新生兔同种主动脉带瓣管道移植的形态学研究

目的 :观察新生动物的同种主动脉带瓣管道 （VAHC）移植后的形态学变化。方法 :以体重 15 0～ 2 0 0 g的新西兰兔 2 4只作为 VAHC的供体 ,0 .9～ 1.2 kg的幼兔和 2 .1～ 2 .9kg的成年兔各 12只为受体 ,建立新生兔的 VAHC移植模型。术后 1个月和 6个月分别取材作大体形态测量及组织学观察。结果 :发现植入的 VAHC内膜光滑 ,无血栓 ;与植入时相比 ,各组 VAHC血管壁厚度及植入幼兔体内 6个月 VAHC长度和管径明显增加 （P<0 .0 5 ） ;与未植入的新生兔 VAHC相比 ,植入幼兔体内 6个月的 VAHC瓣叶高度、游离缘长度均增加 （P<0 .0 5 ）。组织学检查显示 VAHC血管壁存在三层结构 ,内膜及中层轻度增厚 ,管壁有少量单核细胞及淋巴细胞浸润 ,植入成年兔体内 6个月的变化最为明显。结论 :新生兔的 VAHC植入幼兔体内后其血管的直径和长度、瓣叶的高度和游离缘长度可随幼兔的发育而增加 ,提示在临床上应用小的 VAHC是可行的。     

新生动物同种主动脉带瓣管道移植的免疫反应与钙含量的相关性

目的 :探讨新生动物同种主动脉带瓣管道 （VAHC）移植后免疫反应与钙含量之间关系。方法 :体重 15 0～ 2 0 0g的新生新西兰兔 2 4只作为 VAHC的供体 ,0 .9～ 1.2及 2 .1～ 2 .9kg的幼兔和成年兔各 12只为受体 ,建立新生兔的 VAHC移植模型。术后 1个月和 6个月分别取材作免疫荧光染色及钙含量测定。结果 :免疫荧光检查显示各移植组 VAHC血管壁 Ig G荧光染色结果均为阳性。半定量分析显示植入幼兔体内 1个月及成年兔 1个月和 6个月体内的阳性积分显著高于植入幼兔体内 6个月的 VAHC（P<0 .0 5 ）。各移植组 VAHC血管壁的钙含量及植入幼兔体内 6个月和成年兔体内瓣膜的钙含量显著高于对照组 （P<0 .0 5 ）。血管壁免疫荧光强度积分结果与钙含量呈明显的正相关 （r=0 .6 2 ,P<0 .0 5 ）。结论 :新生兔的 VAHC植入幼兔和成年兔体内后移植物的免疫反应程度与钙含量有明显的相关性     

同种带瓣管道在儿童先心病治疗中的应用

目的 :报告应用同种带瓣管道 (VHC)在儿童先心病治疗中的经验。方法 :全组 12例患儿男 7例 ,女 5例。平均年龄 7.5 (2 .2～ 13)岁 ,平均体重 2 1(12 .5～ 32 )kg。病种包括右室双出口 5例 ,共同动脉干 2例 ,矫正性大动脉转位合并室缺 2例 ,完全性大动脉转位 1例 ,法乐四联症合并肺动脉闭锁 1例 ,主动脉瓣关闭不全 1例。主动脉VHC应用 2例 ,肺动脉VHC应用 10例 ,均用于右室流出道重建。结果 :本组病例无手术死亡。平均随访 9.5 (3～ 19)个月 ,死亡 1例。存活患儿心功能明显改善 ,超声心动图检查显示吻合口无狭窄 ,VHC管腔通畅 ,瓣膜无明显返流。结论 :本组结果表明VHC是儿童先心病右室流出道重建的理想材料。     

