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Division of Cardiothoracic Surgery, Department of Surgery, Emory University School of Medicine, and Pediatric Cardiac Surgery, Children's Healthcare of Atlanta at Egleston, Atlanta, Georgia
Accepted for publication February 8, 2012.
* Address correspondence to Dr Kanter, Pediatric Cardiac Surgery, Emory University School of Medicine, 1405 Clifton Rd, Atlanta, GA 30322 (Email: kkanter{at}emory.edu).
Presented at the Fifty-eighth Annual Meeting of the Southern Thoracic Surgical Association, San Antonio, TX, Nov 9-12, 2011.
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Abstract |
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Methods: From 2002 to 2011, 21 neonates aged 3 to 55 days (mean 12.2 days, median 7 days) had IAA/LVOTO (n = 13), AA/VSD (n = 7), or AA/IAA with aortopulmonary window (n = 1); ten (48%) had genetic abnormalities (8 with DiGeorge syndrome). Based on clinical characteristics and surgeon preference, 6 had a primary Yasui repair (4 AA/VSD, 2 IAA/LVOTO); 15 were staged with an initial Norwood repair (3 AA/VSD, 12 IAA) followed by Yasui completion in 13 (2 await completion) 4.3 to 26.6 months later (median 6.9 months).
Results: Early mortality was zero with no interstage deaths in the staged patients. One patient died 2 months after staged repair. Since biventricular repair, 8 survivors (44%) had reoperation for conduit replacement (n = 6), recurrent LVOTO (n = 1), or a residual VSD (n = 1). No patient requires a pacemaker. There were 3 late deaths after biventricular repair, all in patients with genetic syndromes and IAA/LVOTO. Actuarial survival after initial operation was 100% at 1 year and 75% at 5 years. Actuarial freedom from reoperation or death after biventricular repair was 14% at 5 years.
Conclusions: The Yasui operation is effective for patients with IAA/LVOTO and AA/VSD. Primary and staged repair have comparable results. Reoperation after biventricular repair seems inevitable, mostly for conduit replacement. Genetic factors may affect long-term survival.
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Introduction |
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A one-stage primary repair of IAA/LVOTO was first reported in 1987 by Yasui and colleagues [2]. Two patients had an 8-mm ascending aorta to descending aorta interposition graft, a Damus-Stansel-Kaye connection of the proximal pulmonary trunk to the small ascending aorta, closure of the VSD channeling the left ventricular outflow through the VSD to the pulmonary valve, and construction of a right ventricle-to-pulmonary artery conduit (RV-PA) with a 14-m Hancock valve (Medtronic, Minneapolis, MN). The concepts of the Yasui operation (redirection of left ventricular outflow through the VSD to the pulmonary valve, placement of a conduit from the right ventricle to the pulmonary circulation) were also applied to infants with AA/VSD as a primary repair, initially with a conduit from the pulmonary trunk (the new systemic outflow) [3, 4], and then with a Norwood-type arch reconstruction [5–7]. In addition to use as a primary neonatal repair, the Yasui operation has also been employed as a staged repair both for IAA/LVOTO [8–12] and for AA/VSD [6, 12].
With this background in mind, we reviewed our experience with 21 infants from 2002 to 2011 with either IAA/LVOTO or AA/VSD for whom the Yasui operation was applied, either as a primary or as a staged repair.
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Patients and Methods |
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TopAbstractIntroductionPatients and MethodsResultsCommentDiscussionReferences |
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Patient Population
From January 2002 to October 2011, 21 neonates presented with either interrupted aortic arch and severe left ventricular outflow tract obstruction (IAA/LVOTO; n = 13), aortic atresia or severe aortic valve hypoplasia (aortic annulus < 3 mm) with a VSD and 2 well-formed ventricles (AA/VSD; n = 7) or interrupted aortic arch with aortic atresia, VSD, and aortopulmonary window (n = 1). All had 2 well-formed ventricles. Table 1
shows the patient characteristics at the time of the initial operation. The age at initial operation was similar between the IAA/LVOTO patients (9.3 ± 1.8 days) and the AA/VSD patients (13.4 ± 18.4 days; p = 0.41), as was the weight (3.0 ± 0.45 vs 3.1 ± 0.39 kg; p = 0.71).
