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Biomedical subjects

H H Scheld

Publications and source records attributed to H H Scheld.

At least 73 records · Page 4Linked to original sources
PubMed2001

Lung cancer surgery--preoperative risk assessment and patient selection.

Lung resection remains the therapy of choice offering the greatest potential for cure in non spread lung cancer. As these procedures have a significant rate of cardiopulmonary complications, risk assessment and evaluation of functional operability is essential for successful resectional surgery. The most valuable parameters for evaluation of lung function and risk assessment are FEV1, DLCO and VO2max as well as the calculation of predicted postoperative lung function. With preoperative preparatory physical therapy and treatment of comorbidities, also marginal patients may become operable for resectional surgery.

Humans↗
PubMed2001

The impact of anti-endotoxin core antibodies on endotoxin and cytokine release and ventilation time after cardiac surgery.

OBJECTIVES: We hypothesized that a temporary cardiopulmonary bypass (CPB)-induced reduction of endotoxin antibody levels contributes to elevated endotoxin levels and the associated inflammatory consequences, with a significant influence on the postoperative ventilation time period. BACKGROUND: Cardiac surgery using CPB induces a systemic inflammatory response syndrome with an associated risk of increased postoperative morbidity and mortality. METHODS: A total of 100 consecutive patients undergoing elective coronary artery bypass graft surgery using CPB were prospectively investigated. Endotoxin core antibodies (immunoglobulin [Ig] M/IgG against lipid A and lipopolysaccharide), endotoxin, interleukin (IL)-1-beta, IL-6, IL-8 and tumor necrosis factor-alpha were measured serially from 24 h preoperatively until 72 h postoperatively. RESULTS: Eighty-five patients had no complications (group 1), whereas 15 patients required prolonged ventilation (group 2). In both groups, there was a decrease of all antibodies 5 min after CPB onset, compared with baseline values (p < 0.001), an increase of endotoxin and IL-8 peaking at 30 min postoperatively (p < 0.001) and an increase of IL-6 peaking 3 h postoperatively (p < 0.001). In group 2, preoperative antibody levels were lower (p < 0.01)--specifically, the decrease in IgM was significantly stronger and of longer duration (p < 0.002)--and levels of endotoxin (p < 0.001) and IL-8 (p < 0.001) were higher at 30 min postoperatively. CONCLUSIONS: We conclude that an CPB-associated temporary reduction of anti-endotoxin core antibody levels contributes to elevated endotoxin and IL-8 release. Furthermore, lower levels of IgM anti-endotoxin core antibodies were associated with a greater rise in endotoxin and IL-8, as well as prolonged respirator dependence.

Adult↗
PubMed2001

Leiomyosarcoma of the pulmonary artery--a diagnostic chameleon.

A 60-year-old woman suffered from right-sided pain in the back and dyspnea suspicious for chronic pulmonary thromboembolism. Since computed tomography demonstrated a progressive filling defect within the left pulmonary artery, a transvenous biopsy was taken, which demonstrated malignant sarcoma. The patient underwent left-sided pneumonectomy with the aid of cardiopulmonary bypass. In case of a suspected 'chronic' pulmonary embolism with occlusion of a main pulmonary artery, as may be seen with imaging techniques, a sarcomatous disease should be ruled out, especially if there are no coagulation disorders, and the tumor obliterations progress in serial CT scans despite effective anticoagulation.

Diagnosis, Differential↗
PubMed2001

Activation of the cardiac interleukin-6 system in advanced heart failure.

OBJECTIVES: The study objective was to assess the cardiac expression of interleukin-6 (IL6) and its receptor (IL6R) in advanced heart failure. BACKGROUND: While IL6 plasma levels are elevated and associated with an impaired prognosis in advanced heart failure, little is known about the intracardiac expression of the IL6 system. METHODS: Heart tissue was obtained from 20 patients (n=10, idiopathic dilated cardiomyopathy, age 44+/-15 years; n=10, ischemic cardiomyopathy, age 55+/-8 years) at the time of transplantation. Left and right ventricular tissue was subjected to in situ hybridization, Northern blot analysis, and RT-PCR. Signals were quantified by densitometric scanning and corrected for G3PDH-mRNA levels. Right ventricular biopsy specimens (n=11) of patients with arrhythmias and normal cardiac function served as controls. In addition, data were correlated with cardiac catheterization and echocardiography data obtained at transplant evaluation. RESULTS: Ventricular IL6 and IL6R transcripts were detected in all explant specimens examined. Expression of both mRNA species was higher than in controls (P=0.001). Left ventricular IL6 mRNA levels correlated positively with heart rate (r=0.77; P=0.009), pulmonary capillary wedge pressure (r=0.53; P=0.03), right atrial pressure (r=0.77; P=0.003), and inversely with left ventricular ejection fraction (r=-0.61; P=0.03). Right ventricular IL6 mRNA levels correlated inversely with cardiac index (r=-0.48; P=0.05). IL6R expression did not correlate with hemodynamic data. CONCLUSIONS: In advanced heart failure, cardiac IL6/IL6R mRNA expression is increased and may play a role in the pathophysiology of advanced heart failure.

