Medical management of three asymptomatic infants with severe valvar Aortic stenosis

Summary We report on the clinical course and serial hemodynamic studies of three patients with severe valvar aortic stenosis diagnosed in the neonatal period. None of the children were symptomatic in the first year of life. In each case, a conservative initial management approach was adopted. Between the time of initial study (mean age, 1.8 months) and the follow-up at 12–27 months of age (mean, 14.3 months), mean left ventricular systolic pressure decreased from 151 to 125 mmHg, the mean peak systolic pressure gradient across the aortic valve decreased from 61 to 33 mmHg, and the mean calculated aortic valve area index increased from 0.24 to 0.60 cm²/m². One patient was operated on for symptoms that appeared at 14 months of age. The patient followed longest is now 5 years old, is growing well, has a normal electrocardiogram and an echo-predicted left ventricular systolic pressure of 128 mmHg. This experience suggests that not all asymptomatic neonates with severe valvar aortic stenosis require surgical intervention early in life. In some, the aortic valve orifice may increase in size with somatic growth and obviate the need for surgery in infancy or early childhood.     

自体心包修复儿童主动脉瓣狭窄9例病例系列报告

目的：总结并分析以自体心包修复儿童先天性主动脉瓣狭窄的手术方法和早期预后。方法：纳入2013年7月至2015年6月在复旦大学附属儿科医院行自体心包主动脉瓣成形术的先天性主动脉瓣狭窄患儿,收集患儿的一般资料,围手术期情况,并发症,术前、术中、术后和随访时的超声心动图资料。结果：符合本文纳入标准的9例患儿进入本文分析,男6例,女3例,年龄4月龄至9岁。术前超声提示,三叶式和二叶式主动脉瓣分别为3例和6例;重度狭窄6例,中度狭窄1例,重度狭窄伴中度返流2例。9例均以自体心包再造或扩大主动脉瓣瓣叶。术后即刻与术前超声心动图比较：主动脉瓣最大跨瓣压差［（31.6±9.4）mm Hg vs（73.0±22.2）mm Hg, P=0.000］和主动脉瓣平均跨瓣压差［（15.8±18.3）mmHg vs （35.8±18.3）mmHg, P= 0.004］均下降。术后随访24～48（32±8）月,无死亡和再干预病例,未见严重不良事件,未见主动脉瓣重度狭窄或重度反流、升主动脉狭窄或扩张、主动脉瓣瓣环狭窄与扩张、瓣膜脱垂或瓣膜赘生物病例;3例患儿分别在随访18、24和12个月时出现瓣叶活动僵硬,瓣叶开放不完全。术后左室后壁厚径均呈下降趋势;末次随访时,8例患儿左室后壁厚径Z值（Z-LVPWd）均下降至正常水平（＜2）。结论：以自体心包修复主动脉瓣可改善先天性主动脉瓣狭窄患儿的血流动力学,手术风险低,术后早期疗效可,避免或延缓儿童主动脉瓣置换术,减少施行ROSS手术机会。     

Postoperative echocardiographic study of patients following valvulotomy for critical valvular aortic stenosis

Authors report on long term follow up of 12 patients operated with critical valvular aortic stenosis. They could perform control echocardiography in 11 patients 4-83 (mean 29) months after valvulotomy. The size and function of the left ventricle was found to be satisfactory, with elevated ejection fraction. The cause of the significant pressure gradient between the left ventricle and the aorta is discussed emphasizing the importance of echocardiography in determining the optimal time for valve replacement or homograft implantation.     