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Seven patients with a VSD and 2 well-formed ventricles had either severe LVOT obstruction defined as an aortic valve annulus less than 3 mm (n = 2) or AA (n = 5). All had a hypoplastic aortic arch and 3 had a tight coarctation. None had a genetic syndrome (Table 1). The incidence of genetic syndrome was statistically higher in the IAA/LVOTO group compared with the AA/VSD group (69% vs 0%; p < 0.05).
The final patient (patient 21, Table 1) had aortic atresia, type B interrupted aortic arch and an aortopulmonary window. Genetic evaluation revealed that he had a supernumerary isodicentric chromosome 22 (cat-eye syndrome).
Operative Technique
We have described the surgical technique for the Yasui operation previously [13]. Patients had either a primary one-stage repair in the neonatal period or a staged repair depending on the characteristics of the patient and surgeon preference. Six patients had a primary repair (4 with AA/VSD and 2 with IAA/LVOTO); the remainder had a staged repair (Table 2). Primary repair consisted of channeling the VSD to the pulmonary valve, reconstructing the aortic arch with a Norwood-type homograft patch (including primary repair of the interrupted aortic arch, if present), and creation of RV-PA continuity with a valved conduit. Initial palliation for the staged patients involved a Norwood aortic arch reconstruction as with the primary repair. Pulmonary blood flow was provided by a modified Blalock-Taussig (BT) shunt or a RV-PA shunt (Sano shunt). The atrial septum was not opened. The eventual biventricular "repair" in the staged patients channeled the VSD to the pulmonary valve with enlargement of the VSD (if necessary), creation of RV-PA continuity with a valved conduit, and takedown of the shunt.
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2 analysis with the Fisher exact test. Life table analysis was done with the Kaplan-Meier survival method with significance determined by log-rank analysis. Significance was defined as a p value less than or equal to 0.05. |
Results |
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With the biventricular repair, whether primary or staged, all patients had a Yasui-type operation except patient 4 (the only IAA/LVOTO patient with an aortic annulus z score greater than –3.0; his z score was –2.6). He had takedown of his Norwood proximal aorta-to-pulmonary connection, resection of LVOTO, VSD closure, and reestablishment of continuity between his native pulmonary valve and his branch pulmonary arteries. He is the only patient in this series to require reoperation for recurrent LVOTO (33 months after his biventricular repair). The remaining 18 repaired patients had routing of the left ventricular outflow through the VSD (enlarged in 7 of the 13 staged repairs and none of the primary repairs; Table 2). No patient required a pacemaker. One child (patient 9) had neoaortic valve replacement (the native pulmonary valve) at the time of biventricular repair due to significant neoaortic insufficiency not amenable to valve repair. Right ventricular to pulmonary artery continuity was established with a valved homograft or a valved bovine jugular vein conduit. The RV-PA conduits used in the primary repair patients were significantly smaller than in the staged patients (9.7 ± 0.5 mm vs 13.8 ± 1.5 mm; p < 0.0001). Patient 2, who had his initial palliation in 2002, is the only operative mortality after biventricular repair; he died 2 months postoperatively of multisystem organ failure.
Follow-Up
On average, follow-up of 4.1 ± 2.9 years (range 5 weeks to 9.5 years), there have been 3 late deaths; 2 in the staged group of infection and respiratory failure 3.4 months (patient 9) and 8.1 months (patient 5) after biventricular repair and 1 in the primary repair group of cerebral hemorrhage 3.1 years postoperatively (patient 12). All 4 deaths were in patients with a genetic syndrome (DiGeorge syndrome in 3, trisomy 22 in 1) and with IAA/LVOTO. Overall freedom from death after the initial operation was 100% at 1 year and 75% at 5 years (Fig 1). There were no statistically significant differences in survival between the patients with a primary Yasui procedure and those with a staged repair. Five patients had balloon dilatation of a recurrent arch obstruction or coarctation in the catheterization laboratory 3.1 to 7.9 months (mean 5.3 months) postoperatively.
