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Biomedical subjects

M Hofbeck

Publications and source records attributed to M Hofbeck.

At least 73 records · Page 4Linked to original sources
PubMed1995

[Echocardiographic findings before and after interventional occlusion of a persistent ductus arteriosus Botalli using the Rashkind Occluder System].

AIM: The aim of this study was to investigate whether before releasing the Rashkind occluder system for occlusion of persistently patent ductus arteriosi Botalli from the delivery catheter its position can be adequately demonstrated sonographically to avoid angiography. METHOD: From March to August 1993 occlusion of a persistently patent ductus arteriosus by means of the Rashkind system was carried out in 10 patients. A standard technique using transthoracic echocardiography was used. RESULTS: Echocardiography allowed to demonstrate and locate the occluder system in all cases. CONCLUSION: Echocardiography is a reliable means for locating the Rashkind occluder system avoiding angiography.

Adolescent↗
PubMed1995

[Thrombolysis of modified Blalock-Taussig shunts in childhood with recombinant tissue-type plasminogen activator].

Since 1983, when c-DNA was isolated, recombinant tissue plasminogen activator (rtPA), an endothelial-cell-produced activator of fibrinolysis is used, more increasingly often in therapy of thrombosis. Whereas some studies have been published regarding efficacy and safety rtPA in different thrombotic states of adults, only case reports exist in children. Doses vary widely (0.8-6 mg/kg/d), bleeding complications are reported in up to 50%. We report on four infants with complex cyanotic congenital heart disease who developed an early post-operative thrombosis of a modified Blalock-Taussig shunt. By local low dosage application of rtPA we could achieve a complete lysis of the thrombus in three of our four patients. In one patient we were unsuccessful due to a distal stenosis of the shunt. This infant required repeat surgery with creation of a central aortopulmonary shunt. We saw severe bleeding in one, requiring transfusion of packed cells, and formation of a perigraft reaction in another patient. In our experience local application of rtPA in low doses is a good therapeutical option in patients with thrombosis of aorto-pulmonary shunts, especially in the first postoperative days.

Dose-Response Relationship, Drug↗
PubMed1995

[Balloon dilatation of the pulmonary valve within the first 40 days of life in critical valvular pulmonary stenosis, Fallot's tetralogy and following surgical or interventional high-frequency opening of pulmonary atresia].

A balloon-valvuloplasty of the pulmonary valve (BVP) was carried out in 14 patients within the first 40 days of life. Six infants had a critical valvular pulmonary stenosis with intact ventricular septum (group S), 5 infants had a pulmonary atresia with intact ventricular septum (group A), and 3 infants had a tetralogy of Fallot (group F). In 4 of the 5 patients of group A the BVP was preceded by operative opening of the pulmonary valve. In one case radiofrequency perforation of the valve during the first diagnostic cardiac catheterization could be carried out successfully. The average value of the ratio of the balloon diameter to the diameter of the pulmonary valve was 1.31 +/- 0.20. The systolic pressure in the right ventricle dropped 51 mm Hg (from 106 +/- 32 mm Hg to 55 +/- 9 mm Hg) in group S and 33 mm Hg (from 101 +/- 27 mm Hg to 68 +/- 19 mm Hg) in group A. In group F the arterial oxygen saturation increased 15%, however the pressure of the right ventricle was, after the BVP, slightly higher than before. The average residual gradients after BVP were in group S 28 +/- 15 mm Hg, in group A 34 +/- 12 mm Hg and in group F 48 +/- 18 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)

Catheter Ablation↗
PubMed1994

Estimation of cardiac index by means of the arterial and the mixed venous oxygen content and pulmonary oxygen uptake determination in the early post-operative period following surgery of congenital heart disease.

OBJECTIVE: To assess the reliability of estimation of cardiac index based on the mixed venous oxygen saturation and methods of improving the estimation of cardiac index. SETTING: PICU in an university hospital. DESIGN: In the post-operative period following complete repair of congenital heart disease we carried out 55 measurements of blood gases in 25 infants and children (mean age 16.1 months, mean body surface 0.43 m2) from a systemic artery (arterial) and the pulmonary artery (mixed venous). We also determined the pulmonary oxygen uptake and calculated the cardiac index (CI) using Fick's principle. In the analysis we compared the CI with the mixed venous oxygen saturation (SvO2) and with the quotient of the arterial oxygen content (CaO2) and the oxygen extraction (Ca-vDO2). This quotient is equal to arterial oxygen delivery (DO2) divided by the oxygen consumption (VO2). RESULTS: Pearson's correlation coefficient was 0.77 when SvO2 was compared to CI in a linear regression model. Assuming an inverse relationship between SvO2 and CI the correlation was much better (r = 0.90). However, the best estimation of CI provides the quotient CaO2/Ca-vDO2 (r = 0.93). CONCLUSIONS: CaO2/Ca-vDO2 correlates much better with CI than the SvO2, therefore CI could be better estimated based on CaO2/Ca-vDO2. Furthermore CaO2/Ca-vDO2 provides good information about the oxygen supply situation of the body.

