Early and late results in pulmonary atresia

Influence of right heart size on outcome in pulmonary atresia with intact ventricular septum

BACKGROUND

Neonates with pulmonary atresia and intact ventricular septum (PA-IVS) are frequently born with hypoplastic right heart structures that must grow after right ventricular decompression (RVD) procedures for a complete two-ventricle physiology to be achieved. Previous authors have asserted that neonatal right heart size or morphology will predict right heart growth potential. Since 1983, our bias has favored early RVD regardless of initial right heart size. In 1986, we recognized a subset of patients with coronary artery abnormalities associated with poor outcome after RVD and have defined these patients as having a right ventricular-dependent coronary circulation (RVDCC).

METHODS AND RESULTS

To assess the influence of right heart size on outcome independent of the presence of RVDCC, we measured echocardiographic right ventricular (RV) dimensions in 37 neonates with adequate studies presenting between 1983 and 1990. Coronary artery anatomy was adequately assessed by angiography in 36. RV volume and tricuspid valve (TV) diameter were significantly smaller in patients with RVDCC than in those without. However, there was no statistically significant association between RV volume or TV diameter and survival among patients with or without RVDCC: Among 29 patients without RVDCC, 23 of 24 (95.8%) who achieved RVD are alive compared with 1 of 5 (20%) who did not achieve RVD (P = .001). Twenty-one of the 23 survivors have a complete two-ventricle physiology with low right atrial pressure. Among 7 patients with RVDCC, 2 patients who underwent RVD died early of left ventricular failure, whereas 4 of 5 who did not undergo RVD have survived single ventricular palliation.

CONCLUSIONS

Small right heart size is associated with RVDCC but is not associated with survival in PA-IVS. Patients without RVDCC have improved survival after RVD regardless of neonatal right heart size.

Technique of percutaneous laser-assisted valve dilatation for valvar atresia in congenital heart disease

OBJECTIVE

To investigate the efficacy and safety of transcatheter laser-assisted valve dilatation for atretic valves in children with congenital heart disease.

DESIGN

Prospective clinical study.

SETTING

Supraregional paediatric cardiology centre.

SUBJECTS

Eleven children (aged 1 day-11 years; weight 2.1-35.7 kg) with atresia of pulmonary (10) or tricuspid (one) valve underwent attempted laser-assisted valve dilatation as part of the staged treatment of their cyanotic heart disease.

INTERVENTION

After delineating the atretic valve by angiography and/or echocardiography a 0.018 inch "hot tip" laser wire was used to perforate the atretic valve. Subsequently the valve was dilated with conventional balloon dilatation catheters up to the valve annulus diameter.

RESULTS

Laser-assisted valve dilatation was successfully accomplished in nine children. In two neonates with pulmonary valve atresia, intact ventricular septum, and coexistent infundibular atresia the procedure resulted in cardiac tamponade: one died immediately and one later at surgery. During a follow up of 1-17 months (mean 11) two infants with pulmonary valve atresia and intact ventricular septum died (one with congestive cardiac failure). The remainder are either well palliated and do not require further procedures (three), or are awaiting further transcatheter or surgical procedures because of associated defects (four).

CONCLUSIONS

Laser-assisted valve dilatation is a promising adjunct to surgery in this high risk group of patients. It may avoid surgery in some patients, and may reduce the number of surgical procedures in those requiring staged operations.

Pulmonary atresia with intact ventricular septum: surgical management based on right ventricular infundibulum

