Biomedical subjects

B Stiller

Publications and source records attributed to B Stiller.

27 records · Page 2Linked to original sources

PubMed1999

Children may survive severe myocarditis with prolonged use of biventricular assist devices.

The outcome of acute myocarditis with cardiogenic shock is poor. In some children in whom aggressive medical treatment fails, artificial replacement of heart function may offer lifesaving support until the myocardium has recovered. Four previously healthy children (three boys aged 4, 6, and 1 years; one girl aged 5) developed acute myocarditis with ventricular failure and multiorgan dysfunction caused by low cardiac output. Biventricular assist devices (BVAD) were implanted for prolonged support. In three children cardiac function improved and after up to 21 days mechanical support could be withdrawn. They had full recovery of heart function. In the fourth patient there was no myocardial recovery after a period of 20 days. He underwent orthotopic heart transplantation with an uneventful postoperative course. Prolonged circulatory support with BVAD is an effective method for bridging until cardiac recovery or transplantation in children.

Child↗

PubMed1998

Soluble L-selectin plasma concentrations in infants undergoing heart surgery: no association with capillary leak syndrome or need for respiratory support.

OBJECTIVE: In critical care patients at risk of developing the acute respiratory distress syndrome (ARDS), low soluble L-selectin (sCD62L) plasma concentrations have been shown to be associated with progression to ARDS and prolonged subsequent mechanical ventilation. This study aimed to determine the usefulness of sCD62L plasma concentrations to identify infants undergoing cardiovascular surgery who are at risk for postoperative pulmonary dysfunction and capillary leaks. DESIGN: Serial measurements of sCD62L plasma concentrations in a cohort of infants with congenital heart disease before, during, and after surgery for 4 consecutive days. SETTING AND PATIENTS: Infants aged 3-337 days undergoing cardiovascular surgery with (N = 27) or without (N = 12) cardiopulmonary bypass in a tertiary care center. RESULTS: sCD62L concentrations before surgery showed a strong correlation with the infant's age (r = 0.77, p < 0.001). During surgery, sCD62L levels dropped from 9.0 +/- 0.7 to 5.6 +/- 0.4 nmol/l (mean +/- SEM; p < 0.001). The minimum sCD62L concentration during and after surgery did not differ between infants operated upon with or without cardiopulmonary bypass (p > 0.1) or in infants who did (N = 10) or did not (N = 29) develop capillary leak syndrome. Whereas capillary leak syndrome was associated with prolonged mechanical ventilation (p < 0.01), there was no relationship between sCD62L concentrations at baseline or at any time thereafter and number of hours on the ventilator(p > 0.1). CONCLUSION: sCD62L concentrations before or after surgery are not apt to identify infants at increased risk of prolonged mechanical ventilation.

Age Factors↗

PubMed1998

[Initial clinical results with the Amplatzer septal occluder--a self-centering double disc for occlusion of atrial septal defects].

UNLABELLED: In recent years many different systems for transcatheter closure of an atrial septal defect (ASD) have been developed and tested. However, all systems presently available have some special disadvantages. The recently introduced Amplatzer Septal Occluder (ASO), though, appears promising. It is a self-expanding and self-centering double disc made from a Nitinol mesh, which is tightly woven to give mechanical strength. Both discs are separated by a connecting cylindrical portion. Its diameter may be chosen, so that it corresponds to that of the ASD. Discs of polyester patches are sewn into the retention discs as well as into the cylindrical portion of the device in order to augment thrombogenicity. After measuring the diameter of the ASD with a balloon, an appropriate ASO is selected and advanced into the left atrium through a 7 or 8 French sheath. Then the distal disc and part of the connecting cylindrical portion is developed in the left atrium and pulled against the atrial septum, so that the cylindrical portion is occluding the ASD. Thereafter, proximal disc is deployed and the delivery cable disconnected. As long as the cable is connected to the device repositioning is easily achieved by pulling the device back into the sheath. Within a time period of 4 months in 29 out of 31 patients (median age: 12.1 years, median weight: 45.0 kg) complete closure of the ASD with a mean diameter of 11.0 mm (6-20 mm) was achieved without complications, the average fluoroscopy time being 8.3 min (2.9-21.5 min). Mean Qp:Qs was 1.5 (0.9-2.2). During a mean follow-up period of 2.1 months post implantation fixed seating of the ASO without residual shunt, arrhythmias, thrombembolic events and impairment of A-V valves was observed in all patients. CONCLUSION: The Amplatzer septal occluder allows quick, safe, and complete closure of atrial septal defects without complications if one adheres to strict implantation criteria. For a final judgement, however, long-term follow-up studies are necessary.

