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Biomedical subjects

A Haverich

Publications and source records attributed to A Haverich.

At least 325 records · Page 18Linked to original sources
PubMed1992

Decreased incidence of bronchial complications following lung transplantation.

Despite omental wrap and avoidance of prophylactic administration of corticosteroids in the early postoperative phase, ischemic bronchial complications still represent an important source of early morbidity and mortality following lung transplantation. In a retrospective analysis, the effect of pharmacological enhancement of pulmonary collateral flow on bronchial healing was investigated. Thirty-nine consecutive unilateral or bilateral transplant procedures (Tx) were analyzed. Immunosuppression consisted of rabbit antithymocyte globulin (RATG), cyclosporine A, and azathioprine. In group 1 (10 Tx, 12 anastomoses) routine immunosuppression was employed and the anastomoses wrapped with an omental or pericardial pedicle. In group 2 (29 Tx, 41 anastomoses) PGI2 (4 ng/kg per min x 48 h), heparin (200 U/kg per day), and prednisolone (0.5 mg/kg per day) were added to the therapeutic regimen. The 2 groups were comparable with respect to age and sex of the patients, primary diagnosis, type of transplant, intraoperative use of extracorporeal circulation, graft ischemia, duration of mechanical ventilation, and mortality. Bronchoscopic evidence of a significant bronchial ischemia (extending more than 1 cartilaginous ring beyond the anastomosis) was seen in 8 of 12 anastomoses in group 1 vs 14 of 53 anastomoses in group 2 (P = NS). In group 1, significant bronchial stenosis required implantation of an endobronchial silicone stent in 6 of 12 anastomoses, whereas in group 2, no significant bronchial stenosis occurred (P less than 0.01). No negative effects possibly related to the prophylactic administration of corticosteroids could be observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

[Artificial intravascular oxygenation (IVOX). Application to the treatment of postoperative respiratory failure].

Very recently, the concept of artificial intracorporeal oxygenation of blood for patients suffering from respiratory failure has been introduced into clinical practice through development of a totally implantable intravascular oxygenator (IVOX). We report on the use of such a device in a patient who developed severe respiratory insufficiency secondary to prolonged hypovolaemic shock and pneumonia following successful repair of a ruptured abdominal aortic aneurysm in September, 1990. Postoperatively, severe hypoxaemia occurred (AaDO2 548-602 torr) despite extensive mechanical ventilatory support. There was no obvious chance to overcome this situation by conventional therapeutic measures and the decision was made to institute IVOX therapy. Hypoxaemia was resolved immediately and both FiO2 and tidal volume could be reduced within hours. The patient's respiratory condition continued to improve over the next days leading to termination of IVOX therapy after 71 hours. However, the necessity of long-term ventilatory support secondary to recurrent pneumonia and sepsis, multiple abdominal reoperations for ischemic colitis and retroperitoneal abscess prolonged his recovery. He was discharged from the hospital after four months and is alive and well now 14 months after his operation. He is the first long-term survivor after IVOX therapy in Europe. IVOX may be successfully used in selected patients while the indications and it's potential role in the therapy of severe respiratory failure still need to be defined.

Humans↗
PubMed1992

Prevention of graft infection by bonding of gentamycin to Dacron prostheses.

To increase the efficacy of perioperative antibiotic prophylaxis in vascular surgery an experimental study including topical application of the gentamicin derivative EMD 46/217 and fibrin sealant as antibiotic carrier to Dacron prostheses was initiated. In vitro treatment of Dacron with gentamicin and fibrin was followed by constant antibiotic release for 3 weeks. In a subsequent animal study Dacron grafts were implanted in the aorta of 10 pigs after direct contamination with Staphylococcus aureus solution. One graft was pretreated with the antibiotic/fibrin compound, a second with the antibiotic alone. Grafts 3 (no pretreatment) and 4 (fibrin alone) served as controls. After 1 week the grafts and their corresponding implantation sites were excised for measurement of antibiotic content and for culture. The antibiotic content of grafts with the antibiotic/fibrin compound was 25.0 +/- 7.2 micrograms/gm wet weight, whereas Dacron pretreated with the antibiotic alone contained no measurable drug amounts except for one specimen (0.5 microgram/gm) (antibiotic/fibrin vs antibiotic, p less than .0005). The corresponding implantation sites to antibiotic/fibrin grafts contained 1.07 +/- 0.54 microgram/gm antibiotic, whereas in only 2/10 implantation sites of antibiotic grafts low antibiotic levels were found (0.05 and 0.2 microgram/gm) (antibiotic/fibrin vs antibiotic, p less than 0.005). All control grafts and 9/10 antibiotic grafts were infected. By contrast, only five were contaminated, and 5 of 10 remained sterile after culture (antibiotic/fibrin vs antibiotic, p less than 0.05). This finding correlates with the antibiotic content in the Dacron. It is concluded that pretreatment of prosthetic Dacron grafts with the antibiotic/fibrin compound results in binding of sufficient amounts of antibiotic for at least 1 week.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1992

Enoximone, a post-operative inodilator in patients following mitral valve operation: a prospective and controlled study.