Aortic stenosis

Valvular aortic stenosis in pediatric age group is mostly congenital in origin. The aortic valve may be unicuspid, bicuspid, tricuspid or rarely quadricuspid. Left ventricle undergoes concentric hypertrophy secondary to obstruction to its outflow tract. In neonatal aortic stenosis, left ventricle may be hypoplastic. The pathophysiology and clinical presentation vary with the age of onset and severity of obstruction. Echocardiography and Doppler are indispensible for the diagnosis of aortic stenosis and its severity. Cardiac catheterization is not necessary for the diagnosis, however it is performed as a part of balloon aortic valvuloplasty in severe cases. Balloon valvuloplasty is an effective alternative to surgery in pédiatrie age group. Some of these patients require surgical valve repair or replacement on follow-up. Neonates and young infants with critical aortic stenosis present with cardiogenic shock and need aggressive treatment with prostaglandin E1 infusion along with inotropic support. In experienced hands, balloon valvuloplasty is a safe procedure in neonates and infants with critical stenosis. Patients with mild and moderate aortic stenosis may be left on medical follow-up.     

Autologous Ross Operation for Congenital Aortic Stenosis

Congenital aortic stenosis is a relatively common cardiac anomaly encountered in approximately 5% of all children with heart disease. The Ross procedure is increasingly used for replacement of the aortic valve in children. We report a 12-year-old boy who was born with congenital aortic stenosis secondary to a bicommissural aortic valve. The patient underwent open valvotomy in infancy and aortic valvuloplasty 2 years later. Residual/recurrent stenosis prompted referral for aortic valve replacement, and he underwent an autologous Ross procedure, in which the aortic root was replaced with a pulmonary autograft and the repaired aortic valve was used to restore right ventricular-to-pulmonary artery continuity. The postoperative course was unremarkable. Nitroprusside, esmolol, and labetolol were used to control postoperative hypertension. He was discharged 4 days after surgery on oral furosemide and aspirin, and he has had no cardiovascular symptoms during follow-up. Recent echocardiography demonstrated mild right ventricular outflow tract obstruction with a peak velocity of 3.6 m/sec, with a gradient of 42 mmHg and moderate pulmonary insufficiency. There was no left ventricular outlet tract obstruction or aortic insufficiency.     

Prenatal Diagnosis of Severe Aortic Stenosis

We sought to identify echocardiographic markers that might be useful for managing fetuses with significant aortic stenosis. The study was a retrospective review of fetal echocardiographic studies and postnatal outcomes of all fetuses diagnosed with significant aortic stenosis who did not have a hypoplastic left ventricle on the initial echocardiogram. Where possible, fetal echocardiographic measurements included the aortic, mitral, pulmonary, and tricuspid valve annulus sizes; left ventricular dimensions and volume; septal and left ventricular wall thicknesses; and echocardiographic Doppler interrogation of the left heart and oval fossa. Observations also included an assessment of ascites, pericardial effusion, and endocardial fibroelastosis. Prenatal measurements were compared to postnatal outcomes. Four patients (group 1) had either clinically successful relief of their aortic obstruction (n= 3) or required no intervention (n= 1). Five fetuses evolved to the hypoplastic left heart syndrome (group 2). These infants demonstrated little or no growth in left ventricular, aortic valve, or mitral valve dimensions on serial examination. They also more often exhibited mitral stenosis, severe restriction of interatrial shunting, and early to mid second trimester left ventricular dilatation. Serial measurements of fetal cardiac size and function are helpful for predicting the postnatal outcome of fetuses with aortic stenosis.     

Assessment of the severity of aortic stenosis: comparison of gradient and valve area

Hemodynamic data, including simultaneously measured left ventricular pressure, aortic pressure, and cardiac output, were obtained in 17 patients with isolated valvar aortic stenosis, before and during infusion of dobutamine, isoprenaline, dopamine, and pacing. Infusion of sympathomimetic drugs resulted in a significant increase of both mean and peak systolic aortic valve gradient, cardiac output, heart rate, and systolic aortic valve flow per second. On the other hand, the calculated aortic valve area did not change significantly in spite of variable alterations of all values used for calculating aortic valve area and different causes of hemodynamic changes induced. Aortic valve area is considered a better indicator of the severity of aortic stenosis than is the aortic valve gradient and thus a more suitable indicator for operation.     