Arteries↗
PubMed1994

[Doppler echocardiography assessment of hemodynamic values and additional heart defects in atrial septal defects].

Due to the rapid progress in (Doppler-) echocardiography "one must question whether cardiac catheterisation remains a necessary prelude to cardiac surgery in atrial septal defects" (8). Although the estimation of the magnitude of the intracardiac shunt and the anatomical size of the defect ist possible by (Doppler-) echocardiography there remains the problem of associated disorders (e.g. anomalies of the pulmonary venous connection) which may not be detected by transthoracic echocardiography. In 25 children submitted to cardiac catheterisation studies in the period between 1990 and 1992, the anatomical size of an atrial septal defect was measured echocardiographically. The haemodynamic parameters Qp/Qs and Rp/Rs were employed to calculate the so-called effective resistance of the defect (Rd/Rs), which was derived from an electrical analogue and represents the ratio of the resistance of the defect (Rd) to the systemic vascular resistance (Rs). The echocardiographically measured anatomical size (expressed as the ratio of the area of the defect to the cross-sectional area of the ascending aorta) was related to the effective resistance of the defect. A significant (non-linear) correlation was found between Rd/Rs and the anatomical size of defect. Based on these data we developed a nomogram describing the relationship of the size of the defect to the haemodynamic parameters (Qp/Qs and Rp/Rs). If the data of a patient do not comply with this nomogram there is strong evidence of an additional cardiovascular malformation, necessitating further evaluation. A second cohort of four patients with associated defects (partial and total anomalous pulmonary venous connection and a corresponding sinus venosus defect) was clearly identified by the nomogram method.

Adolescent↗
PubMed1994

Frequency of stress lesions of the upper gastrointestinal tract in paediatric patients after cardiac surgery: effects of prophylaxis.

BACKGROUND: Stress lesions of the upper gastrointestinal tract are well recognised in adult patients in intensive care. There are no controlled studies of the incidence of these lesions and the effects or side effects of prophylactic treatment in high risk paediatric patients. METHODS: 79 paediatric patients in intensive care were studied prospectively after operation for congenital heart disease. All patients had at least one endoscopic examination. The first 36 patients were not given prophylactic medication: later 43 children were treated randomly either with pirenzepine (n = 21) or with famotidine (n = 22). Gastric and tracheal secretions were taken daily for culture in those patients given prophylactic medication. RESULTS: Severe inflammation or ulceration of the upper gastrointestinal tract was less common in those patients who were given prophylactic medication (18% v 44%). Prophylactic treatment did not, however, reduce the total incidence of postoperative stress lesions: it shifted the severity of these changes towards mild lesions and reduced the incidence of ulcerations from 25% to 2%. None of the patients developed a pneumonia caused by an organism previously isolated from the stomach. CONCLUSIONS: The incidence of stress lesions in children after cardiac surgery resembles that in high risk adult patients. Children in intensive care after cardiac surgery should be treated prophylactically with famotidine or pirenzepine until they can be fed by mouth.

Adolescent↗
PubMed1994

Thrombolysis of a modified Blalock-Taussig shunt with recombinant tissue plasminogen activator in a newborn infant with pulmonary atresia and ventricular septal defect.

A 10 day old infant with pulmonary atresia, ventricular septal defect, and collateral pulmonary blood supply through a left sided ductus arteriosus developed complete shunt thrombosis four days after the creation of a modified Blalock-Taussig shunt. Recombinant tissue plasminogen activator was given locally into the proximal end of the shunt as two bolus injections of 0.1 mg/kg and two bolus injections of 0.2 mg/kg over 10 minutes, followed by a continuous infusion of 1.4 mg/kg/day for 16 hours and 0.7 mg/kg/day for 18 hours with systemic low dose heparin 5 IU/kg/h. This resulted in complete clot dissolution and reperfusion without haemorrhagic complications and without laboratory signs of systemic fibrinolytic activation.

Abnormalities, Multiple↗
PubMed1994

[Total cavopulmonary anastomosis: risk factors and results in patients under 4 years of age].