新生动物同种主动脉带瓣管道移植的组织形态学观察

目的 :观察新生动物同种主动脉带瓣管道 (VAHC)移植后的组织形态学变化。方法 :新生兔为供体 ,其VAHC抗生素灭菌后经腹膜外植入幼兔及成年兔的腹主动脉 ,术后 1个月和 6个月取材作组织形态学观察。结果 :移植的VAHC搏动良好 ,内膜光滑 ,无血栓。瓣膜无皱缩 ,交界无粘连。光镜下血管壁内膜和中层有不同程度的增厚 ,可见炎性细胞浸润。电镜下的超微结构均有所改变 ,以植入成年兔体内 6个月的VAHC最为明显 ,主要表现为血管壁平滑肌细胞增生 ,胞内细胞器少 ,内质网明显扩张 ,甚至呈空泡样改变 ,可见淋巴细胞和单核细胞浸润及钙化斑。瓣膜胶原纤维排列散乱 ,部分成纤维细胞内质网扩张 ,胞浆内有脂褐素沉积。结论 :本实验表明 ,新生动物的VAHC移植后的组织形态呈较明显的慢性排异反应征象。它提示在临床上应用小的VAHC移植时进行组织配型和免疫抑制治疗可能是必要的     

Doppler evaluation of homograft valved conduits in children

To assess the flow characteristics of homograft valved conduits in the immediate postoperative period, 69 children with 71 homograft conduits underwent 2-dimensional and Doppler echocardiographic examination at 1 to 40 days (mean 8) after surgery. Of the 71 conduits studied, 19 were aortic and 52 were pulmonary homograft valved conduits. Two aortic homograft valved conduits were inserted in the aortic position, whereas all remaining homografts were placed in the pulmonary position. On the immediate postoperative echocardiogram, 25 (35%) of the conduit valves had no regurgitation and 44 (62%) had 1+ (mild) regurgitation. Two pulmonary valved conduits (3%) in the pulmonary position had 2+ (moderate) regurgitation and right ventricular dimensions greater than 95% for body surface area. The peak velocity across the homograft valve was normal (less than 1.3 m/s) in 58 valves (82%). In the remaining 13 valves, peak velocity ranged from 1.4 to 2.6 m/s. No homograft valve had a peak velocity greater than 2.6 m/s in the immediate postoperative period. To assess the fate of homograft valved conduits in the intermediate-term follow-up period, 38 children with 38 conduits had a repeat echocardiogram at 6 to 25 months (mean 15 +/- 6) after surgery. Of the 38 conduits examined, 10 (26%) had no regurgitation, 25 (66%) had 1+ regurgitation and 3 (8%) had 2+ regurgitation. Progression of the amount of regurgitation occurred in 11 (29%) patients. At the follow-up examination, peak velocity was less than or equal to 1.4 m/s across 34 conduit valves, between 1.4 and 2.6 m/s across 3 valves and greater than 2.6 m/s across 1 valve.(ABSTRACT TRUNCATED AT 250 WORDS)     

Use of aortic homograft conduit in bidirectional Glenn shunt

We present our experience with a patient in whom a homograft conduit was used to connect the superior vena cava (SVC) to the right pulmonary artery (RPA) in a functionally univentricular heart where corrective repair was impossible.     

Percutaneous valved stent repair of a failed homograft: implications for the Ross procedure

A case of percutaneous pulmonary valve implantation following a failed homograft in the pulmonary position is reported. A 16-year-old boy developed infective endocarditis of his pulmonary homograft, which was implanted four years earlier during a Ross procedure for congenital aortic stenosis. Following successful medical therapy, the boy was symptomatic due to pulmonary stenosis and regurgitation. A 22 mm Melody valve (Medtronic, USA) was successfully implanted percutaneously. His symptoms resolved and he was discharged home one day after the procedure. Echocardiography at the six-month follow-up demonstrated a normally functioning pulmonary valve. Percutaneous pulmonary valve replacement may make the Ross procedure a more attractive option for patients with aortic stenosis, particularly in the pediatric population.     

