Expectations and limitations after bilateral pulmonary artery banding ^†

Abstract

OBJECTIVES

Bilateral pulmonary artery banding (bil-PAB) has been developed as a part of a hybrid procedure for hypoplastic left heart syndrome (HLHS). We use this procedure for palliation of complex congenital heart disease, particularly in patients with arch anomaly. We reviewed our experience with bil-PAB.

METHODS

Sixty-six consecutive cases between 2003 and 2014 were reviewed retrospectively.

RESULTS

Fifty-one patients (77%) had single ventricle physiology (HLHS: 37, HLHS variant: 13, others: 1). Twelve patients had biventricular physiology [5 interrupted aortic arch with ventricular septal defect (VSD); 4 coarctation of the aorta with VSD; 2 truncus arteriosus; 1 other]. In 3 patients, it was difficult to determine if the physiology was single ventricle or biventricle due to borderline left ventricle size. Age and body weight at the time of operation were 4.3 ± 3.4 days and 2.7 ± 0.5 kg, respectively. Overall hospital mortality was 11% (7/66). Of the 42 patients from 2010, only 1 with multiple anomalies died between bil-PAB and the second-stage operation. Thirteen patients (20%) required reoperation of bil-PAB. The mean waiting time for the next operation was 44.3 ± 42.8 days. The body weight at the second-stage operation was 3.2 ± 0.8 kg. Seven (11%) patients developed patent ductus arteriosus obstruction during the waiting period. Twenty-four patients were 2.5 kg or less; 20 patients in this group progressed to the second-stage operation and of these 19 gained body weight. Forty-two patients were above 2.5 kg, but of these only 23 patients gained body weight. Ten patients underwent bil-PAB because of shock and 8 of these recovered from shock. In 2 borderline cases, the patients underwent the Norwood procedure and 1 patient had arch repair and VSD closure.

CONCLUSIONS

Bil-PAB could be applied to a wide variety of complex diseases. Our mortality rates with bil-PAB improved significantly post-2010. Good indications for bil-PAB were shock and situations where it was unclear whether the physiology was single ventricle or biventricular. Body weight gain was difficult to predict, but patients weighing less than 2.5 kg could be expected to gain body weight after the procedure.

INTRODUCTION

Bilateral pulmonary artery banding (bil-PAB) was first described for palliation of truncus arteriosus [ 1 ]. Although bil-PAB has not yet become standard practice in the treatment of truncus arteriosus, the procedure has recently received more attention as a part of a hybrid procedure for initial palliation of hypoplastic left heart syndrome (HLHS) [ 2 , 3 ]. In some institutions, a hybrid procedure is used as an alternative to the Norwood procedure [ 4 ] and recent reports demonstrated that bil-PAB improved the results in severely ill patients with HLHS [ 5 , 6 ].

These reports showed the advantages of bil-PAB, which has been used for palliation of complex congenital heart diseases, such as a single ventricle with arch anomaly and arch anomaly with ventricular septal defect (VSD) or transposition of the great arteries (TGA), in addition to HLHS [ 7–10 ]. Bil-PAB has been shown to be useful as a palliative procedure while awaiting a second-stage operation or heart transplantation. Furthermore, it was also effective in helping patients recover from shock or a severely compromised preoperative status.

We now appreciate some advantages of bil-PAB; however, there are still several limitations with this procedure. In clinical practice, we sometimes obtained suboptimal results with bil-PAB.

Since 2003, in our hospital, we have performed bil-PAB for palliation of complex congenital heart diseases, particularly in patients with arch anomaly. In this report, we review our experience with bil-PAB, focusing on the advantages and limitations of this procedure.

MATERIALS AND METHODS

Patients

Between January 2003 and December 2014, at the Children's Heart Center in Chukyo, 66 consecutive patients underwent bil-PAB and were included in this study. Sixty-four patients had prostaglandin E1 (PGE1) infusion preoperatively and continued PGE1 after the operation. One patient had a single ventricle physiology with persistent truncus arteriosus. His intracardiac anatomy was single ventricle with a single artery arising from the ventricle and the right and left pulmonary arteries originating from this single artery. Bil-PAB was required due to pulmonary overcirculation. He did not require PGE1 infusion because of this unique anatomical structure. One patient underwent bil-PAB with the diagnosis of truncus arteriosus and balanced ventricles.