Adolescent↗

PubMed1998

Complement and contact activation during cardiovascular operations in infants.

BACKGROUND: By comparing the results of cardiac operations with or without cardiopulmonary bypass (CPB) in infants in a prospective study, we sought to determine which part of the postoperative systemic inflammatory response was caused by CPB. METHODS: Thirty-five patients were divided into two groups: 11 infants operated on without CPB and 24 infants operated on with CPB. Blood samples were drawn before, during, and after the operation. We assessed complement function and the concentrations or activities of C1q, C3, C4, C1 inhibitor, factor B, the activated split product C3a, and prekallikrein and factor XIIa of the contact system. RESULTS: All of the patients exhibited a decrease of complement proteins. This was greater in infants who underwent CPB. A increase in C3a and factor XIIa and changes in prekallikrein activity occurred only in infants during CPB. CONCLUSIONS: Complement activation occurs in all infants, but is significantly higher in the group with CPB. Contact activation only occurs in patients who undergo CPB. Thus, the inflammatory response is caused by the use of a CPB circuit and to a lesser degree by surgical procedures and anesthesia.

Cardiac Surgical Procedures↗

PubMed1998

Circulatory support with pneumatic paracorporeal ventricular assist device in infants and children.

BACKGROUND: Mechanical circulatory support in intractable heart failure in children has been limited to centrifugal pumps and extracorporeal membrane oxygenation: Since 1990 small adult-size pulsatile air-driven ventricular assist devices "Berlin Heart" (VAD) and, since 1992 miniaturized pediatric VAD (12, 15, 25, 30 mL pumps), have been used in our institution. Since 1994 the blood-contacting surfaces of the device system have been heparin-coated. In this report the experiences with VAD support in 28 children are presented. METHODS: In 28 children-ages between 6 days and 16 years-the Berlin Heart VAD has been applied for periods of between 12 hours and 98 days (mean, 16.9 days) aiming at keeping the patient alive and allowing for recovery from shock sequelae until later transplantation or myocardial recovery. There were three groups. Group I: with primary intention of "bridge-to-transplantation" in various forms of cardiomyopathy (n = 13) or chronic stages of congenital heart disease (n = 5). Group II: "Rescue" in intractable heart failure early after corrective surgery for congenital heart disease (n = 4) or in early graft failure after a heart transplantation (n = 1). Group III: "Acute myocarditis" (n = 5) aiming at either myocardial recovery or transplantation. Twelve were brought to the operating room under cardiac massage and 25 had been on the respirator for more than 24 hours. RESULTS: Twelve patients died on the system from sequelae of profound shock-multiorgan failure, sepsis, loss of peripheral circulatory resistance-or from hemorrhagic complications (n = 4) or brain death (n = 1). Thirteen patients (groups I and III) were transplanted after support periods of between 3 and 98 days with 7 long-term survivors living now up to 7.5 years (mean, 4.4 years). Three patients (groups II and III) were weaned from the system with two long-term survivors (both in group III). There were no patients in group II who survived and the "rescue" indication has been discarded for VAD since 1992. Such patients are since treated by extracorporeal membrane oxygenation (ECMO) in our institution. Out of the 8 patients placed on VAD during 1996 and 1997, 7 were successfully supported until transplantation or weaning. Thirteen patients were extubated and mobilized on the system. Whereas with the earlier systems thrombi in the blood pumps were seen in 15 instances and 2 patients suffered from thromboembolic complications, no thrombotic events occurred with the heparin-coated systems. CONCLUSIONS: After accumulating clinical experience and several technical improvements since 1990 the use of the pediatric Berlin Heart VAD has matured into a reliable and safe system to keep patients with otherwise intractable heart failure alive until complete myocardial recovery is reached or transplantation becomes feasible. Whereas heart failure early after cardiac operation is now primarily treated by ECMO, acute myocarditis appears to be a promising precondition for complete cardiac recovery during VAD support.

Adolescent↗

PubMed1997

Anaphylatoxins in fresh-frozen plasma.

