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Pulmonary Artery Banding for Functionally Single Ventricles: Impact of Tighter Banding in Staged Fontan Era
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Pulmonary Artery Banding for Functionally Single Ventricles: Impact of Tighter Banding in Staged Fontan Era Noriyoshi Kajihara, MD, Toshihide Asou, MD, Yuko Takeda, MD, Yoshimichi Kosaka, MD, Yasuko Onakatomi, MD, Hiroyuki Nagafuchi, MD, and Seiyo Yasui, MD Department of Cardiovascular Surgery, Intensive Care Unit, and Department of Pediatric Cardiology, Kanagawa Children’s Medical Center, Yokohama, Japan
Background. In this study, we assessed our surgical strategy, tighter pulmonary artery banding (PAB) during the neonatal period, as an initial step followed by early application of bidirectional cavopulmonary shunts (BCPS) in infancy, to treat functionally single ventricles with unobstructed pulmonary blood flow. Methods. On the basis of our surgical strategy, 68 consecutive patients underwent PAB and were divided into two groups, group 1 (January 1990 to June 2003; n ⴝ 30) and group 2 (July 2003 to August 2008; n ⴝ 38). The median age at PAB was 45 days in group 1 and 9 days in group 2. The circumference of the bands was significantly shorter in group 2 than in group 1, corresponding to the patient’s weight in kg plus 19.0 ⴞ 0.6 mm in group 1 or 17.0 ⴞ 0.3 mm in group 2 (p ⴝ 0.003). Results. Cardiac catheterization before the right heart bypass operation showed that the pulmonary artery in-
dex (group 1, 322 ⴞ 29; group 2, 283 ⴞ 27 mm2/m2; p ⴝ 0.01), pulmonary resistance index (group 1, 2.4 ⴞ 0.2; group 2, 1.9 ⴞ 0.1 U ⴛ m2; p ⴝ 0.03), and ventricular end-diastolic volume (group 1, 212 ⴞ 19%; group 2, 166 ⴞ 9%; p ⴝ 0.04) were significantly different between the two groups. The rates for achievement of right heart bypass at 12 months (group 1, 19%; group 2, 81%; p < 0.01) and survival at 3 years (group 1, 70%; group 2, 87%; p ⴝ 0.04) were significantly higher in group 2 than in group 1. Conclusions. Our present strategy could prevent volume overload and improve the achievement and survival rates of right heart bypass operations.
P
early application of BCPS during infancy. The application of a tighter PAB in the neonatal period might prevent volume overload, protect the pulmonary vascular beds and ventricular function, and improve the BCPS achievement rate and the Fontan completion rate. It seems likely that tighter PABs are empirically performed in many institutes that have adopted the staged Fontan strategy to manage functionally single ventricles with increased pulmonary blood flow. However, we have found no reported evidence to support this approach. The purpose of this study was to assess the impact of our current surgical strategy for the treatment of functionally single ventricles with unobstructed pulmonary blood flow in terms of protecting pulmonary vascular beds and ventricular function, and consequently achieving successful right heart bypass operation. Accordingly, we compared two groups of patients; patients were treated using the previous strategy before the staged Fontan era and patients treated using our current strategy.
ulmonary artery banding (PAB) plays an important role as an initial step in the successful management of functionally single ventricles with unobstructed pulmonary blood flow, but not in biventricular hearts because of the high prevalence of primary repair [1, 2]. It is essential to reach an adequate balance between systemic and pulmonary blood flow in the surgical management of functionally single ventricles with unobstructed pulmonary blood flow. Accordingly, the tightness of the pulmonary arterial band is an important factor. Using the staged approach to the Fontan operation, tighter pulmonary arterial banding can be applied because it allows us to perform the next step at an earlier stage. Consequently, beneficial effects on the ventricle and pulmonary beds can be achieved using tighter banding. Because younger patients can tolerate bidirectional cavopulmonary shunt (BCPS), even at 2 months old [3], we believe that PAB in the staged Fontan era should be tighter than that used in the nonstaged Fontan era. To treat functionally single ventricles with unobstructed pulmonary blood flow, our current strategy involves applying a tight PAB in the neonatal period as an initial step, followed by
Accepted for publication Sept 14, 2009. Address correspondence to Dr Kajihara, Kanagawa Children’s Medical Center, 2-138-4 Mutsukawa, Minami-ku, Yokohama, Kanagawa, 232-8555, Japan; e-mail: [email protected].
© 2010 by The Society of Thoracic Surgeons Published by Elsevier Inc
(Ann Thorac Surg 2010;89:174 – 80) © 2010 by The Society of Thoracic Surgeons
Patients and Methods Patients This study was approved by the ethics committee of Kanagawa Children’s Medical Center. The need for in0003-4975/10/$36.00 doi:10.1016/j.athoracsur.2009.09.027
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Table 1. Characteristics of the Patients in Both Groups
Age (days): Mean Median (range) Body weight (kg): Mean Median (range) Dominant ventricle (RV/LV) Heterotaxy syndrome Down syndrome Diagnosis Tricuspid Atresia DORV with hypoplastic ventricle Unbalanced AVSD Other Complex of Single Ventricle Coarctation of aortic arch TAPVD
Group 1 (n ⫽ 30)
Group 2 (n ⫽ 38)
p Value
80.2 ⫾ 16.0 45 (0–367) 4.2 ⫾ 0.4 3.7 (2.7–7.3) 13/17 4 (13%) 1 (3%)
23.4 ⫾ 5.2 9 (0–132) 3.1 ⫾ 0.1 3.0 (1.9–5.4) 25/13 8 (21%) 4 (10%)
⬍0.01
13 (44%) 4 (13%)
3 (8%) 12 (32%)
⬍0.01 0.09
3 (10%) 10 (33%)
11 (29%) 12 (31%)
0.07
4 (13%) 2 (7%)
19 (50%) 2 (5%)
⬍0.01 0.60
ation for the first stage. In these five patients, the subaortic, aortic valve, or bulboventricular foramen area was less than 0.7 cm2/m2, as measured on the preoperative echocardiogram.
Operative Technique 0.03 0.09 0.36 0.26
AVSD ⫽ atrioventricular septal defect; DORV ⫽ double outlet right ventricle; LV ⫽ left ventricle; RV ⫽ right ventricle; TAPVD ⫽ total anomalous pulmonary venous drainage.