The clinical perioperative data, such as surgical outcomes, waiting time and body weight gain, were obtained from the patients' medical records. Individual informed consent was waived because of the retrospective nature of the study.

Operative indications for bilateral pulmonary artery banding

In our institution, the operative indications for bil-PAB have changed over time. Bil-PAB was initially performed for palliation of HLHS, with the goal of combined Norwood and bidirectional Glenn (BDG) procedures in the second stage. However, since 2009 we have moved to a rapid two-stage Norwood procedure, which includes elective bil-PAB after birth and the Norwood procedure ∼1 month after bil-PAB. The reason for changing the strategy was the suboptimal results with the combined Norwood and BDG procedures in Stage 2. In our hospital, no patient underwent the Norwood procedure without bil-PAB during this study period. Thus, it was our policy to perform bil-PAB for all HLHS or HLHS variants to stabilize the patient's haemodynamic status and to optimize the timing of the Norwood procedure. We also performed bil-PAB for other complex arch anomalies, mainly to increase the body weight of the patient, especially when the infant had a low birth weight. Another indication for bil-PAB was an arch anomaly in patients that were severely ill or in shock. If complete repair under cardiopulmonary bypass was considered too invasive, bil-PAB was performed to improve the infant's haemodynamic status. Recently, we also performed bil-PAB for borderline left ventricle (LV) patients and selected cases of truncus arteriosus.

Surgical technique

Bil-PAB was performed through a standard median sternotomy. After minimal dissection of the pulmonary artery, bil-PAB was performed using a 2-mm Gore-Tex (WL Gore, Newark, DE, USA) strip. The Gore-Tex strip was made of a 3.5 mm Gore-Tex shunt graft tube. The evaluation of bil-PAB was performed using epicardial colour-flow Doppler echocardiography. Initially, we tried to adjust the tightness to achieve a peak flow velocity of 3.5 m/s at both bilateral banding sites, according to the previous paper [ 11 ]. However, some patients required reoperation of bil-PAB; most of them were tight banding and required loosening the band. We changed the less tight banding gradually and since 2010 we aimed the peak velocity at ∼3.2 m/s with an arterial oxygen saturation of 75–85%.

At the second-stage operation, we preferred right ventricle to pulmonary artery (RV-PA) shunt-type Norwood operation for HLHS, or HLHS variant. In the selected LV-dominant morphology, such as tricuspid atresia, or double inlet left ventricle with hypoplastic aortic arch or coarctation of aorta (CoA), we used modified Blalock–Taussig shunt. Direct arch reconstruction in Norwood procedure was performed if it is possible without tension of the native tissues, but if needed glutaraldehyde-treated autologous pericardium patch was used, because of the very limited availability of homograft patch in our country.

Follow-up and reintervention

All patients remained in the hospital until the second operation. All but 2 patients had continuous PGE1 infusion through peripherally inserted central catheter. Up to now, no vascular stents were officially approved for use in patent ductus arteriosus (PDA) in the paediatric population in Japan and only off-label use of biliary stent has been tried in some hospitals here. We tried 2 cases of PDA stents in this study, but the stent dislocated into the descending aorta in 1 patient and the other patient received cardiopulmonary resuscitation due to haemodynamic instability and shock during the procedure. With the poor results of the initial 2 cases and off-label adoption of the device, we stopped using the PDA stent and it is now our policy to keep the duct open by pharmacological methods. Routine echocardiography was performed weekly to monitor obstruction of the ductus arteriosus or aortic arch and ventricular function. If progressive cyanosis or pulmonary overcirculation became obvious, repeat bil-PAB or an earlier second-stage operation was considered. If PDA started to become obstructive, despite adequate PGE1 infusion dosage, the second-stage operation was considered.

Statistics

Data were examined using the statistical software package, Graphpad PRISM (version 5.0d; GraphPad Software, La Jolla, CA, USA). Data are presented as the frequency or mean ± standard deviation. A probability value of less than 0.05 was taken to represent a statistically significant difference between the two groups. The Fisher exact test was used to analyse differences between the categorical data.

