First experience with the 2005 modified Gore Helex ASD occluder system.

We report about our initial experience for the in 2005 modified Helex (Gore) device for closure of atrial septal defects (ASD) and persistent foramen ovale (PFO). Major changes were made at the delivery system for simplifying the Helex implantation procedure. We treated 11 patients, 8 children and 3 adults, with ages between 3 and 62 years. In 10 patients the diagnosis was a relevant ASD with volume overload of the right heart (Left to right shunts between 30 and 50%). One adult (age 58 years) have had a small left to right shunt with a PFO-like defect and the history of 2 neurologic embolic events. In 3 patients we found 2 defects. In all patients a Helex occluder was implanted successfully. The mean fluoroscopy time was 8,4 minutes. The immediate occlusion rate after 24 hours was 91%. In all cases there was a very good adaptation of the device to the anatomical structures. In this small series, the Helex occluder appears to offer a reliable system of occlusion for small and moderate ASDs and for PFO with minimal risk of major complications.

[Extracorporeal membrane oxygenation (ECMO) as cardiac assist device in pediatrics]. / Extrakorporale Membranoxygenierung (ECMO) als kardiales Unterstützungssystem in der Pädiatrie.

Extracorporeal membrane oxygenation (ECMO) is a common treatment for severe respiratory failure. However, ECMO can also be used as cardiac support. ECMO is the most common mechanical circulatory assist device in pediatrics, followed by pulsatile ventricular assist devices. Advantages are the simultaneous support of respiratory and hemodynamic functions and the fast bedside availability. The major disadvantage is the limited duration of therapy. The transthoracic connection of ECMO after cardiac failure in cardiothoracic surgery in childhood allows a controlled weaning on the intensive care unit. Weaning from ECMO is successful in about 45 to 80 % in cases of circulatory support; survival rates depend on patient selection, treatment protocol and indication. Bleeding problems, thromboembolic complications, hemolysis, infections, renal and neurologic complications are major problems.

Experience with an adjustable pulmonary artery banding device in two cases: initial success--midterm failure.

Retraining of the left ventricle in congenitally corrected TGA or after Senning or Mustard operation is necessary when right-ventricular failure is developing and an arterial switch operation is indicated. As these hearts have little tolerance of marginal overbanding, a long-term adjustable pulmonary artery banding device would lower stress and risk of training. Although the inserted device (Osypka) allowed convenient intraoperative pressure ratio adjustment, mid-term adjustment failed due to dysfunction of the system.

Closure of atrial septal defects via limited right anterolateral thoracotomy as a minimal invasive approach in female patients.

OBJECTIVE: The closure of atrial septal defects via sternotomy is a low-risk and high-benefit procedure. Limited right anterolateral thoracotomy is an alternative approach with regard to cosmetic aspects. However, it is discussed that a lateral approach is not appropriate for more complex lesions and is associated with an increased incidence of phrenic nerve damage. METHODS AND RESULTS: The perioperative and long-term outcomes (mean follow-up time: 73.2 months) of 87 female patients, mean age 20.4 years (range: 3-56 years), operated on for all types of atrial septal defects via limited right anterolateral thoracotomy between 1982 and 1993, were analysed retrospectively. Special features of the operation technique were a limited skin incision, protection of mammary gland tissue, prevention of phrenic nerve damage, and aortic cannulation in all patients. There were no intraoperative complications. Postoperative complications occurred in 12/87 patients including one rethoracotomy for postoperative bleeding and one late pericardial tamponade due to coumadine overdose. Follow-up was assessed by a survey obtained by the patients or their parents, and their family doctors in 79 patients (90.8%) Cardiac symptoms, mostly supraventricular arrhythmias, were observed in 13.9%. Echocardiography revealed mild tricuspid valve regurgitation (one patient) and mild mitral valve incompetence (one patient with ostium primum defect); there were no residual shunts. Cosmetic results were considered good and excellent in 87.3% and satisfactory in 8.9%. Three patients (3.8%) complained of a broad scar. Anaesthetic areas and optional scar pain were quite frequent (16.5%), whereas restriction of shoulder movement, breast asymmetry and scoliosis were rare. In summary, only one patient, suffering from intercostal neuralgia, would prefer sternotomy. CONCLUSION: Limited right anterolateral thoracotomy has a high cosmetic acceptance and was proven to be safe and effective for closure of any kind of atrial septal defects. Therefore, it is recommended as standard approach for atrial septal defects especially in female patients. reserved.