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Comment |
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TopAbstractIntroductionPatients and MethodsResultsCommentDiscussionReferences |
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A more recent series from Children's Hospital, Boston [20], examined the results with a primary Yasui repair in 17 neonates with AA/VSD (n = 7) or IAA/LVOTO (n = 5). Despite 3 early deaths (17.6% 30-day mortality), the 10-year actuarial survival was 82%. Freedom from reoperation at 3 years was less than 40%. A similar study of a primary Yasui operative approach in 21 neonates from Philadelphia [21] reported no operative mortality but intraventricular baffle leak in 11 patients, 4 of whom required reoperation. On median follow-up of 34.2 months, there was 1 late death. Even with their relatively short follow-up, half of the survivors required at least 1 reoperation. Another report of primary Yasui repair in 16 infants from Birmingham, England [22], reported a 19% early mortality with a 60% 1-year actuarial survival and 5-year freedom from reoperation of 20%.
This current report demonstrates that the Yasui operation can be applied safely to infants with IAA/LVOTO or AA/VSD, either as a primary or as a staged approach. For the initial operation, there were no operative deaths in either group with a 1-year actuarial survival after the initial operation of 100% (Fig 1). There was 1 postoperative death at the time of biventricular repair in a staged patient with a 5-year actuarial survival of 75%.
No patient required a pacemaker even though 7 had VSD enlargement at the time of biventricular repair (all in the staged group; Table 2). The only patient who developed recurrent LVOTO was the only patient in this series who had VSD closure with preservation of left ventricular to aortic continuity without a Rastelli-type approach (patient 4). No other patient developed LVOTO either in the primarily repaired group or the staged group. This freedom from LVOTO has been reported by others with the Yasui operation [20–24].
Our choice of a primary or a staged approach was based on the clinical status of the patient and the discretion of the surgeon. Although more patients with AA/VSD had a primary repair than those with IAA/LVOTO, this was not statistically different. Mortality rates and the need for reoperation were comparable between the 2 approaches (Figs 1 and 2) as has been demonstrated by others [12]. Despite concerns raised by others about interstage mortality in patients initially palliated with a Norwood operation and staged to a Yasui repair [20], there were no interstage deaths in this series as we [10] and others [11] have previously reported.
For patients with IAA/LVOTO, predicting which patients have a left ventricular outflow tract too small for an anatomic repair (closure of the VSD with maintenance of left ventricular to aortic continuity with or without subaortic resection) and will thus need a Yasui approach can be difficult. The 13 patients with IAA/LVOTO in this series managed with a Yasui approach represent 23% of the 57 neonates presenting to our institution between 2002 and 2011 with interrupted aortic arch and VSD. This is similar to the experience from Michigan; 15 of 50 neonates (30%) presenting with interrupted aortic arch had such severe left ventricular outflow tract obstruction that a Yasui approach was used [25]. Only one of our IAA/LVOTO patients had an aortic annulus z score greater than –3.0. In general, we apply the Yasui approach to neonates in whom the smallest diameter of the left ventricular outflow tract (either at the valve or the subaortic region) is less than 4.0 mm. For those with a minimum value between 4.0 and 4.5 mm, we would consider either a conventional repair or a Yasui, and for those patients with a value greater than 4.5 mm, we would tend to perform a standard biventricular repair. Although we have previously described the use of the Ross-Konno procedure in patients with IAA/LVOTO after initial Norwood palliation [10], we now reserve the Ross-Konno for patients who have had a more standard anatomic interrupted aortic arch repair and develop recurrent LVOTO.
The high reoperation rate in this series (Fig 2) was mostly due to the need for RV-PA conduit replacement. This is not dissimilar to other institutions' experience [20–23] and is not unexpected when one uses valved RV-PA conduits in small babies. It is important to note that all reoperations in this series were performed safely without mortality.
