M Schneider

Goethe-Universität Frankfurt am Main, Frankfurt, Hesse, Germany

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Publications (61)123.84 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Testicular sections of 50 deceased drug addicts were examined by light microscopy using morphometric methods and determining the extent of spermatogenesis by application of the Johnsen score count. Twenty cases of violent death served as reference sample. The study was aimed at obtaining data about the degree of germinal gland damage following the duration of the individual drug career, which was correlated to the histologic findings. Progressively reduced maturation of germinal cells, decrease of tubular diameter and height of sperm-producing epithelium were found the longer the individual case history has been. The results clearly indicated a substantial impairment of male fertility in the course of a drug career, but etiology seems to be multifactorial, since most of the deceased were polytoxicomanic and more than 40% were under the influence of alcohol at the time of death. Testicular damage is obviously a sequel of long-lasting abuse and a very complex process, presumably progressing with the duration of the adverse habit.
    Forensic Science International 02/2001; 115(3):171-81. · 2.12 Impact Factor
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    ABSTRACT: The epidemiology, management, and long-term survival of invasive aspergillosis was assessed in a prospective, 5-year observational study in 346 unselected paediatric cancer patients receiving dose-intensive chemotherapy for newly diagnosed or recurrent malignancies. Invasive aspergillosis occurred exclusively in the context of haematological malignancies, where it accounted for an incidence of 6.8% (n = 13 of 189). The lung was the primary site in 12 cases, and dissemination was present in three of those. Prior to diagnosis, the overwhelming majority of patients had been profoundly neutropenic for at least 14 days (n = 11 of 13) and were receiving systemic antifungal agents (n = 10 of 13). Clinical signs and symptoms were nonspecific but always included fever. All 11 patients who were diagnosed and treated during lifetime for a minimum of 10 days responded to either medical or combined medical and surgical treatment, and seven were cured (64%). Nevertheless, the overall long-term survival was merely 31% after a median follow-up of 5.68 years after diagnosis. Apart from refractory or recurrent cancer, the main obstacles to successful outcome were failure to diagnose IA during lifetime and bleeding complications in patients with established diagnosis. The frequency of invasive aspergillosis of greater than 15% in paediatric patients with acute myeloblastic leukaemia and recurrent leukaemias warrants the systematic investigation of preventive strategies in these highly vulnerable subgroups.
    Mycoses 02/1999; 42(7-8):431-42. · 1.81 Impact Factor
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    ABSTRACT: A clinical trial was conducted to assess the feasibility, safety, and efficacy of the atrial septal defect (ASD) occlusion system for transcatheter closure of secundum ASD and patent foramen ovale (PFO) after episodes of cerebral embolism. Occlusion was attempted in 200 patients aged 1 to 74 years (mean 32). The procedure failed in 26 patients (13%); the device was retrieved through a catheter in 20 and through surgery in 6 patients. Procedure-related complications necessitating surgical removal of the device included device embolization in 2, device entrapment within the Chiari network in 1, frame fracture in 1, and perforation of atrial wall in 2. All 6 patients experienced an uneventful postoperative course. An additional 11 patients (6%) underwent surgical removal of the device during follow-up. There were 163 patients (81%) with an implanted ASD occlusion system at follow-up of from 6 to 36 months (mean 17). Thrombus formation around the device was detected by transesophageal echocardiography in 9 patients 1 to 4 weeks after implantation. One of these patients (who had a coagulation factor XII deficiency) suffered a cerebral thromboembolism. Late atrial wall perforation (5, 6, and 8 months after implantation) occurred in 3 adult patients. Infectious endocarditis developed in 2 adult patients (1%). No late device embolization and no atrioventricular valve injury occurred. An asymptomatic device frame fracture was found in 14% and frame deformity in 4% of all patients during the follow-up period of >230 patient-years. Immediately after closure, a moderate/large residual shunt remained in 8% and a small shunt in 29% of patients. After 1 year, a moderate/large shunt was present in 2% and a small one in 26% of patients. During a total follow-up of 49 patient-years, only 1 of 46 patients with PFO had a transient neurologic event after the closure. The study indicates that patients with centrally situated secundum ASD and those with PFO after cerebral embolism can be treated with this system with a high success rate and an acceptable morbidity.