Doppler echocardiography in the assessment of the homograft aortic valve

To determine the utility of Doppler echocardiography in the evaluation of the homograft valve in the aortic position, 27 patients with normally functioning valves (group 1) and 30 patients with suspected malfunctioning valves (group 2) were examined. Simultaneous cardiac catheterization and Doppler echocardiography were performed in 23 group 2 patients. Doppler and surgical findings were compared in 7 patients too ill for invasive studies. In group 1 patients, the maximal velocity (+/- standard deviation) was 1.8 +/- 0.37 m/s, the mean pressure gradient was 7.1 +/- 3.07 mm Hg and the mean aortic valve area was 2.2 +/- 0.79 cm2. The maximal velocity in group 2 patients with aortic regurgitation (AR) classified as moderate or greater was 2.5 +/- 0.55 m/s, compared with 1.8 +/- 0.44 m/s in patients with mild AR or less (p less than 0.01). In the quantitation of AR, pulsed-wave mapping and angiographic grades were identical in 18 patients and differed by 1 grade in 5. Seven patients too ill for catheterization had severe destruction of valve leaflets at cardiac surgery. In 6 patients, both Doppler grading methods suggested severe AR. In a seventh patient, who had an obstructed Starr-Edwards valve in the mitral position, AR was graded as mild by pulsed-wave mapping. Only 1 patient had homograft valve stenosis, with a withdrawal gradient at catheterization of 34 mm Hg and a Doppler maximal gradient of 36 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pathological findings of the aortic homograft in a patient with tetralogy of Fallot twenty years after implantation

Summary We report pathological findings of the aortic homograft in a 27-year-old patient who died 20 years after implantation at the time of correction of tetralogy of Fallot. Although calcification of the homograft was severe with degeneration of valve leaflets, no functional obstruction of the homograft was found as a conduit. This observation may suggest a beneficial aspect of the aortic homograft as the right ventricle to the pulmonary artery conduit late after corrective surgery even if calcification was not avoided.     

主动脉夹层动脉瘤的彩色多普勒超声诊断

目的评价彩色多普勒超声心动图对主动脉夹层动脉瘤（AD）的诊断价值。方法应用彩色多普勒超声心动图对18例疑诊AD的患者进行检查。结果17例经超声检查准确诊断。AD者主动脉均增宽，主动脉壁分离形成真、假两腔，可见内膜片回声；彩色多普勒能直接观察血流由撕裂口进入假腔以及真、假腔内血流变化，并能评价主动脉瓣返流程度。结论彩色多普勒超声心动图能快速、安全、准确地检出本病，对诊断本病具有重要价值。     

Transcatheter aortic valve implantation for treatment of failing homograft with preexisting mechanical mitral prosthesis

Transcatheter aortic valve implantation is increasingly used to treat bioprosthetic degeneration. Valve‐in‐valve technique has been performed successfully to treat homograft, stentless, and stented bioprosthetic dysfunction. The presence of a prosthesis in the mitral position can make the transcatheter aortic valve implantation procedure challenging due to proximity of the mitral and aortic annuli. We describe the case of a 66‐year‐old who underwent the first successful implantation of Edwards Sapien device in a failing homograft in the presence of a mechanical mitral valve prosthesis. © 2013 Wiley Periodicals, Inc.     

Doppler echocardiography in the evaluation of left ventricular diastolic function

The examination of diastolic filling velocities by Doppler echocardiography has provided increasing insights into the understanding of left ventricular diastolic performance in health and disease. However, several recent studies have emphasized the importance of a wide variety of physiologic variables, including heart rate, respiration, age, and loading conditions that need to be considered as potential confounding factors in the interpretation of these filling patterns. Despite this, Doppler echocardiographic assessment has been useful in the evaluation and prognostication of a variety of restrictive cardiomyopathies. Furthermore, the study of Doppler diastolic filling velocities has improved our understanding of common cardiac diseases, including hypertensive and ischemic myocardial disease. Further enhancement of our understanding of left ventricular diastolic filling in health and disease will depend on more precise elucidation of the mechanisms responsible for diastolic function.     

