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BACKGROUND: Hybrid procedure with ductal stenting and bilateral pulmonary banding offers a temporary approach in high-risk neonates with complex congenital heart defects aiming biventricular repair. This procedure may also have negative impact concerning post-banding pulmonary stenosis resulting in right ventricular pressure load. METHODS: Between 2010 and 2021 we identified 5 patients with interrupted aortic arch and complex congenital heart defect who underwent hybrid procedure and staged biventricular repair ("hybrid-group"). Other 7 cases with interrupted aortic arch were corrected in the neonatal phase without hybrid procedure ("nonhybrid-group"). Detailed intra- and extracardiac features and surgical procedures were documented as well as pulmonary interventions during follow up. Pulmonary vessel size was assessed by diameter of left and right pulmonary artery in absolute and indexed values. RV pressure was evaluated invasively via catheterization. RESULTS: Survival in cases with hybrid procedure and staged biventricular repair was 91% for a follow-up time of 40.7 months (95% CI 26-55 months) and 100% in the non-hybrid-group. Postoperative results concerning left ventricular function showed normal LV dimensions and systolic function without relevant stenosis on distal aortic arch. Hybrid procedure was associated with impaired local pulmonary arterial diameter after debanding resulting in increased right ventricular pressure and need for interventions (number intervention per patient: hybrid group 1.7 ± 0.95, non-hybrid group 0.17 ± 0.41; P 0.003). CONCLUSIONS: Hybrid procedure in high-risk cases with interrupted aortic arch and staged biventricular repair shows good postoperative results with low perioperative mortality and normal left ventricular function. Due to potential risk of relevant pulmonary stenosis and right ventricular pressure load, follow up examinations must not only focus on left but also on the right heart.
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Coartação Aórtica , Cardiopatias Congênitas , Comunicação Interventricular , Hipertensão Pulmonar , Estenose da Valva Pulmonar , Recém-Nascido , Humanos , Lactente , Artéria Pulmonar/cirurgia , Comunicação Interventricular/cirurgia , Resultado do Tratamento , Coartação Aórtica/cirurgia , Ventrículos do Coração/cirurgiaRESUMO
BACKGROUND: Neonatal coarctation of the aorta (CoA) is primarily treated by surgical repair. However, under certain high-risk constellations, initial stent angioplasty may be considered followed by surgical repair. We report our experience with this staged approach. Methods: All patients undergoing surgical CoA repair following prior stenting at our institution between January 2011 and December 2019 were included in this retrospective analysis. The patients were classified to be at high risk because of cardiogenic shock, associated complex cardiac malformations, neonatal infection, necrotizing enterocolitis, and extracardiac conditions, respectively. Outcomes were analyzed and compared with neonates who underwent surgical CoA repair without prior stenting in the same observation period. RESULTS: Twenty-six neonates received stent implantation at a median age of 20 days (IQR 9-33 days). Subsequent surgical repair was conducted at an age of 4.2 months (IQR 3.2-6.1 months) with a median body weight of 5.6â kg (IQR 4.5-6.5â kg). Cardiopulmonary bypass was applied in 96% of cases. Extended end-to-end anastomosis was possible in 11 patients. Extended reconstruction with patch material was necessary in the remaining patients. One fatality (3.8%) occurred 33 days postoperatively. At a median follow-up of 5.2 years after initial stenting, all remaining patients were alive; 15/25 patients (60%) were free from re-intervention. Of note, re-intervention rates were comparable in neonates (n = 76) who were operated on with native CoA (28/74 patients; 38%; P = .67). CONCLUSIONS: Neonatal stent angioplasty for CoA results in increased complexity of the subsequent surgical repair. Nevertheless, this staged approach allows to bridge high-risk neonates to later surgical repair with reduced perioperative risk and acceptable midterm outcomes.