    The American Journal of Cardiology 01/1999; 82(11):1405-13. · 3.43 Impact Factor
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    ABSTRACT: To establish the implantation technique for the atrial septal defect occluder system (ASDOS) device in an experimental animal model and to determine long term mechanical stability of the device and its in vivo properties in terms of biocompatibility and tissue reaction. An atrial septal defect was created and the device implanted in 17 pigs (mean weight 30 kg). The implantation technique was refined and modified because of initial technical and anatomical complications during nine acute pilot studies. The technique proved to be feasible in eight subsequent survival studies. Four pigs were electively killed three months after implantation (group 1). The remaining four pigs were killed six months after implantation (group 2). Necropsy showed all devices were embedded in soft tissue three months after implantation. Microscopic examination of atrial septal tissue showed an acute granulomatous inflammatory reaction in group 1 and fibrosis in group 2. The intensity of the inflammatory reaction around the device was clearly milder in group 2, indicating a decline in the inflammatory response with time. Clinical and biochemical investigations indicated acceptable biocompatibility of the device. The implantation technique for the ASDOS device in a chronic pig model has been established. Biocompatibility of the device was acceptable.
    Heart (British Cardiac Society) 01/1999; 80(6):606-11. · 6.02 Impact Factor
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    ABSTRACT: Little is known about the medium term results after stenting of the arterial duct in neonates and infants with duct-dependent cyanotic congenital heart disease. We report the results of stent implantation of the arterial duct in 21 neonates and infants. The defects for which the arterial duct was stented included pulmonary atresia with intact ventricular septum, critical pulmonary stenosis, and more complex defects with associated reduced pulmonary blood flow. Palmaz stents were used and successfully implanted in all the 21 patients. There were no major complications during the stent implantation procedure although two hospital deaths occurred 2 and 14 days after stent implantation. Cardiac catheterization was repeated electively 3 to 6 months after stent implantation. Stent stenosis due to intimal proliferation was noted in 11/13 patients who underwent recatheterization. Stenosis of the inner stent lumen ranged from 25% to 100%, mean 74%. Re-dilatation of the stent was required in five patients who were awaiting corrective surgery. In babies with pulmonary atresia or critical pulmonary stenosis, who also underwent additional balloon dilatation of the pulmonary valve, spontaneous closure of the stented arterial duct was well tolerated and when it occurred, the right ventricular size had increased and the circulation was no longer duct-dependent. In patients who required subsequent surgical corrective treatment, stenting of the duct allowed the definite corrective operation to be performed as the first surgical procedure. During the follow-up period, ranging between 2 months and 2 years, mean 8.7 months increased growth of the pulmonary arteries was seen in all the patients. No distortion of the branch pulmonary arteries was seen. In patients with cyanotic congenital heart disease stenting of the arterial duct is an effective alternative to surgical aorto-pulmonary shunts.
