If you don't remember your password, you can reset it by entering your email address and clicking the Reset Password button. You will then receive an email that contains a secure link for resetting your password
If the address matches a valid account an email will be sent to __email__ with instructions for resetting your password
Address reprint requests to José Pedro da Silva, MD, Division of Cardiovascular Surgery, Hospital Beneficencia Portuguesa-São Paulo, Rua Maestro Cardim, 769, 01323-001 São Paulo, Brazil
Pulmonary root translocation is a technique that we have used since April 1994 as an alternative treatment for transposition of the great arteries with ventricular septal defect (VSD) and pulmonary stenosis and for selected cases of double-outlet right ventricle with a subpulmonary VSD.
More recently, we have extended its use as part of the double-switch procedure in patients with congenitally corrected transposition, pulmonary stenosis, and large VSD.
This technique was aimed at maintaining pulmonary valve function, including the capacity for growth, as an attempt to avoid the problems inherent in a right ventricle to pulmonary artery conduit. Furthermore, by not incising or mobilizing the aorta (as in the Nikaidoh procedure,
or aortic translocation), we have attempted to preserve aortic valve anatomy and function as an important measure to improve the patient's clinical outcome. Leaving the aorta in its native position makes the Lecompte maneuver undesirable, because it would require extensive mobilization of the branch pulmonary arteries, along with aortic transection. Conversely, the space created behind the aorta after mobilization of the pulmonary artery and the elongation of the pulmonary artery due to retention of its root allow the anastomosis of the pulmonary artery to the right ventricle to be done without tension. This absence of tension is consistent with our finding that branch pulmonary artery stenosis has not been observed in the long-term follow-up of patients submitted to pulmonary root translocation.
The best age at which to perform pulmonary root translocation has still not been determined. Theoretically, the procedure should be done as early as possible, given the advantages of resolving cyanosis, and providing full blood flow through the pulmonary root, which may be beneficial for its development. The lower age limit for surgery is controversial; the immature newborn myocardium may present more technical difficulties to performing this operation, resulting in higher surgical risk. Therefore, in the cyanotic newborn requiring early intervention, we have performed a modified Blalock-Taussig shunt as the initial procedure and deferred pulmonary root translocation, to be done electively at 4 to 6 months of age.
Limitations
Pulmonary root translocation does not seem to be a good option in patients with a VSD located far from the aortic valve, in patients with a very small VSD, or in any case in which construction of the left ventricle-to-aorta pathway is difficult. Additionally, patients with a small, heavily trabeculated right ventricle are not good candidates for this operation. Some of these patients may be better approached by the Nikaidoh procedure or even by single-ventricle palliation.
Operative Technique
Figure 1The preoperative anatomy of transposition of the great arteries with VSD and pulmonary stenosis is shown in the (A) anterior and (B) cross-section views. The dashed line indicates the usual place for the right ventricular incision.
Figure 2The pulmonary artery mobilization begins before bypass. This includes the dissection of any previously placed systemic-pulmonary shunt, to be divided on the initiation of cardiopulmonary bypass. The pulmonary artery branches are extensively dissected from their distal attachments into both pulmonary hila. (A) The pulmonary trunk is freed from the aorta, and a plane of dissection developed close to the pulmonary artery wall, staying away from the coronary arteries. This dissection advances toward the left ventricle and stops when it is 2 to 3 mm inside the myocardium, to be resumed once the heart is arrested. (B) The completion of the pulmonary root harvesting is performed from both outside and inside the heart. A vertical right ventriculotomy is performed, with care taken to avoid injury to large conal right ventricular branches and the left anterior descending coronary artery, especially if intrapericardial adhesions obscure visualization of their courses. The tissue underlying the pulmonary valve is inspected and resected through the right ventriculotomy. These careful steps are important to harvest the pulmonary artery root with an intact valve and to prevent damage to the adjacent aortic sinus of Valsalva and the mitral valve annulus. It is also important to avoid entering the interventricular septum, which can occur if the dissection is performed solely from outside of the heart. The pulmonary valve is inspected; any remaining subvalvar fibrous tissue and excessive myocardial muscle are removed. The resultant opening in the left ventricle is checked for mitral valve disruption and closed using a glutaraldehyde-treated autologous pericardial patch with running 6-0 polypropylene suture. Biological fibrin glue (Beriplast) is applied to prevent bleeding at this site.