Pulmonary artery stenosis after systemic-to-pulmonary shunt operations.

OBJECTIVE: Systemic-to-pulmonary shunt operations are still required for palliation of certain congenital heart defects. The aim of this study was to analyze the incidence and etiology of the development of pulmonary artery stenosis after these procedures. METHODS AND RESULTS: Pre- and post-operative angiograms of 59 patients who underwent 54 peripheral and 12 central shunt operations were analyzed retrospectively. Patients without prior cardiovascular interventions (group I, n = 47) were differentiated from patients with prior interventions (group II, n = 12). In group I, all peripheral shunts were inserted contralaterally to the ductus arteriosus. Follow-up for all patients was 1.8 years (4 days-7.8 years). Pulmonary artery stenosis was diagnosed in 12/59 patients (20.3%, group I 12/47; group II 0) after a time interval of 4 days up to 5.3 years and only after Blalock-Taussig shunts (one classical, 11 modified) (12/40 = 30%). The stenoses were located ipsilaterally to the shunt in 7/12 and contralaterally in 5/12. Statistical analysis did not show any impact of age, weight, sex, shunt type or size, pulmonary artery diameters, Nakata and McGoon indices and prior interventions on the development of pulmonary artery stenosis. However, a patent ductus arteriosus and administration of Prostaglandin E1 had a significant impact on the development of pulmonary artery stenosis on the side of the ductus arteriosus. CONCLUSION: Pulmonary artery stenosis is not a rare event after systemic-to-pulmonary shunt operations. A patent ductus arteriosus with or without administration of Prostaglandin E1 is related to pulmonary artery stenosis on the side of the ductus arteriosus. Pulmonary artery stenosis on the side of a peripheral shunt may be caused by inappropriate surgical technique, increased intimal proliferation, or pulmonary artery kinking. Treatment depends on severity of cyanosis and on further surgical plans.

Growth of pulmonary artery after arterial switch operation for simple transposition of the great arteries.

UNLABELLED: This retrospective study attempts to assess the size and growth pattern of the pulmonary artery about 1 year after neonatal arterial switch operation for simple transposition of the great arteries. Sixty-seven patients underwent cardiac catheterization, including catheterization of the right and left pulmonary arteries, and right ventricular angiography an average of 13.9 months after arterial switch operation. In 34 of these patients pre-operative right ventricular angiocardiograms were available. The diameter of the main pulmonary artery and that of its proximal right and left branches were measured. The values were compared to those of normal children matched for body surface area, taken from the literature and, for the branch values, related to the degree of branch stenosis and to the corresponding values, measured on pre-operative angiocardiograms. The cross-section of the main pulmonary artery after arterial switch operation with Lecompte manoeuvre becomes oval. The branches of the pulmonary artery are sometimes underdeveloped and this finding is related to branch stenosis. The ratio of the branch gradients is inversely proportional to the growth ratio of both branches while the pre- and postoperative Nakata indices are identical. CONCLUSION: The Lecompte manoeuvre induces a flattening of the main pulmonary artery with concomitant reduction of its cross-sectional area. There is also frequently trivial or rarely moderate branch pulmonary stenosis which is accompanied by growth retardation of the concerned branch.

Results of the Bruce treadmill test in children after arterial switch operation for simple transposition of the great arteries.