The optimal management of infants with pulmonary atresia with intact ventricular septum (PA.IVS) remains a controversy. Attempts have been made to base the surgical approach on various geometrical or morphological characteristics of the right ventricle (RV). However, the overall results remain poor when compared to other complex congenital heart defects. Forty-eight neonates with PA.IVS were admitted to our unit between 1980 and 1992. The management plan has evolved to be based entirely on the echocardiographic assessment of the state of development of the infundibulum of the RV. In neonates with a well-formed infundibulum (n = 31), the initial palliation consisted mainly of pulmonary valvotomy (without cardiopulmonary bypass) and PTFE shunt from the left subclavian artery to the main pulmonary artery. There was one death from initial palliation in this subgroup. If necessary, the RV cavity was later enlarged by excision of the hypertrophic muscle of both the trabecular and infundibular portions, before finally attempting biventricular repair. The actuarial probability of achieving a biventricular repair at 40 months of age was 60% (95% CL = 39.5% to 71.3%). Thirteen patients have undergone biventricular repairs with one late death over a total follow-up of 1,720 patient months. In one patient, the RV failed to grow satisfactorily, necessitating a Fontan procedure. Seventeen patients without a well-formed infundibulum were approached with a Fontan procedure in mind. The initial palliation in these patients consisted of a modified Blalock-Taussig shunt only. Ten have undergone a Fontan procedure so far and five are awaiting such repairs. In this group there were four operative deaths: two after initial palliation, and two after Fontan procedures. In patients with a well-developed infundibulum, the actuarial survival probability was 93% (95% CL = 74% to 98%) at 8 months with no further late deaths over 120 months follow-up, whereas in patients without a well-formed infundibulum it was 75% at 40 months (95% CL = 46% to 89%). The overall survival probability at 104 months was 77% (95% CL = 51% to 90%).

Diagnosis and management of right ventricle-dependent coronary circulation in pulmonary atresia with intact ventricular septum

BACKGROUND

Coronary artery anomalies including 1) right ventricle (RV)-to-coronary artery fistulas, 2) coronary artery stenoses, and 3) coronary occlusions occur in patients with pulmonary atresia with intact ventricular septum (PA-IVS). In some, a large part of the coronary blood supply may depend on the RV. This RV-dependent coronary circulation may determine survival after right ventricular decompression (RVD): RVD may cause RV "steal" in the presence of fistulas alone and ischemia, coronary isolation, or myocardial infarction in the presence of coronary stenoses.

METHODS AND RESULTS

Eighty-two patients with PA-IVS who presented between January 1979 and January 1990 were reviewed; 26 (32%) had RV-to-coronary artery fistulas. Of these 26, 23 had adequate preoperative coronary angiograms for analysis. RVD was achieved in 16. Seven of 16 had fistulas only; each survived RVD. Six of 16 had stenosis of a single coronary artery [left anterior descending coronary artery (LAD), four; right coronary artery (RCA), two]; four of six survived RVD. Three of 16 had stenoses and/or occlusion of both the RCA and LAD; all three died shortly after RVD of acute left ventricular dysfunction.

CONCLUSIONS

1) Potential RV steal alone does not preclude successful RVD. 2) Fistulas with stenoses to a single coronary artery may not preclude successful RVD. 3) RVD appears to be contraindicated in the presence of stenoses and/or occlusion involving both the right and left coronary systems. Nonsurvival after RVD seems to depend on the amount of the left ventricular myocardium at risk, i.e., that which is distal to coronary artery stenoses, especially when involvement of both coronary arteries limits effective collateralization. Precise definition of coronary arterial anatomy is mandatory in neonates with PA-IVS.

Cross-sectional echocardiographic measurements of right ventricular size and growth in patients with pulmonary atresia and intact ventricular septum

Fifteen patients with pulmonary atresia or critical pulmonary stenosis and intact ventricular septum were studied. All were operated on in the neonatal period, with valvotomy or a systemic to pulmonary arterial shunt, or both. In 12 patients, right ventricular to pulmonary arterial communication was established in the neonatal period. In three patients, only systemic to pulmonary arterial shunts were constructed. Six patients died. The median follow-up period for the surviving patients was 64 months (range, 12-87 months). Right and left atrial and ventricular dimensions and areas, the tricuspid annular diameter, and the cross-sectional area of the aortic root were measured in cross-sectional echocardiograms from the neonatal period, at the age of 1 year, and at the latest clinical follow-up. A classification of right ventricular morphology was made, based on identification of the inlet, the trabecular, and the outlet parts. Most of the patients had hypoplastic right ventricles at birth but at the latest follow-up, seven of nine surviving patients had right ventricles in the normal range. Right ventricular growth was better in patients who were given a right ventricular to pulmonary arterial communication in the neonatal period and those with complete right ventricular anatomy. The patients who died had severely hypoplastic right ventricles and small tricuspid valves.