Adult↗
PubMed2001

Implantation of a dual chamber pacing and sensing single pass defibrillation lead.

Dual-chamber ICDs are increasingly used to avoid inappropriate shocks due to supraventricular tachycardias. Additionally, many ICD patients will probably benefit from dual chamber pacing. The purpose of this pilot study was to evaluate the intraoperative performance and short-term follow-up of an innovative single pass right ventricular defibrillation lead capable of bipolar sensing and pacing in the right atrium and ventricle. Implantation of this single pass right ventricular defibrillation lead was successful in all 13 patients (age 63 +/- 8 years; LVEF 0.44 +/- 0.16; New York Heart Association [NYHA] 2.4 +/- 0.4, previous open heart surgery in all patients). The operation time was 79 +/- 29 minutes, the fluoroscopy time 4.7 +/- 3.1 minutes. No perioperative complications occurred. The intraoperative atrial sensing was 1.7 +/- 0.5 mV, the atrial pacing threshold product was 0.20 +/- 0.14 V/ms (range 0.03-0.50 V/ms). The defibrillation threshold was 8.8 +/- 2.7 J. At prehospital discharge and at 1-month and 3-month follow-up, atrial sensing was 1.9 +/- 0.9, 2.1 +/- 0.5, and 2.7 +/- 0.6 mV, respectively, (P = NS, P < 0.05, P < 0.05 to implant, respectively), the mean atrial threshold product 0.79, 1.65, and 1.29 V/ms, respectively. In two patients, an intermittent exit block occurred in different body postures. All spontaneous and induced ventricular arrhythmias were detected and terminated appropriately. Thus, in a highly selected patient group, atrial and ventricular sensing and pacing with a single lead is possible under consideration of an atrial pacing dysfunction in 17% of patients.

Aged↗
PubMed2001

Primary tissue failure of bioprostheses: new evidence from in vitro tests.

BACKGROUND: Primary tissue failure, which is mainly caused by calcification, is still the limiting factor in the long-term outcome of heart valve bioprostheses. Even though the precise nature of this process is not fully understood, in vitro tests have been developed to reproduce and predict calcification for individual bioprostheses. METHODS: In vitro calcification testing was performed by using an accelerated pulsatile valve tester which was adapted for testing stented as well as stentless bioprostheses with physiological fluid dynamics. A total of 84 bioprostheses (porcine, pericardial and stentless porcine of different manufacturers) were cyclically loaded at a test rate of 300/min at 37 degrees C within a rapid calcification fluid with CaxP = 130(mg/dl)2 at pH 7.4. Calcification was assessed by microradiography after 12 x 10(6) cycles. In a previous step, holographic interferometry was performed to identify irregularities of valve leaflets in order to predict later calcification. Selected specimens of calcified bioprostheses underwent histology, transmission (TEM) and scanning (SEM) electron microscopy. Tissue mineralization was investigated by coupling SEM, electron microprobe analysis (EMPA) and X-ray powder diffraction (XRPD) methods. RESULTS: For all tested bioprostheses, a significant calcification was achieved within 4 to 6 weeks of ongoing testing, and the degree of calcification increased with time. A significant correlation between calcification and leaflet irregularities (detected by holographic interferometry) was found (r = 0.80, p = 0.001). Calcification varied between individual bioprostheses, and significant differences were detected for different groups (calculated as percentage of total leaflet area, mean +/- SD): porcine stented (37.3 +/- 12.0%), bovine stented (23.0 +/- 8.9%), porcine stentless (16.2 +/- 7.6%). Histological and ultrastructural investigation showed intrinsic calcification involving both the spongiosa and fibrosa with collagen fibrils, interfibrillar spaces and cells as early sites of calcification. There was clear evidence of apatite crystallization, and observations made with in vitro calcification were quite similar to those occurring with in vivo implanted bioprostheses. CONCLUSION: In vitro tests can reproduce intrinsic calcification of bioprostheses even in the absence of viable biologic host factors. Moreover, degree and sites of calcification have become predictable. This enables the development and evaluation of bioprostheses with reduction of animal experiments. From our results obtained with a broad range of available bioprostheses, stented bovine and stentless porcine valves seem to be superior to conventional stented porcine bioprostheses with regard to leaflet calcification.