dividual consent was waived. The authors had full access to the data and take full responsibility for their integrity. Between October 1990 and August 2008, 68 neonates or infants with a functionally single ventricle and unobstructed pulmonary blood flow underwent main PAB at Kanagawa Children’s Medical Center. The PAB was the first step performed in all patients. Based on the strategy used to determine the tightness of the pulmonary banding, we divided the patients into two groups: group 1 (n ⫽ 30), patients who underwent PAB between 1990 and June 2003; and group 2 (n ⫽ 38), patients who underwent PAB after July 2003. The age, body weight, specific anatomic lesions in this series with a functionally single ventricle, and associated anomalies are presented in Table 1. The age ranged from 0 to 367 days (median, 45 days) in group 1, and from 0 to 132 days (median, 9 days) in group 2. Although there was a significant difference in body weight between the two groups, there was no difference in the size of the main pulmonary trunk before PAB (group 1, 11.2 ⫾ 2.4 mm; group 2, 10.8 ⫾ 3.1 mm; p ⫽ 0.76). The incidence of associated aortic coarctation was higher in group 2. Morphologic features of the aortic arch, the pulmonary artery (PA), and intracardiac defects were evaluated preoperatively on an echocardiogram or threedimensional helical computed tomography. The surgical approach to be used was selected based on these data and considering the general conditions of the individual case. The presence of an aortic arch obstruction suggested a right to left shunt across the ductus. The distal aortic arch was hypoplastic if its diameter was less than the body weight in kilograms plus 1 mm [4]. Five patients with a functionally single ventricle and severe subaortic or aortic valve stenosis were excluded from the present study because they were indicated for a Norwood oper-
The chest was entered through an anterolateral thoracotomy or a median sternotomy according to concomitant procedures. We used a 0.6-mm thick, 4-mm wide, expanded polytetrafluoroethylene (ePTFE) patch as a tape to band the main pulmonary artery. Concomitant coarctectomy plus extended aortic arch anastomosis with or without distal arch augmentation from a median sternotomy was performed in 10 patients. In the other patients, concomitant subclavian flap aortoplasty was performed through a posterolateral thoracotomy. The circumference of the band was calculated as the patient’s weight in kilograms plus 20 mm for group 1 or 18 mm for group 2, according to a modified version of Trusler’s formula [5]. The tightness of the band was considered appropriate when the oxygen level was around 35 mm Hg at 21% or 40% of fraction of inspired oxygen during surgery in group 1 or at 60% in group 2. As a result, the circumference of the band was tighter in group 2 than in group 1. The final circumference of the band was the patient’s weight in kilograms plus 19.0 ⫾ 0.6 mm in group 1 and 17.0 ⫾ 0.3 mm in group 2 (p ⬍ 0.01). The circumference of the bands is shown in Figure 1. At discharge, the median percutaneous oxygen saturation was 80% (75% to 90%) in group 2. Concomitant procedures in group 1 included repair of the aorta coarctation in four patients, repair of total anomalous venous drainage in 2, tricuspid valve plasty in one, and enlargement of the ventricular septal defect (VSD) in one. In group 2, the aorta coarctation with or without distal arch hypoplasia was repaired in 19 patients.
Statistical Analysis The continuous data in this study are expressed as mean values ⫾ standard error of the mean. Analyses were 35
Circumference (mm)
Characteristics
175
30 Group 1
25 20
Group 2
15 10 0.0
2.0
4.0
6.0
8.0
Weight (kg) Fig 1. Association between body weight and band circumference. The white symbols represent the patients in group 1; black symbols represent the patients in group 2.
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Fig 2. The graphs show the pulmonary artery (PA) index (group 1, 322 ⫾ 29 mm2/m2; group 2, 283 ⫾ 27 mm2/m2, p ⫽ 0.01) and the pulmonary resistance index (group 1, 2.4 ⫾ 0.2 U · m2; group 2, 1.9 ⫾ 0.1 U · m2, p ⫽ 0.03).
performed using SPSS software (version 11.0J; SPSS Inc, Chicago, IL). Normally distributed clinical parameters were compared with t tests. The Fisher exact test was used for binary variables. Non-normally distributed clinical parameters were compared with the Mann-Whitney test. The rate of achieving right heart bypass and the survival rate were calculated using the Kaplan-Meier method with log-rank and Breslow comparison of groups.
Results Treatments Required Before Right Heart Bypass GROUP 1. Two patients in group 1 died in hospital as a result of heart failure. A repeat PAB after the initial PAB was performed in nine patients and modified BlalockTaussig shunts (BTS) due to distortion of the PA and poor growth of PA were required in three patients. Systemic outflow tract obstruction developed in 3 patients, in whom surgery involving Damus-Kaye-Stansel (DKS) anastomosis with systemic-pulmonary shunt was required for two patients at 20 days or 4 years after PAB, while ligation of the main pulmonary artery with a modified BTS was required in one patient at 1 month after PAB. GROUP 2. None of the patients died in hospital and none of the patients developed a systemic outflow tract obstruction after PAB. Six surgical interventions were required after the initial PAB in five patients, including repeat PAB in two patients, loosening of the band in one, modification of the BTS due to distortion of the PA in one, repair of the aortic coarctation in one, and creation of an atrial septal defect (ASD) in one.
Fig 3. The graphs show the ventricular enddiastolic volume (group 1, 212 ⫾ 19% of normal value; group 2, 166 ⫾ 9%, p ⫽ 0.04) and the ventricular end-diastolic pressure (group 1, 8.3 ⫾ 0.5 mm Hg; group 2, 7.3 ⫾ 0.6 mm Hg, p ⫽ 0.16). (V-EDV ⫽ ventricular end-diastolic volume; V-EDP ⫽ ventricular end-diastolic pressure.)
Cardiac Catheterization Before Right Heart Bypass Operation Cardiac catheterization before the right heart bypass operation revealed two patients with a significant pressure gradient (⬎20 mm Hg) between the systemic ventricle and the ascending aorta (systole) in group 1, but none in group 2. There was a significant difference in the pressure gradient of the systemic ventricle-ascending aorta between the two groups (group 1, 6.6 ⫾ 1.7 mm Hg; group 2, 3.4 ⫾ 0.8 mm Hg, p ⫽ 0.02). The PA index (group 1, 322 ⫾ 29 mm2/m2; group 2, 283 ⫾ 27 mm2/m2, p ⫽ 0.01) and the pulmonary resistance index (group 1, 2.4 ⫾ 0.2 U · m2; group 2, 1.9 ⫾ 0.1 U · m2, p ⫽ 0.03) were significantly different between the two groups (Fig 2). The pulmonary to systemic flow ratio (group 1, 1.1 ⫾ 0.1; group 2, 1.2 ⫾ 0.1, p ⫽ 0.28) and the pulmonary arterial pressure (group 1, 13.7 ⫾ 0.8 mm Hg; group 2, 15.2 ⫾ 1.2 mm Hg, p ⫽ 0.20) were comparable in both groups. With regard to ventricular function, the ventricular enddiastolic volume was significantly smaller in group 2 than in group 1 (group 1, 212 ⫾ 19% of the normal value; group 2, 166 ⫾ 9%, p ⫽ 0.04) (Fig 3), although the ejection fraction of the systemic ventricle (group 1, 0.598 ⫾ 0.024; group 2, 0.634 ⫾ 0.025, p ⫽ 0.29) and the ventricular end-diastolic pressure (group 1, 8.3 ⫾ 0.5 mm Hg; group 2, 7.3 ⫾ 0.6 mm Hg, p ⫽ 0.16) were similar and were stable in both groups.
Achievement of Right Heart Bypass Operation GROUP 1. Twenty-four patients (80%) in group 1 underwent
a successful right heart bypass operation between 7.0 and 80.3 months (median, 22.9 months) after PAB, and the age at surgery ranged from 8.4 to 80.6 months (median, 29.3
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plished at an earlier stage with a higher rate of achievement compared with that in group 1. Logistic regression analysis revealed that group 2 (p ⬍ 0.01) and the band circumference (p ⫽ 0.02) were determinants for achievement of the right heart bypass.