    European Heart Journal 10/1998; 19(9):1401-9. · 14.72 Impact Factor
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    ABSTRACT: Establishment of Fontan circulation in complex univentricular hearts often requires several surgical procedures. We developed a procedure which maintains the advantages of a staged approach, however, during the initial surgery additional preparatory measures are performed to allow subsequent non-surgical Fontan completion. The operation is a lateral baffle Fontan procedure. The baffle bears multiple perforations to allow the inferior vena cava blood to drain into the systemic atrium. Total cavopulmonary connection is performed as usual and the cardiac end of the superior vena cava is subtotally banded. Formally the operation establishes a bi-directional Glenn physiology. During subsequent catheter intervention the banding of the superior vena cava is dilated and the holes in the baffle are closed with appropriate devices. From April 1994 to December 1995, 18 children having at least two risk factors for Fontan operation received the above described operation. Ages ranged from 3 months to 15 years. Ten patients had one or more previous operations. Bypass time ranged from 86 to 128 min and cross clamp time from 14 to 79 min. O2 saturation after discontinuation of cardiopulmonary bypass was 76% (70-81%). The postoperative recovery of all patients was rapid with early extubation (mean 6 h) and discharge to the ward the morning of the first postoperative day. One patient died. No fluid retention as pericardial, pleural or abdominal fluid effusions occurred. At discharge O2 saturation was 77% (75-82%). In thirteen children successful conversion to total cavopulmonary connection with interventional debanding of the superior vena cava and closure of the fenestrations was performed. After a hospital stay of only a couple of days the children were discharged with normal O2 saturation after Fontan completion. We suggest that this modification of the staged Fontan procedure reduces the need for surgical interventions by applying balloon angioplasty and occluder technology to this unique subset of patients.
    European Journal of Cardio-Thoracic Surgery 06/1998; 13(5):509-12; discussion 512-3. · 2.81 Impact Factor
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    A H Groll, H G Keul, R Brodt, M Schneider
    Clinical Infectious Diseases 05/1998; 26(4):1005-6. · 9.42 Impact Factor
  • M Claus, J Ritter, M Schneider, W Konertz
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    ABSTRACT: We report a case of a successful orthotopic heart transplantation in a seven year old boy with heterotaxia syndrome, d-transposition of the great arteries, rudimentary right ventricle, double inlet left ventricle, valvular pulmonary stenosis, left-sided peripheral pulmonary artery stenosis, deficient atrial septation, and left-sided superior and inferior vena cava. In this case of congenital heart defects, three specific surgical procedures were necessary to make heart transplantation feasible. A synthetic patch was interposed in the single atrium to create two separate atria. To handle the mismatch of the donor's and recipient's aortic diameters, the donor's aortic diameter was enlarged by including the aortic arch into the anastomosis. The left-sided superior vena cava was led to the right appendage by interposing a piece of autogenous aorta.
    The Journal of Heart and Lung Transplantation 01/1998; 16(12):1275-8. · 5.61 Impact Factor
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    ABSTRACT: Two relatively young women died suddenly due to myocardial sarcoidosis. Necropsy in both cases revealed compact infiltration of the ventricular septum by fibrous tissue. Histologic sections elucidated extensive granulomatous degeneration and giant cells of the Langhans' and foreign body type without central necrosis of the granulomas. Both women had been entirely free of symptoms, but in the second case of a 35-year-old, who had been 6 months pregnant, an ultrasound sonography of the heart had documented a suspicious area in the ventricular septum interpreted as a scar. Further investigations had been postponed until delivery. Isolated myocardial sarcoidosis should be taken into account as one possible cause of sudden death, especially in young people.
    Forensic Science International 11/1997; 89(3):145-53. · 2.12 Impact Factor
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    ABSTRACT: The need of pediatric cardiac assist is growing because of the complexity of the congenital conditions operated on and the increasing number of pediatric transplantations. We evaluated the newly developed pediatric MEDOS HIA-VAD ventricular assist device. The pneumatic paracorporeal ventricular assist device has three left ventricular sizes (10-, 25-, and 60-mL maximum stroke volume) and three right ventricular sizes (9, 22.5, and 54 mL) and can be operated effectively with up to 180 cycles/min. We used this device in 6 consecutive pediatric patients. Intention of treatment was to bridge to transplantation in 3 patients and to aid in recovery from a cardiac operation in 3. Age ranged from 5 days to 8 years. Two children died during assist, 2 were weaned from the system and discharged home, and 2 had successful transplantation. During assist, laboratory variables indicative of impaired renal, hepatic, or pulmonary function normalized or showed a trend toward normalization. Both deaths were related to infection. With the new MEDOS HIA-VAD ventricular assist device system, pediatric mechanical cardiac assist can be performed successfully. It requires timely implantation, careful monitoring, and adequate size-matched devices.