In recent years, an increasing number of modified Fontan-operations has been performed in children younger than 4 years of age. The purpose of this study was to identify preoperative risk factors in this age group. From February 1990 until February 1993, we performed in our center a modified Fontan-operation using the technique of total cavopulmonary anastomosis (TCPA) in 37 consecutive patients (17 pts. < 4 years = group I, 20 pts. > 4 years = group II). Early postoperative mortality occurred in patients of group I only (n = 3 pts.). All of these patients had additional preoperative risk factors. Pulmonary vascular resistance (PVRI) > 2 U x m2 was a significant risk factor for the younger patients while pulmonary artery size alone (expressed as the McGoon-ratio or Nakata-index) could not be identified as a separate risk factor. Using two additional indices (McGoon-ratio/PVRI and Nakata-index/PVRI), we were able to identify patients with unfavorable postoperative hemodynamics as high-risk patients. In our experience, TCPA can be performed in patients younger than 4 years of age with a low mortality, if there are no additional preoperative risk factors. For high-risk patients we recommend either a bidirectional Glenn-anastomosis as a first step procedure or a TCPA with fenestration of the intraatrial tunnel-patch.

Adolescent↗
PubMed1994

[Aorto-left ventricular tunnel with origin in the left sinus of Valsalva: a rare cause of congenital aortic insufficiency].

Aortico-left-ventricular tunnel is a rare congenital cardiac lesion that often results in severe aortic insufficiency in infancy. Normally, the defect appears immediately above the right coronary sinus of Valsalva and consists of a tunnel-like connection between the aortic root and the left ventricle. The differential diagnosis to coronary artery fistulae and ruptured aneurysms of the sinus of Valsalva is often difficult. We describe a patient with an aortico-left-ventricular tunnel originating from the left aortic sinus. Similar findings have been described in only three case reports. Additionally, in our case there was a stenosis in the midportion of the tunnel which was connected to an intraseptal aneurysm communicating with the left ventricular chamber via a "septal" defect. The infant underwent successful surgical correction of this malformation at 1 year and 5 months of age.

Angiocardiography↗
PubMed1993

Total cavopulmonary anastomosis: selection criteria related to postoperative results.

In this study we review our experience with total cavopulmonary anastomosis (modified Fontan procedure) which was performed in 31 patients. One patient died from postoperative cardiac low-output syndrome, the other died from a neurological complication (early mortality 6.5%). During a mean follow-up period of 15 months there was no late mortality. Preoperative assessment showed that one, two, or three of the Choussat criteria (defining the ideal Fontan candidate) were not fulfilled by 39%, 16% and 6% of our patients. In the 2 patients who died 2 and 3 of those criteria were not fulfilled. Poor outcome could not be predicted based on assessment of the pulmonary artery size (expressed as the McGoon-ratio or the Nakata-index) alone. In order to assess the relationship of pulmonary artery size and pulmonary arteriolar resistance (PVR) as a predictor of outcome, we introduced two new indices (McGoon-ratio/PVR and Nakata-index/PVR). The patient who died from poor postoperative hemodynamics had the lowest values of all patients. Among the 29 survivors we did not observe significant acquired postoperative arrhythmias. In our experience the total cavopulmonary anastomosis can be performed with a low mortality and good postoperative results. Patients who do not fulfill at least 8 of the Choussat criteria and children with a low ratio of pulmonary artery size to PVR are high-risk patients. In these children we recommend either a bidirectional Glenn anastomosis as a first-step procedure or a total cavopulmonary anastomosis with a fenestration of the intraatrial tunnel.

Adolescent↗
PubMed1993

Improved visualisation of a coronary artery fistula by the "laid-back" aortogram.

The preoperative assessment of patients with a coronary artery fistula requires exact angiographic evaluation of the coronary artery anatomy. A technique of transvenous balloon occlusion angiography of the aorta is described. This can be applied easily in infants with a persisting foramen ovale. Combination of this technique with the so-called "laid-back" aortogram gave excellent visualisation of a fistula between the right coronary artery and the right ventricle. This technique is a major improvement in the angiographic assessment of infants with coronary artery abnormalities and normal cardiac connections.

Aortography↗
PubMed1993

Diagnosis of subclavian steal in infants with coarctation of the aorta and interruption of the aortic arch by color-coded Doppler sonography.

We report the noninvasive diagnosis of subclavian steal by color-coded Doppler ultrasonography in nine infants with congenital heart disease. The underlying cardiovascular malformations included coarctation of the aorta in four infants, interrupted aortic arch type B in three patients, truncus arteriosus communis type A4 (one patient), and isolation of the right subclavian artery (one patient). In all patients both vertebral arteries could be displayed through the anterior fontanel in coronal sections. Normally the flow in both vertebral arteries, as well as the flow in the basilar artery, is displayed in red. In eight patients with angiographically proved unilateral subclavian steal, an antegrade (red) flow could be shown in one vertebral artery, whereas the contralateral vertebral artery was displayed blue, indicating reverse flow. In one infant with interrupted aortic arch type B and associated aberrant right subclavian artery, both vertebral arteries and the basilar artery were displayed blue, indicating bilateral subclavian steal. Color-coded Doppler sonography seems to be a sensitive, noninvasive method for diagnosing congenital subclavian steal, especially in infants with obstruction of the aortic arch.

