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Biomedical subjects

A Haverich

Publications and source records attributed to A Haverich.

At least 361 records · Page 20Linked to original sources
PubMed1990

Management of mycotic rupture of the ascending aorta after heart-lung transplantation.

A 19-year-old woman underwent heart-lung transplantation for obstructive bronchiolitis. Eleven days later mycotic rupture of the ascending aorta occurred. Emergency cardiopulmonary bypass was instituted via the femoral vessels and the chest was reopened under cardiac massage. Perforation of the aorta at the site of insertion of the cardioplegic cannula in the donor aorta was seen. Under circulatory arrest the infected area was excised, a pericardial patch plasty was performed, and the region was covered with a muscle flap. Postoperatively, Candida albicans was found in the excised specimen of the aorta, in drainage fluid, and in the bronchoalveolar lavage. High doses of antimycotics were administered intravenously and for irrigation of the mediastinum, which resulted in an eradication of fungi in all cultures 7 days later. Six weeks after reoperation the patient was discharged home, and she remains well 9 months postoperatively.

Abdominal Muscles↗
PubMed1990

Pulmonary reperfusion injury: evidence for oxygen-derived free radical mediated damage and effects of different free radical scavengers.

Blood granulocyte-mediated reactions involving generation of oxygen-derived free radicals have recently been shown to be capable of causing injury to the lungs. These findings suggest a similar mechanism also to be involved in the development of pulmonary ischemia/reperfusion injury. In the present study, therefore, the effects of three oxygen-derived free radical scavengers, superoxide dismutase (SOD; 1 mg/kg), catalase (20,000 IU/kg) and allopurinol (45 mg/kg), were evaluated during reperfusion in a rabbit model after 2 h normothermic ischemia of the lung. During reperfusion, ischemic lungs were found to have an elevated pulmonary vascular resistance, increased total and extravascular lung water content, and decreased arterial oxygen tension (PaO2) compared to control animals. SOD and catalase, but not allopurinol, were able to reduce pulmonary injury by lowering the pulmonary vascular resistance, but could not prevent pulmonary damage as shown by total lung water (TLW) or PaO2. It is concluded that oxygen-derived free radicals such as hydrogen peroxide and the superoxide anion may play an important role in precipitating pulmonary injury after ischemia. The failure of xanthine oxidase inhibition (allopurinol) to exert protective effects may suggest that oxygen-derived free radical generation following pulmonary ischemia occurs predominantly via leukocyte-mediated reactions.

Allopurinol↗
PubMed1990

Coarctation of the aorta in complex congenital heart disease: simultaneous repair via sternotomy.

Coarctation of the aorta (CoA) is often associated with complex congenital heart disease. Patients with such a combination may not benefit from coarctectomy alone. Eight children who presented with complex malformations of the heart underwent simultaneous repair of CoA and intracardiac surgery via sternotomy. After extensive mobilization of the aortic arch, cardiopulmonary bypass was established. During the cooling phase for deep hypothermic circulatory arrest (six cases), a persistent temperature gradient between the upper and lower half of the body confirmed the significance of CoA. One child was operated upon in deep hypothermia with low flow and one underwent valve repair on cardiopulmonary bypass. Mobilization of the descending aorta enabled CoA resection and end-to-end anastomosis with a running absorbable suture. The average descending aortic cross-clamping time was 15 min. By this time, the patient had been cooled sufficiently for the intracardiac procedure. There were two operative deaths not related to coarctectomy. The remaining children showed no arm-to-leg pressure gradient. Five were discharged from hospital and one patient died late from septicaemia. In our hands, this technique has served to accomplish simultaneous relief of CoA and repair of the intracardiac lesion thus sparing critically ill infants the hazards of repeated procedures.

Aorta, Thoracic↗
PubMed1990

Pretreatment of prosthetic valve sewing-ring with the antibiotic/fibrin sealant compound as a prophylactic tool against prosthetic valve endocarditis.