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Coartação Aórtica , Humanos , Lactente , Recém-Nascido , Angioplastia , Coartação Aórtica/cirurgia , Estudos Retrospectivos , Stents , Resultado do TratamentoRESUMO
BACKGROUND: The indication and extent of cardiac screening before oral propranolol therapy (OPT) in patients with infantile hemangioma (IH) has been challenged. In this study, we evaluated pre-OPT cardiac diagnostics in a pediatric IH cohort in our department. METHODS: Retrospective chart review of infants ≤ 12 months old with IH undergoing OPT. The diagnostics prior to OPT, occurrence of complications, and outcome were recorded. RESULTS: A total of 234 patients were evaluated. The mean age at the onset of OPT was 4.2 ± 0.3 months, the average duration of OPT was 6.1 ± 0.1 months, and the average follow-up was 12.3 ± 0.7 months. Echocardiograms and electrocardiograms were performed prior to OPT in all patients. One hundred and three (44.0%) echocardiograms revealed pathological findings, 19 (8.1%) of which were minor (including atrial septal defects, pulmonary stenosis, and patent ductus arteriosus). Pathological findings were observed in 17 (7.3%) of electrocardiograms, only one (0.4%) of which was minor (suspected cardiac arrhythmia, subsequently excluded by long-term electrocardiogram analysis). These findings did not contraindicate OPT and no severe adverse events associated with OPT occurred during the follow-up period. CONCLUSIONS: Routine cardiac screening by electrocardiogram and echocardiogram before OPT is debatable and not routinely indicated in children with IH. Further studies are necessary to draw definite conclusions on the reasonable indication and extent of this diagnostic approach.
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Técnicas de Imagem Cardíaca , Cardiopatias Congênitas/diagnóstico por imagem , Hemangioma Capilar/tratamento farmacológico , Propranolol/uso terapêutico , Neoplasias Cutâneas/tratamento farmacológico , Administração Oral , Antagonistas Adrenérgicos beta/efeitos adversos , Antagonistas Adrenérgicos beta/uso terapêutico , Estudos de Coortes , Ecocardiografia/métodos , Eletrocardiografia/métodos , Feminino , Seguimentos , Hemangioma Capilar/complicações , Hemangioma Capilar/diagnóstico , Humanos , Lactente , Masculino , Programas de Rastreamento/métodos , Propranolol/efeitos adversos , Estudos Retrospectivos , Medição de Risco , Neoplasias Cutâneas/complicações , Neoplasias Cutâneas/diagnóstico , Resultado do TratamentoRESUMO
BACKGROUND: Cardiovascular surveillance is important in Turner syndrome because of the increased risk of aortic dilation and dissection with consecutively increased mortality. OBJECTIVE: To compare 4-D flow MRI for the characterization of aortic 3-D flow patterns, dimensions and vessel wall parameters in pediatric patients with Turner syndrome and age-matched controls. MATERIALS AND METHODS: We performed 4-D flow MRI measuring in vivo 3-D blood flow with coverage of the thoracic aorta in 25 patients with Turner syndrome and in 16 female healthy controls (age mean ± standard deviation were 16 ± 5 years and 17 ± 4 years, respectively). Blood flow was visualized by time-resolved 3-D path lines. Visual grading of aortic flow in terms of helices and vortices was performed by two independent observers. Quantitative analysis included measurement of aortic diameters, quantification of peak systolic wall shear stress, pulsatility index and oscillatory shear index at eight defined sites. RESULTS: Patients with Turner syndrome had significantly larger aortic diameters normalized to BSA, increased vortices in the ascending aorta and elevated helix flow in the ascending and descending aorta compared to controls (all P<0.03). Patients with abnormal helical or vortical flow in the ascending aorta had significantly larger diameters of the ascending aorta (P<0.03). Peak systolic wall shear stress, pulsatility index and oscillatory shear index were significantly lower in Turner patients compared to controls (p=0.02, p=0.002 and p=0.01 respectively). CONCLUSION: Four-dimensional flow MRI provides new insights into the altered aortic hemodynamics and wall shear stress that could have an impact on the development of aortic dissections.
