Characterization of cardiac tumors in children by cardiovascular magnetic resonance imaging: a multicenter experience.

OBJECTIVES: The aim of this study was to report the results of an international multicenter experience of cardiac magnetic resonance imaging (MRI) evaluation of cardiac tumors in children, each with histology correlation or a diagnosis of tuberous sclerosis, and to determine which characteristics are predictive of tumor type. BACKGROUND: Individual centers have relatively little experience with diagnostic imaging of cardiac tumors in children, because of their low prevalence. The accuracy of cardiac MRI diagnosis on the basis of a pre-defined set of criteria has not been tested. METHODS: An international group of pediatric cardiac imaging centers was solicited for case contribution. Inclusion criteria comprised: 1) age at diagnosis ≤18 years; 2) cardiac MRI evaluation of cardiac tumor; and 3) histologic diagnosis or diagnosis of tuberous sclerosis. Data from the cardiac MRI images were analyzed for mass characteristics. On the basis of pre-defined cardiac MRI criteria derived from published data, 3 blinded investigators determined tumor type, and their consensus diagnoses were compared with histologic diagnoses. RESULTS: Cases (n = 78) submitted from 15 centers in 4 countries had the following diagnoses: fibroma (n = 30), rhabdomyoma (n = 14), malignant tumor (n = 12), hemangioma (n = 9), thrombus (n = 4), myxoma (n = 3), teratoma (n = 2), and paraganglioma, pericardial cyst, Purkinje cell tumor, and papillary fibroelastoma (n = 1, each). Reviewers who were blinded to the histologic diagnoses correctly diagnosed 97% of the cases but included a differential diagnosis in 42%. Better image quality grade and more complete examination were associated with higher diagnostic accuracy. CONCLUSIONS: Cardiac MRI can predict the likely tumor type in the majority of children with a cardiac mass. A comprehensive imaging protocol is essential for accurate diagnosis. However, histologic diagnosis remains the gold standard, and in some cases malignancy cannot be definitively excluded on the basis of cardiac MRI images alone.

Feasibility of perfusion cardiovascular magnetic resonance in paediatric patients.

AIMS: As coronary artery disease may also occur during childhood in some specific conditions, we sought to assess the feasibility and accuracy of perfusion cardiovascular magnetic resonance (CMR) in paediatric patients. METHODS AND RESULTS: First-pass perfusion CMR studies were performed under pharmacological stress with adenosine and by using a hybrid echo-planar pulse sequence with slice-selective saturation recovery preparation. Fifty-six perfusion CMR examinations were performed in 47 patients. The median age was 12 years (1 month-18 years), and weight 42.8 kg (2.6-82 kg). General anaesthesia was required in 18 patients. Mean examination time was 67 +/- 19 min. Diagnostic image quality was obtained in 54/56 examinations. In 23 cases the acquisition parameters were adapted to patient's size. Perfusion CMR was abnormal in 16 examinations. The perfusion defects affected the territory of the left anterior descending coronary artery in 11, of the right coronary artery in 3, and of the circumflex coronary artery in 2 cases. Compared to coronary angiography, perfusion CMR showed a sensitivity of 87% (CI 52-97%) and a specificity of 95% (CI 79-99%). CONCLUSION: In children, perfusion CMR is feasible and accurate. In very young children (less than 1 year old), diagnostic image quality may be limited.

Muscle-sparing extrapleural approach for the repair of aortic coarctation.

BACKGROUND: This paper describes a muscle-sparing, extrapleural approach to repair aortic coarctation, and evaluates the results with established standards. METHODS: Forty consecutive patients with aortic coarctation (median age, 8 days; weight, 3.3 kg) were approached with a less invasive technique consisting of a short posterior thoracotomy, with only minimal (24 patients) or no (16 patients) division of thoracic wall muscles and a subperiosteal-extrapleural approach. Extended resection of the coarctation with enlargement of the distal aortic arch was performed in all patients. The median cross-clamp and operative times were 22 and 90 minutes, respectively. RESULTS: The repair was possible in all patients without needing conversion. There was no intraoperative or postoperative related complication. Two patients died early of low cardiac output as a result of ventricular fibroelastosis and respiratory failure. One patient died late of unrelated cause. The perioperative mean gradients across the neoarch were less than 5 mm Hg in all but 3 patients with proximal (2 patients) or mid arch (1) stenosis. The median ventilation time, intensive care unit stay, and hospital stay in isolated coarctation repairs was 2, 4.5, and 11 days, respectively. One patient had a recurrent stenosis at the site of surgical repair. Two patients underwent successful balloon dilatation, and 2 had surgical enlargement plasty of the proximal aortic arch at the time of intracardiac repair. None of the patients required chronic antihypertensive medication. At 29 months, freedom from reintervention on the isthmus and arch plus isthmus was 97.1% and 89.7%, respectively. CONCLUSIONS: A muscle-sparing, extrapleural approach for the repair of aortic coarctation is possible and provides results similar to conventional techniques. The approach reduces postoperative morbidity related to division of thoracic wall muscles and handling of the lung, restores a normal intercostal space, and produces superior cosmetic results, while at the same time leading to early and permanent relief of proximal hypertension.

Early insertion of a pulmonary valve for chronic regurgitation helps restoration of ventricular dimensions.

BACKGROUND: This study assesses the results of early insertion of a pulmonary valve for chronic pulmonary regurgitation based on right ventricular volume measurements. METHODS: Valved conduits were prospectively inserted in 39 patients (aged 14 to 39 years) when the right ventricular (RV) end-diastolic volume index on magnetic resonance imaging (MRI) exceeded 150 mL/m2. Changes in morphology and function of the RV were prospectively analyzed by an MRI at 6 months postoperatively (available in 21 patients). RESULTS: There were no early or late deaths. All conduits showed good function at a median 15 month follow-up. Postoperative RV end-systolic and end-diastolic volumes showed a significant positive correlation (p = 0.005 and p < 0.0001), while postoperative left ventricular (LV) ejection fraction showed a significant negative correlation (p = 0.03) with preoperative RV end-diastolic volume index. Seven patients who achieved normal RV end-diastolic volume index (< or = 100 mL/m2) (group 1) when compared with 14 remaining patients (group 2) showed that they differed significantly with respect to their preoperative RV end-diastolic volume index (170.3 +/- 21.1 vs 203.6 +/- 35.6; p = 0.02) and postoperative LV ejection fraction (59.9 +/- 4.2 vs 54 +/- 7%, p = 0.03). CONCLUSIONS: Our results show that the improvement in ventricular dimensions and functions directly correlates with the timing of pulmonary valve insertion. Early insertion leads to normalization and late insertion leads only to improvement. These observations, along with a low morbidity for these reoperations, justify earlier reintervention in cases of chronic pulmonary regurgitation. A RV end-diastolic volume index of 150 mL/m2 seems to be a practical cutoff value to prescribe pulmonary valve insertion.