Animals↗
PubMed2001

A forgotten gauze swab--clinical and legal considerations.

In this report, we will present two cases of retained gauze swabs following open heart surgery. We will discuss diagnostic and treatment strategies as well as medicolegal implications with regard to individual liability and possible penalties according to the German law.

Aged↗
PubMed2001

In vitro modelling of tissue using isolated vascular cells on a synthetic collagen matrix as a substitute for heart valves.

BACKGROUND: Tissue engineering is a promising approach for obtaining lifetime durability in biological heart valves. Basic questions with respect to the selection of suitable cell populations as well as scaffolds remain unsolved. The purpose of this study was to develop a tissue-like substitute in vitro for replacement of diseased valves in vivo. METHODS: Smooth-muscle cells (SMCs) were isolated from human and porcine aortic tissue using the 'explant technique' and endothelial cells from collagenase digestion. Seeding and cultivation of isolated cells was performed on a type-I collagen matrix. The scaffold-cell specimen was investigated using light and electron microscopy. Cupromeronic blue and immunoprecipitation were used for ultracytochemical staining. RESULTS: SMCs were allowed to grow to multilayers and migrate into the collagen network. We found a tissue-like morphology in these samples characterised by several layers of cells, spaces between the cell layers filled with newly formed extracellular matrix components, compartmentalisation of proteoglycans and their association with fibrilar matrix and the cell surface. Endothelium cells covered the SMCs of the scaffold with a histological topography similar to heart valves. CONCLUSIONS: This is an approach for in vitro modelling of tissue-like substitutes and preparing plane multicellular tissues as substitutes for heart valves. This model may also be used for cell biological investigations of cell-matrix interactions.

Animals↗
PubMed2001

Primary pigmented malignant schwannoma in the posterior mediastinum.

This paper describes a rare case of primary pigmented malignant schwannoma arising from the sympathetic trunk in the posterior mediastinum. A 30-year-old woman underwent a thoracoscopic tumor extirpation. A primary pigmented malignant schwannoma was diagnosed histologically. The tumor presented fascicles and whorls of pigmented plump spindle cells and positive immunoreactivity to S-100 protein, vimentin, and HMB-45. Postoperative radiotherapy of the mediastinum was performed. Our case demonstrates the successful thoracoscopic resection and postoperative radiation treatment of a malignant schwannoma.

Adult↗
PubMed2001

Does a suitable animal model for research on partial left ventriculectomy exist? Animal models for PLV.

Partial left ventriculectomy is a new surgical option quickly introduced into clinical use worldwide for treating end-stage heart failure in patients with dilated cardiomyopathy. Due to the overwhelming success of this new kind of surgical treatment for dilated cardiomyopathy, experimental research on the physiological and pathophysiological basis was initially not performed. Now, demands for an appropriate animal model have arisen more and more since the outcome of patients treated by partial left ventriculectomy has differed considerably. This review summarizes available experimental models for heart failure in large animals, and discusses their suitability for research on partial left ventriculectomy.

Animals↗
PubMed2001

Treatment strategy and perioperative risk in patients with idiopathic thrombocytopenic purpura undergoing cardiac surgery.

Patients suffering from idiopathic thrombocytopenic purpura undergoing cardiac surgery with extracorporeal circulation may be at increased risk for postoperative bleeding complications. Therefore, different treatment strategies, such as conservative treatment, splenectomy, transfusion of platelet concentrates and therapy with immunoglobulins have been proposed. We report on our experiences with preoperative immunoglobulin treatment in selected patients with special regard on the optimal dosage.

Aged↗
PubMed2001

Medical liability disputes involving thoracic and cardiovascular surgeons.

BACKGROUND: Medical malpractice claims against surgeons are increasing. In Germany, as in most other European countries, there is no central registry of medical malpractice claims. It is not known at which rate medical liability claims are decided in favor of the physician or the patient. METHODS: All cases of reproaches of medical malpractice in which our clinic was involved within the 10-year period between 1989 to 1999 were reviewed. To compare our results with the general experience in the field of thoracic and cardiovascular surgery, we reviewed the data of the regional medical society in the same time period. RESULTS: From 1989 to 1999, our Clinic was involved in 74 medical liability disputes. There were 28 reproaches of medical malpractice against our department (0.1% of cases performed). Malpractice was detected in only 7 of 74 claims (9.5%). Most reproaches were made for incorrectly performed operations (80%), but only 4 (6.8%) of 59 claims were regarded as medical malpractice. CONCLUSIONS: Reliable data on reproaches of medical malpractice are virtually absent. Only 10% of all reproaches in our study were finally regarded as medical malpractice. A central registry of medical malpractice cases would allow analysis of the areas in which we have to improve performance, and how unjustified reproaches of medical malpractice can be avoided.