Management of pulmonary atresia or critical pulmonary stenosis and intact ventricular septum with a small or hypoplastic right ventricle

Twenty-one neonates and infants less than 3 months old undergoing cardiac surgery for an obstructed right ventricular outflow tract, intact ventricular septum and a small or hypoplastic right ventricle were retrospectively analyzed, in order to assess the effects of a change in management protocol. Seven of the 8 patients with critical pulmonary stenosis survived surgery using a transannular outflow patch, whereas only 1 of the 8 patients with pulmonary atresia survived the same operation. Two patients in the latter group died 2 and 3 months after surgery but with complications arising from surgery. Of 5 patients with pulmonary atresia who had a modified Blalock Taussig shunt, 3 patients survived the surgery and were discharged home. These results significantly indicate that there is an unacceptably high mortality for the relief of pulmonary atresia (with intact septum) using a transannular outflow patch, and a Blalock Taussig shunt is the preferred operation. The transannular outflow patch is a safe operation for neonates with critical pulmonary stenosis, irrespective of the size of the right ventricle.

Operative balloon dilatation for pulmonary atresia with intact ventricular septum

In six infants with pulmonary atresia and intact ventricular septum operative balloon dilatation was used to achieve continuity between the right ventricle and the main pulmonary artery as the initial procedure. Two of the six subsequently needed an aortico pulmonary shunt. All six are alive and well.

Concomitant valvotomy and subclavian-main pulmonary artery shunt in neonates with pulmonary atresia and intact ventricular septum

Our current approach to the management of neonates with pulmonary atresia and intact ventricular septum is to perform a transarterial pulmonary valvotomy through a left anterolateral thoracotomy followed by a polytetrafluoroethylene shunt between the left subclavian artery and the pulmonary trunk at the site of the pulmonary arteriotomy. From October, 1983, to December, 1985, 7 consecutive neonates with pulmonary atresia and intact ventricular septum were managed in this fashion. Mean age was 5.1 days (5 patients, less than 48 hours old), and mean weight was 3.3 kg (range, 2.5-4.3 kg). Right ventricular morphology was type I (tripartite) in 4 patients, type II (absent trabecular portion) in 2, and type III (absent trabecular and infundibular portions) in 1. The mean right ventricular to left ventricular peak systolic pressure ratio was 1.5. One patient who initially had valvotomy alone required a left subclavian-pulmonary trunk shunt the next day for hypoxemia. All other patients had a valvotomy and shunt during the same procedure. There were no operative or hospital deaths. Follow-up of 3.5 to 34 months (mean, 17.5 months) confirmed shunt patency in all patients. Three of 4 patients undergoing postoperative catheterization have shown good right ventricular growth; 2 have undergone successful repair at 10 and 23 months. There have been 3 late deaths at 3.5, 4, and 8 months. Two other patients are doing well and are awaiting postoperative catheterization. This procedure permits synchronous valvotomy and shunting without the need for cardiopulmonary bypass in these critically ill neonates.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical treatment of pulmonary atresia with intact ventricular septum

A concept of management of pulmonary atresia in infancy has been presented. The basic theme employed is that pulmonary valvotomy or an outflow patch should be applied to most infants so that a biventricular heart is achieved in as many children as possible. Clearly, a functioning right ventricle cannot result in all instances and systemic to pulmonary shunts have an important adjunctive and sometimes primary therapeutic role. Our ability to judge right ventricular capability has been improved by preoperative assessment of segmental cavitary hypoplasia by noninvasive echocardiography and angiographic techniques.