    The Annals of Thoracic Surgery 05/1997; 63(4):1138-44. · 3.63 Impact Factor
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    G Hausdorf, M Schneider, W Konertz
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    ABSTRACT: A new, staged procedure for univentricular repair of "high risk" patients using a combined surgical transcatheter technique is reported. As first step a surgical hemifontan procedure was performed and a multifenestrated patch inserted into the right atrium. For later transcatheter completion of univentricular repair, a subtotal banding just above the cavoatrial junction was performed. Two months later transcatheter completion was performed by balloon dilatation of the banded cavo-atrial junction and additionally either by inserting a covered stent as intracardiac conduit between the superior and inferior vena cava or by inserting a (non-covered) stent into the cavo-atrial junction and occluding the fenestrations in the right atrial patch using Rashkind-PDA occluders. This new technique was successfully applied without mortality in eight patients with a preoperative mean pulmonary pressure of 18 to 23 mm Hg. No complications typical for Fontan-like corrections occurred within the follow up period of 4 to 14 months.
    Heart (British Cardiac Society) 05/1996; 75(4):403-9. · 6.02 Impact Factor
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    ABSTRACT: A three-week-old neonate underwent aortic valve replacement with a pulmonary autograft (Ross procedure). The right ventricular outflow tract was reconstructed with a downsized pulmonary allograft. The surgical technique is presented. Six months after operation the girl is doing well and both the autograft and allograft function are excellent.
    The Journal of heart valve disease 04/1996; 5(2):176-7; discussion 174-5. · 0.73 Impact Factor
  • Journal of the American College of Cardiology 02/1996; 27(2):119-119. · 15.34 Impact Factor
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    ABSTRACT: To report initial experiences with transcatheter occlusion of atrial septal defects using a new occlusion device. 10 children aged 1.1 to 14.9 years. Patients with a body weight above 10 kg, normal pulmonary resistance and an indication for surgical closure of a secundum atrial septal defect, a residual tissue rim of interatrial septum surrounding the defect of more than 5 mm, and a maximum defect diameter of 20 mm. The defects were closed by a transcatheter device (ASDOS) consisting of two umbrellas which are introduced over a guidewire loop. Both umbrellas consist of a central body and five arms formed from preshaped nitinol wire covered with a thin polyurethane patch. The central body of the distal umbrella contains a thread, the proximal umbrella contains a bolt. The two umbrellas are connected by screwing the bolt on the thread using a screwdriver catheter. The implantation was performed under echocardiographic guidance; in six of 10 patients, transoesophageal echocardiography was necessary. The "stretched" diameter of the defect evaluated during balloon sizing ranged from 10 to 20 mm, and the pulmonary to systemic blood flow ratio from 1.5:1 to 2.8:1. Transcatheter closure was successfully performed in 9/10 patients using devices with a diameter of 25 mm to 40 mm. No severe complications occurred. However, in one patient with a pre-existing prolonged PR interval brief periods of second and third degree atrioventricular block occurred after the implantation but normalised within 3 d. During a follow up period of 21 to 29 weeks no device embolisation, thromboembolic complications, fractures of the implanted device, atrial perforations, pericardial effusions, obstructions of systemic or pulmonary veins, atrioventricular valve dysfunction, or other complications occurred. The new device is a promising transcatheter approach for the occlusion of secundum atrial septal defects in children. However, further evaluation and long term data are needed before this transcatheter technique can be recommended.
    Heart (British Cardiac Society) 02/1996; 75(1):83-8. · 6.02 Impact Factor
  • Journal of Thoracic and Cardiovascular Surgery 10/1995; 110(3):865-7. · 3.99 Impact Factor
  • G Hausdorf, C Kampmann, M Schneider
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    ABSTRACT: Coronary balloon angioplasty seems to be an adequate therapy for proximal coronary stenoses developing after the arterial switch operation, with adequate medium-term results. Overexpansion of the lesion seems to be necessary.
