is now made while on cardiopulmonary bypass in a manner analogous to that in the arterial switch operation. The right pulmonary artery is mobilized on the right side of the superior vena cava, and the left pulmonary artery is mobilized well past the left atrial appendage and fold of Marshall. Both arteries are mobilized well past the take-off of their first parenchymal branches. This step is of central importance in order to later achieve a tension-free right ventricle to pulmonary artery anastomosis.
• The pulmonary valve is excised from the right ventricular outflow tract in a manner analogous to that of the pulmonary autograft operation. First, the pulmonary artery is incised distal to the top of the commissures, but proximal to the pulmonary artery bifurcation. A right-angled clamp is passed retrograde into the right ventricle through the pulmonary artery incision, and comfortably past the pulmonary valve. A spot on the right ventricular free wall is marked using the right-angled clamp, and it is at this point that the incision into the infundibulum is started. Full excision of the pulmonary valve is then made, staying within the myocardial muscle layer posteriorly in order to avoid damaging the first septal branch of the left anterior descending coronary artery. Great care is also taken to preserve and any crossing infundibular branch coronary arteries.
• The excised pulmonary trunk is retracted cephalad, and the infundibulotomy is extended as needed in order to carefully study the intraventricular anatomy and allow placement of a relatively large baffle. Careful attention is paid to the location of the ventricular septal defect, the location of the aortic, pulmonary and tricuspid valves,

• Septal and parietal extensions of the outlet septum, including the outlet septum itself, may be resected as indicated. If deemed technically feasible, an intraventricular baffle routing blood from the ventricular septal defect to the aorta is constructed using a GoreTex patch through the infundibulotomy.
• Careful consideration is given to performing a Lecompte maneuver, and if decided upon, the ascending is aorta is first divided. The aorta is reconstructed by direct anastomosis with continuous absorbable suture. When the great arteries are related directly anterior and posterior, it is useful to bring both branch pulmonary arteries anterior to the aorta. If this is not done, either one of the branch pulmonary arteries will need to traverse an excessively long distance around the aorta, depending on whether the main pulmonary artery has been around the left side or the right side of the aorta once the aorta has been moved posteriorly. The advantage of the Lecompte maneuver is considerable for antero-posteriorly relationship of the great arteries, but significantly less so when the great vessels take up a more side-by-side relationship. The Lecompte maneuver is probably useful only until the aorta lies in a plane posterior to the main pulmonary artery. It is not possible to establish an absolute rule as to when to apply the Lecompte maneuver, because not only are the pulmonary arteries being translocated in an anteroposterior direction, but there is also translocation in a superoinferior plane. The amount of superoinferior movement necessary will be determined by the development of the right ventricular outflow tract.
• During either the end of the insertion of the intraventricular baffle, or during the repair of the ascending aorta following the Lecompte maneuver if one was done, rewarming is started.
• Any atrial septal defect that is present is closed. Careful consideration is given to leaving a patent foramen ovale, especially if a large infundibulotomy or ventriculotomy was performed.
• The aortic cross-clamp is now removed and the pulmonary root is reattached to the right ventricle. The most inferior rim of the pulmonary artery is attached directly to the infundibulotomy by continuous suture, and the connection completed with a hood of pericardium or GoreTex. Transannular patching can be incorporated into the repair if needed, as assessed in a manner analogous to that for tetralogy of Fallot. .
• All remaining ventriculotomy and atriotomy incisions are now closed, and the weaning off cardiopulmonary bypass is done routinely.
• Lines to be placed are a left atrial, right atrial, and a pulmonary artery line. Atrial and ventricular pacing wires are placed. The chest and mediastinum are appropriately drained.
• Checklist:

1. 2. arterial duct ligated
   4. intraventricular baffle placed
   6. Lecompte maneuver performed
   8. pulmonary artery translocated
   10. atrial septal defect closed

Ventricle-and-a-half Repair for DORV

For DORV in which there is relative hypoplasia of one of the ventricles, as may occur with complete unbalanced atrioventricular sepatal defect or straddling of one of the atrioventricular valves, the hypoplastic ventricle may be used in a ventricle-and-a-half repair. The dominant ventricle is assigned to the systemic circulation, while the relatively hypoplastic ventricle is assigned to the pulmonary circulation. Differing scenarios are possible, and must be carefully assessed:

DORV, dominant left ventricle, normally related great vessels.

This is the most straight-forward of the situations, and calls for closure of the VSD to direct LV flow into the aorta, closure of any intra-atrial communications, and a bidirectional Glenn operation.

DORV, dominant left ventricle, d-TGA.

Various options are available for DORV with d-TGA and a dominant left ventricle, depending on the size of the LV, the presence of PS or sub-PS, the presence of a complete atrioventricular septal defect, AV valve regurgitation, and the ventricular function. Most of these patients are candidates for a univentricular staged palliation. A Damus-Kaye-Stansel anastomosis may be required depending on the degree, if any, of subaortic stenosis. Pulmonary blood flow is provided by either a modified B-T shunt, a bidirectional Glenn, or a complete Fontan operation, depending on the age of the patient and the associated risk factors.

The ventricle-and-a-half repair, consisting of an arterial switch operation, closure of the VSD to the aorta, and a bidirectional Glenn anastomosis is indicated for the occasional patient in whom the right ventricle is of a sufficient so as to not completely exclude it from the circulation, and not large enough in order to achieve a safe 2-ventricle repair.

DORV, dominant right ventricle, normally or d-transposed related great vessels

Patients with this complex are at risk of having subaortic stenosis, coarctation of the aorta or interuptted aortic arch, especially if the great vessels are normally related. Any left ventricular outflow tract obstruction of this sort must be addressed at the initial operation, in order to minimize the risk of the eventual Fontan operation. A staged univentricular repair, with a low threshold for performing a Damus-Kaye-Stansel operation, is typically indicated for these patients.