Myocardial ischemia in patients with pulmonary atresia and intact ventricular septum

Children who die after operation for pulmonary atresia and intact ventricular septum may have myocardial ischemia. The relation between histologic evidence of myocardial ischemic injury and the presence of a right ventricle to coronary artery fistula, coronary artery dysplasia and operation in 17 autopsy specimens was assessed. Age at death ranged from 1 day to 16 years (median, 11 days). Of the 17 hearts, 6 (35%) had right ventricle to coronary artery fistulas, 5 of which had coronary artery dysplasia. In three cases, there was segmental or complete absence of a coronary artery. Ischemia was present in four of these six hearts, two of which had right ventricular outflow reconstruction. Six of the 11 hearts without right ventricle to coronary artery fistulas also had myocardial ischemia. Of these six cases, four had right ventricular outflow reconstruction and two had shunt operations. Death occurred from 1 to 8 days (mean 3) after operation. Hearts with pulmonary atresia and intact ventricular septum may have myocardial ischemia with or without either right ventricle to coronary artery fistulas or coronary artery dysplasia. Myocardial ischemia may occur after right ventricular outflow reconstruction or shunt operations. Thus, myocardial ischemia occurs commonly in patients with pulmonary atresia and intact ventricular septum and is not always related to coronary abnormalities or operation.

Late right ventricular reconstruction following valvotomy in pulmonary atresia with intact ventricular septum

Experience over two decades in the surgical management of pulmonary atresia with intact ventricular septum demonstrates that eventual right ventricular (RV) reconstruction is possible in the majority of patients surviving valvotomy in infancy. Ten of 17 operative survivors of early valvotomy have eventually received a patch graft to the RV outflow tract, with no reoperative deaths (mean follow-up, 7.4 years). RV systolic pressures, suprasystemic prior to reoperation, are near normal after outflow patch reconstruction. Serial cineangiograms show evidence of RV growth by measurement of tricuspid annulus diameter (TAD), and demonstrate a rate of growth [d(TAD)/d(body length)] greater than a normal rate derived from autopsy data. The mean TAD growth rate is significantly greater than that of patients with less favorable ventricle types treated with a systemic-pulmonary shunt alone. Measurement of TAD is a useful method for following RV growth, and may aid in selecting patients for RV reconstruction.

Comprehensive management of pulmonary atresia with intact ventricular septum

The prognosis for patients with pulmonary atresia with intact ventricular septum is poor with or without conventional surgical intervention. Therefore, a comprehensive program of medical and surgical treatment is necessary to improve long-term outlook for these infants. Such a program consists of management of the neonate at initial presentation with prompt administration of prostaglandins and institution of a combination of surgical procedures (isolated pulmonary valvotomy, valvotomy plus modified Blalock-Taussig shunt, Blalock-Taussig shunt plus balloon atrial septostomy, or Blalock-Taussig shunt alone) depending on the results of morphological analysis of the right ventricle; this treatment regimen is designed to relieve hypoxemia, encourage right ventricular growth, and provide adequate egress of blood from the right atrium. Another important element of management is to perform follow-up hemodynamic and angiographic studies when the patient is between 6 and 12 months old to ensure that the objectives of the comprehensive program are being met. Finally, a definitive repair should be offered. This can be done by using or bypassing the right ventricle, depending on whether it can support the pulmonary circuit.

Surgical management of hypoplastic right ventricle with pulmonary atresia or critical pulmonary stenosis and intact ventricular septum

