Congenital double-orifice mitral valve. Report of a case with valve replacement

Presentation, natural history, and outcome in children and adolescents with double orifice mitral valve

Forty-six children, aged 2 days to 16 years (median 2.4 years) with double orifice mitral valve (DOMV), were studied. Partial atrioventricular septal defect was the most commonly associated cardiac lesion. Symptoms were related to the degree of mitral insufficiency and/or stenosis when present. Surgical intervention directed at DOMV was required in the minority of patients who underwent repair of associated cardiac lesions. The long-term morbidity attributable to DOMV was low.

Surgical repair of the congenitally malformed mitral valve in infants and children

BACKGROUND

Mitral valve remodeling techniques were applied to 26 infants and children (mean age, 6.0 years, range, 0.4 to 15.9 years) with various forms of congenital mitral valve disease over a 7-year period. Patients with atrioventricular canal, L-transposition and single ventricle were excluded. Intraoperative transesophageal echocardiography (TEE) was utilized to assess the repair and guide the need for immediate intervention.

METHODS

Twenty-one patients had mitral regurgitation: 10 with cleft anterior mitral leaflet, 7 with annular dilatation, 1 with normal leaflets with an obstructing cord, 2 with prolapsed leaflets and elongated cords, and 1 with restricted leaflet motion, normal papillary muscles, and shortened cords. Of the 5 mitral stenosis patients, 3 had supravalvular mitral ring, 1 had midvalvular mitral ring, and 1 had a parachute valve. Three of the mitral stenosis patients had additional stenotic lesions. Concurrent repair of associated lesions was performed in 21 patients (78%).

RESULTS

Operative mortality was 3.8% (n = 1). There were no late deaths. Immediate rerepair in 4 patients resulted in improved function. All mitral stenosis patients improved. A total of 20 mitral regurgitation patients (95%) improved; 1 required mitral valve replacement. Mean follow-up is 31 months (range, 2 to 81 months). All patients are in New York Heart Association functional class I or II.

CONCLUSIONS

Mitral valve repair can be successfully performed in infants and children with excellent short- and midterm results. Assessment using transesophageal echocardiography can guide the necessity for immediate rerepair to achieve improved function.

Double Orifice Mitral and Tricuspid Valves

Atrioventricular valve duplication is a rare congenital cardiac anomaly. The anomaly is usually recognized as an incidental finding at autopsy, open heart surgery, or two-dimensional echocardiography. In this article we present the transthoracic and transesophageal presentation of a case of mitral and a case of tricuspid valve duplication. The hemodynamic consideration of the lesions is discussed with a review of the literature. (ECHOCARDIOGRAPHY, Volume 13, January 1996)

Double-orifice mitral valve: a study of 27 postmortem cases with developmental, diagnostic and surgical considerations

What is double-orifice mitral valve anatomically and embryologically? In 27 postmortem cases, an anomaly of the tensor apparatus was always found. These malformations may be summarized as: (1) chordal ring; (2) accessory papillary muscle or muscles; (3) subdividing muscular ridge; (4) fused papillary muscles (parachute mitral valve); (5) crossing chordae tendineae; and (6) central fibrous subdivision. More than 1 of these anomalies often coexisted per case. Double-orifice mitral valve almost always consisted of abnormal holes in essentially normal leaflets, rather than of abnormal fibrous bridges or adhesions between normal leaflets. Since these fibrous "bridges" between the smaller accessory orifice and the larger main orifice are composed of mitral leaflet tissue and chordae, not fibrous adhesions, these bridges should not be transected surgically, to avoid iatrogenic mitral regurgitation. The accessory (smaller) orifice was at the anterolateral commissure in 11 cases (41%), at the posteromedial commissure in 12 (44%) and there was a central fibrous subdivision with approximately equal-sized orifices in 4 (15%). The atrioventricular (AV) canal was normally divided in 12 cases (44%) and a common AV canal was present in 15 (56%). When the accessory orifice was at the anterolateral commissure, the AV canal usually was normally divided (8 of 11, 73%). But when the accessory orifice was at the posteromedial commissure, a common AV canal almost always was present (11 of 12, 92%). Functionally, the mitral valve was normal in 13 (48%), regurgitated in 7 (26%) and stenotic in 7 (26%). The key to the diagnostic and surgical understanding of the double-orifice mitral valve is the underlying tensor apparatus.

Severe mitral regurgitation in a woman with a double orifice mitral valve

A 64 year old woman with partial atrioventricular canal and double orifice mitral valve presented with severe mitral regurgitation secondary to a torn leaflet. The double orifice regurgitant mitral valve is an unusual finding at operation.

Two-dimensional echocardiographic findings in double orifice mitral valve

Between December 1981 and April 1984, five children ranging in age from 1 month to 5 1/2 years examined by two-dimensional echocardiography appeared to have a double orifice mitral valve. The diagnosis was verified in one patient at surgery, one patient by angiography and one patient by necropsy. Associated malformations included mitral stenosis and regurgitation, coarctation of the aorta, ostium primum and secundum atrial septal defect, ventricular septal defect and hypoplastic left heart syndrome. Three varieties of double orifice mitral valve were observed: an incomplete bridge type (one patient), in which a small strand of tissue connected the anterior and posterior leaflets at the leaflet edge level; a complete bridge type (three patients), in which a fibrous bridge divided the atrioventricular orifice completely into equal or unequal parts and a hole type (one patient), in which an additional orifice with subvalvular apparatus occurred in the posterior commissure of the mitral valve. These three types could be distinguished by sweeping the transducer in cross-sectional view from the apex toward the base of the heart. Both orifices could be seen throughout the scan in the complete bridge type while in the incomplete bridge type the two orifices could be seen only at the level of the papillary muscles. In the hole type, the second orifice was seen at about midleaflet level. In all three types, the chordae surrounding each orifice attached to only one papillary muscle. Congenital mitral stenosis or regurgitation was evident in three patients. The type of the double orifice mitral valve did not predict the presence or severity of symptoms.

Two-dimensional echocardiography in double orifice mitral valve

In a patient with endocarditis and significant aortic insufficiency, two-dimensional echocardiography revealed an abnormal mitral valve configuration with division of the valve into two separate orifices. At autopsy, a double orifice mitral valve with two sets of valve leaflets was observed. Appreciation of this echocardiographic abnormality is important because double orifice mitral valve is associated with other congenital anomalies and this echocardiographic configuration may be confused with other cardiac abnormalities.