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Ann Thorac Surg 2004;78:1994-1998
© 2004 The Society of Thoracic Surgeons

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Original Article: Cardiovascular

Interim Mortality in Pulmonary Atresia With Intact Ventricular Septum

^a Department of Cardiothoracic Surgery, Children's Hospital, Omaha, Nebraska, USA
^b Departments of Cardiothoracic Surgery and Cardiology, Children's Hospital, Pittsburgh, Pennsylvania, USA

Accepted for publication June 2, 2004.

^* Address reprint requests to Dr Fenton, Cardiothoracic Surgery, Children's Hospital, 8300 Dodge St, Omaha, NE 68114 (E-mail: kfenton{at}chsomaha.org).

	Abstract

Top Abstract Introduction Patients and Methods Results Comment References

 
BACKGROUND: Recent work has focused attention on interim mortality (death after hospital discharge and before second-stage surgery) in hypoplastic left heart syndrome. This study investigates interim mortality in infants undergoing systemic-to-pulmonary artery shunts for pulmonary atresia with intact ventricular septum.

METHODS: At two centers in 11 years (January 1991 through December 2001), 35 infants underwent placement of shunts for palliation of pulmonary atresia with intact septum. Patients were identified from the cardiology database at each institution, and data were collected retrospectively. The infants were classified into two groups, with and without severe right ventricular hypoplasia, based on the initial surgical plan (Fontan or two-ventricle repair).

RESULTS: The mean age and weight of the infants were 9 days and 3.1 kg. The right ventricle was severely hypoplastic in 22 of 35 infants. Hospital death occurred in 2 patients (9.1%), 1 with severe right ventricular hypoplasia. The remaining 33 patients form the study population. There were a total of 5 deaths (15%) after discharge and before second-stage operation, all in patients with severe right ventricular hypoplasia. Two patients, 1 with hypoplastic right ventricle, died after second-stage operation.

CONCLUSIONS: These data confirm a significant incidence of interim death in infants with pulmonary atresia and hypoplastic right ventricle. The interim mortality rate in the current two-institution study of infants with pulmonary atresia with intact ventricular septum is similar to that in hypoplastic left heart syndrome if all patients are considered (15%), and is somewhat higher (24%) than that for hypoplastic left heart syndrome if only patients with severe right ventricular hypoplasia are considered. This rate of interim death must be considered when different treatment options (such as shunt or transplant) are contemplated.

	Introduction

Top Abstract Introduction Patients and Methods Results Comment References

 

This article has been selected for the open discussion forum on the CTSNet Web site: http://www.ctsnet.org.discuss

 

Systemic-to-pulmonary artery shunts, although used less commonly in the current era than in the past, remain indispensable in the management of selected neonates and infants with complex congenital heart defects. Many infants with pulmonary atresia with intact ventricular septum (PAIVS) are palliated with shunts as a sole or additional source of pulmonary blood flow.

As perioperative mortality for neonatal palliation of complex congenital heart disease has fallen, it has become increasingly apparent that there is a significant rate of interim death (death after discharge from the shunt procedure and before second-stage palliation or definitive repair). These deaths are particularly striking because they commonly occur in infants who are at home and are doing well. Recent studies have evaluated interim mortality in patients with hypoplastic left heart syndrome (HLHS) [1–4] and in patients undergoing shunt placement for palliation of various defects [5]. The purpose of the current investigation is to study the risk and cause of interim death in infants undergoing shunts for palliation of PAIVS. We hypothesized that the interim mortality rate in infants with PAIVS and severe right ventricular (RV) hypoplasia would be similar to that in HLHS, and that infants without severe RV hypoplasia would have a lower interim death rate, similar to other shunted patients with two ventricles.

	Patients and Methods

Top Abstract Introduction Patients and Methods Results Comment References

 
Between January 1991 and December 2001, at two centers, a total of 35 infants 60 days of age or younger underwent placement of systemic-to-pulmonary artery shunts as a source of pulmonary blood flow in patients undergoing palliative management of PAIVS. The period for the study was selected to allow evaluation of at least midterm outcome in all patients. Patients with PAIVS who had pulmonary valvotomy alone (no shunt), either in the cardiac catheterization laboratory or in the operating room, were not included in this study. All infants in the study (by definition) had RVs that were too small to fully support the pulmonary circulation. The infants were classified into two groups, with and without severe RV hypoplasia, on the basis of the initial surgical plan (Fontan or two-ventricle repair). The infants had a mean age of 9.3 days (range, 0 to 60 days) and a mean weight of 3.1 kg (range, 1.6 to 4.3 kg).