Persistent truncus arteriosus operated during infancy: Long-term follow-up

Summary Between July 1974 and October 1988 19 consecutive infants (mean age 2.7 months, range 5 days to 11.7 months) underwent surgical correction for persistent truncus arteriosus by one surgeon (J.L.M.). Continuity between the right ventricle and pulmonary arteries was achieved with an antibiotic-sterilized aortic homograft (diameter 13–18 mm) together with patch closure of the ventricular septal defect. There were 3 early postoperative deaths (16%): 1 patient had severe aortic regurgitation, the other 2 had preoperative cardiac arrests. Of the latter, 1 had suffered severe cerebral damage, and the other developed recurrent pulmonary hypertensive crises and low cardiac output. The 16 survivors have been followed for 3.1–17.3 years (mean 7.8 years). Four patients required subsequent replacement of the homograft for stenosis, aortic valve replacement for regurgitation, or both (3.0, 4.0, 8.5, and 12.0 years postoperatively). Of the 16 survivors, 15 are in NYHA class I. Of the 13 patients who have not had aortic valve surgery, 9 have no evidence of stenosis or regurgitation. In the 14 children with the original homograft the median of the residual peak gradient across the right ventricular outflow tract is 15 mmHg (range 10–40 mmHg), and no patient has severe homograft regurgitation at follow-up. Repair of persistent truncus arteriosus has been achieved with low early mortality and no late mortality, which reflects excellent long-term function of the homograft. Furthermore, if truncal valve function is good at presentation, patients are unlikely to require aortic valve surgery.     

Influence of stenotic valve geometry on measured pressure gradients and ventricular work: The relationship between morphology and flow

The physiologic impact of aortic valve stenosis is most directly reflected by an increased workload placed on the ventricle. In the pediatric population the morphology of aortic stenosis varies considerably. Fluid dynamic principles suggest that different morphologies may require the ventricle to accelerate blood to different maximal velocities for constant cardiac outputs and valve areas, resulting in different ventricular workloads. This study examined this important concept in in vitro models designed to isolate the effect of valve geometry on distal velocity, pressure gradients, and proximal work. Four stenotic valve morphologies were examined using a variable-voltage pump system. For constant orifice areas and flows, markedly different workloads were required by the pump, and this difference was reflected in direct measurements of pressure gradient and Doppler predictions of gradient. These fundamental fluid dynamic studies isolate the relationship between flow, work, and stenotic valve morphology. Different orifice geometries affect the value of the coefficient of contraction, which is reflected in different maximum velocity values for stenosis with constant anatomic areas and flows. The proximal pumping chamber must generate different levels of force to achieve these different velocities, and this variability is reflected in the clinically measured pressure gradient.     

Successful percutaneous balloon valvuloplasty of the aortic valve in an infant

Summary Percutaneous balloon aortic valvuloplasty was attempted in an eight-month-old infant with severe aortic valve stenosis. The procedure resulted in a fall in the resting transvalvular systolic pressure gradient from 106 mmHg to 40 mmHg and no aortic regurgitation. Clinical and Doppler echocardiography findings suggest persistent improved status 3 1/2 months after the procedure.     

Mitral Valve Injury During Balloon Valvuloplasty for an Infant with Severe Aortic Stenosis: Spatial Evaluation Using Three-Dimensional Echocardiography

We report on a 4-month-old infant with mitral valve injury that was induced by percutaneous balloon valvuloplasty for severe aortic valve stenosis. Three-dimensional echocardiography revealed a laceration at the anterior leaflet of the mitral valve. The mitral valve injury was successfully repaired by surgical operation 1 year after the valvuloplasty. This unexpected complication is associated with anatomical disorders of congenital aortic stenosis, including hypoplastic left ventricle, short chordae tendae, and large papillary muscles.     