Follow-Up
Fig 4. Rates of achieving right heart bypass. Group 1 (dashed line): 19% at 12 months, 48% at 24 months, and 56% at 36 months. Group 2 (solid line): 30% at 6 months and 81% at 12 months.
months old). Four patients died before the right heart bypass operation due to heart failure in one and sepsis in one. The other two patients developed systemic outflow tract obstruction and died after the DKS anastomosis with a systemic-pulmonary shunt. Sixteen of the 24 patients underwent BCPS and the others underwent a modified Fontan operation. Concomitant procedures included DKS anastomosis in one patient, relief of subaortic stenosis in one, VSD enlargement in one, atrioventricular valve repair in two, ASD creation in one, and PA plasty in two. The rate of achieving right heart bypass operation was 19%, 48%, and 56% at 12, 24, and 36 months after the initial PAB, respectively (Fig 4). GROUP 2. Thirty-three patients (87%) underwent a successful right heart bypass operation between 1.5 and 23.3 months (median, 6.6 months) after PAB, and the age at surgery ranged from 3.4 to 23.7 months (median, 7.6 months old). Two patients with atrioventricular septal defects and a hypoplastic left ventricle died before the achievement of BCPS because of ventricular failure in one and an unknown cause in the other. The other patients underwent BCPS during the subsequent second-stage operation. The subaortic space looked morphologically stenotic in 14 patients on angiography or echocardiogram before BCPS, although a significant pressure gradient was not observed in any patient. In patients with potential systemic ventricular outflow tract obstruction, an active approach to the subaortic lesion was taken at the BCPS. Concomitant procedures included DKS anastomosis in 12 patients, relief of the subaortic stenosis in one, VSD enlargement in one, atrioventricular valve repair in three, ASD creation in eight, repair of total anomalous venous drainage in two, and PA plasty in four. The rate of achieving right heart bypass operation was 30 and 81% at 6 and 12 months after the initial PAB, respectively (Fig 4). The rate of achievement of right heart bypass operation was significantly different (p ⬍ 0.01) between the two groups based on the log-rank and Breslow comparisons. In group 2, the right heart bypass operation was accom-
All patients have attended our center for follow-up, with a follow-up interval ranging from 4.5 months to 18.4 years. The survival rate was 80%, 70%, and 63% at 1, 3, and 5 years, respectively, in group 1, and 94% at 1 year and 87% at both 3 and 5 years in group 2 (Fig 5). The survival rates were significantly different (p ⫽ 0.04) between the two groups based on the log-rank and Breslow comparisons. In the logistic regression analysis, the results indicated that group 2 was the only independent factor predicting survival with a p value of 0.43. The Fontan operation was performed successfully in a total of 41 patients, including 19 in group 1 with a mean follow-up of 134.8 ⫾ 51.2 months and 22 in group 2 with a mean follow-up of 30.5 ⫾ 16.9 months. The central venous pressure 1 year after the Fontan procedure was significantly lower in group 2 than group 1 (11.8 ⫾ 1.3 vs 9.0 ⫾ 1.7, p ⫽ 0.01).
Comment In this study we assessed our current surgical strategy to treat functionally single ventricles with unobstructed pulmonary blood flow, which involves application of a tight PAB during the neonatal period as an initial step with subsequent application of BCPS during infancy, at an earlier time than previously used. The aim of this strategy is to protect the pulmonary vascular beds and ventricular function, and to achieve a right heart bypass operation. The major findings in the present study, using the present strategy, are as follows: (1) the ventricular volume overload was significantly attenuated; (2) the pulmonary vascular beds appear to be better protected; and (3) the rate of achieving right heart bypass operation and the survival rate were significantly improved.
Fig 5. Survival rates after initial pulmonary artery banding. Group 1 (dashed line): 80% at 1 year, 70% at 3 years and 63% at 5 years. Group 2 (solid line): 94% at 1 year, 87% at both 3 and 5 years.
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Staged Fontan Strategy
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The BCPS plays an important role as a staged procedure in the Fontan operation and has led to a decrease in ventricular volume overload at a younger age [6, 7]. Furthermore, the survival rate after BCPS is high [8 –10]. Lee and colleagues [8] reported that the mortality in the pre-Fontan stage was 41.3% in the non-BCPS group and 16.3% in the BCPS group. The BCPS decreased the mortality in the pre-Fontan stage, and increased the likelihood of proceeding to the Fontan procedure. Cochrane and colleagues [9] analyzed the outcome of the Fontan operation at various times to assess the effect of prior BCPS, and reported that the mortality associated with the Fontan operation decreased from 8.5% (1980 to 1987) to 1.8% (1988 to 1995), coinciding with the introduction of the BCPS. Furthermore, Tanoue and colleagues [7] examined cardiac catheterization data before and after the Fontan operation, and reported that the volume reduction achieved with BCPS preceding the Fontan operation allowed for the correction of any after-load mismatch and improved the ventricular energetics after the Fontan operation. These findings prompted us to use the staged strategy for all Fontan candidates. On the other hand, it was demonstrated that the rate of achieving the right heart bypass operation was low in patients with a functionally single ventricle [11, 12]. For example, Rodefeld and colleagues [11] reported that only 49 of 76 patients (64%) who had previously undergone PAB for a functionally single ventricle underwent a successful right heart bypass operation. The right heart bypass operation tends to be performed at a younger age [3, 13]. We consider that PAB in the staged Fontan era could be tighter than that used in the non-staged Fontan era. Using a tighter PAB during the neonatal period as an initial step may allow us to achieve successful BCPS at an earlier stage and ultimately complete the staged Fontan procedure.
Systemic Outflow Tract Obstruction To avoid the development of systemic outflow tract obstruction, ventricular dysfunction, or morbidity associated PAB, several reports have demonstrated that a strategy based on the progressive application of DKS or a palliative arterial switch on cardiopulmonary bypass in infancy was effective [14 –16]. These reports were based on the hypothesis that the PAB accelerated the systemic outflow tract obstruction secondary to muscular hypertrophy and restriction of the VSD in the subaortic area [11, 17, 18]. However, these reports have also revealed that the patients developed subaortic stenosis at the age of 1.3 to 3 years. This is one reason why we apply the BCPS earlier with aggressive concomitant DKS in infancy. Despite the early PAB, more patients in group 2 than group 1 in this study required an approach to the subaortic lesion. One reason seems to be that there were many patients with coarctation of the aortic arch in group 2, with a high probability of later development of systemic ventricular outflow tract obstruction; therefore, we fre-
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quently applied arch reconstruction and used a tight PAB. Another reason is that our strategy was altered to BCPS in infancy with active DKS actively, if indicated by the morphology, because we found that some patients needed repeated release from the subaortic stenosis after the Fontan operation. Jensen and colleagues [19] suggested that the high-risk group of patients with subaortic obstruction and a functionally single ventricle could undergo PAB as an initial step, with a subsequent intervention for subaortic obstruction, and that acceptable pre-Fontan hemodynamic parameters could be achieved. Webber and colleagues [20] performed PAB in infants with a double-inlet left ventricle and transposition of the great vessels in the absence of severe subaortic stenosis, and recommended early relief of subaortic stenosis in combination with BCPS in infancy. The benefits of PAB include the relative simplicity and the low mortality associated with the procedure. The PAB offers improved survival rates and does not preclude the performance of more complex surgical interventions in the neonatal period. As described above (in the “Patients” section), we performed a Norwood operation in five patients with successful outcomes. Although the Norwood or DKS operations offer useful approaches, we consider that these should not comprise the primary step for patients with a functionally single ventricle with unobstructed pulmonary blood flow. The main limitation to the Norwood operation is that it is a complex procedure that entails cardiopulmonary bypass in a neonate [21, 22]. In addition, the patients are at increased risk of shunt thrombosis, pulmonary over-circulation with systemic hypoperfusion, and low diastolic blood pressure with resulting coronary ischemia. Fiore and colleagues [23] and Daenen and colleagues [24] reported that prior PAB did not appear to cause significant pulmonary insufficiency in patients who required DKS, and the incidence of clinically significant pulmonary insufficiency after the DKS operation was relatively low. Thus, in our patients with potential systemic ventricular outflow tract obstruction, DKS anastomosis or relief of the stenotic systemic outflow tract was performed concomitantly with BCPS in infancy as the second stage.