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Aorta Torácica/diagnóstico por imagem , Aorta Torácica/fisiopatologia , Hemodinâmica/fisiologia , Imageamento Tridimensional/métodos , Angiografia por Ressonância Magnética/métodos , Síndrome de Turner/fisiopatologia , Adolescente , Adulto , Velocidade do Fluxo Sanguíneo/fisiologia , Criança , Feminino , Humanos , Estudos Prospectivos , Adulto JovemRESUMO
BACKGROUND: Echocardiographic examinations have revealed functional cardiac abnormalities in children with chronic kidney disease. OBJECTIVE: To assess the feasibility of MRI tissue phase mapping in children and to assess regional left ventricular wall movements in children with chronic kidney disease. MATERIALS AND METHODS: Twenty pediatric patients with chronic kidney disease (before or after renal transplantation) and 12 healthy controls underwent tissue phase mapping (TPM) to quantify regional left ventricular function through myocardial long (Vz) and short-axis (Vr) velocities at all 3 levels of the left ventricle. RESULTS: Patients and controls (age: 8 years-20 years) were matched for age, height, weight, gender and heart rate. Patients had higher systolic blood pressure. No patient had left ventricular hypertrophy on MRI or diastolic dysfunction on echocardiography. Fifteen patients underwent tissue Doppler echocardiography, with normal z-scores for mitral early diastolic (VE), late diastolic (VA) and peak systolic (VS) velocities. Throughout all left ventricular levels, peak diastolic Vz and Vr (cm/s) were reduced in patients: Vzbase -10.6 ± 1.9 vs. -13.4 ± 2.0 (P < 0.0003), Vzmid -7.8 ± 1.6 vs. -11 ± 1.5 (P < 0.0001), Vzapex -3.8 ± 1.6 vs. -5.3 ± 1.6 (P = 0.01), Vrbase -4.2 ± 0.8 vs. -4.9 ± 0.7 (P = 0.01), Vrmid -4.7 ± 0.7 vs. -5.4 ± 0.7 (P = 0.01), Vrapex -4.7 ± 1.4 vs. -5.6 ± 1.1 (P = 0.05). CONCLUSION: Tissue phase mapping is feasible in children and adolescents. Children with chronic kidney disease show significantly reduced peak diastolic long- and short-axis left ventricular wall velocities, reflecting impaired early diastolic filling. Thus, tissue phase mapping detects chronic kidney disease-related functional myocardial changes before overt left ventricular hypertrophy or echocardiographic diastolic dysfunction occurs.
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Insuficiência Renal Crônica/complicações , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/etiologia , Adolescente , Estudos de Casos e Controles , Criança , Ecocardiografia Doppler , Feminino , Humanos , Transplante de Rim , Masculino , Insuficiência Renal Crônica/cirurgia , Adulto JovemRESUMO
BACKGROUND: Coarctation of the aorta is one of the most common congenital heart diseases. Despite different treatment opportunities, long-term outcome after surgical or interventional therapy is diverse. Serial morphologic follow-up of vessel growth is necessary, because vessel growth cannot be predicted by primer morphology or a therapeutic option. OBJECTIVES: For the analysis of the long-term outcome after therapy of congenital diseases such as aortic coarctation, accurate 3D geometric analysis of the aorta from follow-up 3D medical image data such as magnetic resonance angiography (MRA) is important. However, for an objective, fast, and accurate 3D geometric analysis, an automatic approach for 3D segmentation and quantification of the aorta from pediatric images is required. METHODS: We introduce a new model-based approach for the segmentation of the thoracic aorta and its main branches from follow-up pediatric 3D MRA image data. For robust segmentation of vessels even in difficult cases (e.g., neighboring structures), we propose a new extended parametric cylinder model that requires only relatively few model parameters. Moreover, we include a novel adaptive background-masking scheme used for least-squares model fitting, we use a spatial normalization scheme to align the segmentation results from follow-up examinations, and we determine relevant 3D geometric parameters of the aortic arch. RESULTS: We have evaluated our proposed approach using different 3D synthetic images. Moreover, we have successfully applied the approach to follow-up pediatric 3D MRA image data, we have normalized the 3D segmentation results of follow-up images of individual patients, and we have combined the results of all patients. We also present a quantitative evaluation of our approach for four follow-up 3D MRA images of a patient, which confirms that our approach yields accurate 3D segmentation results. An experimental comparison with two previous approaches demonstrates that our approach yields superior results. CONCLUSIONS: From the results, we found that our approach is well suited for the quantification of the 3D geometry of the aortic arch from follow-up pediatric 3D MRA image data. In future work, this will enable to investigate the long-term outcome of different surgical and interventional therapies for aortic coarctation.
