The Efficacy of Mitral Valve Surgery in Children with Dilated Cardiomyopathy and Severe Mitral Regurgitation

Severe mitral regurgitation predicts poor outcomes in adults with left ventricular dysfunction. Frequently, adult patients now undergo initial mitral valve surgery instead of heart transplant. Pediatric data are limited. This study evaluates the efficacy of mitral valve surgery for severe mitral regurgitation in children with dilated cardiomyopathy. This is a single-institution experience in seven children (range, 0.5–10.9 years) with severe mitral regurgitation and dilated cardiomyopathy who underwent mitral valve surgery between January 1988 and February 2005, with follow-up to January 2006. Children with dilated cardiomyopathy had a depressed fractional shortening preoperatively (24.4% ± 6.1%) that remained depressed (22.9% ± 7.6%) 1.3 ± 1.2 years after surgery (p = 0.50). Left ventricular end-diastolic (6.5 ± 1.5 to 4.8 ± 1.8 z-scores, p < 0.01) and end-systolic (6.8 ± 1.5 to 5.5 ± 2.1 z-scores, p < 0.05) dimensions improved. Hospitalization frequency had a median decrease of 6.0 hospitalizations per year (p < 0.02). Three patients were transplanted 0.2, 2.4, and 3.5 years after surgery. There was no perioperative mortality. Mitral valve surgery in children with dilated cardiomyopathy was performed safely and improved symptoms, stabilizing ventricular dysfunction in most patients. Mitral valve surgery should be considered prior to heart transplant in children with dilated cardiomyopathy and severe mitral regurgitation.     

Incidence and Risk Factors for Mitral Valve Prolapse in Severe Adolescent Idiopathic Scoliosis

Mitral valve prolapse (MVP) is known to be associated with thoracic skeletal anomalies. To determine the incidence and risk factors for mitral valve prolapse in the adolescent population with severe idiopathic scoliosis (IS), a prospective follow-up study on 139 adolescent patients with IS from the Pediatric Orthopedic Service was undertaken. Data collected included age, sex, medical and family history, physical exam, electrocardiogram and echocardiogram, spinal x-rays, and pulmonary function tests. MVP was detected by echocardiogram in 13.6% (19/139) of patients with IS as compared with 3.2% in 154 age- and weight-matched controls (p < 0.006). All patients with MVP were asymptomatic and a systolic click or murmur was detected on the single preoperative exam only in 37% (7/19) of them. Patients with MVP and IS weighed less (45.1 ± 2.0 vs 51.8 ± 0.1 kg, p < 0.002) as compared with those IS patients without MVP. The electrocardiogram was abnormal in 21% (4/19) of patients with MVP as compared with only 1.6% (2/120) of patients with IS but no MVP. The two groups did not differ with respect to age at diagnosis, severity of scoliosis, positive family history of scoliosis, or the presence of restrictive lung disease. Though IS was more prevalent in females (79%), the presence of MVP was not related to gender. MVP was persistent in 10 of the 19 patients reevaluated by echocardiogram 2–4 years after spinal surgery. We conclude that MVP is four times more common in patients with severe IS than in the normal adolescent population, and is associated with a lower body weight in IS patients with MVP than in IS patients without MVP. The persistent nature of MVP, even after corrective spinal surgery, may be related to factors other than geometric changes of the heart caused by abnormal thoracic curvature.     