Conclusion The findings presented here suggest that our present strategy for treating functionally single ventricles with unobstructed pulmonary blood flow, namely using a tighter PAB in the neonatal period as an initial step and subsequent early application of BCPS in infancy, improves the rate of achieving the right heart bypass operation and the survival rate.
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2. Günther T, Mazzitelli D, Haehnel CJ, Holper K, Sebening F, Meisner H. Long-term results after repair of complete atrioventricular septal defects: analysis of risk factors. Ann Thorac Surg 1998;65:754 – 60. 3. Bradley SM, Mosca RS, Hennein HA, Crowley DC, Kulik TJ, Bove EL. Bidirectional superior cavopulmonary connection in young infants. Circulation 1996;94(9 suppl):II5–11. 4. Karl TR, Sano S, Brawn W, Mee RB. Repair of hypoplastic or interrupted aortic arch via sternotomy. J Thorac Cardiovasc Surg 1992;104:688 –95. 5. Trusler GA, Mustard WT. A method of banding the pulmonary artery for large isolated ventricular septal defect with and without transposition of the great arteries. Ann Thorac Surg 1972;13:351–5. 6. Allgood NL, Alejos J, Drinkwater DC, Laks H, Williams RG. Effectiveness of the bidirectional Glenn shunt procedure for volume unloading in the single ventricle patient. Am J Cardiol 1994;74:834 – 6. 7. Tanoue Y, Sese A, Ueno Y, Joh K, Hijii T. Bidirectional Glenn procedure improves the mechanical efficiency of a total cavopulmonary connection in high-risk Fontan candidates. Circulation 2001;103:2176 – 80. 8. Lee JR, Choi JS, Kang CH, Bae EJ, Kim YJ, Rho JR. Surgical results of patients with a functional single ventricle. Eur J Cardiothorac Surg 2003;24:716 –22. 9. Cochrane AD, Brizard CP, Penny DJ, et al. Management of the univentricular connection: are we improving? Eur J Cardiothorac Surg 1997;12:107–15. 10. Scheurer MA, Hill EG, Vasuki N, et al. Survival after bidirectional cavopulmonary anastomosis: analysis of preoperative risk factors. J Thorac Cardiovasc Surg 2007;134: 82–9. 11. Rodefeld MD, Ruzmetov M, Schamberger MS, Girod DA, Turrentine MW, Brown JW. Staged surgical repair of functional single ventricle in infants with unobstructed pulmonary blood flow. Eur J Cardiothorac Surg 2005;27:949 –55. 12. Takayama H, Sekiguchi A, Chikada M, Noma M, Ishizawa A, Takamoto S. Mortality of pulmonary artery banding in the current era: recent mortality of PA banding. Ann Thorac Surg 2002;74:1219 –24. 13. Cleuziou J, Schreiber C, Cornelsen JK, Hörer J, Eicken A, Lange R. Bidirectional cavopulmonary connection without additional pulmonary blood flow in patients below the age of 6 months. Eur J Cardiothorac Surg 2008;34:556 – 62.
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14. McElhinney DB, Reddy VM, Silverman NH, Hanley FL. Modified Damus-Kaye-Stansel procedure for single ventricle, subaortic stenosis, and arch obstruction in neonates and infants: midterm results and techniques for avoiding circulatory arrest. J Thorac Cardiovasc Surg 1997;114:718 –26. 15. Bradley SM, Simsic JM, Atz AM, Dorman BH. The infant with single ventricle and excessive pulmonary blood flow: results of a strategy of pulmonary artery division and shunt. Ann Thorac Surg 2002;74:805–10. 16. Tchervenkov CI, Shum-Tim D, Béland MJ, Jutras L, Platt R. Single ventricle with systemic obstruction in early life: comparison of initial pulmonary artery banding versus the Norwood operation. Eur J Cardiothorac Surg 2001;19:671–7. 17. Akagi T, Benson LN, Williams WG, Freedom RM. The relation between ventricular hypertrophy and clinical outcome in patients with double inlet left ventricle after atrial to pulmonary anastomosis. Herz 1992;17:220 –7. 18. Ilbawi MN, DeLeon SY, Wilson WR Jr, et al. Advantages of early relief of subaortic stenosis in single ventricle equivalents. Ann Thorac Surg 1991;52:842–9. 19. Jensen RA Jr, Williams RG, Laks H, Drinkwater D, Kaplan S. Usefulness of banding of the pulmonary trunk with single ventricle physiology at risk for subaortic obstruction. Am J Cardiol 1996;77:1089 –93. 20. Webber SA, LeBlanc JG, Keeton BR, et al. Pulmonary artery banding is not contraindicated in double inlet left ventricle with transposition and aortic arch obstruction. Eur J Cardiothorac Surg 1995;9:515–20. 21. Galli KK, Zimmerman RA, Jarvik GP, et al. Periventricular leukomalacia is common after neonatal cardiac surgery. J Thorac Cardiovasc Surg 2004;127:692–704. 22. Hsia TY,Gruber PJ. Factors influencing neurologic outcome after neonatal cardiopulmonary bypass: what we can and cannot control. Ann Thorac Surg 2006;81:S2381– 8. 23. Fiore AC, Rodefeld M, Vijay P, et al. Subaortic obstruction in univentricular heart: results using the double barrel DamusKaye Stansel operation. Eur J Cardiothorac Surg 2009;35: 141– 6. 24. Daenen W, Eyskens B, Meyns B, Gewillig M. Neonatal pulmonary artery banding does not compromise the shortterm function of a Damus-Kaye-Stansel connection. Eur J Cardiothorac Surg 2000;17:655–7.
