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

[Pulmonary stenosis and atresia with intact ventricular septum]

Pulmonary atresia and critical pulmonary stenosis with intact ventricular septum includes a wide spectrum of cardiopathies with great morphological heterogeneity. The pulmonary valve may be completely atretic or may contain a puncture hole if stenosis is present. The obstruction may be membranous and/or muscular. All components of the right ventricle can be affected, even the coronary circulation with ventriculocoronary connections and stenosis or atresia of the pulmonary arteries. Prenatal diagnosis is made when the right ventricle is hypoplastic and hypertrophic. The pulmonary valve is thickened and the pulmonary artery is perfused retrogradely through the ductus arteriosus. Right ventriculocoronary connections may sometimes be seen with fetal echocardiography. Postnatal survival depends on the patency of the ductus arteriosus, requiring prostaglandin E1 infusion. When hypoplastic right ventricle and/or ventricle-dependent coronary circulation exists, biventricular circulation is not possible. In these cases, surgical treatment is palliative. In cases with well-developed right ventricle, transcatheter therapy is usually provided with perforation and balloon dilation of the pulmonary valve. In cases of muscular obstruction of the right ventricle outflow tract, surgery may be considered as first-line therapy. In case of prenatal diagnosis, the medical termination of pregnancy is possible when severe right ventricular hypoplasia exists, precluding biventricular circulation. Postnatally, the prognosis of the patients is highly variable, mainly related to the size of the right cavities and the presence of coronary anomalies.

[A successful case report of one and one half ventricle repair for pure pulmonary stenosis in a 4-year-old girl]

A 4-year-old girl with pure pulmonary stenosis, hypoplastic right ventricle and atrial septal defect, underwent left modified Blalock-Taussig shunt at the age of 2 year. Her RVEDV was 62.7% of normal and TVD was 64.2% of normal at the age of 3 year. We observed development of right ventricle and performed simultaneously Glenn shunt and right ventricular outflow reconstruction (one and one half ventricle repair). Her general condition after operation became better. The size of tricuspid valve and right ventricle grew on Cardiac ultrasonography and catheterization examined after one year operation. In future, If the size of RV and TV might grow further, we should recommend her biventricular repair.

Transcatheter perforation of the right ventricular outflow tract as initial therapy for pulmonary valve atresia and intact ventricular septum in the newborn

The clinical impact of transcatheter perforation and dilatation of the right ventricular outflow tract in neonates with pulmonary atresia and intact ventricular septum was reviewed. Between April 1992 and December 1994, 8 neonates underwent transcatheter perforation of the right ventricular outflow tract. Radiofrequency energy was employed in 6 patients and wire perforation in 2 patients. Mean patient age at intervention was 1.9 +/- 0.6 days and weight 3.4 +/- 0.5 kg. Median tricuspid valve annulus was 10.9 mm (range: 4.0-13.0 mm) and Z-value -0.85 (range: -4.5-1.0). The mean right ventricular systolic pressure fell from 117 +/- 16 to 55 +/- 15 mm Hg (P < 0.0001), and the right ventricular to aortic pressure ratio decreased from 1.81 +/- 0.33 to 0.82 +/- 0.28 (P < 0.0001). The arterial duct was patent in all. No acute complications occurred. Aortopulmonary shunts were performed in 7 patients at a median 6 days (range: 3-23 days) following catheterization. One patient developed sepsis and died after surgical resection of infected tissue, while a second patient died of a blocked aortopulmonary shunt 17 months following discharge. Median follow-up for the 6 surviving patients was 8 months (range: 4-32 months). One patient has achieved and a second is awaiting biventricular repair. Transcatheter perforation appears to be a promising form of therapy in selected patients with pulmonary atresia, and potentially facilitates algorithms leading to a biventricular repair.

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%).

Surgical closed pulmonary valvotomy for critical pulmonary stenosis: implications for the balloon valvuloplasty era

BACKGROUND

Closed pulmonary valvotomy for critical pulmonary stenosis has no apparent advantage over the percutaneous balloon technique, though it is used when balloon valvuloplasty fails. Experience of this technique at the Heart Institute, Tel Hashomer, since it was first used in 1973 has been reviewed.

METHODS

Thirty eight infants up to 1 year old (25 of them neonates--that is, nil to 1 month old) with critical pulmonary stenosis were operated on from 1973 to 1989. All had a transventricular valvotomy, by a modification of the Brock method, and all underwent cardiac catheterisation before surgery.

RESULTS

Five of the 25 neonates (20%) died, but none of the other infants, so that the total mortality (five out of 38) was 13%. Three of the 38 required an aortopulmonary shunt. All 38 survivors were followed up--from one month to 14 years (mean 7.5 years). All were symptom free at the last check up. Fifteen of the survivors had required further surgery; this was successful in all cases.

CONCLUSIONS

For the balloon valvuloplasty era surgical pulmonary valvotomy provides a good back up for failed attempts at percutaneous valvuloplasty. Review of outcome provides data for comparison with balloon valvuloplasty in the future.

Surgical intervention in neonates with critical pulmonary stenosis

The surgical experience with 18 consecutive neonates with critical pulmonary stenosis (PS) and intact ventricular septum was reviewed. All patients had cardiac catheterization with calculation of right ventricular volume. Group A patients (N = 8) had a small right ventricular end-diastolic volume (RVEDV less than 72% of predicted). Group B patients (N = 10) had a normal or enlarged RVEDV. All patients had a closed pulmonary valvotomy. Five Group A patients required a systemic-pulmonary shunt or prostaglandin (PGE1) after operation; one patient died. Nine Group B patients did well after valvotomy; one moribund patient died after valvotomy and shunt. Six of 16 survivors required reoperation: valvectomy in four patients and shunt takedown in two patients. Four of the six patients who had reoperation also had a transannular patch. There was one unrelated late death. All long-term survivors are asymptomatic. Recatheterization in four patients with a small right ventricle (RV) documented significant RV growth. In conclusion, most neonates with critical PS can be managed with closed valvotomy. Patients with a small RV may require PGE1 or a shunt after operation for persistent hypoxemia. Some patients with a small RV will have significant RV growth after valvotomy.

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)

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.

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.