Hypoplastic right retro-oesophageal aortic arch: similarities to interrupted aortic arch.

Abstract

trophy and the chest radiograph showed mild cardiomegaly and pulmonary congestion. The thymus obscured details of the aortic arch and there was no obvious tracheal deviation.Cross sectional echocardiography showed normal atrioventricular and ventriculoarterial connections. The right heart chambers were enlarged. The left atrium, mitral valve, and left ventricle were hypoplastic. The end diastolic left ventricular dimension was only 10 mm. A perimembranous ventricular septal defect ofmoderate size was seen. The pulmonary artery was much larger than the ascending aorta, which had a diameter of only 6 mm. The aortic valve was small but otherwise normal. The ascending aorta did not arch posteriorly but simply bifurcated. The descending aorta was to the left of the spine and of normal size. It was connected to the pulmonary artery by way of the ductus arteriosus, which was only slightly constricted. The left subclavian artery arose from its postero-superior extremity.Cardiac catheterisation showed a large left to right atrial and ventricular shunt with equal systolic pressures in both ventricles and pulmonary trunk. There was a 20 mm Hg systolic pressure drop across the ductus arteriosus to the descending aorta. The ascending aorta was not entered. Cineangiography confirmed the echocardiographic details of cardiac anatomy. Separate injections of contrast into the left ventricle (fig la and b) and ductus arteriosus (fig lc) confirmed a lack of continuity between the left common carotid and left subclavian arteries. However, the right branch of the bifurcation of the ascending aorta was not an innominate artery-as 477

Congenital arch malformation: a review of morphology and surgical management of circumflex aortic arch

“…The retroesophageal arch segment is usually of adequate caliber, but significant hypoplasia can occur particularly with concomitant ventricular septal defect, which can mimic interruption [6,28,29] . When arch hypoplasia is present, it can be tubular with a long segment, or tortuous, extending from the proximal to distal transverse arch as it courses around the side of the trachea and back of the oesophagus [5][6][7]28] . A long hypoplastic retroesophageal segment can be mistaken as an Abbott artery which is an anomalous artery arising from the posterior wall of the aortic arch or others in coarctation of the aorta [30][31][32] .…”

“…Other reported cardiac lesions include atrial septal defect and bicuspid aortic valve [14,33] . Less commonly, Tetralogy of Fallot or double outlet RV, a lesion with a higher frequency of right aortic arch than in the normal population, had also been reported in circumflex aorta [15] ; as well as left heart hypoplasia [5,34] .…”

“…Therefore, based on this hypothetical model, involutions that occur in circumflex aorta with right aortic arch are (1) the right sixth aortic arch; and (2) the left fourth aortic arch with persistence of the left sixth aortic arch and left dorsal aorta (dorsal aortic root segment 8). Alternatively, it may also share a common pathway with embryological formation of a cervical aortic arch or a double aortic arch [5,12,41] . In the latter, if obliteration between the left common carotid and subclavian arteries occurs early in-utero, the segment may completely involute giving rise to a true form of circumflex arch at birth [12] .…”

“…As with other types of aortic obstruction, hemodynamic mechanisms resulting in reduced flow in the ascending aorta during fetal life may contribute to the development of arch hypoplasia [5] . In addition, compression of the retrooesophageal component between oesophagus and spine during fetal development may also contribute.…”

“…Simple vascular ring division may not fully address all the deleterious effects of circumflex aorta, and a major aortic arch uncrossing procedure may be required [1][2][3][4] . The aortic arch is often unobstructed or presents with variable degrees of obstruction from hypoplasia to near-interruption requiring major arch repair [5][6][7] . When there is also obstruction of the proximal aberrant subclavian, it can be confused clinically with aortic dissection in adult patients [8] .…”