Prosthetic valve endocarditis (PVE) remains a dreaded complication following heart valve replacement despite perioperative antibiotic (AB) prophylaxis. In order to increase the AB concentration in the sewing ring, an experimental study including topical application of the gentamicin derivative EMD 46/217 and fibrin sealant (F) as AB-carrier was initiated. In vitro pretreatment of Dacron with the gentamicin derivative and F was followed by constant AB release for 3 weeks. In a subsequent animal study, four Dacron rings with different pretreatment were implanted in the descending aorta of 10 pigs after direct contamination with 10(8) Staphylococcus aureus solution. One ring was pretreated with the AB/F compound, a second ring with the AB alone. Ring 3 (no pretreatment) and ring 4 (F alone) served as controls. After 1 week, the sewing rings and their corresponding implantation sites were assayed for measurement of AB-content and for culture. The AB content of AB/F-rings was 24.99 +/- 7.16 micrograms/g wet weight, while rings pretreated with the AB alone contained no measurable drug amounts with the exception of one specimen (0.5 microgram/g) (AB/F vs. AB-rings: P less than 0.0005). The corresponding implantation sites to AB/F rings contained 1.07 +/- 0.54 micrograms/g AB, whereas in only 2 of 10 implantation sites of AB rings, low AB levels were found (0.05 and 0.2 micrograms/g) (AB/F vs. AB ring implantation sites: P less than 0.0005). While all control rings and 9 of 10 AB rings were infected, 5 of 10 AB/F rings remained sterile after culture (AB/F vs. AB rings: P = 0.05). This finding correlated with the AB content in the suture rings.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1990

Distant organ procurement in clinical lung- and heart-lung transplantation. Cooling by extracorporeal circulation or hypothermic flush.

The scarcity of suitable donors for single lung and heart-lung transplantation calls for methods of medium-term pulmonary preservation to allow for distant organ procurement. At our institution, the first five grafts (four heart-lung, one single lung) were cooled by means of a transportable extracorporeal circulation unit, while the last eight grafts (four heart-lung, four single lung) were flush-perfused with modified cold Euro-Collins solution. The technique of extracorporated circulation included aortic and right atrial cannulation and cooling to 12 degrees-14 degrees C (rectal temperature) using a bubble oxygenator. Bypass times ranged between 41 and 52 min. Following excision, the organs were transported in ice-cold donor blood for ischemic times from 171 to 310 min. For cold flush preservation, simultaneous coronary (cold St. Thomas's solution) and pulmonary artery perfusion (Euro-Collins solution, 50 ml/kg over 4 min) were initiated simultaneously. The organs were transported in cold Euro-Collins solution for ischemic times of 175 to 270 min. In heart-lung transplantations the first postoperative arterial PO2 upon arrival at the intensive care unit was 120 +/- 38 Torr in the extracorporeal circulation and 140 +/- 38 Torr in the Euro-Collins solution group. Six of eight patients were extubated within 48 h after cardiopulmonary grafting. We conclude that pulmonary function following heart-lung or single lung preservation with simple hypothermic flush is as good or better than that following extracorporeal circulation. Since distant organ retrieval is much more convenient without the latter, preservation using Euro-Collins solution is preferred.

Adolescent↗
PubMed1990

Heart transplantation: intraoperative management, postoperative therapy and complications.

Currently, heart transplantation (HTX) is performed as an orthotopic cardiac replacement according to the technique of Lower and Shumway in over 95% of the cases with good results. Survival after heterotopic HTX, by contrast, remain poor (one year survival: 50%). Postoperative therapy compiles primarily prophylactic measures to prevent complications, especially organ rejection and infections. Immunosuppressive prophylaxis generally includes a triple drug therapy consisting of cyclosporin, prednisolone, and azathioprine for maintenance therapy. Initially there is often an additional application of poly- or monoclonal antibodies. The prime measure to prevent infection during the initial hospital stay will be reversed isolation of the recipient. Initial antibiotic prophylaxis resembles that of conservative cardiac surgery, but in addition antiviral and antifungal prophylaxis is applied. The most common postoperative complication following HTX is cardiac rejection, which is detected by routine endomyocardial biopsies. At our institution the incidence of rejection decreases from 3.07 episodes per patient in the first 3 months to 1.97 episodes during the last 6 months of the first year after HTX. In general, acute rejection is treated by methylprednisolone (3 x 500 mg/day) or anti-T-cell-antibodies. Infections often occur following intervals of increased immunosuppression, usually early postoperatively and following therapy of acute rejections. Often, invasive diagnostic measures have to be taken rapidly in order to allow for specific therapy (antibiotics, antimycotic treatment, virostatic agents). Close follow-up of the heart transplant recipient and rapid therapy of possible postoperative complications enable the current one-year survival rates of 80% or more.