INVITED COMMENTARY The long-term outcome of single ventricle physiology remains pretty dismal without surgical interventions. The current management ultimately favors toward the path of the Fontan operation, and these patients could be managed with relatively good palliation. However, the management between the times of clinical diagnosis and the optimal achievement of the Fontan operation remains much more debatable. It is well documented that the second-stage bidirectional cavopulmonary shunt has optimized the preparation for the ultimate Fontan operation. The goal of the interim surgical therapy for single ventricle is to establish unobstructed systemic circulation and competent atrioventricular and semilunar valves that serve to preserve the systolic and diastolic ventricular function crucial for the Fontan physiology. Equally important is the avoidance of excessive pulmonary blood flow and obstructive vasculature that may compromise the long-term Fontan outcome. © 2010 by The Society of Thoracic Surgeons Published by Elsevier Inc
Although many alternative surgical procedures have been described, the two main contenders are the early Norwood or Damus-Kaye-Stansel procedure vs pulmonary artery banding (PAB), particularly in the presence of concomitant systemic obstruction, depending on the comfort and results of various procedures between different centers [1]. Traditional PAB has the advantage of avoiding a complex operation, cardiopulmonary bypass, and systemic-pulmonary shunt early during the neonatal period, but it has been related to increased reintervention and poor preparation for the Fontan candidate due to the presence of systemic obstruction, as suggested by the group 1 patients in this study [2]. This may arguably compromise the Fontan operation if not addressed aggressively. Over the decades, the experience of many pediatric centers and surgical intensive care teams has gained comfort and good results with neonatal and infant complex operations. Although some are more comfortable with the 0003-4975/10/$36.00 doi:10.1016/j.athoracsur.2009.10.024
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Pulmonary Artery Banding for Functionally Single Ventricles: Impact of Tighter Banding in Staged Fontan Era Noriyoshi Kajihara, MD, Toshihide Asou, MD, Yuko Takeda, MD, Yoshimichi Kosaka, MD, Yasuko Onakatomi, MD, Hiroyuki Nagafuchi, MD, and Seiyo Yasui, MD Department of Cardiovascular Surgery, Intensive Care Unit, and Department of Pediatric Cardiology, Kanagawa Children’s Medical Center, Yokohama, Japan
Background. In this study, we assessed our surgical strategy, tighter pulmonary artery banding (PAB) during the neonatal period, as an initial step followed by early application of bidirectional cavopulmonary shunts (BCPS) in infancy, to treat functionally single ventricles with unobstructed pulmonary blood flow. Methods. On the basis of our surgical strategy, 68 consecutive patients underwent PAB and were divided into two groups, group 1 (January 1990 to June 2003; n ⴝ 30) and group 2 (July 2003 to August 2008; n ⴝ 38). The median age at PAB was 45 days in group 1 and 9 days in group 2. The circumference of the bands was significantly shorter in group 2 than in group 1, corresponding to the patient’s weight in kg plus 19.0 ⴞ 0.6 mm in group 1 or 17.0 ⴞ 0.3 mm in group 2 (p ⴝ 0.003). Results. Cardiac catheterization before the right heart bypass operation showed that the pulmonary artery in-
dex (group 1, 322 ⴞ 29; group 2, 283 ⴞ 27 mm2/m2; p ⴝ 0.01), pulmonary resistance index (group 1, 2.4 ⴞ 0.2; group 2, 1.9 ⴞ 0.1 U ⴛ m2; p ⴝ 0.03), and ventricular end-diastolic volume (group 1, 212 ⴞ 19%; group 2, 166 ⴞ 9%; p ⴝ 0.04) were significantly different between the two groups. The rates for achievement of right heart bypass at 12 months (group 1, 19%; group 2, 81%; p < 0.01) and survival at 3 years (group 1, 70%; group 2, 87%; p ⴝ 0.04) were significantly higher in group 2 than in group 1. Conclusions. Our present strategy could prevent volume overload and improve the achievement and survival rates of right heart bypass operations.
P
early application of BCPS during infancy. The application of a tighter PAB in the neonatal period might prevent volume overload, protect the pulmonary vascular beds and ventricular function, and improve the BCPS achievement rate and the Fontan completion rate. It seems likely that tighter PABs are empirically performed in many institutes that have adopted the staged Fontan strategy to manage functionally single ventricles with increased pulmonary blood flow. However, we have found no reported evidence to support this approach. The purpose of this study was to assess the impact of our current surgical strategy for the treatment of functionally single ventricles with unobstructed pulmonary blood flow in terms of protecting pulmonary vascular beds and ventricular function, and consequently achieving successful right heart bypass operation. Accordingly, we compared two groups of patients; patients were treated using the previous strategy before the staged Fontan era and patients treated using our current strategy.
ulmonary artery banding (PAB) plays an important role as an initial step in the successful management of functionally single ventricles with unobstructed pulmonary blood flow, but not in biventricular hearts because of the high prevalence of primary repair [1, 2]. It is essential to reach an adequate balance between systemic and pulmonary blood flow in the surgical management of functionally single ventricles with unobstructed pulmonary blood flow. Accordingly, the tightness of the pulmonary arterial band is an important factor. Using the staged approach to the Fontan operation, tighter pulmonary arterial banding can be applied because it allows us to perform the next step at an earlier stage. Consequently, beneficial effects on the ventricle and pulmonary beds can be achieved using tighter banding. Because younger patients can tolerate bidirectional cavopulmonary shunt (BCPS), even at 2 months old [3], we believe that PAB in the staged Fontan era should be tighter than that used in the nonstaged Fontan era. To treat functionally single ventricles with unobstructed pulmonary blood flow, our current strategy involves applying a tight PAB in the neonatal period as an initial step, followed by
Accepted for publication Sept 14, 2009. Address correspondence to Dr Kajihara, Kanagawa Children’s Medical Center, 2-138-4 Mutsukawa, Minami-ku, Yokohama, Kanagawa, 232-8555, Japan; e-mail: [email protected].
© 2010 by The Society of Thoracic Surgeons Published by Elsevier Inc
(Ann Thorac Surg 2010;89:174 – 80) © 2010 by The Society of Thoracic Surgeons
Patients and Methods Patients This study was approved by the ethics committee of Kanagawa Children’s Medical Center. The need for in0003-4975/10/$36.00 doi:10.1016/j.athoracsur.2009.09.027
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Table 1. Characteristics of the Patients in Both Groups
Age (days): Mean Median (range) Body weight (kg): Mean Median (range) Dominant ventricle (RV/LV) Heterotaxy syndrome Down syndrome Diagnosis Tricuspid Atresia DORV with hypoplastic ventricle Unbalanced AVSD Other Complex of Single Ventricle Coarctation of aortic arch TAPVD
Group 1 (n ⫽ 30)
Group 2 (n ⫽ 38)
p Value
80.2 ⫾ 16.0 45 (0–367) 4.2 ⫾ 0.4 3.7 (2.7–7.3) 13/17 4 (13%) 1 (3%)
23.4 ⫾ 5.2 9 (0–132) 3.1 ⫾ 0.1 3.0 (1.9–5.4) 25/13 8 (21%) 4 (10%)
⬍0.01
13 (44%) 4 (13%)
3 (8%) 12 (32%)
⬍0.01 0.09
3 (10%) 10 (33%)
11 (29%) 12 (31%)
0.07
4 (13%) 2 (7%)
19 (50%) 2 (5%)
⬍0.01 0.60
ation for the first stage. In these five patients, the subaortic, aortic valve, or bulboventricular foramen area was less than 0.7 cm2/m2, as measured on the preoperative echocardiogram.
