Accessory Mitral Valve Tissue Research Articles

Estenosis subaórtica progresiva causada por tejido mitral accesorio

Accessory mitral valve tissue is a rare cause of subaortic obstruction. The reported case correspond to a two days old patient diagnosed by 2D-Echocardiography. Serial doppler flow analysis showed progressive left ventricular outflow obstruction. A cardiac catheterization at the age of 9 months confirmed the obstruction without defining the cause. Five months later, transesophageal echocardiography clearly defined the intraventricular connections of the accessory mitral tissue. At the age of 18 months the patient suffered from cardiac failure and underwent surgery for removing the accessory tissue, assisted by intraoperative transesophageal echocardiography pre and post by-pass. Follow-up echocardiography at 25 months showed no left ventricle outflow obstruction and the patient is now asymptomatic.

Nonobstructing Accessory Mitral Valve Tissue and Ventricular Septal Defect

A 4-month-old boy with ventricular septal defect was found to have accessory mitral valve tissue attached to the anterior leaflet of the mitral valve. Operation was successfully performed to excise the accessory mitral tissue in the left ventricular outflow tract and close the ventricular septal defect. Most previously reported cases with accessory mitral valve tissue were associated with left ventricular outflow tract obstruction. This boy had no pressure gradient across the left ventricular outflow tract. The indications for prophylactic excision of nonobstructing accessory mitral valve tissue in a patient with other forms of congenital cardiac disease are discussed.

Role of echocardiography in the diagnosis and surgical management of accessory mitral valve tissue causing left ventricular outflow tract obstruction

We report an unusual case of left ventricular outflow tract obstruction caused by accessory mitral valve tissue. This case illustrates the importance of transthoracic echocardiography in preoperative evaluation and the usefulness of transesophageal echocardiography for intraoperative assessment. If the accessory mitral valve has no functional significance it may be surgically excised, thereby relieving the outflow tract obstruction.

Trans-ventricular septal defect approach for resection of accessory mitral valve tissue

Accessory mitral valve tissue is a rare cause of left ventricular outflow tract obstruction, which can be difficult to recognize. Surgical resection by the conventional transaortic approach with or without left atriotomy is extremely difficult in infants with a small aorta. When a ventricular septal defect is present, it may be the best way to approach tha accessory mitral valve tissue, because the ventricular septal defect is located just in front of it. Five infants underwent resection of accessory mitral valve tissue together with repair of other intracardiac malformations. In 3 infants, resection of accessory mitral valve tissue was easily performed through the ventricular septal defect, which required enlargement in 2 patients.

Accessory Mitral Valve Tissue Causing Left Ventricular Outflow Obstruction (Two-Dimensional Echocardiographic Diagnosis and Surgical Approach)

Accessory mitral valve tissue, a rare cause of left ventricular outflow tract obstruction, can be difficult to diagnose preoperatively and confusing even at surgery. The reported case illustrates how preoperative evaluation can be made using two-dimensional echocardiography combined with Doppler flow analysis. The intraoperative technique for removing the accessory tissue without causing damage to the native mitral valve is discussed.

Accessory mitral valve tissue causing left ventricular outflow tract obstruction.

Although left ventricular outflow tract obstruction is commonly associated with congenitally corrected transposition of the great vessels, this obstruction is seldom caused by accessory mitral valve tissue. Three cases in which accessory mitral valve tissue caused left ventricular outflow tract obstruction in children are described. Two had congenitally corrected transposition and one had normally connected great vessels. The accessory leaflet tissue, which was identified by echocardiography and angiography, was attached by chordae tendineae to normally sited papillary muscles and herniated into the left ventricular outflow tract during systole. Operation was successful in these patients. The accessory valve tissue was excised via an arteriotomy in the great vessel that arose from the left ventricle. The obstructive tissue was excised close to its peripheral attachments in the outflow tract and its chordae tendineae were divided. Resection was performed without injury to the abnormally placed conduction system or to the normal valve structures.

Unusual mitral valve abnormalities complicating surgical repair of endocardial cushion defects

A review of 155 cases of surgically repaired endocardial cushion defects revealed 16 patients (10%) with additional unusual mitral valve abnormalities that complicated the surgical procedure. Eight patients had accessory mitral valve tissue that connected the anterior and posterior leaflets to form a double-orifice valve (Group I). In four (50%), the lesion was associated with intermediate atrioventricular canal and small left ventricle; all four died following repair. In the other four, it was associated with ostium primum defect; all survived and are well. A single papillary muscle in the left ventricle was present in six patients (Group II). Two had intermediate atrioventricular canal and both died postoperatively. The other four had complete endocardial cushion defect and three are well following the operation. Perforation of the valve leaflets was present in two patients with ostium primum (Group III). Both patients are well postoperatively. Modification of the surgical technique is required to effect satisfactory repair. The bridge connecting the posterior and anterior leaflets of the mitral valve should be left undisturbed. Otherwise, severe regurgitation may result. In patients with single papillary muscle and complete atrioventricular canal, repair may be accomplished by borrowing from the tricuspid portion of the anterior leaflet, rotating that part posteriorly, and partially closing the cleft. Small perforations of the mitral leaflet do not require closure and do not result in regurgitation. Echocardiographic and angiographic delineation of these abnormalities and thorough intraoperative exploration are important in avoiding pitfalls at the time of repair.

Accessory mitral valve tissue causing left ventricular outflow tract obstruction in D-transposition of the great arteries.

Two patients with D-transposition of the great arteries (D-TGA) were found to have an unusual form of left ventricular outflow tract obstruction. Both had ball-like accessory mitral valve tissue that partially occluded the outflow tract. In one patient there was an intact septum, while in the other there were ventricular septal defects. The appearances have been described previously, although not in D-TGA. Recognition of accessory mitral valve tissue may allow resection of the tissue at the time of repair of the transposition complex.