All 4 deaths in this series were in patients with genetic syndromes (DiGeorge syndrome in 3, trisomy 22 in 1). The association of genetic syndrome and poorer long-term outcome previously has been reported in patients with pulmonary atresia and VSD [26] and in patients undergoing a Norwood procedure [27]. Interestingly, in this series there were no early or late deaths in the AA/VSD patients. This lower mortality in patients with AA/VSD compared with those with IAA/LVOTO previously has been noted in a multiinstitutional Congenital Heart Surgeons' Society study [24] as well as a paper from Saudi Arabia [23]. Perhaps this favorable effect is due to a lower incidence of genetic syndromes in the AA/VSD patients compared with the IAA/LVOTO patients (none of our patients with AA/VSD had a genetic syndrome; Table 1).
In summary, the Yasui operation is effective for children with IAA/LVOTO and with AA/VSD. Primary and staged repair have comparable results. Reoperation after biventricular repair seems inevitable, mostly for conduit replacement. Genetic factors may affect long-term survival.
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Discussion |
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Your paper highlights the very high incidence of extracardiac abnormalities, particularly chromosomal defects, which were a risk factor for outcome, a finding that has been replicated in many, many other studies looking at all types of congenital heart defects.
Our experience at the University of Michigan is very similar to yours, even including the fact that we had a mixture of single-stage and two-stage repairs. Early in our own experience, which we reported some years ago, we selected the highest risk patients, low birth weight, prematurity, chromosomal anomalies, et cetera, for single-stage repairs, believing that these patients were likely to fare poorly with a shunt-dependent circulation. When we reviewed our data we found, as you did, that there was no difference, which significantly influenced our own group into eliminating two-stage repairs and going to a one-stage repair essentially for all of these patients.
I have a few questions for you and the excellent data that you showed. First, how did you determine when the ventricular septal defect needed to be enlarged or did you do that routinely for those patients who had a Yasui repair?
Second, at least it seems to me that one of the major difficulties with this operation from a technical point of view is fashioning and inserting a conduit in some of these very tiny babies when the conduit sits so anteriorly in the chest. Do you have any tricks about that? And might you comment on those that feel that a posterior translocation of the pulmonary root, like a Ross procedure, is a better approach, because it allows a more orthotopic position for the right ventricular outflow tract conduit? And along those same lines, would you then consider perhaps not placing a conduit or using a transannular patch to try to decrease the reoperation rate?
And then last, what will you do now looking at your own data? How will you determine when the next baby comes along whether you perform a single versus two-stage approach? What criteria do you and your colleagues use?
Thank you. I enjoyed the paper immensely.
DR KANTER: Thank you, Ed. Your group clearly is a pioneer in this operation and have published two very important papers on it.
We evaluate the VSD [ventricular septal defect] in the operating room, and if it looks like it is going to be restrictive, we will enlarge it. Certainly if it is less than the diameter of the pulmonary valve, which is going to be the neoaortic valve, then we will enlarge the VSD. In the infants undergoing a primary repair, none of them required ventricular septal defect enlargement, because all had large VSDs. Therefore, it is a subjective approach. We don't do it routinely; only about half the patients in the staged group had a VSD enlargement.
The conduit is extraanatomic and is right behind the sternum, which can be challenging on sternal reentry. We do make an effort to bring it as far lateral as possible. Certainly for the staged patients who will have an RV [right ventricle] to PA [pulmonary artery] conduit for the original operation, we construct the Sano as a marking point and bring it well over to try to put it more in the left chest so it is away from the sternum. However, we are not always able to accomplish that.
The use of the Ross procedure is intriguing. For our patients with interrupted aortic arch, we have saved the Ross procedure for the reoperation for the patients who have a bicuspid aortic valve or a marginal left ventricular outflow tract. About three-quarters of our interrupted arch patients had a more standard repair. A fair number of them have come back, I would say at least 10 or 20%, requiring aortic valve replacement, and then we will do a Ross-Konno procedure. I am not sure how you could do a Ross-Konno procedure in a patient with aortic atresia, especially with an aorta of 1 mm, but certainly that's a possibility for a patient with an interrupted aortic arch and left ventricular outflow tract obstruction. The thought of doing a primary repair with a Ross-Konno, a Norwood arch reconstruction, interrupted arch repair just seems a little daunting to me. So the first time we do it, we are going to ask you to come down and scrub on the case.
