Transposition of the great arteries and narrowing of the aortic arch. Emphasis on right ventricular characteristics.

Abstract

Of 279 patients with transposition of the great arteries, 14(5%) had narrowing of the aorta, including local coarctation (6), isthmus hypoplasia (6), isthmus atresia (1), and kinking of the aorta (1). There were six deaths in 10 surgically treated patients; in addition four patients died before operation. Two of the four survivors had a subpulmonary malalignment ventricular septal defect with angiocardiographic narrowing of the right ventricular outflow tract, two had evidence of redundant muscle tissue obstructing the right ventricular outflow tract. Necropsy showed the presence of anatomical right ventricular outflow tract or inflow tract obstruction or both in all 10 cases. Outflow tract obstruction was represented by anterior displacement of the infundibular septum and ventriculoinfundibular fold (in hearts with a subpulmonary malalignment ventricular septal defect) or by redundant muscle tissue; inflow tract obstruction was represented by hypoplasia of the tricuspid valve. It is concluded that the combination of transposition of the great arteries and narrowing of the aorta is always accompanied by right ventricular outflow or inflow tract obstruction or both; the right ventricular abnormalities are probably responsible for the presence of the aortic arch anomalies by reducing aortic flow during morphogenesis. Successful surgical treatment of this complex anomaly is feasible in selected cases.

Long-Term Results After Primary One-Stage Repair of Transposition of the Great Arteries and Aortic Arch Obstruction

“…Perioperative RV dysfunction was the strongest predictor of death and the only variable that reached statistical significance at multivariate analysis. The association between aortic arch obstruction and ventriculoarterial discordance encompasses a wide spectrum of anatomic variants, and the rate of RV hypoplasia is higher than for isolated TGA (2,4,13). Conceptually, the resulting malformation at the extreme end could be called, with a provocative term, "hypoplastic right heart syndrome."…”

“…Although longterm mortality and freedom from reoperation rates among survivors were, in some series, similar to patients who underwent the ASO for "uncomplicated" classical TGA, several aspects seem to pertain specifically to this subset of surgical candidates. No death could be related to the aortic arch repair, per se, but complex anatomy is more common and determines a higher complexity of the surgical strategy and, consequently, an increased operative mortality (2,14,19,20).…”

“…Also, the relationship between the great vessels varied widely, with almost one-half of the patients showing a non-anteroposterior anatomy. An unbalanced anatomy with a smaller than normal RV is more common in TGA with arch obstruction (2,4,13). In such instances, RV hypoplasia was retrospectively defined when the tricuspid valve annulus diameter measured two standard deviations below normal values.…”

“…When this combination occurs, the natural history is very poor and the treatment constitutes a difficult task (1)(2)(3)(4)(5). Hypoplasia of the aortic arch is more commonly encountered in specific forms of ventriculoarterial discordance, being reported in up to 50% of cases in some subgroups of double outlet right ventricle (RV), especially in the presence of a subpulmonary VSD (Taussig-Bing anomaly) (6).…”

Surgical management of transposition in the setting of obstruction within the aortic arch

“…In the setting of transposition with concordant atrioventricular connections and an intact ventricular septum, however, obstruction of the aortic arch occurs in less than one-twentieth of patients. [2][3][4] It is more common in transposition with ventricular septal defect, reported to occur in up to one-third of the cases, [2][3][4][5] and is particularly frequent in the presence of anterior malalignment of the muscular outlet septum, being seen in almost nine-tenths of these cases. 6 Obstruction of the aortic arch is reported in at least half of patients with double outlet right ventricle with subpulmonary interventricular communication, the so-called Taussig-Bing malformation.…”