Right ventricular outflow reconstruction with aortic homograft conduit: analysis of the long-term results

One hundred and four patients with complex congenital heart disease were operated between 1966 and 1978 for reconstruction of the right ventricular outflow using an aortic homograft conduit. The average age was 14 years, ranging between 3 years and 28 years of age with an equal male/female ratio. Hospital mortality was 50% and there were 3 late deaths (6%) amongst the surviving 52 patients. Seventy-nine percent of the survivors are well and asymptomatic between 1 year and 12 years follow-up. Only 2 patients (4%) developed homograft conduit obstruction with a peak systolic gradient over 40 mmHg and 1 patient needed reoperation 9 years after the original primary reconstruction. Thirty-one patients underwent cardiac catheterization between 1 year and 9 years following the original operation, and a further 9 patients underwent a second cardiac catheterization at a mean of 36 months after their first cardiac catheterization. Ninety-three percent of these 31 patients had a resting peak systolic gradient across the homograft conduit of between 0 and 55 mmHg (mean 14.16 +/- 14.03). Calcification in the wall of the aortic homograft appeared within the first 2 years in about 80% of the patients but this had no correlation to the gradient across the homograft, nor did it interfere with the valve performance.     

Doppler evaluation of aortic valve area in children with aortic stenosis

To evaluate the usefulness of the Doppler-derived aortic valve area calculated from the continuity equation in assessing the hemodynamic severity of aortic valve stenosis in infants and children, two-dimensional and Doppler echocardiographic examinations were performed on 42 patients (aged 1 day to 24 years) a median of 1 day before or after cardiac catheterization. The left ventricular outflow tract diameter was measured from the parasternal long-axis view at the base of the aortic cusps from inner edge to inner edge in early systole. The flow velocities proximal to the aortic valve were measured from the apical view with use of pulsed Doppler echocardiography; the jet velocities were recorded from the apical, right parasternal and suprasternal views by using continuous wave Doppler echocardiography. The velocity-time integral, mean velocity and peak velocity were measured by tracing the Doppler waveforms along their outermost margins. Seventeen patients (all less than or equal to 6 years old) had a very small left ventricular outflow tract diameter (less than or equal to 1.4 cm) and cross-sectional area (less than or equal to 1.5 cm2). The Doppler aortic valve area calculated with use of velocity-time integrals in the continuity equation (0.57 +/- 0.25 cm2/m2, mean value +/- SD) correlated well with the Doppler aortic valve area calculated by using mean (0.55 +/- 0.25 cm2/m2) and peak (0.54 +/- 0.24 cm2/m2) velocities, with correlations of r = 0.97 and 0.95, respectively. Thirty-four patients had sufficient catheterization data to calculate aortic valve area from the Gorlin formula.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cardiac rupture in embolic myocardial infarction after implantation of a valved aortic conduit

This report describes a rare case of an embolic coronary artery occlusion causing an acute myocardial infarction and cardiac rupture as an early mechanical complication of ST-elevation myocardial infarction. Early recognition of the underlying disease is important to guide further therapy.     

Quantitative evaluation of left heart obstructions (including aortic isthmus stenosis) in children using Doppler echocardiography

To assess the accuracy of pulsed and continuous-wave Doppler echocardiography (DE) in evaluating pressure drops across left heart outflow obstructions we examined 27 children with valvular aortic stenosis (n = 13), fixed subaortic stenosis (n = 14) and 16 children with coarctation. Doppler examination was performed within 24 hours of cardiac catheterization in 15 patients, in 17 patients 2-42 months (mean 13 months) after catheterization. Simultaneous blood pressure measurements in both upper and lower limbs with an automated oscillometer were taken in 12 cases with coarctation. Using three standard positions (suprasternal, high right parasternal and apical) we found a close Doppler-catheter correlation in patients with aortic and subaortic stenosis (r = 0.94). The correlation in cases with coarctation was poor (r = 0.17) because of one patient with severe stenosis and another with atresia and a huge collateral vascularization, in whom a poststenotic jet could not be located. Surprisingly the postoperative pressure gradient was much overestimated in one of these patients by DE. We conclude that a "multi-channel system" due to collateral vascularization excludes the use of the simplified Bernoulli equation. Apart from these anatomically related false Doppler estimates we found a good correlation (r = 0.90), with slight overestimation in mild stenosis. Thus, Doppler ultrasound provides an accurate noninvasive method for estimating pressure gradients in patients with aortic and subaortic stenosis and to a lesser extent in patients with coarctation. In particular DE is helpful for determining subsequent clinical management.