Cardiac Surgical Procedures↗
PubMed2001

Noncardiac surgery in patients with left ventricular assist devices.

BACKGROUND: Noncardiac surgery, especially abdominal surgical procedures in patients with long-term mechanical circulatory support and strong anticoagulation, is difficult. METHODS: We report on 14 patients (aged 44 +/- 15 years) with a portable Novacor or HeartMate system, who underwent noncardiac surgical procedures while being supported by the device. RESULTS: The patients underwent 20 procedures for noncardiac reasons; most had an intestinal operation or cholecystectomy. Half of the procedures were performed within 30 days after placement of the device (mean interval, 53 +/- 57 days), only 6 interventions were necessary after 100 days of mechanical support. Complications occurred in 8 patients (57%), 5 of whom had undergone cholecystectomy and had unacceptably high sanguineous drainage losses. CONCLUSIONS: An elective surgical procedure can be performed with an acceptable risk if the operation is carefully managed. Postponing resumption of full anticoagulation is advisable as it may reduce bleeding complications without apparently increasing the risk for thromboembolism. Emergency interventions remain a difficult task.

Adult↗
PubMed2001

Heart transplantation indicated only in the most severely ill patient: perspectives from the German heart transplant experience.

The COCPIT study, performed in a complete national cohort of adult patients consecutively listed for cardiac transplantation in Germany in 1997, found a beneficial effect only in the group that was at high risk of dying from heart failure without transplantation. If these results can be reproduced in other countries, the discussion on the respective roles of pharmacological and organ-saving surgical therapies for advanced heart failure, medical urgency and waiting time as heart transplantation allocation criteria, and the feasibility of a randomized clinical trial testing the survival benefit of transplantation must be reopened.

Adult↗
PubMed2001

Prediction of clinical outcome after cardiac surgery: the role of cytokines, endotoxin, and anti-endotoxin core antibodies.

Coronary artery bypass grafting (CABG) using cardiopulmonary bypass (CPB) can lead to a systemic inflammatory response syndrome with organ failure and increased morbidity and mortality. The mechanisms of these findings are still under discussion. We investigated whether anti-endotoxin core antibodies, endotoxin, and proinflammatory cytokines influence the clinical course after cardiac surgery. Seventy-eight patients undergoing CABG using CPB were investigated. Anti-endotoxin core antibodies, endotoxin, interleukin (IL)-6, IL-8, IL-1beta, and TNF-alpha were measured 24 h preoperatively and up to 72 h postoperatively. Patients with a postoperative mechanical ventilation time below 24 h (n = 65; Group A) were compared to patients with prolonged respirator therapy (>24 h; n = 13; Group B). Preoperative antibody levels were significantly lower in Group B (P < 0.001). In this group, antibody levels remained decreased during the observation period (P < 0.001). Endotoxin significantly increased 30' postoperatively in both groups (P < 0.002). The increase in Group B was 3-fold higher (P< 0.001). IL-8 increased postoperatively in both groups, peaking 3 h after surgery (P < 0.001). In Group B, the IL-8 release was significantly higher than in Group A (P < 0.001). IL-6 significantly increased in both groups, reaching its maximum 24 h postoperatively (P < 0.001). No differences between groups were observed. No significant changes of IL-1beta and TNF-alpha were observed. We conclude that anti-endotoxin core antibodies may be predictive of adverse outcome after cardiac surgery. The imbalance between antibodies and endotoxin results in an exaggerated increase in endotoxin and IL-8 with an impact on clinical outcome.

Aged↗
PubMed2001

Selection of long-term ventricular assist devices in heart failure patients.

Selection of long-term ventricular assist devices in heart failure patients depends on indication, intention of mechanical support, and availability of devices. Even if many more issues of mechanical support like infection, thromboembolism, and device failure are still unresolved, acceptable results can already be achieved with the current systems.

Equipment Failure↗
PubMed2001

Successful cardiac transplantation after Novacor implantation in a HIT II-patient using heparin.

The anticoagulative management of patients tested positive for heparin-induced thrombocytopenia type II (HIT II) and requiring cardiac surgery has been difficult until now. A special challenge arises, when left ventricular assist devices have to be implanted for bridging to cardiac transplantation. We report on the anticoagulative management of such a patient, based on the consideration of HIT II-pathophysiology and using heparin for Novacor LVAD implantation and cardiac transplantation.

Adult↗