Hypoplasia of the systemic ventricle in congenitally corrected transposition of the great arteries Preoperative documentation and possible implications of operation

"Classic" repair of congenitally corrected transposition and ventricular septal defect

BACKGROUND

This study examined the results of "classic" repair of congenitally corrected transposition of the great arteries and ventricular septal defect.

METHODS

From 1974 to 1994, 52 patients underwent a classic complete repair of lesions associated with congenitally corrected transposition. They were divided into two groups: ventricular septal defect plus left ventricular outflow tract obstruction (group I, 37 patients) and isolated ventricular septal defect (group II, 15 patients). Tricuspid plasty or replacement was performed primarily in 1 patient of group I (3%) and in 8 patients of group II (53%).

RESULTS

The overall operative mortality was 15% (8/52 patients), and the incidence of postoperative atrioventricular block was 27% (14/52 patients). Eight patients died secondarily, 5 of heart failure. Survival rates were 83% +/- 6% at 1 year and 55% +/- 14% at 10 years for group I and 86% +/- 9% at 1 year and 71% +/- 12% at 10 years for group II (not significant). Redo tricuspid plasty or replacement was performed in 12 patients.

CONCLUSIONS

Results of classic complete repair of lesions associated with congenitally corrected transposition are not satisfactory in our experience because (1) the operative mortality and the incidences of tricuspid valve replacement and atrioventricular block are high and (2) secondary heart failure is frequent. However, a retrospective review of morphologic findings shows that "anatomic" complete repairs would not have been feasible in 6 of our patients.

Tricuspid valve abnormalities in patients with atrioventricular discordance: surgical implications

From 1975 to 1990, 90 patients (age, 6 months to 30 years; mean, 9.1 years) underwent operation for defects associated with atrioventricular discordance. Twenty-one had an anatomically abnormal tricuspid (systemic) atrioventricular valve (SAVV) of the following types: Ebstein, 11; straddling, 6; and dysplastic, 4. Sixteen valves were regurgitant: regurgitation was trivial to mild in nine and moderate to severe in seven. Two patients underwent a successful Fontan-type operation. None of the 5 patients with a competent SAVV underwent valve repair or replacement; 1 of these patients died. A ventricular septal defect was closed in 14 and an extracardiac valved conduit was placed in 7. Sixteen had a regurgitant valve: it was replaced in 10 and repaired in 2 (early mortality, 25%). All 4 patients who did not undergo repair or replacement of their regurgitant SAVV died. Two patients died late after repeat replacement. Four other reoperations (closure of a residual ventricular septal defect, SAVV replacement, left ventricle-to-pulmonary artery conduit replacement, and a redo Fontan procedure) were successful. Two patients are lost to follow-up, and 9 have been followed up for them 27 to 156 months (median, 117 months). All were well when last seen. We suggest that an abnormal regurgitant SAVV should be replaced. Alternatively, a "double-switch" procedure that leaves the tricuspid valve in the pulmonary circulation may be used.

Severe obstruction to systemic blood flow in congenitally corrected transposition (discordant atrioventricular and ventriculo-arterial connexions): an analysis of 14 patients

The more common associated cardiac anomalies in any cohort of patients with discordant atrioventricular and ventriculo-arterial connexions (congenitally corrected transposition) include ventricular septal defect, left ventricular (subpulmonary) outlet obstruction, and displacement and/or dysplasia of the morphologically tricuspid valve. There is scant mention in the literature of severe obstruction to systemic blood flow at aortic valve level or beyond in these hearts. The present study reviews those pertinent morphological-clinical and follow-up data on 14 patients with congenitally corrected transposition and aortic valve atresia (one patient); aortic arch interruption or aortic arch atresia (two patients) and coarctation of the aorta (11 patients). All but one patient (the patient with aortic valve atresia) had a perimembranous ventricular septal defect. Mild outflow tract obstruction of the morphologically left ventricle was identified in one patient. Nine patients, however, demonstrated a significant structural and functional disturbance (Ebstein-like with dysplasia) of the systemic morphologically tricuspid valve. No patient in this series was identified with isolated aortic coarctation.

Assessment of ventricular size and function in congenitally corrected transposition of the great arteries

Twenty-four quantitative cineangiographic studies were performed in 19 patients with congenitally corrected transposition of the great arteries to assess right and left ventricular size and function. Ages ranged from 7 days to 44 years and associated lesions included ventricular septal defect (13 of 19), pulmonary stenosis (9 of 19), and systemic (tricuspid) valvular insufficiency (7 of 19). Systemic (anatomically right) ventricular end-diastolic volume was within normal limits in most patients and averaged 119% of predicted normal. Pulmonary (anatomically left) ventricular end-diastolic volume also was normal in most patients, averaged 112% of predicted, and was not different from systemic (right) ventricular end-diastolic volume. Systemic ventricular ejection fraction (RVEF) averaged 0.61 +/- 0.02 and was not different from pulmonary ventricular ejection fraction (LVEF) (0.65 +/- 0.02), but important differences were apparent when age was considered. With exclusion of 2 patients with hypoplastic systemic ventricles and 2 studies performed less than 6 months after open heart surgery, all 12 patients aged less than 10 years had a normal RVEF, whereas 2 of 5 patients aged greater than 17 years had a definitely low RVEF and 1 of 5 had a value at the lower limit of normal. In children, systemic and pulmonary ventricular pump function is usually normal in congenitally corrected transposition of the great arteries and any deviation from normal should suggest ventricular hypoplasia or an increase in afterload. After childhood, systemic ventricular dysfunction is more common and may reflect the inability of the anatomic right ventricle to function as the systemic pumping chamber over a normal lifetime in most patients with congenitally corrected transposition of the great arteries.

Repair of major intracardiac anomalies associated with atrioventricular discordance

Thirty-five patients with atrioventricular (AV) discordance underwent repair of major intracardiac defects. Ventricular septal defect (VSD) was the most frequently encountered lesion, present alone or in combination with other lesions in 86% of these patients. Pulmonary stenosis (51%) and tricuspid insufficiency (37%) were the other lesions encountered. The initial operative mortality of 8.6% is approaching that for these same defects when repaired in the patient with normal atrioventricular connections. However, the late mortality of 19% with an average follow-up of 4.4 years is higher than expected in the absence of AV discordance. Reoperation for residual or recurrent defects was required in 9 of the 32 survivors and was associated with a mortality of 33%. Seven of the 9 reoperations were required for tricuspid valve dysfunction. Elective repair of major anomalies in association with AV discordance can be accomplished safely, but these patients require careful long-term follow-up in anticipation of late problems.