Our experience with the surgical management of hypoplastic right ventricle with intact ventricular septum includes 26 patients with pulmonary atresia and 4 with critical pulmonary stenosis. Group 1 consisted of 8 neonates managed initially by transventricular valvotomy; 6 later required a secondary procedure, with 100% survival. Group 2 had 11 neonates managed by aorta-pulmonary artery shunting without operative death. However, only 3 have survived over the long term and 1 has required an additional shunt procedure. Group 3 had 9 infants who underwent concomitant valvotomy and shunting. There were 4 operative deaths and 1 late death. Finally, Group 4 included 2 infants managed by primary repair at 3 days and 6 days old with prosthetic enlargement of the right ventricle; 1 required the addition of a shunt. Both are alive. Seven of the 15 patients in Groups 1, 2, and 3 who survived neonatal palliative procedures have undergone reparative operations. Two had no growth of the right ventricle and underwent repair after conversion to tricuspid atresia, by a Fontan procedure. Five had prosthetic enlargement of the right ventricle in childhood with 1 late death. Findings of this review were as follows: (1) effective palliation of pulmonary atresia and intact ventricular septum or critical pulmonary stenosis with cavitary hypoplasia of the right ventricle is rare unless transventricular flow can be established; (2) establishment of transventricular flow produces a high incidence of cavitary "growth," which permits later repair; (3) the Fontan operation is available for repair in patients who have no cavitary growth; and (4) when all three portions of the right ventricular cavity can be identified by angiography, a primary repair can be performed in the neonatal period with a good long-term prognosis.

Evaluation and surgical treatment of pulmonary atresia and intact ventricular septum in infancy

The initial surgical approach to the infant with pulmonary atresia and intact ventricular (PA-IVS) is to establish an adequate source of pulmonary blood flow and, when possible, relieve right ventricular (RV) outflow obstruction. The selection of patients for pulmonary valvotomy, alone or in combination with a systemic-pulmonary arterial shunt, depends on the presence of an RV outflow tract and the adequacy of the RV chamber. To evaluate the size of the RV cavity in PA-IVS, an RV index (RVI) was developed using biplane angiographic measurements of the sum of the tricuspid valve annulus and the RV inflow and the RV outflow tracts. The RVI was normalized by relating it to the aortic diameter (Ao) at the diaphragm (RVI/Ao). The RVI/Ao was 13.5 +/- 1.4 in 20 control subjects and only 7.3 +/- 2.6 in 26 PA-IVS patients (p less than 0.001), and was within the normal range in only two of the 26. Since 1976, pulmonary valvotomy plus a Blalock-Taussig shunt has been performed in 10 infants, with one death. Serial cardiac catheterizations in five of nine survivors demonstrated substantial RV growth in all, with the RVI/Ao increasing from an average of 8.0 to 12.5. In contrast, patients who underwent a shunt alone had no change in RV cavity size. We conclude that pulmonary valvotomy may be performed successfully in most PA-IVS patients, but usually must be combined with a systemic-pulmonary shunt. In a small minority of patients, a normal RV cavity, as evidenced by an RVI/Ao greater than or equal to 11, appears to be sufficient to sustain adequate pulmonary blood flow after valvotomy alone. The RVI/Ao ratio is a simple method of quantitatively evaluating RV cavity size and is helpful in planning the initial surgical approach for these infants.

Pulmonary atresia and intact ventricular septum: surgical management based on a revised classification

Sixty patients with pulmonary atresia and intact ventricular septum (PA:IVS) presenting from 1970 to 1980 are reviewed. Three groups of patient are discussed: those with tripartite right ventricles, those with no trabecular portion to the cavity, and those with neither trabecular nor infundibular portions. The decrease in early mortality for neonates with PA:IVS since 1977 (one death in 15 patients) supports our current management policy of preoperative prostaglandin E1 infusion with transpulmonary valvotomy (for patients with an infundibular cavity) combined with a left modified Blalock-Taussig shunt using a Gore-Tex prosthesis. Tricuspid valve growth, estimated by serial angiograms in 12 patients, was greater if right ventricle-to-pulmonary artery continuity was established. Later definitive repair was attempted in nine patients, with two early deaths; five underwent right ventricular outflow tract reconstruction and four had modified Fontan procedures. Neonates with critical pulmonary stenosis are also discussed. Their neonatal mortality (nine deaths in 20 patients) was similar to that of comparable patients with PA:IVS, but their actuarial survival at 5 years (55%) was superior (36% at 5 years).