The initial diagnosis was made in all infants by transthoracic echocardiogram, and the surgical plan was formulated on the basis of the overall appearance of the RV, tricuspid valve, and branch pulmonary arteries. Although the general strategy at both institutions is to perform cardiac catheterization in infants with PAIVS to evaluate the coronary arteries, 4 patients (2 at each institution) did not undergo neonatal cardiac catheterization. Three of these patients were early in the study period (1991, 1992, and 1995), before catheterization was routine, and the fourth was a 1.6-kg premature infant with sinusoids visualized on echocardiogram, and in whom the risks of catheterization were thought to outweigh the potential benefit. Angiography included a RV injection in 29 of 31 newborns and an aortic root injection in 13 of 31. Selective coronary artery injections were not done.

The surgical approach was by sternotomy in 13 and right or left thoracotomy in the remainder, with the majority of isolated shunts being performed by thoracotomy. The shunts ranged in size from 3 mm to 5 mm and were uniformly polytetrafluoroethylene grafts. The size and location of the shunt were the decision of the operating surgeon, and in general were based on patient size and the anatomy of the great vessels. Five patients had surgical valvotomy (n = 4) or transannular patch (n = 1) to open the RV outflow tract. Antiplatelet therapy (low-dose aspirin) was given after discharge at the discretion of the operating surgeon beginning in 1994, and was used in a total of 14 patients (40%).

Patients were identified from the cardiology and cardiac surgery databases at the respective institutions. Inpatient and outpatient medical records were reviewed. In cases in which an autopsy was performed, the report was obtained, reviewed, and correlated with clinical information.

Independent variables examined included the infant's age and weight, presence or absence of severe RV hypoplasia, presence or absence of coronary sinusoids and fistulas, and use of antiplatelet therapy. Tricuspid valve diameter was recorded in fewer than half of the neonatal echocardiograms, so we did not attempt to stratify patients on the basis of Z score. Outcome variables included perioperative death, interim death (defined as death after hospital discharge from the shunt procedure, and before second-stage operation), and late death (death after second-stage operation). Two-ventricle repair was defined as the successful complete separation of the pulmonary and systemic circulations, with each ventricle pumping into its respective great artery. One-and-one-half ventricle repair was defined as the end point in which the right upper body venous return drains passively to the pulmonary arteries by a bidirectional Glenn or hemi-Fontan anastomosis, and lower body venous return is pumped by the hypoplastic RV to the pulmonary arteries.

	Results

Top Abstract Introduction Patients and Methods Results Comment References

 
There were 22 patients with severe RV hypoplasia (61%), and 14 with two ventricles. One of the patients with two ventricles ultimately underwent a one-and-one-half ventricle repair. Twenty-two patients (including 6 without severe RV hypoplasia) had identifiable sinusoids or right-ventricle-to-coronary-artery fistulas. Only 1 patient was identified with RV-dependent coronary circulation. Two patients had Ebstein's malformation of the tricuspid valve. Four infants were premature (<35 weeks), 2 were twins, and 5 had significant extracardiac anomalies. Mean age and weight at operation were 3.12 kg and 8 days, respectively, for the RV hypoplasia group and 3.07 kg and 11 days, respectively, for the two-ventricle group (not significant).

There were two hospital deaths (5.7%, Table 1). One was an intraoperative death early in the study period. The infant underwent an uneventful placement of a modified Blalock-Taussig shunt, followed by a pulmonary valvotomy using inflow occlusion. After the pulmonary valvotomy, the infant sustained a cardiac arrest from what appeared to be severe pulmonary insufficiency, and could not be resuscitated. The second hospital death occurred suddenly 1 day postoperatively in a 1.6-kg, 33-week gestation infant with PAIVS and RV hypoplasia, who had undergone a 3-mm right modified Blalock-Taussig shunt through a sternotomy. Autopsy revealed pulmonary edema, and was consistent with the clinical impression of pulmonary overcirculation as the cause of death.

View larger version (29K): [in this window] [in a new window]   Fig 1. Relationship between shunt size used and outcome. (N = total number of patients; Discharged = patients who were discharged from the hospital alive; Stage 2 = patients who have successfully completed second-stage operation.)