Aortic Arch Syndromes↗
PubMed1993

[Treatment of acute pulmonary hemorrhage in a patient with pulmonary atresia and ventricular septal defect by coil embolization of a systemico-pulmonary collateral artery].

Pulmonary hemorrhage due to rupture of pulmonary arteries causes significant morbidity and mortality in the natural history of older patients with pulmonary atresia and ventricular septal defect. The only therapeutical option for patients with persisting pulmonary hemorrhage was surgical resection of the involved pulmonary segments. In this case report we describe the successful termination of an acute pulmonary hemorrhage in a 9-year-old patient by coil-embolization of a systemicopulmonary collateral artery, which provided additional blood supply to the left upper-lobe segments. The hemorrhage ceased within 24 h and has not recurred during a follow-up period of 7 months. In our opinion, the success of the embolization can be attributed to a reduction of the perfusion pressure and a normalization of the arterial blood flow in the affected lung segments.

Cardiac Catheterization↗
PubMed1992

Diagnosis of intralobar lung sequestration by colour-coded Doppler sonography.

Intralobar lung sequestration in a 5-month-old dyspnoeic infant was diagnosed by colour-coded Doppler sonography (CDS). Grey scale imaging showed an echogenic mass adjacent to the right hemidiaphragm. CDS demonstrated an abnormal arterial blood supply via a vessel originating from the descending aorta at the level of the diaphragm.

Bronchopulmonary Sequestration↗
PubMed1992

Diagnosis of moyamoya disease with additional renal artery stenosis by colour coded Doppler sonography.

Moyamoya disease is a rare vascular anomaly of the cerebral arteries. The etiology of the disease has not yet been clearly identified. We report the noninvasive diagnosis of Moyamoya disease in a patients with a very early onset of symptoms in infancy. The diagnosis was made by colour coded Doppler sonography and confirmed by angiography at the age of 6 months, following two episodes of cerebral infarction. A bilateral encephalodurosynangiosis was performed at the age of 7 months with subsequent slight improvement of the neurological deficits. Colour Doppler sonography revealed early vascularisation from the fascia temporalis graft into the arachnoid space. At the age of 10 months the patient developed arterial hypertension caused by left renal artery stenosis. Our case suggests, that in infancy Moyamoya disease can be suspected noninvasively by colour Doppler sonography of the cerebral arteries. Patients should be carefully screened for possible extracranial arterial stenoses which may develop in the course of time. Encephalodurosynangiosis seems to be a good therapeutic option for patients with severe neurological symptoms.

Cerebral Arteries↗
PubMed1991

Analysis of survival in patients with pulmonic valve atresia and ventricular septal defect.

This study reviews the clinical course of 104 consecutive patients with pulmonic valve atresia and ventricular septal (VSD) defect who were diagnosed in the first year of life and followed for a mean period of 4.95 years (range 2 days to 13.75 years). Specific attention was paid to the nature of the pulmonary blood supply and to its influence on patient outcome. Confluent pulmonary arteries supplied by a single ductus arteriosus were present in 72 patients (69%, group I), whereas 32 patients (31%, group II) had a pulmonary blood supply that was partially or exclusively dependent on systemic collateral arteries. An estimate of the probability of survival for 10 years was 69% in the entire cohort, with no different between patients in group I and group II. Definitive surgical repair was performed in 33 of 72 group I patients (46%), compared with 5 of 32 group II patients (16%). Arborization and distribution abnormalities of the pulmonary arteries as well as intrapulmonary stenoses that were exclusively present in patients with systemic collateral arteries (p less than 0.00001) accounted for the significantly lower probability of undergoing corrective surgery in group II patients.

Analysis of Variance↗
PubMed1991

Determination of the anatomical size of ventricular septal defects on the basis of hemodynamic data and noninvasive assessment of pulmonary to systemic vascular resistance ratio Rp/Rs by Doppler-echocardiography.

The pulmonary and systemic flow (Qp/Qs) and resistance ratios (RP/Rs) were determined in children with isolated ventricular septal defects (VSD) to derive an "effective defect resistance" (Rd/Rs) representing the ratios of the resistance of the defect to the systemic vascular resistance. The defect size (expressed as the ratio of the area of the defect to the cross-sectional area of the ascending aorta) was related to the calculated "effective defect resistance," where a significant (non-linear) correlation was found. The effective resistance of the defect is a useful aid for estimation of the anatomical size of a ventricular septal defect. The close correlation between anatomical size and the hemodynamic parameter Rd/Rs allows one to calculate the ratio Rp/Rs with this concept using noninvasive Doppler-ultrasound and echocardiography. This was performed in 21 children with VSD who underwent cardiac catheterisation. The noninvasive calculated flow ratio Qp/Qs and the resistance ratio Rp/Rs showed a close correlation to the values measured at cardiac catheterisation.

Cardiac Catheterization↗