Operative Technique 0.03 0.09 0.36 0.26
AVSD ⫽ atrioventricular septal defect; DORV ⫽ double outlet right ventricle; LV ⫽ left ventricle; RV ⫽ right ventricle; TAPVD ⫽ total anomalous pulmonary venous drainage.
dividual consent was waived. The authors had full access to the data and take full responsibility for their integrity. Between October 1990 and August 2008, 68 neonates or infants with a functionally single ventricle and unobstructed pulmonary blood flow underwent main PAB at Kanagawa Children’s Medical Center. The PAB was the first step performed in all patients. Based on the strategy used to determine the tightness of the pulmonary banding, we divided the patients into two groups: group 1 (n ⫽ 30), patients who underwent PAB between 1990 and June 2003; and group 2 (n ⫽ 38), patients who underwent PAB after July 2003. The age, body weight, specific anatomic lesions in this series with a functionally single ventricle, and associated anomalies are presented in Table 1. The age ranged from 0 to 367 days (median, 45 days) in group 1, and from 0 to 132 days (median, 9 days) in group 2. Although there was a significant difference in body weight between the two groups, there was no difference in the size of the main pulmonary trunk before PAB (group 1, 11.2 ⫾ 2.4 mm; group 2, 10.8 ⫾ 3.1 mm; p ⫽ 0.76). The incidence of associated aortic coarctation was higher in group 2. Morphologic features of the aortic arch, the pulmonary artery (PA), and intracardiac defects were evaluated preoperatively on an echocardiogram or threedimensional helical computed tomography. The surgical approach to be used was selected based on these data and considering the general conditions of the individual case. The presence of an aortic arch obstruction suggested a right to left shunt across the ductus. The distal aortic arch was hypoplastic if its diameter was less than the body weight in kilograms plus 1 mm [4]. Five patients with a functionally single ventricle and severe subaortic or aortic valve stenosis were excluded from the present study because they were indicated for a Norwood oper-
The chest was entered through an anterolateral thoracotomy or a median sternotomy according to concomitant procedures. We used a 0.6-mm thick, 4-mm wide, expanded polytetrafluoroethylene (ePTFE) patch as a tape to band the main pulmonary artery. Concomitant coarctectomy plus extended aortic arch anastomosis with or without distal arch augmentation from a median sternotomy was performed in 10 patients. In the other patients, concomitant subclavian flap aortoplasty was performed through a posterolateral thoracotomy. The circumference of the band was calculated as the patient’s weight in kilograms plus 20 mm for group 1 or 18 mm for group 2, according to a modified version of Trusler’s formula [5]. The tightness of the band was considered appropriate when the oxygen level was around 35 mm Hg at 21% or 40% of fraction of inspired oxygen during surgery in group 1 or at 60% in group 2. As a result, the circumference of the band was tighter in group 2 than in group 1. The final circumference of the band was the patient’s weight in kilograms plus 19.0 ⫾ 0.6 mm in group 1 and 17.0 ⫾ 0.3 mm in group 2 (p ⬍ 0.01). The circumference of the bands is shown in Figure 1. At discharge, the median percutaneous oxygen saturation was 80% (75% to 90%) in group 2. Concomitant procedures in group 1 included repair of the aorta coarctation in four patients, repair of total anomalous venous drainage in 2, tricuspid valve plasty in one, and enlargement of the ventricular septal defect (VSD) in one. In group 2, the aorta coarctation with or without distal arch hypoplasia was repaired in 19 patients.
Statistical Analysis The continuous data in this study are expressed as mean values ⫾ standard error of the mean. Analyses were 35
Circumference (mm)
Characteristics
175
30 Group 1
25 20
Group 2
15 10 0.0
2.0
4.0
6.0
8.0
Weight (kg) Fig 1. Association between body weight and band circumference. The white symbols represent the patients in group 1; black symbols represent the patients in group 2.
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Fig 2. The graphs show the pulmonary artery (PA) index (group 1, 322 ⫾ 29 mm2/m2; group 2, 283 ⫾ 27 mm2/m2, p ⫽ 0.01) and the pulmonary resistance index (group 1, 2.4 ⫾ 0.2 U · m2; group 2, 1.9 ⫾ 0.1 U · m2, p ⫽ 0.03).
performed using SPSS software (version 11.0J; SPSS Inc, Chicago, IL). Normally distributed clinical parameters were compared with t tests. The Fisher exact test was used for binary variables. Non-normally distributed clinical parameters were compared with the Mann-Whitney test. The rate of achieving right heart bypass and the survival rate were calculated using the Kaplan-Meier method with log-rank and Breslow comparison of groups.
Results Treatments Required Before Right Heart Bypass GROUP 1. Two patients in group 1 died in hospital as a result of heart failure. A repeat PAB after the initial PAB was performed in nine patients and modified BlalockTaussig shunts (BTS) due to distortion of the PA and poor growth of PA were required in three patients. Systemic outflow tract obstruction developed in 3 patients, in whom surgery involving Damus-Kaye-Stansel (DKS) anastomosis with systemic-pulmonary shunt was required for two patients at 20 days or 4 years after PAB, while ligation of the main pulmonary artery with a modified BTS was required in one patient at 1 month after PAB. GROUP 2. None of the patients died in hospital and none of the patients developed a systemic outflow tract obstruction after PAB. Six surgical interventions were required after the initial PAB in five patients, including repeat PAB in two patients, loosening of the band in one, modification of the BTS due to distortion of the PA in one, repair of the aortic coarctation in one, and creation of an atrial septal defect (ASD) in one.
Fig 3. The graphs show the ventricular enddiastolic volume (group 1, 212 ⫾ 19% of normal value; group 2, 166 ⫾ 9%, p ⫽ 0.04) and the ventricular end-diastolic pressure (group 1, 8.3 ⫾ 0.5 mm Hg; group 2, 7.3 ⫾ 0.6 mm Hg, p ⫽ 0.16). (V-EDV ⫽ ventricular end-diastolic volume; V-EDP ⫽ ventricular end-diastolic pressure.)
Cardiac Catheterization Before Right Heart Bypass Operation Cardiac catheterization before the right heart bypass operation revealed two patients with a significant pressure gradient (⬎20 mm Hg) between the systemic ventricle and the ascending aorta (systole) in group 1, but none in group 2. There was a significant difference in the pressure gradient of the systemic ventricle-ascending aorta between the two groups (group 1, 6.6 ⫾ 1.7 mm Hg; group 2, 3.4 ⫾ 0.8 mm Hg, p ⫽ 0.02). The PA index (group 1, 322 ⫾ 29 mm2/m2; group 2, 283 ⫾ 27 mm2/m2, p ⫽ 0.01) and the pulmonary resistance index (group 1, 2.4 ⫾ 0.2 U · m2; group 2, 1.9 ⫾ 0.1 U · m2, p ⫽ 0.03) were significantly different between the two groups (Fig 2). The pulmonary to systemic flow ratio (group 1, 1.1 ⫾ 0.1; group 2, 1.2 ⫾ 0.1, p ⫽ 0.28) and the pulmonary arterial pressure (group 1, 13.7 ⫾ 0.8 mm Hg; group 2, 15.2 ⫾ 1.2 mm Hg, p ⫽ 0.20) were comparable in both groups. With regard to ventricular function, the ventricular enddiastolic volume was significantly smaller in group 2 than in group 1 (group 1, 212 ⫾ 19% of the normal value; group 2, 166 ⫾ 9%, p ⫽ 0.04) (Fig 3), although the ejection fraction of the systemic ventricle (group 1, 0.598 ⫾ 0.024; group 2, 0.634 ⫾ 0.025, p ⫽ 0.29) and the ventricular end-diastolic pressure (group 1, 8.3 ⫾ 0.5 mm Hg; group 2, 7.3 ⫾ 0.6 mm Hg, p ⫽ 0.16) were similar and were stable in both groups.