Anesthesia↗
PubMed1990

Long-term follow-up after orthotopic heart transplantation.

While infection and acute rejection continue to be the most frequent cause of early postoperative mortality, chronic rejection including both coronary vasculopathy and unspecific myocardial allograft failure and side effects of immunosuppressive therapy determine late survival and quality of life. Some data are presented of a systematic program for long-term follow-up of cardiac transplant recipients with particular emphasis on coronary vasculopathy and modern concepts in rejection detection and control. Infections remain a notable source of morbidity and mortality. The importance of continued efforts to prevent infection even in the Cyclosporin era has to be emphasized. Tricuspid insufficiency is influenced by the mismatch of recipient and donor heart size. Intraoperative adaptation of the recipient pericardium to the size of the donor heart reduces the magnitude. Unspecific graft failure has been observed to occur at an incidence of 8% three years after transplantation. Three types of rejection can be distinguished after heart replacement, the hyperacute rejection as a rare complication precipitated by preformed recipient antibodies to donor antigens, the acute rejection as a major risk factor for survival in the postoperative first year, and, finally, the chronic rejection which is an important factor for long-term survival and quality of life. Considering the detection and classification of the acute rejection, a semiquantification is advantageous because of its therapeutic relevance. The chronic rejection is characterized by vascular abnormalities, interstitial changes, and myocardial alterations. Of these, the vascular component is the most important clinically. The incidence of this coronary vasculopathy, taking all forms visible angiographically, is about 30-40% of surviving patients three years after transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1990

T-cell lymphoma after heart transplantation.

A 26-year-old woman who had undergone orthotopic heart transplantation because of dilative cardiomyopathy received a triple-drug immunosuppressive regimen (cyclosporine A, azathioprine, and prednisolone). During her relatively frequent episodes of acute rejection, she was treated with methylprednisolone and repeated application of ATG. A short time before the patient's death, a fine-needle aspiration of the liver revealed the cytologic diagnosis of a malignant pleomorphic medium-size cell non-Hodgkin's lymphoma of a higher grade of malignancy. Immunosuppression was reduced, and the patient died in cardiogenic shock related to a histologically confirmed episode of severe acute rejection 264 days after the transplantation. On autopsy, the malignant lymphoma previously diagnosed by fine-needle aspiration cytology was found to be present in the liver as the only extranodal localization. The immunohistologic analysis of the immunophenotype specified the lymphomatous neoplasia as a T-cell lymphoma. The particular importance of this case is that it is, to our knowledge, the third case of proven T-cell lymphoma following organ grafting documented in the literature and the first case described in a cardiac allograft recipient.

Adult↗
PubMed1990

Arterial grafts.

Explore the source record for details and available documents.

Arteries↗
PubMed1990

[Unilateral lung transplantation].

For patients with terminal pulmonary fibrosis unilateral lung transplantation offers a new therapeutic option. At the Hannover Medical School 5 patients have been successfully treated by single lung transplantation. In 3 patients a left, and in 2 patients a right lung transplant was performed. One patient required intraoperative support by cardiopulmonary bypass. Bronchial omentopexy was used in all instances. Currently all patients are alive. A marked improvement of pulmonary function parameters was seen in all cases. The patients are all able to lead a normal life.

Adult↗
PubMed1990

[Lung transplantation].

Following the publication of the first positive results and follow-ups achieved with heart-lung and lung transplants in the United States of America, a joint pneumology/thoracic surgery working group "lung transplantation" was set up in our hospital. The following article presents our lines of thought on the indications governing the various methods, on the technique of operation (including organ removal) and on the aftercare of lung transplant patients, described in a summarising review that also includes the procedure followed by comparable centres. We are also reporting on the first surgical interventions carried out by us.