RESULTS

Patient characteristics and indication

Patient characteristics are summarized in Table 1 . Age and body weight at the time of bil-PAB were 4.3 ± 3.4 days and 2.7 ± 0.5 kg, respectively. Fifty-one patients (77%) had single ventricle physiology; 37 patients (56%) were HLHS and 13 patients (20%) were HLHS variants. One patient had single ventricle with persistent truncus arteriosus. Twelve patients (18%) had biventricular physiology; 5 had interrupted aortic arch (IAA) with VSD; 4 CoA with VSD: 2 truncus arteriosus; 1 CoA with aortic valve stenosis (AS). In 3 patients, it was difficult to decide whether the physiology was single ventricle or biventricular physiology due to a borderline LV size. Indications for bil-PAB are given in Table 2 : initial palliation of HLHS or variants, 40; body weight gain, 13; recovery from shock, 10; border line LV, 3.

Overall results and second-stage procedures

The overall results and the second-stage procedures are described in Table 3 . After bil-PAB, 7 patients (11%) died before the second-stage operation, 3 patients died of sepsis and 1 patient had pneumonia and haemorrhage. One patient had pulmonary overcirculation after bil-PAB and repeat bil-PAB was performed, but this patient did not recover from heart failure. One patient was reoperated with bil-PAB due to continued hypoxia; however, after reopening the chest, the baby became shocked; extracorporeal membrane oxygenation (ECMO) was initiated but the patient subsequently died. One baby was born with a diagnosis of double outlet right ventricle (DORV), TGA, CoA and AS and the birth weight was 2062 g; she had multiple anomalies such as cerebellar hypoplasia, corpus callosum deficiency and external genital abnormalities. One week after birth, the baby suffered heart failure due to pulmonary overcirculation. The baby, with a body weight of 1706 g, underwent bil-PAB. A chromosomal abnormality was suspected but testing could not reveal this despite her multiple anomalies. After the bil-PAB, the baby had repeated infections and was unable to be weaned off the ventilator. Palliative care was discussed with the family members, but they opted for active treatment. She died 9 months after bil-PAB due to respiratory failure.

There was a statistically significant difference in mortality before 2010 and after 2010 ( P = 0.02). We have changed the tightness of the banding since 2010. Before 2010, 24 patients underwent bil-PAB and 5 patients (21%) died before second-stage operation. Since 2010, 42 patients have received bil-PAB, and 1 patient died before second-stage operation. One patient was found to have biliary atresia after bil-PAB and referred to another hospital for appropriate treatment.

Thirteen patients (20%) required reoperation for bil-PAB. In 10 of these patients, the PAB was loosened because of hypoxia due to tight banding or the lack of flow in a PA branch. The PAB was tightened in the remaining 3 patients due to pulmonary overcirculation and heart failure. After 2010, 4 patients required reoperation for bil-PAB, whereas 9 patients died before 2010.

As a second-stage operation, 36 patients had the Norwood operation and 6 patients had the combined Norwood and BDG procedures (Table 4 ). Eleven patients had complete biventricular repair (CoA, VSD, 3; IAA, VSD, 2; Yasui operation, 2; truncus, 2; CoA, AS release, 1; CoA, DORV, 1). Five patients underwent other palliative procedures. Two patients had conversion from bil-PAB to main PAB with arch repair. One patient came to our hospital with renal failure 1 day after birth and he was diagnosed as single right ventricle, hypoplastic aortic arch and coarctation. Arch repair using cardiopulmonary bypass was thought to damage renal function and bil-PAB was preferred as an initial palliation. After the recovery of renal function, cyanosis progressed and arch repair and main pulmonary artery banding was performed successfully with cardiopulmonary bypass about 4 weeks after bil-PAB. Another patient was born with the diagnosis of single right ventricle, hypoplastic arch and coarctation. His body weight was 2180 g and arch repair with cardiopulmonary bypass was deemed difficult due to a low body weight. Bil-PAB was undertaken and 7 weeks after bil-PAB the body weight reached nearly 3 kg and he had arch repair and main pulmonary artery banding with cardiopulmonary bypass.

Two patients received a palliative shunt from the innominate artery to the descending aorta due to complex arch anatomy. One patient was born with the diagnosis of Type B IAA, aberrant right sub-clavian artery, AS and VSD. Pulmonary overcirculation progressed after birth and arch repair was deemed too complex; bil-PAB was performed, but, after bil-PAB, the PDA obstructed the right bronchus; a palliative shunt from the innominate artery to the descending aorta was performed with improvement of the bronchial obstruction. Another patient underwent bil-PAB with the diagnosis of HLHS; after bil-PAB, angiography demonstrated a very long PDA and a right sub-clavian artery coming from a very low descending aorta; arch repair seemed to be almost impossible through a midline sternotomy. She was also diagnosed with Jacobsen syndrome, which included a bleeding disorder. Standard Norwood operation was thought to be high-risk and a palliative shunt from the innominate artery to the descending aorta was undertaken.

