Anatomical-echocardiographic correlations in pulmonary atresia with intact ventricular septum. Use of subcostal cross-sectional views

Echocardiographically guided repair of tetralogy of Fallot

Although 2-dimensional, Doppler, color flow echocardiography is accepted as a safe diagnostic method to guide the surgical treatment of certain heart defects, cardiac catheterization remains mandatory for patients with tetralogy of Fallot. Based on the excellent diagnostic correlation between echocardiography and angiocardiography, a policy of echo-guided primary repair of uncomplicated, selected cases of tetralogy of Fallot was introduced at Ospedale Bambino Gesù. In the last 5 years, of 139 patients who had surgery for tetralogy of Fallot, 105 underwent primary repair. In 56 patients (53.3%), surgery was guided only by echocardiography (group I). In the remaining 49 patients (46.7%) (group II), unclear imaging of cardiovascular anatomy (n = 23), or echo-suspected associated malformations (n = 26) prompted cardiac catheterization. The 2 groups did not differ in age and weight at surgery. Intraoperative examination did not show diagnostic errors in patients of group I; cardiac catheterization and surgery confirmed the suspected associated anomalies in 16 of 26 patients of group II (38.4% false-positive). Echocardiography showed an overall sensitivity of 100% and specificity of 85% for detection of associated malformations. In conclusion, echocardiography proved to be adequate for selection of patients with uncomplicated forms of tetralogy of Fallot for primary repair.

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.

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.

Ductus arteriosus in pulmonary atresia with and without ventricular septal defect. Anatomic and functional differences

The pulmonary circulation is dependent on the ductus arteriosus in all patients with pulmonary atresia and intact ventricular septum and in some with pulmonary atresia and ventricular septal defect (tetralogy of Fallot type). To assess the time of ductal closure in these two patient categories, we compared the ages at first operation in 58 patients with pulmonary atresia and intact ventricular septum and 32 with pulmonary atresia and septal defect. The age distribution differed significantly between the groups. Whereas 90% of the children with intact ventricular septum required surgery in the first week of life, 50% of those with ventricular septal defect underwent surgery after the first month and 25% after the third month. The previously described and now confirmed anatomic differences of ductus arteriosus or different levels of endogenous prostaglandins may explain persistent patency of the ductus in pulmonary atresia with ventricular septal defect. The phenomenon may have important clinical implications regarding the timing and choice of surgical procedure.

Pediatric cardiac surgery guided by echocardiography. Established indications and new trends

Cardiac surgery in 602 children was not preceded by cardiac catheterization, the diagnosis being based on clinical findings and two-dimensional and Doppler echocardiography. In the 355 operations without cardiopulmonary bypass there were nine major and seven minor diagnostic errors (2.5% and 2%). Among the 247 cases with open-heart surgery there were no major and eight (3.2%) minor errors. The malformations most suitable for nonbypass surgery without catheterization seem to be those with reduced pulmonary blood flow requiring systemic-pulmonary artery shunt, aortic coarctation and patent ductus arteriosus. For open-heart surgery without invasive investigation, atrial septal defect, partial atrioventricular canal, aortic and pulmonary stenosis, cardiac tumor and isolated valve disorder are 'classic' candidates. Recent experience indicated that selected cases of complete atrioventricular canal, tetralogy of Fallot, truncus arteriosus, total anomalous pulmonary venous connection and transposition of the great arteries may safely undergo primary repair without cardiac catheterization. Because of its diagnostic potentialities, pediatric cardiac surgeons must become familiar with echocardiography.

Indication for systemic-pulmonary artery shunts guided by two-dimensional and Doppler echocardiography: criteria for patient selection

From June, 1983, to February, 1987, 91 patients with pulmonary outflow tract obstruction underwent a systemic-to-pulmonary artery shunt without an invasive study. The surgical indication was based on two-dimensional (2-D) and Doppler echocardiography only. In 82 patients (90.1%), 2-D and Doppler echocardiography allowed correct assessment of the intracardiac anatomy and of the morphology of the pulmonary arteries, pulmonary veins, and aortic arch. The aortic arch anatomy was misdiagnosed in 6 patients (6.6%) who underwent a modified instead of a classic Blalock-Taussig shunt. In 3 patients (3.3%), the indication for the systemic-pulmonary artery shunt was inappropriate; in 1, operative death resulted from the incomplete diagnosis. After the preselection of patients based on knowledge of the anatomical patterns, a systemic-pulmonary artery shunt may be performed without cardiac catheterization if these rules for definitive patient selection are followed: (1) accurate clinical assessment to identify the patients with restricted pulmonary blood flow; (2) precise intracardiac diagnosis by 2-D and Doppler echocardiography; and (3) definitive 2-D echocardiographic visualization of the pulmonary venous connection and the confluence of the pulmonary arteries.