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Aorta/diagnóstico por imagem , Aorta/patologia , Coartação Aórtica/diagnóstico por imagem , Imageamento Tridimensional , Angiografia por Ressonância Magnética , Adolescente , Adulto , Criança , Seguimentos , Humanos , Adulto JovemRESUMO
BACKGROUND: Increased left ventricular mass (LVM) is an important risk marker of uremic cardiovascular disease. Calculation of LVM by echocardiography (Echo) relies on geometric assumptions and in adults on hemodialysis overestimates LVM compared to cardiac magnetic resonance (CMR). We compare both techniques in children with chronic kidney disease (CKD). METHODS: Concurrent Echo and CMR was performed in 25 children with CKD (14 after kidney transplantation) aged 8-17 years. RESULTS: Compared to normal children, CMR-LVM was increased (standard deviation score (SDS) 0.39 ± 0.8 (p = 0.03)), stroke volume and cardiac output decreased (SDS -1.76 ± 1.1, p = 0.002 and -1.11 ± 2.0, p = 0.001). CMR-LVM index but not Echo-LVMI correlated to future glomerular filtration rate (GFR) decline (r = -0.52, p = 0.01). Mean Echo-LVM was higher than CMR-LVM (117 ± 40 vs. 89 ± 29 g, p < 0.0001), with wide limits of agreement (-6.2 to 62.8 g). The Echo-CMR LVM difference increased with higher Echo-LVMI (r = 0.77, p < 0.0001). Agreement of classifying left ventricular hypertrophy was poor with Cohen's kappa of 0.08. Mean Echo and CMR-ejection fraction differed by 1.42% with wide limits of agreement (-12.6 to 15.4%). CONCLUSIONS: Echo overestimates LVM compared to CMR, especially at higher LVM. Despite this, CMR confirms increased LVM in children with CKD. Only CMR-LVMI but not Echo-LVMI correlated to future GFR decline.
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Ecocardiografia/métodos , Ventrículos do Coração/patologia , Hipertrofia Ventricular Esquerda/diagnóstico , Imageamento por Ressonância Magnética/métodos , Insuficiência Renal Crônica/complicações , Adolescente , Criança , Feminino , Humanos , Hipertrofia Ventricular Esquerda/fisiopatologia , Masculino , Função Ventricular EsquerdaRESUMO
BACKGROUND: National estimates of Kawasaki disease (KD) incidence often do not include incomplete cases (diagnosed based on only laboratory or echocardiographic criteria), and/or they rely on retrospective case reports and data registries where underreporting is known to be a problem. METHODS: We conducted a prospective nationwide KD surveillance study in children younger than 5 years through the hospital-based German Pediatric Surveillance Unit (ESPED). We accounted for underreporting through applying capture-recapture methodology in 2 federal states using hospital discharge records with KD International Statistical Classification of Diseases and Related Health Problems 10th revision code (ie, M30.3). KD diagnosis (complete and incomplete) was established according to the American Heart Association criteria, 2004. RESULTS: Incidence of KD, corrected for underreporting, was 7.2 of 100,000 in children younger than 5 years in Germany. Underreporting to ESPED was estimated at 37%-44%. Overall, 315 validated KD cases were reported. Of the 64 (20%) incomplete cases, 58% (37/64) were detected through echocardiographic findings and 42% (27/64) through laboratory criteria alone. Incomplete cases were younger than complete cases (1.2 vs. 2.0 years, P = 0.0001) and had more coronary aneurysms (43% vs. 11%, P = 0.0001). CONCLUSIONS: A substantial number of incomplete KD cases were diagnosed based on the laboratory and echocardiographic criteria only. This was particularly the case in relation to infants younger than 1 year-an age group known to have an increased risk of developing coronary aneurysms. In addition, we found a high rate of underreporting to national Pediatric Surveillance Units. We suggest that improved surveillance and development of better diagnostic tests remain a high priority.