One case of truncus with a single ventricle developed tracheal stenosis due to dilatation of the central part of the pulmonary artery after bil-PAB. We therefore disconnected the pulmonary artery from the aorta and placed an RV-PA conduit for pulmonary inflow. The patient's tracheal stenosis improved after surgery.

The issue of weight gain

Waiting time until the Stage-2 procedure was 44.3 ± 42.8 days, and 3.2 ± 0.8 kg (Table 5 ). The mean body weight gain was 0.5 ± 0.7 kg. After bil-PAB, many patients had a reduced body weight and took a short while to recover from this. At 15 days after bil-PAB, only 17 of 48 (35%) patients had gained weight. At 30 days after bil-PAB, 76% (26/34) had gained weight. The mean body weight gain was 7.7 ± 16.5 g/day. Only 12 patients gained more than 20 g/day. Fifty percent (33/66) of patients waited more than 4 weeks, 7 patients waited less than 2 weeks and 18 patients waited for 2–4 weeks. In the single ventricle group, 45 of 51 patients reached the second-stage operation and 11 did not gain the body weight, but 34 increased their body weight. Average body weight gain and waiting period were 452 ± 681 g and 42 ± 33 days, respectively, in this group. In the biventricular group, 10 out of 12 patients underwent the second-stage operation; 3 did not gain body weight, 7 gained body weight. Average body weight gain and waiting period were 861 ± 803 g and 48 ± 22 days, respectively, in this group.

At bil-PAB, 24 patients were 2.5 kg or less, and 20 of 24 patients reached the second-stage operation. Forty-two patients were above 2.5 kg at bil-PAB, and 37 of them reached the second-stage operation. At the time of second-stage procedure, significantly more patients gained the body weight among the patients with less than 2.5 kg at bil-PAB ( P = 0.005). Nineteen of the 20 patients with 2.5 kg or less gained body weight, and 23 of 42 patients above 2.5 kg gained body weight. The individual body weight increase was also significantly better in the patients with 2.5 kg or less at bil-PAB than the patients above 2.5 kg ( P = 0.048). The patients with 2.5 kg or less at bil-PAB gained 761 ± 603 g body weight gain at the second-stage operation, and the patients above 2.5 kg gained 331 ± 692 g.

Unplanned earlier second-stage operation

Overall, 58 of 66 reached the second-stage operation. Thirty-three patients safely waited for the second-stage operation after they accomplished their initial goal of bil-PAB. An unplanned earlier second-stage operation was required in 25 (38%) of patients, before they reached their initial goal of bil-PAB. Table 6 shows the reasons for unplanned earlier second-stage operation after bil-PAB. Although PGE1 was continued after the procedure, 7 patients developed PDA obstruction during the waiting period. Five patients developed heart failure due to pulmonary overcirculation, whereas 3 patients developed progressive cyanosis. Two patients developed tracheal stenosis due to enlargement of the main pulmonary artery. Pulmonary venous obstruction was found in 2 patients with progression of the original condition with total anomalous pulmonary venous drainage (TAPVD). Others included arrhythmia ( n = 1), ischaemia ( n = 1), periosteal thickening due to PGE1 ( n = 1) infusion, progression of aortic valve regurgitation ( n = 1) or progression of left ventricular hypertrophy ( n = 1). One patient developed pericardial effusion 6 days after bil-PAB and required surgical drainage with the Norwood operation performed at the same time.

Special indications for bilateral pulmonary artery banding: patients with shock, borderline left ventricle and very low weight at birth

Ten patients underwent bil-PAB mainly because of shock; 8 of these patients recovered from the shock and progressed to the second-stage operation under stable conditions. Seven of 9 patients in preoperative shock were HLHS or HLHS variants. One patient with HLHS presented to our hospital with shock; we performed bil-PAB, but the patient developed sepsis and died. Another patient in shock with VSD and CoA developed pneumonia and haemorrhage and died. The other 8 patients did not develop any infections during the recovery after bil-PAB.