Achievement of Right Heart Bypass Operation GROUP 1. Twenty-four patients (80%) in group 1 underwent
a successful right heart bypass operation between 7.0 and 80.3 months (median, 22.9 months) after PAB, and the age at surgery ranged from 8.4 to 80.6 months (median, 29.3
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plished at an earlier stage with a higher rate of achievement compared with that in group 1. Logistic regression analysis revealed that group 2 (p ⬍ 0.01) and the band circumference (p ⫽ 0.02) were determinants for achievement of the right heart bypass.
Follow-Up
Fig 4. Rates of achieving right heart bypass. Group 1 (dashed line): 19% at 12 months, 48% at 24 months, and 56% at 36 months. Group 2 (solid line): 30% at 6 months and 81% at 12 months.
months old). Four patients died before the right heart bypass operation due to heart failure in one and sepsis in one. The other two patients developed systemic outflow tract obstruction and died after the DKS anastomosis with a systemic-pulmonary shunt. Sixteen of the 24 patients underwent BCPS and the others underwent a modified Fontan operation. Concomitant procedures included DKS anastomosis in one patient, relief of subaortic stenosis in one, VSD enlargement in one, atrioventricular valve repair in two, ASD creation in one, and PA plasty in two. The rate of achieving right heart bypass operation was 19%, 48%, and 56% at 12, 24, and 36 months after the initial PAB, respectively (Fig 4). GROUP 2. Thirty-three patients (87%) underwent a successful right heart bypass operation between 1.5 and 23.3 months (median, 6.6 months) after PAB, and the age at surgery ranged from 3.4 to 23.7 months (median, 7.6 months old). Two patients with atrioventricular septal defects and a hypoplastic left ventricle died before the achievement of BCPS because of ventricular failure in one and an unknown cause in the other. The other patients underwent BCPS during the subsequent second-stage operation. The subaortic space looked morphologically stenotic in 14 patients on angiography or echocardiogram before BCPS, although a significant pressure gradient was not observed in any patient. In patients with potential systemic ventricular outflow tract obstruction, an active approach to the subaortic lesion was taken at the BCPS. Concomitant procedures included DKS anastomosis in 12 patients, relief of the subaortic stenosis in one, VSD enlargement in one, atrioventricular valve repair in three, ASD creation in eight, repair of total anomalous venous drainage in two, and PA plasty in four. The rate of achieving right heart bypass operation was 30 and 81% at 6 and 12 months after the initial PAB, respectively (Fig 4). The rate of achievement of right heart bypass operation was significantly different (p ⬍ 0.01) between the two groups based on the log-rank and Breslow comparisons. In group 2, the right heart bypass operation was accom-
All patients have attended our center for follow-up, with a follow-up interval ranging from 4.5 months to 18.4 years. The survival rate was 80%, 70%, and 63% at 1, 3, and 5 years, respectively, in group 1, and 94% at 1 year and 87% at both 3 and 5 years in group 2 (Fig 5). The survival rates were significantly different (p ⫽ 0.04) between the two groups based on the log-rank and Breslow comparisons. In the logistic regression analysis, the results indicated that group 2 was the only independent factor predicting survival with a p value of 0.43. The Fontan operation was performed successfully in a total of 41 patients, including 19 in group 1 with a mean follow-up of 134.8 ⫾ 51.2 months and 22 in group 2 with a mean follow-up of 30.5 ⫾ 16.9 months. The central venous pressure 1 year after the Fontan procedure was significantly lower in group 2 than group 1 (11.8 ⫾ 1.3 vs 9.0 ⫾ 1.7, p ⫽ 0.01).
Comment In this study we assessed our current surgical strategy to treat functionally single ventricles with unobstructed pulmonary blood flow, which involves application of a tight PAB during the neonatal period as an initial step with subsequent application of BCPS during infancy, at an earlier time than previously used. The aim of this strategy is to protect the pulmonary vascular beds and ventricular function, and to achieve a right heart bypass operation. The major findings in the present study, using the present strategy, are as follows: (1) the ventricular volume overload was significantly attenuated; (2) the pulmonary vascular beds appear to be better protected; and (3) the rate of achieving right heart bypass operation and the survival rate were significantly improved.
Fig 5. Survival rates after initial pulmonary artery banding. Group 1 (dashed line): 80% at 1 year, 70% at 3 years and 63% at 5 years. Group 2 (solid line): 94% at 1 year, 87% at both 3 and 5 years.
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Staged Fontan Strategy
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The BCPS plays an important role as a staged procedure in the Fontan operation and has led to a decrease in ventricular volume overload at a younger age [6, 7]. Furthermore, the survival rate after BCPS is high [8 –10]. Lee and colleagues [8] reported that the mortality in the pre-Fontan stage was 41.3% in the non-BCPS group and 16.3% in the BCPS group. The BCPS decreased the mortality in the pre-Fontan stage, and increased the likelihood of proceeding to the Fontan procedure. Cochrane and colleagues [9] analyzed the outcome of the Fontan operation at various times to assess the effect of prior BCPS, and reported that the mortality associated with the Fontan operation decreased from 8.5% (1980 to 1987) to 1.8% (1988 to 1995), coinciding with the introduction of the BCPS. Furthermore, Tanoue and colleagues [7] examined cardiac catheterization data before and after the Fontan operation, and reported that the volume reduction achieved with BCPS preceding the Fontan operation allowed for the correction of any after-load mismatch and improved the ventricular energetics after the Fontan operation. These findings prompted us to use the staged strategy for all Fontan candidates. On the other hand, it was demonstrated that the rate of achieving the right heart bypass operation was low in patients with a functionally single ventricle [11, 12]. For example, Rodefeld and colleagues [11] reported that only 49 of 76 patients (64%) who had previously undergone PAB for a functionally single ventricle underwent a successful right heart bypass operation. The right heart bypass operation tends to be performed at a younger age [3, 13]. We consider that PAB in the staged Fontan era could be tighter than that used in the non-staged Fontan era. Using a tighter PAB during the neonatal period as an initial step may allow us to achieve successful BCPS at an earlier stage and ultimately complete the staged Fontan procedure.