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Síndrome de Linfonodos Mucocutâneos/epidemiologia , Pré-Escolar , Monitoramento Epidemiológico , Feminino , Alemanha/epidemiologia , Humanos , Lactente , Masculino , Estudos ProspectivosRESUMO
Hypoplastic left heart syndrome (HLHS) is one of the most challenging congenital heart defects. At present, it is expected that - at best - 70% of newborns with HLHS will reach adulthood. This review addresses the problems of right ventricular (RV) failure and insufficient growth of pulmonary vasculature in these patients. In order to further improve long-term prognosis translational research to control RV function, growth of pulmonary arteries and progress in chronic circulatory support are clearly needed to provide a further improvement for adults with HLHS.
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OBJECTIVES: To characterise aortic and pulmonary haemodynamics and investigate the correlation with post-surgical anatomy in patients with dextro-transposition of the great arteries (d-TGA). METHODS: Four-dimensional (4D) MRI was performed in 17 patients after switch repair of TGA and 12 healthy controls (age, 11.9 ± 5.4 vs 23.3 ± 1.6 years). Patients were divided according to the pulmonary trunk (TP) position in relation to the ascending aorta (AAo): anterior (n = 10) and right/left anterior position (n = 7). Analysis included visual grading (ranking 0-2) of pulmonary and aortic vortical and helical flow, flow velocity quantification, blood-flow distribution to the right and left pulmonary arteries (flow ratio rPA:lPA), and vessel lumen areas. RESULTS: Anterior TP position was associated with increased vortices in six out of ten patients compared with right anterior TP position (one out of seven) and controls (none). Reduced systolic lPA and TP lumina in patients resulted in significantly increased peak systolic velocities (P < 0.001). Flow ratio rPA:lPA was more heterogeneous in patients (rPA:lPA = 1.56 ± 0.78 vs volunteers 1.09 ± 0.15; P < 0.05) with predominant flow to the rPA. Eleven patients presented increased helices in the AAo (grade 1.6). CONCLUSIONS: Evaluation of post-surgical haemodynamics in TGA patients revealed increased vortical flow for anterior TP position, asymmetric flow and increased systolic flow velocity in the pulmonary arteries owing to reduced vascular lumina. KEY POINTS: ⢠3D phase contrast MRI with velocity encoding (4D MRI) has numerous cardiovascular applications ⢠4D MRI demonstrates postoperative haemodynamics following surgery for transposition of the great arteries ⢠Flow visualisation depicted enhanced pulmonary vortices in the anterior pulmonary trunk ⢠Narrow pulmonary arterial systolic lumina resulted in increased peak systolic velocities.
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Aorta/fisiopatologia , Procedimentos Cirúrgicos Cardíacos , Hemodinâmica , Imageamento Tridimensional , Imagem Cinética por Ressonância Magnética/métodos , Artéria Pulmonar/fisiopatologia , Transposição dos Grandes Vasos/cirurgia , Adolescente , Adulto , Aorta/patologia , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Masculino , Período Pós-Operatório , Artéria Pulmonar/patologia , Estudos Retrospectivos , Sístole , Transposição dos Grandes Vasos/diagnóstico , Transposição dos Grandes Vasos/fisiopatologia , Adulto JovemRESUMO
We present findings in a 17-year-old with interrupted aortic arch, in whom standard imaging techniques missed functional and morphological problems. Flow-sensitive four-dimensional magnetic resonance (4-D MR) enabled assessment of the complex anatomy and blood-flow characteristics in the entire aorta and direct quantification of blood flow in collateral vessels. Our findings highlight the entire morphological and functional problem of interrupted aortic arch and illustrate the potential of flow-sensitive 4-D MR for surgical planning in congenital heart disease.
