Mitral Valve In Children Research Articles

Replacement of the mitral valve in children—an analysis of 130 cases

SummaryReplacement of the mitral valve was performed in 130 children less than 15 years of age—115 for rheumatic and 15 for congenital disease. Early mortality was 5.4%. Of 123 survivors, 112 were followed postoperatively for a mean period of nine years, with 80 of them on anticoagulants. Thromboembolism is the major late problem, with 25 thromboembolic accidents noted in 25 patients (22.3%). Anticoagulation was ineffective or lacking in 72% of them. Bacterial endocarditis was noted in five cases (4.4%) and a prosthetic leak in three (2.6%). Particular problems are observed in this group of young patients. First, recurrence of rheumatic fever in nine patients with an increasing severity of aortic valvar incompetence; second, with growth the prosthesis can become small as observed in six of our patients. A reoperation was needed in 15 patients, with one requiring two reoperations. Late mortality was 21%. Optimal timing for replacement of the valve is crucial. Appropriate anticoagulation and correct prophylaxis of rheumatic fever and bacterial endocarditis is mandatory. Conservative surgery is certainly preferable to valvar replacement, but if replacement proves necessary, large prostheses should be used.

Reconstruction of the mitral valve in children— long-term follow-up in 63 cases

SummaryBetween June 1985 and June 1991, 63 children underwent surgical reconstruction of the mitral valve for rheumatic (46 cases), congenital (12 cases) and myxoid (five cases) disease. The ages ranged from two to 18 years (mean 14.1±3.7 years). Valvar dysfunction was classified according to its pathophysiological abnormalities. A group of four cases presented with regurgitation secondary to lesions located in the valvar structures but with normal motion of the leaflets. In a second group of 14 cases, mitral regurgitation was due to prolapsed leaflets because of lesions located mainly in the subvalvar structures. A third group was formed by 35 patients with mitral regurgitation with restricted motion of the leaflets due to lesions in the valvar and subvalvar structures. The final group, of 10 cases, presented with mitral stenosis. The overall surgical mortality rate was 4.7% (3/63), and follow-up data were available in all survivors from one to 96 months (mean 33.4±25.4). Four cases underwent reoperation due to residual incompetence, one case due to bacterial endocarditis, and two more are scheduled for replacement of the valve due to unfavorable evolution, giving an overall rate of reoperation of 4.3% per patient/year. One patient died in the period following valvar replacement (late mortality rate of 0.6% per patient/year). Thromboembolism occurred in four cases in the absence of anticoagulation; three of them were in atrial fibrillation (late thromboembolic rate 2.4% per patient/year). Prior to surgery, 28 cases were in functional class II of the New York Heart Association, 34 patients were in class III and one patient in class IV. At the end of the follow-up period, 49 patients were in class I, seven in class II and four in functional class III (p<0.0001). The cardiothoracic ratio before surgery ranged from 0.40 to 0.81 (mean 0.60±0.07) and, after surgery, the values ranged from 0.40 to 0.79 (mean 0.55±0.07) (p<0.0001). Randomized late echocardiographic evaluation in 24 cases revealed residual mild mitral regurgitation in 20 cases, moderate in two and severe in two. The latter are scheduled for valvar replacement. There were no significant differences in the surgical results among the four groups. Reconstruction of the mitral valve, therefore, provides stable functional results with low surgical and late mortality, as well as an acceptable rate of reoperation irrespective of the lesions of the valvar apparatus.

Echocardiographic evaluation of the aortic root and mitral valve in children and adolescents with isolated pectus excavatum: Comparison with Marfan patients