Systemic Outflow Tract Obstruction To avoid the development of systemic outflow tract obstruction, ventricular dysfunction, or morbidity associated PAB, several reports have demonstrated that a strategy based on the progressive application of DKS or a palliative arterial switch on cardiopulmonary bypass in infancy was effective [14 –16]. These reports were based on the hypothesis that the PAB accelerated the systemic outflow tract obstruction secondary to muscular hypertrophy and restriction of the VSD in the subaortic area [11, 17, 18]. However, these reports have also revealed that the patients developed subaortic stenosis at the age of 1.3 to 3 years. This is one reason why we apply the BCPS earlier with aggressive concomitant DKS in infancy. Despite the early PAB, more patients in group 2 than group 1 in this study required an approach to the subaortic lesion. One reason seems to be that there were many patients with coarctation of the aortic arch in group 2, with a high probability of later development of systemic ventricular outflow tract obstruction; therefore, we fre-
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quently applied arch reconstruction and used a tight PAB. Another reason is that our strategy was altered to BCPS in infancy with active DKS actively, if indicated by the morphology, because we found that some patients needed repeated release from the subaortic stenosis after the Fontan operation. Jensen and colleagues [19] suggested that the high-risk group of patients with subaortic obstruction and a functionally single ventricle could undergo PAB as an initial step, with a subsequent intervention for subaortic obstruction, and that acceptable pre-Fontan hemodynamic parameters could be achieved. Webber and colleagues [20] performed PAB in infants with a double-inlet left ventricle and transposition of the great vessels in the absence of severe subaortic stenosis, and recommended early relief of subaortic stenosis in combination with BCPS in infancy. The benefits of PAB include the relative simplicity and the low mortality associated with the procedure. The PAB offers improved survival rates and does not preclude the performance of more complex surgical interventions in the neonatal period. As described above (in the “Patients” section), we performed a Norwood operation in five patients with successful outcomes. Although the Norwood or DKS operations offer useful approaches, we consider that these should not comprise the primary step for patients with a functionally single ventricle with unobstructed pulmonary blood flow. The main limitation to the Norwood operation is that it is a complex procedure that entails cardiopulmonary bypass in a neonate [21, 22]. In addition, the patients are at increased risk of shunt thrombosis, pulmonary over-circulation with systemic hypoperfusion, and low diastolic blood pressure with resulting coronary ischemia. Fiore and colleagues [23] and Daenen and colleagues [24] reported that prior PAB did not appear to cause significant pulmonary insufficiency in patients who required DKS, and the incidence of clinically significant pulmonary insufficiency after the DKS operation was relatively low. Thus, in our patients with potential systemic ventricular outflow tract obstruction, DKS anastomosis or relief of the stenotic systemic outflow tract was performed concomitantly with BCPS in infancy as the second stage.
Conclusion The findings presented here suggest that our present strategy for treating functionally single ventricles with unobstructed pulmonary blood flow, namely using a tighter PAB in the neonatal period as an initial step and subsequent early application of BCPS in infancy, improves the rate of achieving the right heart bypass operation and the survival rate.
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14. McElhinney DB, Reddy VM, Silverman NH, Hanley FL. Modified Damus-Kaye-Stansel procedure for single ventricle, subaortic stenosis, and arch obstruction in neonates and infants: midterm results and techniques for avoiding circulatory arrest. J Thorac Cardiovasc Surg 1997;114:718 –26. 15. Bradley SM, Simsic JM, Atz AM, Dorman BH. The infant with single ventricle and excessive pulmonary blood flow: results of a strategy of pulmonary artery division and shunt. Ann Thorac Surg 2002;74:805–10. 16. Tchervenkov CI, Shum-Tim D, Béland MJ, Jutras L, Platt R. Single ventricle with systemic obstruction in early life: comparison of initial pulmonary artery banding versus the Norwood operation. Eur J Cardiothorac Surg 2001;19:671–7. 17. Akagi T, Benson LN, Williams WG, Freedom RM. The relation between ventricular hypertrophy and clinical outcome in patients with double inlet left ventricle after atrial to pulmonary anastomosis. Herz 1992;17:220 –7. 18. Ilbawi MN, DeLeon SY, Wilson WR Jr, et al. Advantages of early relief of subaortic stenosis in single ventricle equivalents. Ann Thorac Surg 1991;52:842–9. 19. Jensen RA Jr, Williams RG, Laks H, Drinkwater D, Kaplan S. Usefulness of banding of the pulmonary trunk with single ventricle physiology at risk for subaortic obstruction. Am J Cardiol 1996;77:1089 –93. 20. Webber SA, LeBlanc JG, Keeton BR, et al. Pulmonary artery banding is not contraindicated in double inlet left ventricle with transposition and aortic arch obstruction. Eur J Cardiothorac Surg 1995;9:515–20. 21. Galli KK, Zimmerman RA, Jarvik GP, et al. Periventricular leukomalacia is common after neonatal cardiac surgery. J Thorac Cardiovasc Surg 2004;127:692–704. 22. Hsia TY,Gruber PJ. Factors influencing neurologic outcome after neonatal cardiopulmonary bypass: what we can and cannot control. Ann Thorac Surg 2006;81:S2381– 8. 23. Fiore AC, Rodefeld M, Vijay P, et al. Subaortic obstruction in univentricular heart: results using the double barrel DamusKaye Stansel operation. Eur J Cardiothorac Surg 2009;35: 141– 6. 24. Daenen W, Eyskens B, Meyns B, Gewillig M. Neonatal pulmonary artery banding does not compromise the shortterm function of a Damus-Kaye-Stansel connection. Eur J Cardiothorac Surg 2000;17:655–7.
INVITED COMMENTARY The long-term outcome of single ventricle physiology remains pretty dismal without surgical interventions. The current management ultimately favors toward the path of the Fontan operation, and these patients could be managed with relatively good palliation. However, the management between the times of clinical diagnosis and the optimal achievement of the Fontan operation remains much more debatable. It is well documented that the second-stage bidirectional cavopulmonary shunt has optimized the preparation for the ultimate Fontan operation. The goal of the interim surgical therapy for single ventricle is to establish unobstructed systemic circulation and competent atrioventricular and semilunar valves that serve to preserve the systolic and diastolic ventricular function crucial for the Fontan physiology. Equally important is the avoidance of excessive pulmonary blood flow and obstructive vasculature that may compromise the long-term Fontan outcome. © 2010 by The Society of Thoracic Surgeons Published by Elsevier Inc
Although many alternative surgical procedures have been described, the two main contenders are the early Norwood or Damus-Kaye-Stansel procedure vs pulmonary artery banding (PAB), particularly in the presence of concomitant systemic obstruction, depending on the comfort and results of various procedures between different centers [1]. Traditional PAB has the advantage of avoiding a complex operation, cardiopulmonary bypass, and systemic-pulmonary shunt early during the neonatal period, but it has been related to increased reintervention and poor preparation for the Fontan candidate due to the presence of systemic obstruction, as suggested by the group 1 patients in this study [2]. This may arguably compromise the Fontan operation if not addressed aggressively. Over the decades, the experience of many pediatric centers and surgical intensive care teams has gained comfort and good results with neonatal and infant complex operations. Although some are more comfortable with the 0003-4975/10/$36.00 doi:10.1016/j.athoracsur.2009.10.024
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