Children who underwent arterial switch operation for simple transposition of the great arteries in the neonatal period are now reaching an age when exercise testing becomes feasible. This study was conducted to assess exercise tolerance and electrocardiographic response to exercise stress in 50 asymptomatic children, aged 4 to 9 years, using the Bruce walking treadmill protocol to voluntary exhaustion. Heart rate and blood pressure response to exercise stress, endurance time, and electrocardiographic changes were analyzed and compared with those of age-matched normal children. Forty-seven patients had normal exercise capacity and parameters. One patient, whose coronary angiogram showed occlusion of the left main coronary artery, developed electrocardiographic signs of myocardial ischemia during exercise. In 1 patient with a single right coronary artery ostium and in another, who underwent a neonatal internal mammary bypass graft for obstruction of the right coronary artery, the resting electrocardiogram showed ventricular premature complexes and exercise stress-induced salvos of ventricular tachycardia. We conclude that most of the children who underwent the neonatal arterial switch operation for simple transposition of the great arteries have a normal exercise capacity. Exercise testing appears to be useful in detecting ischemic damage or exercise-induced arrhythmias possibly secondary to reduced coronary flow reserve.

Quantitative analysis of the morphology of secundum-type atrial septal defects and their dynamic change using transesophageal three-dimensional echocardiography.

BACKGROUND: A noninvasive method for the determination of size and spatial relationships of atrial septal defects to adjacent cardiac structures, which would be advantageous to those contemplating device closure, is described. The aim of the study was to examine the value of transesophageal three-dimensional echocardiography for this purpose. METHODS AND RESULTS: Three-dimensional reconstruction of transesophageal two-dimensional echocardiography was performed in 17 patients. Left-to-right shunt (by oximetry in 16 of 17 patients) was 2.4 to 16.2 L/min, and the Qp/QS ratio was 1.4 to 4.7. The defect area of the atrial septal defect was measured throughout the whole cardiac cycle each 40 ms from the three-dimensional data set. Results were compared with shunt parameters by oximetry and with intraoperative measurements. Distances between atrial septal defect and mitral and tricuspid annulus and the orifices of the caval and pulmonary veins were also measured. The atrial septal defect area ranged from 0.2 to 2.4 cm2 (diastole) to 0.5 to 5.6 cm2 (systole). The maximal area at end-systole was 108% of the area at beginning of systole, and the minimal area at end-diastole was 43%. The defect area correlated significantly with the Qp/QS ratio (r=.70), and the maximal atrial septal defect diameters as measured by using three-dimensional echocardiography correlated well with intraoperative measurements (r=.87). Distances to mitral and tricuspid annulus and to the superior caval vein were determined in all patients. Distances to orifice of the inferior caval vein were measured in 12 patients, and orifices of right pulmonary veins were visible in 5 patients. CONCLUSIONS: Transesophageal three-dimensional echocardiography of atrial septal defects allows the determination of the instantaneous defect area and its dynamic changes and thus provides valuable information about the distances to adjacent cardiac structures. This may have clinical implications for the selection of patients suitable for interventional closure and for the assessment of procedural success.

Cardiological and general health status in preschool- and school-age children after neonatal arterial switch operation.