Transluminal dilatation of critical aortic stenosis and coarctation of a newborn infant aorta

We present a 20-day-old male infant with severe congestive heart failure. Echocardiography showed left ventricular hypertrophy secondary to critical aortic valve stenosis and severe coarctation of the aorta. The size of aortic annulus valve was 5.2 mm. At catheterization, the gradient of aortic valve stenosis was 104 mmHg and the gradient through aortic coarctation, measuring 14 mm in diameter, was 58 mmHg. Transverse and isthmic aorta showed moderate hypoplasia. After two dilatation procedures performed at an interval of 45 days, the pressure valve gradient decreased to 32 mmHg, that of the coarctation of the aorta decreased to 14 mmHg and the diameter increased to 5.4 mm.     

Aortic Stenosis: The Spectrum of Practice

There is significant variation in practice patterns in managing congenital aortic valve stenosis. Review of medical literature reveals no significant information regarding the current practice methods in the treatment of a simple lesion such as aortic stenosis (AS). Therefore, this survey-based study was conducted in an attempt to better understand the uniformity or heterogeneity of practice in treating AS. A questionnaire was prepared to evaluate the style of management of AS. This survey was designed to assess the practice of follow-up visitations, type and frequency of investigative studies, pharmacological therapy, and exercise recommendations. Questions about therapeutic intervention included those of timing and type of intervention. Questionnaires were sent to all academic pediatric cardiology programs in the United States (48 program) and selected international programs from Europe, Asia, and Australasia (19 program). The total number of surveys sent out was 67, and the total number of respondents was 25 (37%), 15 (31%) from the United States and 9 (53%) from outside the United States. The definition of moderate AS varied among respondents. The range provided for mild AS was identified as that with a peak-to-peak pressure gradient of < 25–30 mmHg, peak instantaneous Doppler gradient of < 36–50 mmHg, or mean Doppler gradient of < 25–40 mmHg. On the other hand, severe AS was defined as that with a peak-to-peak gradient of > 50–60 mmHg, peak instantaneous Doppler gradient of > 64–80 mmHg, or mean Doppler gradient of > 45–64 mmHg. In assessing follow-up patterns, 84% of respondents recommended seeing patients with mild AS annually, the longest time of follow-up listed in the questionnaire, whereas 20% suggested follow-up every 6 months. There was no consensus among survey centers regarding follow-up of patients with moderate AS. For severe AS, 16% recommend immediate intervention, 16% arrange follow-up every 6 months, and 56 and 28% recommend follow-up in 3 and 1 month(s), respectively. In making the decision to proceed with biventricular versus univentricular repair in patients with AS in the neonatal period, many factors were considered. Ninety-two percent of respondents rely on mitral valve z score, 84% on aortic valve z score, 52% on left ventricle length, 48% on the presence of antegrade ascending aorta flow, and only 32% considered significant endocardial fibroelastosis as a factor. Rhodes score was used by 20% of respondents in decision making regarding the approach to management of this subset of AS. This study shows that there is consensus in the management of mild and severe forms of AS. As expected, disagreement is present in the definition, evaluation, and therapy of moderate aortic valve stenosis. There is a tendency for catheter intervention except in the presence of dysplastic aortic valve or moderate to severe aortic regurgitation. There is also disagreement regarding methods used to determine biventricular versus univentricular repair of a borderline hypoplastic left heart.     

Severe Left Ventricular Hypoplasia in Patients with Unbalanced Incomplete Atrioventricular Septal Defect and Pulmonary Hypertension: Feasibility of Biventricular Repair

We report three patients with partial atrioventricular septal defect who presented in the neonatal period with excessive left to right shunting and progressive pulmonary hypertension. Successful biventricular repair was accomplished despite the fact that left ventricular area and left sided structures did not meet the criteria established previously for biventricular management in children with critical aortic stenosis or complete atrioventricular septal defect. Indication for biventricular management was based on the fact that none of our patients had morphological mitral or aortic stenosis and that the hypoplastic left ventricle proved capable to maintain the systemic circulation following closure of the arterial duct. Fenestrated closure of the atrial septum and an individualized approach regarding the closure of the cleft in the left sided atrioventricular valve appear to be important surgical options to reduce postoperative left atrial pressure and to allow the ventricles to adapt to the new loading conditions.     