BACKGROUND: Fresh-frozen plasma (FFP) is widely used in patients with coagulation disorders and simultaneous complement activation. Complement activation in FFP itself is poorly investigated. STUDY DESIGN AND METHODS: The concentration of anaphylatoxins C3a and C5a, the complement precursors C1q and factor B, and complement function were measured in 40 consecutively administered FFP units in two pediatric neonatal intensive care units. In 12 samples, the measurements were also performed after incubation with inulin. RESULTS: In 15 of 40 FFP units, both anaphylatoxin concentrations were below the upper cutoff levels reported for healthy humans (C3a, 500 microg/L; C5a, 5 microg/L). Anaphylatoxin levels were higher in FFP units produced by apheresis than in those from blood donation. Complement activation of FFP by inulin increased anaphylatoxin concentration, whereas C1q and factor B levels, and complement function remained unchanged. CONCLUSION: Elevated concentrations of anaphylatoxin are frequently found in FFP units produced by apheresis. Studies are necessary to investigate the reasons for complement activation and the possibilities of prevention during apheresis. As the concentrations of complement precursors and complement function did not change with activation in FFP, these studies should include measurement of the anaphylatoxins C3a and C5a.

Anaphylatoxins↗

PubMedDate not supplied

Plastic bronchitis in children with Fontan palliation: analogue to protein losing enteropathy?

We studied a 6-year-old boy and a 2-year-old girl with bronchitis fibroplastica following Fontan operation. Large endobronchial casts of rubber-like consistency resulted in life-threatening pulmonary failure. In one patient symptoms improved after optimizing heart function with diuretics, and in the other a dramatic improvement with the resolution of the clinical symptoms and normalized serum albumin followed subcutaneous high-molecular-weight heparin treatment. The severe relapse after discontinuation of the heparin medication and the once more successful treatment with heparin suggest that in addition to optimizing heart function, high-molecular-weight heparin might be a therapeutic option for this poorly understood condition.

Bronchitis↗

PubMedDate not supplied

[Doppler echocardiographic investigation of left ventricular diastolic function in preterm infants with and without a patent ductus arteriosus].

We studied the influence of preload augmentation on Doppler-derived left ventricular diastolic function parameters in infants with a birth weight <1500 g. In 44 neonates with a closed duct and 29 neonates with an open ductus arteriosus a complete echocardiographic study including Doppler investigations of the mitral inflow signals and analysis of diastolic time intervals was performed. Neonates with an open duct had a lower median gestational age (27.1 vs. 29, P<0.01), a higher cardiac index (425 vs. 260 ml/min/kg, P<0.001), and a different M-mode left atrial to aortic diameter ratio (1.36 vs. 0.79, P<0.001), but birth weight, age at examination (6.6 vs. 7.9 days), and heart rate were similar compared to the neonates with a closed duct. Main differences in diastolic indexes existed in early and atrial filling integrals and peak velocities, early filling acceleration time, and isovolumic relaxation time. Most informative in neonates with an open ductus peak early filling velocity (41.2 vs. 30.4 cm, P<0.01) and peak atrial filling velocity (49.2 vs. 35.9, P<0.001) are higher, and isovolumic relaxation time is shorter (45 vs. 53 ms, P<0.001) than in closed duct peers. Isovolumic relaxation time is inversely correlated with the cardiac index (R = -0.78). These parameter changes can be interpreted as incipient left ventricular diastolic failure in extremely low birth weight infants in the presence of a preload challenge. The coincidence of higher peak velocities with a shortened isovolumic relaxation time is very likely a result of left atrial pressure elevation. Preload mismatch has to be considered in preterm infants with a persistent ductus arteriosus. The results of this study can be helpful to find the indication for PDA-closure and to adjust volume replacement therapy, and catecholamine medication to a level appropriate for the individual cardiac performance.

Blood Flow Velocity↗

PubMedDate not supplied

Aqueductal stenosis and hydrocephalus in an infant due to aspergillus infection.

Aqueductal stenosis is a common cause of hydrocephalus during infancy. We report on an infant born with aplasia cutis congenita at the scalp vertex and hypoplastic left heart syndrome developing systemic aspergillosis after cardiac surgery. The infant died at the age of 76 days despite systemic antimycotic therapy with a combination of flucytosine and amphotericin B. Therapy started at post-operative day 17 and was also applied intrathecally. Post-mortem examination revealed meningitis, multiple brain aspergillomas and microabscesses with focal ependymitis, focal bronchopneumonia, and necrotizing enterocolitis. One of the brain aspergillomas was located close to the aqueduct causing an aqueductal stenosis and an obstructive hydrocephalus. Histologically, aspergillus hyphae could only be detected in the aspergilloma of the aqueduct. To the best of our knowledge, this is the first reported case of an aqueductal stenosis caused by an aspergilloma.

Brain Stem↗