Certainly a transannular patch for the right ventricular outflow tract is an attractive idea, and there are people who have discussed the use of a transannular patch for the very reason of avoiding conduit reoperation. The pulmonary vascular resistance in these infants is high, and we are worried about early postoperative right ventricular failure and have not done so. However, everyone's experience with neonatal correction of pulmonary atresia and VSD we know that we can get by without a valve, but that is different physiology early on. We have just not been bold enough to do it, because these operations, as you well know, are very long with long cross-clamp times. So we are afraid not to have a valve in that circuit.
What would we do now with a patient who came along? I think those patients with aortic atresia we would tend to do a primary repair. Those with interrupted arch and left ventricular outflow tract obstruction, we might do a primary repair, but we still might stage them. And the reason I say that is the one tantalizing patient whose left ventricular outflow tract grew, so that eventually we were able to go back and do an anatomic repair, a VSD closure using his native aortic valve for left ventricular outflow. That was the only patient in the series whose z value was greater than –3. His was –2.6.
DR JOHN EDMUND MAYER, JR (Boston, MA): Just to follow up on that last point, what is your cutoff as you are thinking about this for what is an adequate left ventricular outflow tract that could be done as a two-ventricle repair just closing the VSD and repairing the arch, as opposed to this sort of approach where you think the left ventricular outflow tract is basically not going to sustain systemic cardiac output?
DR KANTER: Well, we don't have a hard number and it is certainly subjective, and sometimes we go to the operating room, especially with the interrupted arch with left ventricular outflow tract obstruction, with a plan to do an anatomic repair and then bail out to the Yasui operation. Clearly, anyone with an aortic valve annulus with a z score larger than –2 we would not use this approach, and, in fact, all but one in this study had a z score less than –3. So I think that would be a number that we would hang our hat on. Looking at millimeters, for an average size baby between 2.5 and 3.5 kg, we would say if the aortic annulus is 5 mm, we would never consider this operation, between 4.5 to 5 mm, we would wonder about it, and under 4.5 and certainly under 4 mm, we would do a Yasui procedure.
DR PETER B. MANNING (Cincinnati, OH): You mentioned that early in your series you primarily did B-T [Blalogh-Taussig] shunts, and later performed Sanos. Does this reflect a shift in your institutional bias toward which shunt you perform for all Norwoods, including those with hypoplastic left heart syndrome, or is it unique to this population where you know these kids are going to have an RV to PA conduit at some time?
DR KANTER: It had the desirability of having your ventriculotomy already made and the marking point, so that was one reason, but at the same time we have gravitated towards the Sano shunt in our institution as the preferred shunt for Norwood procedures. We don't do it exclusively, but we do it 90% of the time.
DR BOVE: I just want to clarify one thing, Kirk. Before I get the invitation to come down and scrub on the case, I wouldn't do it any differently than you do, and I am not an advocate of the Ross. I just wanted to hear your thoughts. But I'd love the invitation.
DR CHRISTOPHER BAIRD (Boston, MA): I just wanted to follow up on the comments to Dr Mayer's question. One of the things we have been doing more recently in Boston is looking at the left ventricular outflow tract with 3D echo. It gives us a little bit better assessment, because a lot of these outflow tracts appear to be oval instead of a complete circle. And so making our dimensions in one plane, it fooled us sometimes. So we have critically been trying to assess that ahead of time, and it has given us a pretty good sense going into the operation that these oval type outflow tracts are still amenable to primary repair.
DR KANTER: There is actually a paper I think by Adey and colleagues that did not use 3-dimensional but developed a cross-sectional area of the left ventricular outflow tract and found that some value, which I don't remember, centimeter squared was predictive of left ventricular outflow tract obstruction as opposed to those who would definitely need this approach. So I think that that in the future will help us answer John Mayer's question about which are the patients who should have this approach as opposed to the more standard anatomic repair of interrupted arch with VSD.
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References |
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TopAbstractIntroductionPatients and MethodsResultsCommentDiscussionReferences |
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