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目的观察动脉转位术(ASO)治疗复杂先天性心脏病术后早中期超声心动图的随访结果,评价该手术后左心室的功能和大动脉的发育。方法2000年10月至2004年3月,复旦大学儿科医院对实施ASO后4~37(19.6±11.1)个月的16例患儿进行超声心动图检查,其中室间隔完整的完全性大动脉转位(TGA/IVS)8例,完全性大动脉转位合并室间隔缺损(TGA/VSD)6例,右室双出口合并肺动脉瓣下室间隔缺损(Taussig-Bing畸形)2例。将获取的资料与正常参考值作比较。结果左室短轴缩短率(LVSF)为(38.10±5.90)%,其中14例(87.5%)在正常范围,2例(12.5%)大于正常范围;左室射血分数(LVEF)为(69.16±7.01)%,均在正常范围。主动脉根部直径平均较正常值扩大(5.5±3.2)mm,其中14例(87.5%)大于正常值95%可信区间的上限;瓣环直径较正常值平均扩大(3.6±3.3)mm,其中10例(62.5%)大于正常值95%可信区间的上限。主肺动脉直径较正常值平均小(1.3±1.5)mm,其中9例(56.25%)在正常值95%可信区间内;瓣环直径较正常值平均小(1.1±1.7)mm,其中10例(62.5%)在正常值95%可信区间内。6例存有主动脉瓣轻度反流;肺动脉瓣上狭窄极轻度3例,轻度狭窄1例;2例存有肺动脉瓣轻度反流。结论超声心动图随访结果证实目前在本中心开展ASO治疗TGA等复杂性先天性心脏病术后左心室功能良好,新主动脉根部和瓣环有所扩张,新肺动脉根部和瓣环发育良好。     

ULTRASOUNDCARDIOGRAPHY IN INFANTS AND CHILDREN

Ultrasoundcardiography (UCG) studies have been performed in about three hundred children. The age of the children varied between 1 day and 16 years. Most of the studies have been performed without premedication and all without discomfort. The UCG-technique has been found valuable for demonstration of dilatation of the right ventricle both in cyanotic and acyanotic congenital heart disease. In studies of lesion affecting the tricuspid valve pathological UCG-findings have been obtained in patients with tricuspid atresia and Ebsteins anomaly. The method has also been found useful in evaluation of the state of the mitral valve. Pathological findings have been obtained in congenital mitral stenosis, mitral atresia and other forms of hypoplastic left heart syndrome, in endocardial cushion defects and in mitral regurgitation. The UCG-technique also provides information about the outflow tract of the left ventricle. Pathological findings have been obtained in cases with membraneous subvalvular aortic stenosis and hypertrophic obstructive cardiomyopathy. Pericardial effusion and thrombosis in the right atrium may be demonstrated by this technique. No complications have been observed.     

Single Coronary Artery with Fistula,Right Aortic Arch,Bicuspid Aortic Valve,and Pulmonary Stenosis: A Rare Combination

We report a case of a 10-month-old Chinese girl with single left coronary artery, left coronary artery-to-right ventricle fistula, pulmonary stenosis, and right aorta arch with bicuspid aortic valve. The diagnosis was made by transthoracic echocardiography and confirmed by angiography. A surgical repair was performed with closure of the fistula at the point where it drained into the right ventricle plus a pulmonary valvulotomy.     

Medium-term results of percutaneous transluminal balloon aortic valvuloplasty with Inoue balloon catheter for congenital aortic stenosis