Pectus excavatum, mitral valve prolapse (MVP), and dilated aortic root occur frequently in patients with Marfan's syndrome (MS). Patients with isolated pectus excavatum (IPE) have a high prevalence of MVP, but it is not known whether aortic root dilatation is a risk in those patients. To test the hypothesis that IPE and MS represent a spectrum of connective tissue dystrophy with MV and aortic root involvement, two-dimensional (2D) echocardiography was used to measure the aortic root diameter and assess for MVP in IPE (n = 31), MS (n = 14), and normal (n = 16) gender- and age-matched patients. Aortic root was measured in parasternal long- and short-axis views, just above the aortic sinuses, at end systole, in six cardiac cycles, and averaged. Parasternal long-axis view was used to assess for MVP. Aortic root diameter in IPE patients was not different from that in normal subjects, 24 +/- 4 mm vs 22 +/- 4 mm (p = NS), respectively, both were significantly smaller than that in MS patients (30 +/- 5 mm; p less than 0.05). MVP was present in 17 of 31 (55%) IPE patients vs 12 of 14 (86%) MS patients (p = NS) and in only 1 of 16 (6%) normal subjects (p less than 0.05) vs both IPE and MS. We conclude that young patients with IPE represent an isolated form of connective tissue abnormality because of the presence of pectus excavatum and MVP, but this is different from the systemic involvement of MS because of the lack of other systemic findings, including aortic root dilatation and changes in body habitus.

Repair of congenitally malformed mitral valve in children

We report our experience with 30 children under 15 years of age treated surgically for congenital mitral valve disease from March 1972 to July 1986. Valve reconstruction was possible in 26 patients (87%), whereas in four the valve was replaced with a mechanical prosthesis. Five patients died in the hospital (16.6%), four after conservative operations and one after mitral valve replacement. There was only one late death in a child in chronic congestive heart failure. Three patients, treated conservatively, required valve replacement 2, 22, and 24 months, respectively, after the operation. Follow-up data reveal that 22 of 24 patients are asymptomatic 5 months to 15 years after operation. Two-dimensional echocardiographic studies were performed in 19 patients treated conservatively, 17 of whom are asymptomatic. Eleven of them have no signs of mitral regurgitation or stenosis, six show only mild mitral incompetence, and two have moderate mitral regurgitation or stenosis. Peak pulmonary artery pressure is within normal limits in all. Our results indicate that mitral valve reconstructive procedures for congenital valve dysplasia may be effective and reliable in children despite the frequent severity of valve malformation. Although no major prosthesis-related complications were observed in the present series, we believe that mitral valve repair should always be attempted in the pediatric population to avoid the drawbacks of the currently available prostheses.

Congenital malformations of the mitral valve in children: Pathology and surgical treatment

A systematic study of congenital mitral valve malformations was undertaken on a surgical basis in an attempt to develop techniques of valvular reconstruction adapted to the various lesions. Forty-seven children between the ages of 4 months and 12 years (average 6 years, 4 months) have been operated upon between January, 1970, and March, 1976. Valvular lesions were classified into four group: Group I, mitral insufficiency owing to valvular lesions: Group II mitral insufficiency with subvalvular lesions; Group III, mitral insufficiency and stenosis; Group IV, stenosis. Associated lesions (ventricular or atrial septal defects, coarctation, or aortic valve stenosis) were present in 31 patients (65 per cent) and were corrected during the same operation. Valve reconsruction was possible in 38 patients whereas valve replacement was necessary in 9 patients. In the valve repair group there were three operative deaths (8 per cent), no late deaths, one reoperation for residual ventricular septal defect, and one myocardial infarction. In the valve replacement group of 9 patients, there were three operative deaths, three late deaths, and one case of repeated embolization. Thirty-one of 38 patients in the valve repair group were classified into Functional Class I after the operation (86 per cent), 2 were in Class II, and one in Class III. Minimal or moderate regurgitation and cardiomegaly persisted in the majority of the patients. Pulmonary artery pressure significantly decreased, however, as demonstrated by postoperative catheterization in 17 patients.

Ostium secundum atrial septal defect associated with balloon mitral valve in children

Eight children with an ostium secundum atrial septal defect and balloon mitral valve are described. Leftward-superior QRS forces, abnormal T waves and suggestive apical auscultatory findings (midsystolic click or a late systolic murmur of mitral insufficiency) were frequently observed and led to the erroneous diagnosis of ostium primum atrial septal defect in six cases. Lack of any or all of these manifestations did not preclude the presence of a balloon mitral valve. The prognostic importance of this valvular lesion indicates the need to perform left ventriculography in all patients with an atrial septal defect.