Pulmonary atresia with intact ventricular septum and ventriculocoronary communications: surgical significance

The first stage of a repair of pulmonary atresia with intact ventricular septum (type I) was attempted in a 2-day-old infant. At surgery, decompression of the hypertensive small right ventricle was followed by a sudden loss of myocardial contractility and death. Postmortem examination revealed a fistula with a large orifice in the right ventricular infundibulum that communicated directly with the left main coronary artery. Severe hypertensive changes indicative of abnormally high perfusion pressure were noted in the distal left coronary artery branches. The clinical course suggests that the effect of relieving right ventricular outflow obstruction was a reduction of left main coronary artery blood flow, resulting in fatal intraoperative myocardial ischemia. This unusual case draws attention to the anomalous ventriculocoronary communications often present in pulmonary atresia and their potential for limiting a successful surgical repair.

Angio-pathological appearances of pulmonary valve in pulmonary atresia with intact ventricular septum. Interpretation of nature of right ventricle from pulmonary angiography

Correlative angiographic-anatomical studies in 19 cases of pulmonary atresia with infarct ventricular septum showed the following relations between the angiographic appearance of the pulmonary valve and the morphology of the right ventricle. (1) Doming of the pulmonary valve was associated with a nearly normal-sized right ventricle and a wide infundibulum patent to the level of the pulmonary valve. (2) A fixed valve was associated either with (a) pronounced hypoplasia of the ventricular changer and stenosis of the infundibulum or (b) less commonly, a massive right ventricle and Ebstein's malformation of the tricuspid valve. (3) An intermediate type valve was associated with a small right ventricle and a small infundibulum which was, however, patent to the level of the pulmonary valve. It is suggested that the configuration of the pulmonary valve is a result of haemodynamic stresses placed upon it. These stresses, in turn, are determined by the morphological nature of the right ventricle. Thus, the nature of the pulmonary valve as seen angiographically may ve used as an index of right ventricular morphology.

Cardiac surgery in the critically ill infant during the first three months of life

Major advances have been made in the treatment of congenital heart disease in the past 10 years. Management of the 20 per cent of children who become critically ill during the first 3 months of life remains a major challenge because they represent the most extreme anatomic and physiologic derangements. A review of the recent data accumulated in the NERICP showed an overall mortality of 54 per cent in infants presenting for surgery in the first 2 months of life. We have reviewed our experience with over 400 procedures during the past 5 years in infants less than three months of age, and our overall mortality is 19 per cent. Primary repair remains our goal, but a disappointingly high mortality with primary repair in this group, by us and others, has caused us to perform palliative procedures when palliation in our experience offers an overall lower mortality.

Right ventricular volume determinations in 18 patients with pulmonary atresia and intact ventricular septum. Analysis of factors influencing right ventricular growth

Right ventricular growth was assessed angiocardiographically in 18 patients with pulmonary atresia, intact ventricular septum, and hypoplastic and hypertensive right ventricle. A variety of surgical procedures were performed. In only 12 patients (66.7%) was right ventricular-pulmonary artery continuity achieved (group 1). Nine of these 12 patients persisted with systemic or suprasystemic right ventricular pressures. Among the six patients in whom right ventricular-pulmonary artery continuity was not achieved (group 2), all maintained suprasystemic right ventricular pressures. Right ventricular growth was assessed in groups 1 and 2. The patients were also subdivided according to the qualitative degree of tricuspid regurgitation as determined angiocardiographically on right ventricular cineangiocardiograms at the preoperative catheter study. Right ventricular growth to normal levels as evidenced by change in right ventricular end-diastolic volume was rarely observed in group 2 patients. Among the four patients with severe tricuspid regurgitation and a large tricuspid valve, right ventricular growth to normal levels was achieved whether they were in group 1 or group 2. Right ventricular growth is thus predicated on numerous morphologic factors in these patients. However, reconstitution of right ventricular-pulmonary artery continuity and a nonobstructive tricuspid valve are probably two of the more important factors.