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Aorta Torácica/patologia , Aorta Torácica/fisiopatologia , Síndromes do Arco Aórtico/patologia , Síndromes do Arco Aórtico/fisiopatologia , Circulação Colateral , Imageamento Tridimensional/métodos , Angiografia por Ressonância Magnética/métodos , Adolescente , Velocidade do Fluxo Sanguíneo , Feminino , Humanos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Right ventricular dysfunction represents a common problem in patients with congenital heart defects, such as Tetralogy of Fallot or pulmonary arterial hypertension. Patients with congenital heart defects may present with a pressure or volume overloaded right ventricle (RV) in a bi-ventricular heart or in a single ventricular circulation in which the RV serves as systemic ventricle. Both subsets of patients are at risk of developing right ventricular failure. Obtaining functional and morphological imaging data of the right heart is technically more difficult than imaging of the left ventricle. In contrast to findings on mechanisms of left ventricular dysfunction, very little is known about the pathophysiologic alterations of the right heart. The two main causes of right ventricular dysfunction are pressure and/or volume overload of the RV. Until now, there are no appropriate models available analyzing the effects of pressure and/or volume overload on the RV. This review intends to summarize clinical aspects mainly focusing on the current research in this field. In future, there will be increasing attention to individual care of patients with right heart diseases. Hence, further investigations are essential for understanding the right ventricular pathobiology.
RESUMO
The aim of this study was to quantify changes in thoracic aortic wall shear stress (WSS) in asymptomatic patients with Marfan syndrome (MFS) compared with healthy controls. WSS in the thoracic aorta was quantified based on time-resolved 3D phase contrast MRI with three-directional velocity encoding (4D flow MRI, temporal resolution â¼44 ms, spatial resolution â¼2.5 mm) in 24 patients with confirmed MFS (age = 18 ± 12 years) and in 12 older healthy volunteers (age = 25 ± 3 years). Diameters of the thoracic aorta normalized to body surface area were similar for both groups. Peak systolic velocity, absolute WSS, time-averaged WSS, circumferential WSS, peak systolic WSS, and WSS eccentricity were calculated in eight analysis planes distributed along the thoracic aorta. Plane-wise comparison revealed significant differences between MFS patients and volunteers in the proximal ascending aorta for peak systolic velocities (1.11 ± 0.23 m/s vs. 1.34 ± 0.18 m/s, P = 0.004) and circumferential WSS (0.14 ± 0.03 N/m(2) vs. 0.11 ± 0.02 N/m(2), P = 0.007). WSS eccentricity was altered in most of the ascending aorta and proximal arch (P = 0.009-0.020). MFS patients demonstrated segmental differences in peak systolic WSS with a significantly higher WSS at the inner curvature in the proximal ascending aorta and at the anterior part in the more distal ascending aorta (P < 0.01). These findings indicate differences in WSS associated with MFS despite similar aortic dimensions compared to controls.
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Aorta/fisiopatologia , Doenças da Aorta/fisiopatologia , Técnicas de Imagem por Elasticidade/métodos , Imageamento Tridimensional/métodos , Angiografia por Ressonância Magnética/métodos , Síndrome de Marfan/fisiopatologia , Adolescente , Adulto , Aorta/patologia , Doenças da Aorta/patologia , Velocidade do Fluxo Sanguíneo , Módulo de Elasticidade , Feminino , Humanos , Masculino , Síndrome de Marfan/patologia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Resistência ao Cisalhamento , Estresse Mecânico , Resistência à Tração , Adulto JovemAssuntos
Aorta/anormalidades , Ventrículos do Coração/anormalidades , Atresia Tricúspide/etiologia , Aorta/diagnóstico por imagem , Aorta/cirurgia , Procedimentos Cirúrgicos Cardíacos , Feminino , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/cirurgia , Humanos , Recém-Nascido , Resultado do Tratamento , Atresia Tricúspide/diagnóstico por imagem , Atresia Tricúspide/cirurgia , Ultrassonografia Pré-NatalRESUMO
We report the comprehensive evaluation of the complex hemodynamics in a rare case of a pediatric patient after repair of congenital heart disease with multiple abnormalities including hypoplastic left heart, double outlet right ventricle, transposition of great arteries, ventricular septal defect, aortic coarctation, and total cavopulmonary connection. Based on a single measurement, whole-heart flow-sensitive 4D magnetic resonance imaging (MRI) was able to demonstrate a number of regional flow alterations such as poststenotic helix formation and asymmetric flow distributions for the double arterial outlet and to the left and right lungs. Our findings illustrate the potential role of flow-sensitive 4D MRI as a noninvasive and radiation-free technique for the frequent postinterventional follow-up in these pediatric patients.