OBJECTIVE: Cardiological and general health status 3-9 years after neonatal arterial switch operation for transposition of the great arteries should be evaluated by non-invasive methods. METHODS: A total of 77 unselected children with intact ventricular septum (75.3%) or ventricular septal defect (24.7%) without or with aortic isthmic stenosis (5.2%) were prospectively examined 3.2-9.4 years (5.4 +/- 1.6) after neonatal switch. Clinical pediatric and cardiological examination, standard and 24 h Holter electrocardiogram, M-mode, 2D-, Doppler and colour Doppler echocardiography were performed. Outcome data were compared to published normals. RESULTS: Reoperation rate was 2.6%, 96.1% were without limitation of physical activity and 98.7% without medication. Compared to normals, growth was adequate, weight and head circumference were slightly reduced. After median sternotomy, 23.4% had abnormal thoracic configuration (16.9% asymmetry, 6.5% funnel chest). ECG and Holter: 93.5% were in sinus, 6.5% in ectopic atrial or junctional rhythm. Incidence of complete right bundle branch block was 15.8% in patients with ventricular septal defect and 5.2% in those without. Ischemic ST-T changes during exercise due to coronary artery occlusion and evidence of old myocardial infarction were found in 1 patient (1.3%) each. Occasional atrial ectopy was found in 27.4%, ventricular ectopy in 15.3%: occasional in 12.5% and frequent (> 30/h) in 2.8% presenting bigemini, couplets and short runs of ventricular tachycardia at rest and during exercise. Echocardiography: Left ventricular function was normal in all. Endsystolic diameter of neoaortic valve annulus was beyond 90% confidence interval for controls in 79.2%, neoaortic root diameter in 100%. Mild aortic insufficiency was seen in 10.4%. No correlation was found between aortic insufficiency and aortic dilatation. Neoaortic stenosis was not seen, mild residual coarctation after end-to-end-anastomosis was found in 2.6%, native coarctation corrected later on in 1.3%. Supravalvular pulmonary stenosis was seen in 29.9% (19.5% trivial, 7.8% mild, 2.6% moderate), mild subvalvular pulmonary stenosis in 1.3%, pulmonary insufficiency in 2.6%. CONCLUSION: The study confirms good midterm results after neonatal arterial switch operation for transposition with or without ventricular septal defect. Long-term observation is necessary to assess rhythm, coronary artery and myocardial function as well as development of neo-aorta and pulmonary artery system.

Cognitive and motor development in preschool and school-aged children after neonatal arterial switch operation.

OBJECTIVE: The developmental status of children beyond 3 years of age after the neonatal arterial switch operation has not yet been systematically evaluated and is the topic of the present work. METHODS: Seventy-seven unselected children operated on as neonates with combined deep hypothermic circulatory arrest and low-flow cardiopulmonary bypass were examined at an age of 3.2 to 9.4 years (5.4 +/- 1.6 years, mean +/- standard deviation). Clinical neurologic status, standard scores of intelligence, acquired abilities and vocabulary, and standardized tests on gross motor and fine motor functions were carried out, and the results were related to preoperative, perioperative, and postoperative status and management. RESULTS: Neurologic impairment was more frequent (9.1%) than in the normal population. Intelligence was not different in these patients compared with normal children (p = 0.11), but motor function, vocabulary, and acquired abilities were poorer. Reduced intelligence was found in 9.1%, fine motor dysfunction in 22.1%, and gross motor dysfunction in 23.4% of the children. Intelligence was weakly but significantly inversely related to the duration of bypass (Spearman correlation coefficient -0.25, p = 0.03) and tended to be inversely related to the duration of circulatory arrest (-0.21, p = 0.07), but not to core cooling time on bypass or degree of hypothermia. Gross motor function, vocabulary, and acquired abilities were not significantly related to any of the perioperative parameters considered. No correlation was found between the test results and the variables perinatal asphyxia, perioperative and postoperative cardiocirculatory insufficiency, resuscitation events, and plexal or intraventricular cerebral hemorrhage. CONCLUSIONS: The neonatal arterial switch operation with combined circulatory arrest and low-flow bypass in our experience is associated with neurologic as well as fine and gross motor impairment but appears to be well tolerated concerning cognitive functions as based on formal intelligence testing.

Transcatheter closure of atrial septal defects by the "buttoned" device: complications and need for surgical revision.

Immediate and medium-term experience with transcatheter closure of a secundum atrial septal defect by the "buttoned" device in seven patients is reported. Complications occurred in two patients during the procedure. In one patient with complications, the occluder was partly released in the right atrium. All efforts to correct its position were unsuccessful and caused considerable deformation of the device, which had to be removed surgically. In the other patient with complications, disconnection of the occluder and counteroccluder occurred immediately after removal of the loading wire. Both parts were retrieved by catheter. Five patients had uneventful closure of the atrial septal defect. On follow-up, however, displacement of the device towards the mitral valve was observed in two patients, which caused mitral regurgitation. Surgical removal of the device and repair of the mitral valve was necessary in both patients. Two years after the procedure, the atrial septal defect was closed completely in two of the remaining three patients and a small residual defect persisted in one patient.

Angiographic study of aorta, coronary arteries, and left ventricular performance after neonatal arterial switch operation for simple transposition of the great arteries.