Although percutaneous transluminal balloon aortic valvuloplasty (PTAV) has been performed for congenital aortic stenosis in infants and children for several years, its efficacy and the associated aortic regurgitation (AR) have not been widely discussed. Percutaneous transluminal balloon aortic valvuloplasty using an Inoue balloon catheter was performed for congenital aortic stenosis in 12 patients (4–16 years old) in this study. The systolic aortic valve pressure gradient ranged from 42 to 111 mmHg before PTAV and became < 50 mmHg immediately after PTAV in 10 cases (83%). Eight of these 10 patients had no increase in the gradient during subsequent observation for a period of 9–40 months. Aortic regurgitation increased immediately after PTAV in nine cases (75%). It increased from grade 1 to grade 2 in eight cases and from grade 1 to grade 3 in one patient; no significant enlargement of the left ventricular end-diastolic diameter and no significant change in the left ventricular end-diastolic pressure (LVEDP) or the cardiac index was observed during follow-up in these patients. There was a correlation between the diameter of the balloon and efficacy; an appropriate diameter was considered to be about 90% of the aortic annular diameter. Changes in the hemodynamic parameter after PTAV with an Inoue balloon were small in most patients and this procedure is considered to be a treatment that should be attempted prior to surgery for congenital aortic stenosis.     

Left ventricular pannus causing inflow obstruction late after mitral valve replacement for endocardial fibroelastosis

A case of mitral stenosis following mitral valve replacement in a patient with endocardial fibroelastosis is reported. A 14-year-old boy presented with cardiac failure. He had been diagnosed as having endocardial fibroelastosis at the age of 7 months and had undergone resection of endocardial fibrous tissue in the left ventricle at that time. Five years later his mitral valve was resected owing to mitral stenosis, with Bjork-Shiley valve replacement. Cross-sectional echocardiography on this admission showed restrictive left ventricular inflow due to a thickened immobile prosthetic valve with severely dyskinetic left ventricle (ejection fraction 8%). The electrocardiogram showed atrioventricular reentry tachycardia. Despite direct current cardioversion and continual amiodarone infusion he suffered a cardiac arrest and died 12 days after admission. Postmortem examination showed left ventricular endocardial fibroelastosis with severe inflow obstruction due to the formation of a complete fibrous ring of pannus/fibrosis around the prosthetic margin on the ventricular aspect of the left ventricle. This complication has not previously been described in children after mitral valve replacement.     

Surgical Strategy for Severe Aortic Hypoplasia and Aortic Stenosis With Ventricular Septal Defect and Normal Left Ventricle

At our institution, the strategy for patients with bicuspid aortic valve, aortic valve stenosis (<5 mm), and aortic hypoplasia [hypoplastic aortic arch, coarctation of the aorta (CoA), or interrupted aortic arch (IAA)] with ventricular septal defects (VSDs) as well as normal left ventricular (LV) volume and mitral valve size consists of two parts. The Norwood operation is applied as the first palliation for this group of patients. Second, the decision whether the patients are to undergo the Rastelli operation or a univentricular repair is made depending on the size of the right ventricle after the Norwood operation. This study aimed to examine whether the aforementioned surgical strategy for this group of patients is adequate or not. Seven patients undergoing the Norwood operation as the first palliation for bicuspid aortic valve, aortic valve stenosis (<5 mm), and aortic hypoplasia with VSDs as well as normal LV volume and mitral valve size between February 2005 and March 2010 at Kitasato University Hospital and the Gunma Children’s Medical Center were reviewed. Postoperative serum B-type natriuretic peptide (BNP) and central venous pressure (CVP) were measured in the patients undergoing the staged Norwood–Rastelli operation to assess whether the authors’ right ventricular end-diastolic volume index (RVEDVI) cutoff (80 % of normal) is adequate. At this writing, all seven patients are alive after a mean follow-up period of 58.8 ± 17.8 months. They all had aortic valve stenosis of <5 mm and a bicuspid aortic valve. Four patients had a diagnosis of CoA with VSD, and three patients had IAA with VSD. Six patients underwent biventricular repair, and one patient had univentricular repair due to the small RVEDVI (74 % of normal). The patients with 80–90 % of normal RVEDVI had higher BNP and higher CVP than those with more than 90 % of normal RVEDVI after the Rastelli operation, whereas the patient undergoing the Fontan operation had a low BNP level. In conclusion, the described strategy for patients with severe aortic hypoplasia and aortic stenosis with VSD as well as normal LV and mitral valve size is reasonable.