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Circulação Coronária , Ventrículos do Coração/anormalidades , Ventrículos do Coração/fisiopatologia , Imageamento Tridimensional/métodos , Imagem Cinética por Ressonância Magnética/métodos , Velocidade do Fluxo Sanguíneo , Pré-Escolar , Ventrículos do Coração/cirurgia , Humanos , Masculino , Prognóstico , Volume Sistólico , Resultado do TratamentoRESUMO
PURPOSE: To apply time-resolved three-dimensional (3D) phase contrast MRI with three-directional velocity encoding (flow-sensitive 4D MRI) for the characterization of flow pattern changes in patients with Marfan syndrome (MFS) compared with normal controls. MATERIALS AND METHODS: Flow-sensitive 4D MRI of the thoracic aorta (temporal resolution â¼45 ms, spatial resolution â¼2.4 × 2.1 × 2.8 mm(3) ) was performed in 24 MFS patients and 10 volunteers. Aortic flow patterns were visualized by 3D particle traces and streamlines. Global (affecting the complete lumen) and local (parts of the vessel lumen) helix and vortex flow in the ascending aorta (AAo), aortic arch, and descending aorta (DAo) were graded in 3 categories (blinded reading, two observers): none = 0, moderate = 1, pronounced = 2. RESULTS: Flow grading revealed similar global helix and vortex flow in the AAo and arch for MFS patients and controls. Local helix flow in the AAo was significantly (P = 0.011) increased in patients and was associated with aortic sinus dilatation. The incidence of global helix and vortex flow in the DAo was increased in patients (77% and 50% of subjects) compared with controls (none and 10%). CONCLUSION: The 4D flow analysis revealed marked differences of the aortic flow patterns between Marfan patients and controls: Local helix flow in the patients' AAo may be associated with the increased incidence of aortic root dilatation. The flow alterations in the proximal DAo could explain the occurrence of Type-B dissection originating from this site.
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Doenças da Aorta/fisiopatologia , Imageamento Tridimensional/métodos , Angiografia por Ressonância Magnética/métodos , Síndrome de Marfan/fisiopatologia , Adolescente , Adulto , Doenças da Aorta/diagnóstico por imagem , Velocidade do Fluxo Sanguíneo , Estudos de Casos e Controles , Meios de Contraste , Ecocardiografia , Feminino , Hemodinâmica , Humanos , Masculino , Síndrome de Marfan/diagnóstico por imagem , Meglumina/análogos & derivados , Compostos Organometálicos , Estatísticas não ParamétricasRESUMO
In this work, we present a systematic phantom comparison and clinical application of noninvasive pressure difference mapping in the human aorta based on time-resolved 3D phase contrast data. Relative pressure differences were calculated based on integration and iterative refinement of pressure gradients derived from MR-based three-directional velocity vector fields (flow-sensitive 4D MRI with spatial/temporal resolution â¼ 2.1 mm(3)/40 ms) using the Navier-Stokes equation. After in vitro study using a stenosis phantom, time-resolved 3D pressure gradients were systematically evaluated in the thoracic aorta in a group of 12 healthy subjects and 6 patients after repair for aortic coarctation. Results from the phantom study showed good agreement with expected values and standard methods (Bernoulli). Data of healthy subjects showed good intersubject consistency and good agreement with the literature. In patients, pressure waveforms showed elevated peak values. Pressure gradients across the stenosis were compared with reference measurements from Doppler ultrasound. The MRI findings demonstrated a significant correlation (r = 0.96, P < 0.05) but moderate underestimation (14.7% ± 15.5%) compared with ultrasound when the maximum pressure difference for all possible paths connecting proximal and distal locations of the stenosis were used. This study demonstrates the potential of the applied approach to derive additional quantitative information such as pressure gradients from time-resolved 3D phase contrast MRI.