This retrospective study attempts to assess the growth pattern of the aorta and the coronary arteries and the left ventricular function approximately 1 year after neonatal arterial switch operation for simple transposition of the great arteries. Seventy-one patients underwent cardiac catheterization and cineangiocardiography an average of 13.5 months after the operation. The diameters of aortic annulus, aorta at different sites, and coronary arteries were compared with normal ranges taken from the literature. Left ventricular systolic performance was also evaluated. Observations included the following: Neoaortic annulus and root were larger than normal, trivial or mild neoaortic regurgitation was frequently observed, and the development of aortic anastomosis was normal. One patient had unexpected coronary occlusion, one had a coronary artery fistula, and two had a hypoplastic left anterior descending coronary artery. Except in one child who underwent an internal mammary bypass graft immediately after anatomic correction, the global left ventricular performance was normal. Six patients had regional wall motion abnormalities. Our midterm results are encouraging, but potential late complications remain concerns that must continue to be evaluated in long-term follow-up studies.

[Effect of dietary measures on body weight and height of children with phenylketonuria in East Germany]. / Einfluss der Diätbedingungen auf Körpergewicht und -grösse bei Kindern mit Phenylketonurie in Ostdeutschland.

Body length and body weight of 90 patients with PKU (48 girls and 42 boys) were compared during the years up to 1990 and thereafter. The patients got Berlophen up to 1990 for at least 3 years, and Milupa PKU or PAM (SHS) for 3 years thereafter. The data were compared with the percentiles according to Prader, the significance was calculated with the Chi2-Test. Body length and weight are significantly reduced during the first decade of life compared with normal population. Body length reaches normal values at the age of 12 years, body weight at 9 years respectively. The change of the diet after the german unification had no influence onto body weight and length. The retardation of body length, however, was more marked in patients with very strict dietary control compared to patients with more often dietary faults. The limited availability of essential nutrients seems to be the cause for the somatic retardation of the patients with PKU in the eastern part of germany.

Trial of pulmonary artery banding: a diagnostic criterion for 'one-stage' arterial switch in simple transposition of the great arteries beyond the neonatal period.

OBJECTIVE: Arterial switch operation (ASO) is the procedure of choice for the repair of simple d-transposition of the great arteries (TGA) during the neonatal period. Beyond this time such correction is performed in two stages. The first step incorporates banding of the pulmonary artery with or without a Blalock-Taussig shunt to train the left ventricle (LV). The second step consists of the ASO. To find out whether candidates for a two-stage procedure would tolerate a one-stage correction, a trial of pulmonary artery banding was performed. MATERIAL AND METHODS: Between February 1986 and December 1995, 224 patients less than 3 months of age with TGA, intact ventricular septum or a small restrictive ventricular septal defect, had an ASO. Seven patients were 4 weeks of age or older (28-70 days). Two of these had a pulmonary artery to systemic pressure ratio higher than 0.6 and underwent primary ASO without complications. The remaining five patients had low left ventricular pressure with a pulmonary to systemic pressure ratio of 0.2-0.5; echocardiography showed a banana-shaped LV with left ventricular wall thickness as low as 3 mm. They underwent a trial of pulmonary artery banding to systemic pressure for 15-30 min. As this increase in workload was tolerated well with an anticipated decrease of oxygen saturation but without hemodynamic disturbances anticipated, the ASO was performed immediately. RESULTS: Postoperative course was uneventful in all five patients, although catecholamine dependence was prolonged and three patients received enoximone. There were no severe complications. Echocardiography showed an increase in posterior wall thickness from 3 to 6 mm after 19 days in one infant. CONCLUSION: Some of the children, assigned for a 'two-stage' ASO may tolerate a primary anatomic repair up to an age of at least three months. This subgroup can be selected by a trial of pulmonary artery banding.

Inflammatory reaction and capillary leak syndrome related to cardiopulmonary bypass in neonates undergoing cardiac operations.