Figure 3The size and location of the VSD are inspected, paying particular attention to its relation to the aortic valve. (A) In most cases the VSD needs to be enlarged with partial resection of the conal septum, between the two semilunar valves. Obstructing right ventricular muscle bundles are resected. (B) An intracardiac tunnel, connecting the left ventricle to the aorta, is created with a Dacron patch. The suture line is carried away from the edge of VSD along its posteroinferior margin to avoid damage to the conduction system and is reinforced with interrupted sutures in any area of possible weakness. Generally, the patch is sutured to the base of the septal leaflet of the tricuspid valve, to avoid the posteroinferior margin of the VSD entirely.
Figure 4The intact pulmonary root with valve is translocated anteriorly, to the left side of the aorta, to be connected to the right ventricle, without a Lecompte maneuver. (A) The posterior aspect of the pulmonary root is sutured to the superior edge of the right ventriculotomy, using either interrupted 6-0 polypropylene suture or running 6-0 polydioxanone suture. This suture line is aimed at directly connecting at least 40% of the pulmonary root circumference to the right ventricular wall. (B) The remainder of the right ventricular outflow tract reconstruction is completed, whenever possible, with an in situ autologous pericardial patch, maximizing the potential for growth.
Figure 5If necessary, glutaraldehyde-treated autologous pericardium is used to either augment or substitute for the pedicled pericardial patch as shown in (A) anterior and (B) cross-section final views.
Figure 6Enlargement of the pulmonary root has been performed in approximately 40% of our patients. Enlargement is elected based on measurement of the pulmonary annulus diameter. This diameter is evaluated preoperatively by echocardiogram or angiography and confirmed intraoperatively by calibration with a Hegar dilator. When the pulmonary annulus diameter approximates the normal size for the patient, we do not enlarge the pulmonary root. In general, we do not enlarge when the pulmonary annulus Z-score is greater than −3 in tricuspid pulmonary valves but are more prone to enlarge bicuspid pulmonary valves. This decision is reassessed after coming off of cardiopulmonary bypass, when we measure the right ventricular and pulmonary artery pressures. If the systolic gradient exceeds 35 mm Hg, we go back on pump, remove one or two interrupted sutures, open the pulmonary root at the commissural site, and perform a small enlargement with a valved patch. In the majority of patients the decision to enlarge the pulmonary root is made preoperatively. In general, we augment the pulmonary annulus just enough to prevent an important transpulmonary gradient. We hope that as the patient's own valve grows, better function of the valve will result when using the smallest patch possible.
Figure 7In a few cases we have done major pulmonary root enlargement. Furthermore, we occasionally translocate the pulmonary root to the right side of the ascending aorta. The intraoperative photographs (A and B) illustrate both of these options. In this case the pulmonary root enlargement was done with a valved bovine pericardial patch, and the pulmonary artery was translocated to the right side of the aorta. The three-dimensional computed tomographic reconstruction (C) shows its final appearance. AO = aorta; LV = left ventricle; PR = pulmonary root; RV = right ventricle; RVOT = right ventricular outflow tract.
Figure 8In cases of double-outlet right ventricle with a subpulmonary VSD, we prefer to perform the arterial switch (Jatene) procedure, except when there is either pulmonary stenosis or unfavorable coronary artery anatomy for that operation. In these two situations we translocate the pulmonary artery root as depicted in this illustration. The pulmonary artery root takedown is somewhat easier than in a patient with transposition, due to its more anterior position, removed from the mitral valve and atrioventricular conduction pathway. In addition, the patch diversion of the left ventricle to the aorta is more easily constructed.