Valve Repair in Children with Congenital Mitral Lesions: Late Clinical Results

Mitral valve repair may be performed without ring support with advantages related to results and complications. The objective of this study was to analyze the long-term clinical results following surgical repair and reconstruction without the use of rings in cases of congenital mitral lesions in children less than 12 years of age. Twenty-one patients who had undergone surgery during the period from 1975 to 1998 were evaluated. The mean age was 4.6 +/- 3.4 years. Females represented 47.6% of the total. Mitral regurgitation was present in 57.1% (12 patients), stenosis in 28.6% (6 patients), and the mixed lesion group represented 14.3% (3 patients). Perfusion time was 43.1 +/- 9.5 minutes and ischemic time 29.4 +/- 10.5 minutes. Follow-up time was 41.5 +/- 53.6 months for the regurgitation group, 46.3 +/- 32.0 months for the stenosis group, and 39.41 +/- 37.51 months for the mixed lesion group. Echocardiographical follow-up time was 37.17 +/- 39.51 months for the regurgitation group, 42.61 +/- 30.59 months for the stenosis group, and 39.41 +/- 37.51 months for the mixed lesion group. Operative mortality was 9.5% (two cases). There were no late deaths. In the regurgitation group, 10 patients (83.3%) were asymptomatic (p = 0.004). In the echocardiographical follow-up, most of the patients had minimal regurgitation. In the clinical follow-up of the stenosis group all patients were in functional class I (NYHA). The mean transvalvular gradient measured by echocardiography was from 8 to 12 mmHg with a mean gradient of 10.7 mmHg. In the mixed lesion group there was one reoperation at postoperative month 43. There were no cases of endocarditis or thromboembolism. Mitral valve repair in congenital lesions is associated with good late results. The majority of cases in the regurgitation group remain asymptomatic and do not require reoperation. Rings or annular support are not necessary in such cases. Satisfactory repair is more difficult to achieve in cases of mitral stenosis due to valvular abnormalities and the seriousness of the associated lesions.     

The Abnormal Contralateral Atrioventricular Valve in Mitral and Tricuspid Atresia in Neonates: An Echocardiographic Study

Abnormalities of the mitral valve (MV) or the tricuspid valve (TV) morphology and/or function in patients with functional single ventricle may result in early morbidity and death. The purpose of this study was to determine the incidence of contralateral atrioventricular valve (AVV) pathologies in mitral valve atresia (MA) and tricuspid valve atresia (TA). We retrospectively reviewed the echocardiographic data of 50 neonates with MV and 20 with TA. Appearance of the papillary muscles, chordae tendinae, and valve leaflets was assessed. AVV regurgitation was semiquantitated by color-flow Doppler and the AVV annulus diameter was measured and indexed to body surface area. MV abnormalities were found in 9 of 20 (45%) of patients with TA. The MV was myxomatous in 9 patients, the leaflets were redundant in 5 patients, and prolapsing occurred in 4 patients. Mild regurgitation was found in 2 patients. In 18 of 20 (90%) patients MV annulus size was larger than 95% of predicted normal values. TV abnormalities were found in 12 of 50 (24%) patients with MA. The TV was myxomatous in 4 patients, prolapsing in 2, and redundant in 3, and moderate TV regurgitation was found in 3 patients. In 29 of 50 (58%) patients TV annulus size was larger than 95% of predicted normal values. Contralateral AVV abnormalities in tricuspid and mitral valve atresia are common and should be assessed carefully before surgical procedures.     

Central Venous Catheter Clots: Incidence, Clinical Significance and Catheter Care in Patients with Hematologic Malignancies

In a 7-month period we studied 38 Hickman central venous catheters (CVCs) positioned in children with hematologic malignancies with the aim of evaluating the incidence and clinical impact of CVC clots. Clots were found in 74% of the CVCs. Three methods of catheter care were developed for flushing the clotted CVCs: (a) use of a heparinized solution (400 IU/mL) on alternate days, (b) use of a heparinized solution (400 IU/mL) and saline solution containing urokinase (10,000 IU/mL) on alternate days, and (c) use of a saline solution containing urokinase (10,000 IU/mL) daily. Only method b decreased clot formation (33% success rate). There were no major mechanical complications in any of the CVCs with clots. Eighteen percent of patients with clots in their CVCs presented with CVC-related infections while no infective complications were observed in the patients without clots in their CVCs. In conclusion, CVC clots may predispose the patient to infections, which must be correctly treated.