Thirteen patients underwent bil-PAB mainly aiming for body weight gain. Five patients were less than 2 kg and all of them gained more than 2 kg. However, only 5 patients gained more than 1 kg body weight and others underwent early second-stage intervention due to the instability of their condition. In borderline cases, 2 patients underwent the Norwood procedure and 1 patient had arch repair and VSD closure. Two of them waited more than 1 month and had detailed investigations in this period. One patient undergoing the Norwood procedure waited only 7 days after bil-PAB, but even this was helpful in obtaining detailed investigations for decision-making.

DISCUSSION

Muller and Dammann [ 12 ] introduced main pulmonary artery banding in clinical practice in 1951. This operation has been used as a palliative procedure in small infants with congenital heart defects, such as VSD or complete AVSD, followed by definitive repair at an older age. Recent improvements in surgical management have promoted an early complete repair of these defects; however, simple main PA banding still has its role. When more complex congenital heart diseases became suitable for treatment, bil-PAB was first described as palliation for truncus arteriosus [ 1 ]. Although bil-PAB did not become the standard practice at that time, Gibbs et al . [ 3 ] included it as part of a hybrid approach to palliation for HLHS, which consisted of stenting of the ductus arteriosus, banding of the pulmonary arteries and atrial septectomy.

In our hospital, because of suboptimal results with the Norwood Stage-1 procedure, we initially started bil-PAB as an alternative and planned to complete the combined Norwood and BDG operations in the second stage, as previously reported [ 4 , 11 , 13 ]. However, our results with this procedure were suboptimal and it was not always easy to wait for the combined Norwood and BDG procedures. The reason for suboptimal results may be due to the significant comprehensive Stage-2 procedure or continuous PGE1 infusion instead of ductal stenting. The present study showed adverse sequelae after bil-PAB, which may partly explain the poorer results from the combined Norwood and BDG programme.

More recently, we have started a rapid two-stage Norwood programme and the overall results have improved. Because the rapid two-stage Norwood programme has a shorter interval after bil-PAB, it is much easier to maintain a stable condition between the two stages.

Recent reports have shown other applications of bil-PAB. Bil-PAB is now used for truncus arteriosus, CoA/VSD or other complex arch anomalies to delay the timing of complete repair [ 7 , 9 , 10 , 14 ]. An advantage of a staged repair strategy with prior palliation is that it allows for a delay in the timing of complete repair so that body weight can increase and organs can mature, which should overcome some of the aforementioned risk factors. In contrast to the main PAB, bil-PAB usually requires continuous prostaglandin infusion due to a PDA. In our experience, only 2 patients did not require PGE1 infusion.

One of the questions in this study was how long the baby can wait under stable conditions after bil-PAB. As has been shown, body weight gain was one of our main indications for bil-PAB, but some of the patients were unable to reach appropriate body weight gain. There was no previous report relating to infusion of PGE1 and lack of body weight gain. When we first started using the bil-PAB procedure, we thought that a longer waiting period would be beneficial due to increased weight gain before the second-stage operation. However, unlike main PAB, bil-PAB was found to have some limitations related to the ductus. In this study, 9 patients developed PDA obstruction during the waiting period. In addition, the patient's haemodynamic status was sometimes unstable, due to the original complex anomalies. Therefore, our current expectations of bil-PAB are more limited than before. According to our current study, if the body weight of the patient was more than 2.5 kg, there was no advantage in waiting with bil-PAB in terms of body weight gain. However, a small patient with a body weight less than 2.5 kg would probably gain a decent body weight after bil-PAB. We now consider an upfront initial Norwood procedure in patients with relatively heavier body weight.

Another concern is pulmonary artery growth after bil-PAB. Recent reports showed limited growth of the pulmonary artery after bil-PAB [ 15 , 16 ]. This problem may be related to the period of bil-PAB. We did not evaluate the growth of pulmonary artery in this study. However, because a long duration of banding probably limits the growth of the pulmonary artery, a shorter waiting time may be more appropriate. Therefore, it is reasonable to use bil-PAB within a limited time period.

After initial reports of the hybrid procedure, bil-PAB attracted much attention although the hybrid procedure has not yet become a standard procedure due to several issues. However, bil-PAB itself is useful as palliation for complex arch anomalies or recovery from shock.

From this study, we were able to appreciate the potential role of bil-PAB in clinical practice. Bil-PAB could be applied in a wide variety of complex congenital heart diseases. Bil-PAB is useful as a salvage procedure to postpone the next stage of decision-making for some time. However, there is a learning curve to producing stable results with bil-PAB.