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Aorta Torácica/fisiologia , Coartação Aórtica/fisiopatologia , Adulto , Coartação Aórtica/cirurgia , Velocidade do Fluxo Sanguíneo , Meios de Contraste , Ecocardiografia , Feminino , Hemodinâmica , Humanos , Imageamento Tridimensional , Modelos Lineares , Masculino , Meglumina/análogos & derivados , Compostos Organometálicos , Imagens de Fantasmas , Fluxo PulsátilRESUMO
OBJECTIVE: Dilatation of RV outflow after surgical patch repair represents a problem for seating a percutaneous valve. We present the data of a new catheter-based, self-expanding tissue valve with a diameter up to 31 mm. METHODS: 7 Patients (median 9 years, range 2 to 24 years) with severe PR due to RV outflow tract dilatation after patch repair or percutaneous procedures were treated with a catheter-based, self-expanding porcine pulmonary valve (Biointegral®). Valve diameter ranged between 15 and 29 mm. Maximum follow-up was 40 months. Patients were postoperatively assessed on day 1 and 6 months after the procedure, including physical examination, 12 lead electrocardiography and cross-sectional echocardiography with color Doppler. RESULTS: Valve implantation was successful in all patients. Implantation was performed using three different routes: RVOT after partial sternotomy, pulmonary artery after mini-thoracotomy, or via the RV apex. Median follow-up was 25 months (5-40) identifying no significant morbidity and no death. Echocardiography revealed competent valves, no paravalvular leaks, no valve migration and no significant gradient in the RVOT. CONCLUSION: The new, self-expanding, catheter-based pulmonary valve is easy to implant via an antegrade (RVOT, RV) or retrograde approach (PA) even in dilated RV outflow tracts. The procedure can be done without CPB under echocardiographic guidance.
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Cardiopatias Congênitas/cirurgia , Implante de Prótese de Valva Cardíaca/métodos , Próteses Valvulares Cardíacas , Insuficiência da Valva Pulmonar/cirurgia , Valva Pulmonar/cirurgia , Adolescente , Bioprótese , Cateterismo Cardíaco/instrumentação , Cateterismo Cardíaco/métodos , Criança , Pré-Escolar , Feminino , Implante de Prótese de Valva Cardíaca/instrumentação , Ventrículos do Coração/cirurgia , Humanos , Masculino , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Projetos Piloto , Complicações Pós-Operatórias/cirurgia , Desenho de Prótese , Resultado do Tratamento , Adulto JovemRESUMO
PURPOSE: To investigate feasibility and image quality and to calculate radiation dose estimates for computed tomography angiography (CTA) of the great thoracic vessels in infants and toddlers with congenital heart disease (CHD) using end-systolic prospective electrocardiography-triggered sequential dual-source data acquisition. METHODS: This study was institutional review board approved; informed consent was obtained. Twenty children (age 1.2±1.1 years) underwent 22 prospective ECG-triggered sequential dual-source CTA examinations (Somatom Definition, Siemens) with tube current (250 mAs/rot) centered at 250 ms past the R-peak in the cardiac cycle (end-systole). Tube voltage was set to 80 kV. Image quality was evaluated by two readers independently using a four-point grading scale (4=excellent, 1=non-diagnostic). Radiation dose estimates were calculated from the dose-length-product (DLP). RESULTS: All CT images showed diagnostic image quality (mean score 3.67±0.67, κ=0.85). Stair-step artifacts were present in one and breathing artifacts in 4 patients, with neither impairing diagnostic image quality. Mean heart rate (bpm) was 107.6±12.1 (76-130), mean heart rate variability (bpm) was 2.5±2.0 (1-9). Mean scan length (mm) was 90.7±22.7 (50-134). Mean estimated effective dose was 0.32±0.11 mSv. CONCLUSION: Prospective ECG-triggered sequential dual source CTA is feasible in infants and toddlers with CHD, thereby allowing almost motion-free imaging of the great thoracic vessels with the benefit of a low radiation dose.