	Comment

Top Abstract Introduction Patients and Methods Results Comment References

 
Neonatal cardiac surgery has become almost commonplace throughout the developed world, and excellent early results of both reparative and palliative operations are now essentially expected. Hospital mortality rates are in the single digits for repair or palliation of most cardiac defects, and 30-day survival even for infants with the most complex defects such as HLHS is 70% to 90% in many centers [1, 3, 5]. As a result, our attention has recently been redirected to improving intermediate-term and longer-term outcomes. Interim mortality (defined as death between the first and second stages of palliation) for HLHS ranges from 4% to 14% in recent series [1–4], and is similar in other infants palliated with systemic-to-pulmonary artery shunts [5]. The interim mortality rate in the current two-institution study of infants with PAIVS is similar to that in HLHS if all patients are considered (15%), and is somewhat higher (24%) than that for HLHS if only patients with severe RV hypoplasia are considered. Mortality for infants with PAIVS remains significant, in fact, at every stage (Table 1).

Because PAIVS is a relatively rare malformation in which there are a variety of anatomic subtypes and management strategies, the literature is often difficult to evaluate. The 5-year survival reported in recent studies ranges from 50% to 98% [6–11]. The best results are reported when patients with Ebstein's anomaly, which occurs in 5% to 10% of infants with PAIVS [6], are excluded [9]. Some investigators have achieved better results by routinely decompressing the RV [7], whereas others [9] suggest that avoiding an attempt at a two-ventricle repair in borderline cases may be important. Our study was specifically designed to look at interim mortality rates in patients with PAIVS who had RV hypoplasia significant enough to require placement of a systemic-to-pulmonary artery shunt in the neonatal period. We found an overall mortality rate of 33% in patients who underwent decompression of the RV as compared with 23% in patients left with pulmonary atresia (not significant).

The most common cause of death at all stages in this patient population is related to myocardial perfusion: of seven autopsies (nine deaths), 3 infants had myocardial infarctions and 1 had left ventricular dysfunction associated with histologically abnormal coronary arteries. Abnormal coronary arteries (sinusoids and fistulas) were identified in 61% of our patients; they are seen in 30% to 60% of patients with PAIVS [6, 10, 11] in the literature. Right ventricular–dependent coronary circulation, defined as obstruction of antegrade flow in more than one major coronary artery [7, 10], is seen in 20% to 34% of infants when selective coronary artery injections are routinely done [9–11]. It was diagnosed in only one of our patients, but selective coronary artery injections were not done. Some investigators have recommended selective coronary injections in all patients with PAIVS [7, 11]. Right ventricular–dependent coronary circulation is associated with small right heart size in most series [7, 9, 11]. Three of our 4 patients who died of myocardial ischemia or infarction had coronary sinusoids or fistulas that were identified before death; the fourth patient did not have a cardiac catheterization. We did not find the presence (or at least the detection) of sinusoids to be statistically predictive of death. It is possible that a larger study, or one in which selective coronary injections are routinely done, may disclose such a relationship. Coronary artery abnormalities contribute an additional risk factor in patients with PAIVS beyond that seen in other patients with single-ventricle physiology. Abnormal coronaries should be carefully sought in all infants with PAIVS, even in those with apparently well-formed RVs. Finally, parents of these infants must be counseled that the child has a significant risk of death owing to coronary problems at every stage, although mortality risk seems to be highest in infancy.

Shunt thrombosis remains an important cause of death in this patient population, with an incidence similar to that seen overall [5]. In this small study, as in previous work [5], shunt thrombosis is fatal in single-ventricle but not two-ventricle patients, and is not prevented by aspirin.

For patients with PAIVS and severe RV hypoplasia, the highest risk of death is during the period between first and second stages. To improve results for these patients, then, we need to focus our attention on how to decrease this interim mortality. Patients with PAIVS, like other patients with shunts, have an inherently abnormal physiology: high cardiac output and high pulmonary blood flow, low diastolic blood pressure and thus low coronary reserve. It is logical to suppose that by minimizing these physiologic abnormalities we may decrease the mortality rate of infants with shunts. Use of a smaller shunt was the first step taken with these ideas in mind, and has been successful in reducing death from pulmonary overcirculation but has resulted in a higher rate of death as a result of shunt thrombosis. Our data indicate no relationship between shunt size and overall mortality (Fig 1). More recently, use of a nonvalved right-ventricle-to-pulmonary artery conduit (the Sano shunt) [12] has been helpful in decreasing hospital mortality in patients with HLHS in some series [13–16]. It is too early to tell whether this will also positively affect interim mortality. A modification of this procedure might theoretically be even more helpful in infants with PAIVS, in whom the risk of death from coronary insufficiency seems to be substantially higher. Unfortunately, it would be technically difficult to place such a shunt from the small RV in PAIVS, and would certainly create all the problems associated with decompression of the RV in patients with coronary artery anomalies. Placement of such a shunt from the left ventricle to the pulmonary arteries is another possibility but would require some technical modifications. Use of this procedure in patients with PAIVS has the added disadvantage of requiring cardiopulmonary bypass, which is not otherwise required for the first-stage operation.