This study was limited primarily by the small number of patients, the retrospective nature of the study and the lack of randomization of patients. Furthermore, the indication and strategy for bil-PAB has changed over the time course of our study.

In conclusion, bil-PAB could be applicable in a wide variety of complex diseases. In terms of mortality, we followed a learning curve, but after 2010, bil-PAB was performed with lower mortality rates. Indications for bil-PAB were shock and salvage to allow a second procedure for single ventricle or biventricular physiology. Body weight gain was difficult to predict with patients less than 2.5 kg, expecting to gain relatively more body weight after the procedure. Earlier second-stage intervention may be required, depending on the patient's condition.

Conflict of interest: none declared.

REFERENCES

APPENDIX. CONFERENCE DISCUSSION

Dr J. Hörer(Le Plessis-Robinson, France): You applied bilateral pulmonary artery banding to various different types of complex congenital heart defects. The differences in pathology and the differences in additional risk factors make it difficult to assess the benefit of this strategy as compared to the conventional approach. Therefore, in the following two questions, I would like to focus on the experience of your 37 patients presenting with hypoplastic left heart syndrome.

My first question, the efficacy of the strategy in terms of mortality has to be determined during follow-up, at least beyond the Norwood operation, ideally beyond the Fontan completion. Do you have any data on Kaplan-Meier survival of your patients, with hypoplastic left heart syndrome, let us say, for one year, for example?

Dr Sakurai: Actually, I do not have the Kaplan-Meier data right now, but I could say before this stage of the procedure, more than half of the hypoplastic had died before 2003. Also, after 2003, we tried a sort of hybrid approach, and we did it on 6 patients, but only 3 survived and after we changed to the rapid 2-stage Norwood, I think it is more about the certifiable patient in this paper. Around 30 patients survived after the Norwood. So somehow, we had a significantly better result after this procedure.

Dr Hörer: And that is the reason why now your current practice is to perform routine bilateral pulmonary banding in all neonates, and proceed with the Norwood at 4 weeks.

My last question is what improvements in preoperative status do you think you can achieve by this strategy in a well-developed newborn in the absence of any additional risk factors?

Dr Sakurai: Because we have no comparison group in our study, we have only this routine rapid 2-stage Norwood group. I cannot compare. But from the other article, if you wait a few weeks, they may get better during output or maybe some sort of mature organ system, but this is not very clear. Also, I could say in some centers, they select rapid 2-stage Norwood for high risk patients. That means if you put the rapid 2-stage Norwood even in a low-risk patient, you may get a better result. But you have to see.

Dr A. Corno(Leicester, UK): I have two questions. First you said you were using strips of 2 mm Gore-Tex with the aim to reach 3.2 meter per second velocity, but you did not say how you calibrate the banding for each pulmonary artery. What criteria of measure do you use?

Dr Sakurai: Basically, with a 3.0 kg baby, we usually aim for about 10 mm; and 2.5 kg, we usually tend to use 9 mm and we do just a little change after the 10 or 9 mm.

Dr Corno: This is the size of the conference, of course?

Dr Sakurai: Looking at the echoes, yes.

Dr Corno: Then in 20% of the cases, you had to go back to loosen or tighten the band. Is your policy to close the sternum in all the patients or to leave it open, or based on what kind of criteria do you decide?

Dr Sakurai: In terms of mortality, we had a significant improvement. Also, in terms of reoperation, after 2010, we did have only one reoperation, so we did not need a learning curve.

Dr Corno: Did you routinely close the sternum?

Dr Sakurai: Yes.

Dr V. Hraska(Sankt Augustin, Germany): I have one short question. I understand your philosophy in regards to the hypoplastic left heart, but what confused me a bit is why you applied this policy in biventricular heart with a coarctation. Instead of addressing the coarctation first, you performed a bilateral pulmonary artery banding bilateral, so what is the idea behind that?

Dr Sakurai: Okay, coarctation with ventricular septal defect presenting with shock, or body weight less than 2.2 kg or less than 2.1 kg, we prefer to do the bilateral PA-banding. And also, the patient prepares for a truncus or Yasui type operation. They need an external conduit. In that case, we have to wait for more than 3.0 kg.

Dr Hraska: Yes, we do the stenting of the coarctation first.

Dr Sakurai: I see.

Author notes