Morphologic Analysis of Common Atrioventricular Valves in Patients with Right Atrial Isomerism

Abstract

The objective of the study was to examine the relation between the morphology of the common atrioventricular valve and regurgitation of the valve in patients with right atrial isomerism. We examined seven consecutive patients with documented right atrial isomerism who subsequently underwent postmortem examination during a 10-year period. The degree of regurgitation and the diameters of the common valve were evaluated via cineangiography, and the site of regurgitation was evaluated by echocardiography. The morphology of the common atrioventricular valve was assessed further at autopsy. Cineangiography revealed valve diameters ranging from 14.8 to 27.8 mm (mean 20.9 mm). Valvar regurgitation was revealed within 2 months of birth in all patients. Regurgitation abruptly worsened in three patients after placement of a Blalock-Taussig shunt or a central shunt and postintubation. Autopsies revealed that the common atrioventricular valve consisted of four leaflets in five patients, and three leaflets in two. The anterior leaflets were large and protruding in all patients, and the lateral leaflets were thickened in six. All patients had a mass consisting of the left lateral leaflets and chordae with direct attachment of the chordae to the ventricular muscle (the right lateral leaflet was attached to the ventricular muscle and immobile in one patient). The lateral leaflets clung to the ventricular wall and exhibited poor movement in six patients. Leaflets with poor mobility corresponded to the regurgitant valvar site as assessed by echocardiography in six patients; and the regurgitation in three patients with acute deterioration occurred at the valvar side with poor mobility. It is concluded that the common atrioventricular valve in patients with right atrial isomerism has morphologic characteristics that may be associated with valvar regurgitation and malignant potential for abrupt deterioration after replacement of systemic-pulmonary shunting.

Atrioventricular valve repair in patients with functional single ventricle

“…The choice of repair procedure for patients with FSV is an important issue. AVV morphology varies widely, especially with atrial isomerism, 12,13 and the decision regarding the repair procedure must be based on the preoperative and intraoperative morphologic findings. Therefore, it is most important to reproduce the preoperative echocardiographic findings of the AVV with a reasonable operative field; otherwise, the surgeon may repair an area that has no regurgitation preoperatively, and the AVV may be deformed.…”

“…However, we believe that regurgitant AVV in patients with FSV is mostly caused by structural abnormalities, including abnormal clefts and commissures, dysplastic leaflets, and elongated or shortened chordae, 1,2,10 especially in cases of atrial isomerism. 12,13 Therefore, in later cases, we favored commissural annuloplasty and closure of abnormal clefts or commissures (leaflet apposition), 6 attempting to preserve the normal or functional leaflets and commissures. 5.…”

Compression of the pulmonary veins by the descending aorta in patients corrected surgically by the Fontan procedure

“…Furthermore, Inamura's case 4 and one of our cases had moderate regurgitation across the common atrioventricular valve. Dilation of the atrium, associated with regurgitation of the common atrioventricular valve, which is often encountered in patients with right isomerism and is known to carry a poor prognosis, 6 may also be a factor associated with the compression of the pulmonary vein connecting to the atrium with a morphologically right appendage.…”

Right atrial isomerism in children older than 3 years

“…Previous studies have shown an incidence of 5–12 % of systemic outflow stenosis in patients with RAI (Eronen et al 2013; Ota et al 2012; Kawahira et al 1997). Systemic outflow stenosis may increases the difficulty of the operation.…”

“…AVV regurgitation in RAI is primarily caused by structural abnormalities, including abnormal clefts and commissures, dysplastic leaflets, and elongated or shortened chordae (Uemura et al 1998; Kawahira et al 1997). Ota et al (2012) reported that 13 (21.7 %) patients with RAI had severe systemic AVV regurgitation on their first echocardiogram.…”