We studied the inflammatory reaction related to cardiopulmonary bypass in 24 neonates (median age 6 days) undergoing the arterial switch operation for simple transposition of the great arteries, with respect to the development of postoperative capillary leak syndrome. Complement proteins, leukocyte count, tumor necrosis factor-alpha, and histamine levels were determined before, during, and after cardiopulmonary bypass. Additionally, protein movement from the intravascular into the extravascular space during cardiopulmonary bypass was assessed by the measurement of plasma concentrations of proteins with molecular weights ranging from 21,200 to 718,000. Capillary leak syndrome developed in 13 of the 24 neonates. Patients with capillary leak syndrome, as compared with those without, had preoperatively higher C5a levels (C5a, 3.0 +/- 0.6 microgram/L vs 0.9 +/- 0.2 microgram/L) (mean +/- standard error of the mean) (p < 0.05) and higher leukocyte counts (leukocytes, 17.9 +/- 2.1 X 10(3) cells/ml versus 11.7 +/- 0.8 X 10(3) cells/ml) (p < 0.05), suggesting in these neonates a preoperative inflammatory state. Preoperative clinical and operative data were identical in both patient groups. Before cardiopulmonary bypass, serum protein concentrations were similar in all patients. Ten minutes after institution of cardiopulmonary bypass, protein concentrations fell to significantly lower values in patients with capillary leak syndrome than in those without: albumin (19% +/- 1.5% vs 30% +/- 6% of the prebypass value, p < 0.05), immunoglobulin G (17% +/- 1.5% vs 29% +/- 5.5%, p < 0.001), and alpha 2-macroglobulin (15% +/- 1.2% vs 25% +/- 4%, p < 0.02). During cardiopulmonary bypass, albumin concentrations remained significantly lower in patients with capillary leak syndrome than in those without, whereas hematocrit values were similar in both groups. During cardiopulmonary bypass, patients with capillary leak syndrome also had lower concentrations of complement proteins C3 and C4 but not C1 inhibitor. C3d/C3 ratio and C5a levels were similar in both patient groups. In contrast, histamine liberation during cardiopulmonary bypass was significantly more pronounced in patients with capillary leak syndrome than in those without (725.2 +/- 396.7 pg/ml vs -54.1 +/- 58.4 pg/ml, p < 0.05). Tumor necrosis factor-alpha levels after protamine administration were also significantly higher in patients with capillary leak syndrome (38.1 +/- 10.0 pg/ml vs 15.3 +/- 3.4 pg/ml, p < 0.05). Leukocyte count during and after cardiopulmonary bypass was similar in both patient groups. This study demonstrates increased protein leakage as early as 10 minutes after initiation of.

Characterization of Cu-Sn/Pb diffusion zones of microelectronic contacts by means of electron probe microanalysis and ion beam sputtering.

Physical parameters of material, such as strength and electrical conductivity, can be influenced considerably by the intermetallic compounds formed by diffusion in soldered microelectronic contacts between Cu and Sn/ Pb solders. Therefore, formation and growth of these contact zones were systematically investigated on model specimens in dependence on temperature, time and chemical tin-lead concentration of the solders by means of electron probe microanalytical investigations and characterized by phase growth constants. Compared with the conventional metallographic specimen preparation method, the ion beam etching of the contact surfaces proves to be an excellently suitable means for representing the microstructure after the cooling of the samples. Moreover, the three-dimensional grain structure and technologically caused defects in the contact can be shown by ion beam slope cutting. Effects as e.g. the dendritic growth and Kirkendall pores which increasingly occur at higher temperatures are successfully proved.

Advances in design principle and fluid dynamics of a flexible polymeric heart valve.

The three leaflet J-3 valve is manufactured in a medium open position with almost flat leaflets, whereby the stent is expanded by a cone shaped mold. After manufacturing, the dipcoated leaflets have stable closed and open positions. The transition succeeds with very low membrane stresses. Due to this design, the J-3 polymer valve showed superior hydrodynamic performance compared with commercial valves. In durability tests, prototypes have reached lifetimes up to 17 years. While animal tests are encouraging, they also reveal needed manufacturing improvements.