    The American Journal of Cardiology 10/1995; 76(8):621-3. · 3.43 Impact Factor
  • Journal of Infection 05/1994; 28:57-57. · 4.02 Impact Factor
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    ABSTRACT: In an interdisciplinary study, 53 cases of drug-related death were investigated. Forty per cent of these cases exhibited acute or chronic hepatitis; foreign body granulomas were detected in 30%. By CT-scan of the left lung, small abscesses and pneumonic focuses could be localized. The spectrum of bacterial strains isolated from lung tissue did not differ significantly from that of a control group. Severe alterations of the testes, i.e. reduction of spermatogenesis, was present in a considerable number of cases. The high rate of myocarditis diagnosed (18%) supports the idea that besides acute intoxication, drug-related death is due to multifactorial origin.
    Forensic Science International 12/1993; 62(1-2):147-9. · 2.12 Impact Factor
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    ABSTRACT: Paradoxical emboli are assumed to be one cause for cerebral strokes of unknown etiology. These emboli usually cross from the right to the left heart via a patent foramen ovale. We describe the transvenous catheter occlusion as an alternative to surgical closure. There were no complications. The echocardiographic follow-up of 12 and 14 months demonstrated complete closure of the foramen ovale without recurrence of neurologic symptoms.
    Zeitschrift für Kardiologie 05/1993; 82(4):249-52. · 0.97 Impact Factor
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    ABSTRACT: In 18 patients with pulmonary atresia interventional perforation of the atresia was attempted using radiofrequency. All patients were referred for palliative surgery. The age ranged from 4 days to 19 years. After angiographic delineation of the relations between the right ventricular outflow tract and main pulmonary artery the tip of a radiofrequency perforation catheter (Cerablate-catheter, 2F, Osypka) was brought into contact with the atresia. The radiofrequency was applied in the unipolar fashion (radiofrequency-generator HAT 200, Osypka). Radiofrequency perforation was successfully performed in 14/18 patients, subsequent balloon dilatation was performed in 12 of these patients. In six patients with muscular atresia a Palmaz-stent was implanted into the right ventricular outflow tract. An inadvertent perforation of the right ventricular outflow tract occurred in three patients, of the pulmonary artery in two patients. However, these were tolerated without sequelae or clinical symptoms. The arterial oxygen saturation increased by 21%; in none of the patients was cardiac failure or pulmonary edema observed. Using the Cerablate-catheter even muscular atresias could be perforated. Implantation of a stent into the newly created right ventricular outflow tract results in a predictable communication between the right ventricle and the pulmonary artery. Although this interventional right ventricular outflow tract creation seems to be a promising new technique, experience is limited and there are no long-term results.
    Zeitschrift für Kardiologie 03/1993; 82(2):123-30. · 0.97 Impact Factor

Publication Stats

676 Citations
123.84 Total Impact Points


  • 1986–2001
    • Goethe-Universität Frankfurt am Main
      • • Center for Internal Medicine
      • • Abteilung für Neonatologie
      Frankfurt, Hesse, Germany
  • 1999
    • Aarhus University Hospital
      • Department of Cardiothoracic and Vascular Surgery
      Århus, Central Jutland, Denmark
  • 1996–1999
    • Charité Universitätsmedizin Berlin
      • Department of Pediatrics, Division of Cardiology
      Berlín, Berlin, Germany
  • 1995–1998
    • Humboldt-Universität zu Berlin
      • Department of Biology
      Berlín, Berlin, Germany
  • 1992–1993
    • Deutsches Herzzentrum Berlin
      • Department of Congenital Heart Disease / Pediatric Cardiology
      Berlín, Berlin, Germany
  • 1987
    • Universitätsklinikum Erlangen
      Erlangen, Bavaria, Germany