Figure 9Surgical photographs from a patient with double-outlet right ventricle and a subpulmonary VSD, as well as a left anterior descending coronary artery originating from the proximal right coronary artery. (A) The initial anatomy. (B) Dacron patch diversion of the left ventricle to the aorta.
The operation is performed via median sternotomy. Cardiopulmonary bypass is established with aortic and bicaval cannulation. Systemic hypothermia (22 to 25°C) and cardioplegic arrest with aortic cross-clamping and cold blood antegrade cardioplegia (20 mL/kg) are used, followed by subsequent doses (10 mL/kg) of antegrade blood cardioplegia given at 20- to 25-minute intervals during the period of cross-clamping. The left ventricle is vented with a flexible sump placed into the left atrium across the interatrial septum via a small right atriotomy.
Conclusions
The technique of pulmonary root translocation keeps the aorta untouched in its original anterior position, without any coronary artery manipulation. This is in contrast to the Nikaidoh procedure
As a consequence, postoperative aortic valve dysfunction or coronary artery distortion is not expected after pulmonary root translocation. In our 12-year experience with this procedure, we have not observed these complications to date.
Left ventricular outflow tract obstruction, which is an important problem following the Rastelli operation,
has a low incidence after pulmonary root translocation. The explanation for this is that when harvesting the pulmonary root, some subvalvar myocardium is also removed, giving more room for the left ventricular outflow tract. Furthermore, partial resection of the conal septum favors the construction of an obstruction-free left ventricular outflow tract (Fig. 10).
Figure 10Postoperative computed tomographic images showing widely patent left ventricular (A) and right (B) outflow tracts and (C) 3D view following pulmonary root translocation. (Color version of figure is available online at http://www.optechtcs.com.)
is appealing as an anatomical repair for the same congenital heart defects that we have treated with pulmonary root translocation. However, double-root translocation is a more complex operation that includes transection of the aorta, dissection and suturing of the aortic root, and coronary artery manipulation. In theory, it has a higher risk of immediate and long-term complications related to the aorta and coronary arteries than does our technique.
With regard to preventing mitral valve injury during removal of the pulmonary root, there is great variability in the relationship of the pulmonary root to the mitral valve annulus. Occasionally, the two are so closely related that we have taken a piece of the mitral valve together with the pulmonary root to preserve the integrity of the latter. The resulting hole in the mitral valve is then closed. If some mitral regurgitation results from this maneuver, intraoperative echocardiogram then indicates the need for mitral valve repair (performed via a transatrial septal approach).
From April 1994 to June 2008 we have applied pulmonary root translocation to 39 patients. There have been three hospital deaths (7.7%). One patient who had a good hemodynamic result died because of a Gram-negative sepsis. The other two deaths were related to the surgical procedure. After those deaths, we undertook a general revision of the operation in March 2005. Thereafter, using the concepts expressed in this article, we have operated on 21 consecutive patients without any early or late deaths. The long-term follow-up has shown excellent clinical outcome. Only four reoperations have been needed: closure of a residual VSD in two patients, repair of a right ventricular outflow tract aneurysm in one patient, and resection of left ventricular outflow tract muscular obstruction in one patient. Additionally, one patient has undergone percutaneous balloon dilation for pulmonary stenosis.
References
da Silva J.P.
Baumgratz J.F.
da Fonseca L.
Pulmonary root translocation in transposition of great arteries repair.
00004-X&id=gr1.jpg){kind=link}
00004-X&id=gr2.jpg){kind=link}
00004-X&id=gr3.jpg){kind=link}
00004-X&id=gr4.jpg){kind=link}
00004-X&id=gr5.jpg){kind=link}
00004-X&id=gr6.jpg){kind=link}
00004-X&id=gr7.jpg){kind=link}
00004-X&id=gr8.jpg){kind=link}
00004-X&id=gr9.jpg){kind=link}
00004-X&id=gr10.jpg){kind=link}