Limitations of our study include its retrospective nature, the small number of patients, and the somewhat erratic use of aspirin. In addition, the definition we chose for severe RV hypoplasia, and the fact that all of our patients required shunts, precluded an evaluation of outcome on the basis of management strategy.

Interim mortality in infants with PAIVS and severe RV hypoplasia is 24%, roughly twice that of infants with HLHS. Myocardial ischemia and shunt thromboses are the major causes of death in autopsied infants. Interim death is seen more commonly in patients with very small RVs. Patients with abnormal coronary arteries are at increased risk of death as a result of myocardial ischemia; coronary artery anomalies should be carefully sought in these infants. The absence of known coronary sinusoids or fistulas, or the presence of a well-formed RV, however, does not preclude interim death.

	References

Top Abstract Introduction Patients and Methods Results Comment References

 

1. Ashburn DA, McCrindle BW, Tchervenkov CI, et al. Outcomes after the Norwood operation in neonates with critical aortic stenosis or aortic valve atresia J Thorac Cardiovasc Surg 2003;125:1070-1082.[Abstract/Free Full Text]
2. Ghanayam NS, Hoffman GM, Mussatto KA, et al. Home surveillance program prevents interstage mortality following the Norwood procedure J Thorac Cardiovasc Surg 2003;126:1367-1377.[Abstract/Free Full Text]
3. Mahle WT, Spray TL, Gaynor JW, Clark III BJ. Unexpected death after reconstructive surgery for hypoplastic left heart syndrome Ann Thorac Surg 2001;71:61-65.[Abstract/Free Full Text]
4. Murdison KA, Baffa JM, Farrell PE, et al. Hypoplastic left heart syndrome. Outcome after initial reconstruction and before modified Fontan procedure Circulation 1990;82(Suppl 5):IV-199-207.
5. Fenton KN, Siewars RD, Rebovich B, Pigula FA. Interim mortality in infants with systemic-to-pulmonary artery shunts Ann Thorac Surg 2003;76:152-157.[Abstract/Free Full Text]
6. Bichell DP. Evaluation and management of pulmonary atresia with intact ventricular septum Curr Opin Cardiol 1999;14:60-66.[Medline]
7. Giglia TM, Jenkins KJ, Matitiau A, et al. Influence of right heart size on outcome in pulmonary atresia with intact ventricular septum Circulation 1993;88(Suppl 2):II-183-8.
8. Humpl T, Soderberg B, McCrindle BW et al. Percutaneous balloon valvotomy in pulmonary atresia with intact ventricular septum: impact on patient care. Circulation 200319;108:826–32..
9. Jahangiri M, Zurakowski D, Bichell DA, et al. Improved results with selective management in pulmonary atresia with intact ventricular septum J Thorac Cardiovasc Surg 1999;118:1046-1055.[Abstract/Free Full Text]
10. Powell AJ, Mayer JE, Lang P, Lock JE. Outcome in infants with pulmonary atresia, intact ventricular septum, and right ventricle-dependent coronary circulation Am J Cardiol 2000;86:1272-1274,A9.[Medline]
11. Satou GM, Perry SB, Gauvreau K, Geva T. Echocardiographic predictors of coronary artery pathology in pulmonary atresia with intact ventricular septum Am J Cardiol 2000;85:1319-1324.[Medline]
12. Sano S, Ishino K, Kawada M, et al. Right ventricle-pulmonary artery shunt in first-stage palliation of hypoplastic left heart syndrome J Thorac Cardiovasc Surg 2003;126:504-509.[Abstract/Free Full Text]
13. Maher KO, Pizarro C, Gidding SS, et al. Hemodynamic profile after the Norwood procedure with right ventricle to pulmonary artery conduit Circulation 2003;108:782-784.[Abstract/Free Full Text]
14. Malec E, Januszewska K, Kolec J, Mroczek T. Right ventricle-to-pulmonary artery shunt versus modified Blalock-Taussig shunt in the Norwood procedure for hypoplastic left heart syndrome—influence on early and late haemodynamic status Eur J Cardiothorac Surge 2003;23:728-734.
15. Pizarro C, Malec E, Maher KO, et al. Right ventricle to pulmonary artery conduit improves outcome after stage I Norwood for hypoplastic left heart syndrome Circulation 2003;108(Suppl 1):II-155-60.
16. Pizarro C, Norwood WI. Right ventricle to pulmonary artery conduit has a favorable impact on postoperative physiology after Stage I Norwoodpreliminary results. Eur J Cardiothorac Surg 2003;23:991-995.[Abstract/Free Full Text]

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