Adult↗
PubMed1990

[Unilateral lung transplantation--a new perspective in the treatment of pulmonary fibrosis].

In patients with pulmonary fibrosis and progressive respiratory failure despite conservative treatment, unilateral lung transplantation offers a new therapeutic alternative. At the Medical School in Hannover, five patients--the first to be thus treated in Central Europe--with terminal pulmonary fibrosis of the lung have so far been successfully treated with unilateral lung transplantation. All five patients are still alive, and all experienced a marked improvement in their pulmonary function parameters, such that they have been enabled to lead a normal life again.

Adult↗
PubMed1990

[Perioperative preventive antibiotic treatment with fosfomycin in heart surgery: serum kinetics in extracorporeal circulation and determination of concentration in heart valve tissue].

A prospective clinical study was carried out to assess the adequacy of perioperative antibiotic prophylaxis using fosfomycin in patients undergoing open-heart surgery for valve diseases for the prevention of early postoperative endocarditis, as well as for serious mediastinal infections that are caused mostly by multiresistant staphylococci and Gram-negative bacteria. Perioperative pharmacokinetics and tissue penetration were determined within the harvested heart valves and subcutaneous tissue. Reliable bactericidal serum levels were established at the first measurement 10 min after the end of intravenous infusion (203.7 +/- 44.7 micrograms/ml) and were maintained during surgery for at least 120 min (124.6 +/- 58.4 micrograms/ml), even in cases of prolonged extracorporeal circulation. Cardiopulmonary bypass did not alter the serum elimination of fosfomycin in comparison with patients not undergoing extracorporeal circulation. Peak tissue concentrations were achieved in both aortic and mitral valves after 30 min, ranging between 27.1 and 76.9 micrograms/g for aortic valves and 39.6-69.4 micrograms/g for mitral valves, depending on the degree of valvular degeneration. MIC values of 16 micrograms/g were maintained in both valves for at least up to 60 min. There was no evidence of renal impairment, adverse reactions or infections during the postoperative course or thereafter for a period of 3 months. It is concluded that perioperative intravenous antibiotic prophylaxis using fosfomycin (5 g t.i.d. in adults), beginning with induction of anesthesia and continued for 48 h postoperatively, provides rapid, reliable bactericidal serum levels and valvular tissue concentrations that will inhibit most Gram-positive and Gram-negative organisms that cause bacterial endocarditis and other serious infections following cardiac surgery.

Aged↗
PubMed1990

Diastolic dysfunction during acute cardiac allograft rejection.

Left ventricular diastolic function was evaluated in 41 heart transplant patients during acute rejection by an analysis of echocardiograms and surgically implanted intramyocardial tantalum markers. In 35 patients, isovolumic relaxation time was calculated from M-mode tracings selected from two-dimensional echocardiographic recordings. A total of 84 biopsy findings of no rejection, moderate rejection, and severe acute rejection after treatment were correlated with measurements of isovolumic relaxation time. In six patients, end-diastolic volume, end-systolic volume, stroke volume, ejection fraction, and peak filling rate were obtained from biplanar cineradiographic images of intramyocardial markers. Data from 11 prerejection periods were compared with those of moderate acute rejection. All echocardiograms and marker images were analyzed without previous knowledge of biopsy findings. At times of acute rejection, isovolumic relaxation time decreased from 107 to 65 msec (p less than 0.01) and returned to 98 msec after immunosuppressive therapy. Ejection fraction and end-systolic volume did not change significantly with acute rejection, whereas stroke volume decreased from 76 to 67 ml (p less than 0.05). In contrast to the effects on systolic function, episodes of acute rejection were accompanied by a decrease in end-diastolic volume from 166 to 153 ml (p less than 0.01) and a reduction in peak filling rate from 514 to 460 ml/sec (p less than 0.05). These data suggest that acute cardiac rejection is associated with relative preservation of left ventricular systolic performance but with alterations in diastolic dynamics similar to those seen in "restrictive" cardiomyopathy.

Acute Disease↗