Inotropic support is often required for post-operative management of patients following mitral valve operation. The use of positive inotropes is limited by tolerance development and increase in myocardial oxygen demand. We have compared i.v. enoximone (E) (group E, n = 13), a recently developed phosphodiesterase (PDE) inhibitor, to the conventional i.v. therapeutics dopamine (D) and glyceroltrinitrate (G) in patients following mitral valve operation. The two groups were comparable in terms of physical and pre-operative haemodynamic data. Haemodynamic measurements including cardiac index (CI) determinations were recorded for the first 18 h post surgery in both groups. Group E received a bolus of 1 mg.kg-1 E followed by 4-20 micrograms.kg-1.min-1 (mean = 5 +/- 2 micrograms.kg-1.min-1) for 14 h according to therapeutic requirements, while group D received dopamine (4-10 micrograms.kg-1.min-1, mean = 3.8 +/- 1.9 micrograms.kg-1.min-1) and glyceroltrinitrate (0.5-5 micrograms.kg-1.min-1; mean = 4 +/- 2 micrograms.kg-1.min-1). Adrenaline was added if the MAP was below 60 mmHg or the CI was below 2.5 in both groups (range 50-500 ng.kg-1.min-1; mean E = 0.7 +/- 2 ng.kg-1.min-1; mean D = 2 +/- 2.8 ng.kg-1.min-1). Bolus injection of E resulted in a rise in CI from 2.6 to 3.21.min-1.m-2 (P less than 0.05) within 30 min, followed by a further rise to a maximum of 3.51.min-1.m-2 6 h post bolus. Termination of the E drip resulted in a drop of CI to baseline values (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Heart transplantation, assist devices, and cardiomyoplasty.

Allograft replacement of the heart in pediatric patients has gained growing interest within the spectrum of cardiac transplantation. Here and in other age groups, new immunosuppressive agents are under investigation, hopefully providing more selective reduction of the immune response with lower side effects compared with conventional therapy. Many clinical investigators and basic scientists are working to understand, prevent, and possibly treat chronic cardiac allograft rejection, one of the major threats in long-term survivors. Within the scope of mechanical assist device application, bridge to transplantation does provide the best results. New developments include emergency treatment of cardiogenic shock by an intravascular left ventricular assist device and cardiopulmonary bypass, both designed as life support systems. Clinical studies on permanent implants of ventricular assist devices are on the way. As another alternative to heart transplantation, dynamic cardiomyoplasty using the latissimus dorsi muscle has gained increasing clinical attention. Results relating to clinical and hemodynamic improvement, however, remain conflicting, and long-term results are not yet available.

Assisted Circulation↗
PubMed1992

Comparison of enoximone and piroximone in patients after mitral valve operation: a prospective and controlled clinical study.

Phosphodiesterase III (PDEII) inhibitors as so-called inodilators have previously proven a valuable alternative to positive inotropes in patients with cardiac insufficiency. In this study we compared patients receiving piroximone (P, n = 14, 0.5-mg/kg bolus in 30 min and then 3-6 micrograms/kg/min) with enoximone patients (E, n = 13, 1-mg/kg bolus and then 4-20 micrograms/kg/min) and with a third group (D, n = 14) receiving a combination of dopamine (4-10 micrograms/kg/min) and glyceroltrinitrate (0.5-5 micrograms/kg/min) for hemodynamic support. All three groups were comparable in terms of age, body surface area, and preoperative cardiac function [cardiac index (CI) less than or equal to 2.5 L/min/m2, LAP greater than 15 mm Hg]. Hemodynamic measurements (10) and Holter monitoring were performed until 18 h post MVR. In all groups, epinephrine was used for additional inotropic therapy if mean arterial pressure (MAP) was less than 60 mm Hg and/or CI was less than 2.5 L/min/m2. There was no early or late postoperative mortality in either group. Continuous support with epinephrine was necessary in 8 patients in group D, whereas initially 8 patients in group E and 6 patients in group P required epinephrine support. After PDE III inhibitor infusion, 2 patients in group E and 2 patients in group P remained epinephrine dependent (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Increased messenger RNA level of the inhibitory G protein alpha subunit Gi alpha-2 in human end-stage heart failure.

In human heart failure the positive inotropic and cAMP-elevating effects of both beta-adrenoceptor agonists and phosphodiesterase inhibitors are diminished. This has been explained at least in part by an increase in the inhibitory signal-transducing G protein (Gi) and unchanged stimulatory G protein (Gs). In the present study we determined the mRNA expression pattern of the alpha subunits of Gi-1, Gi-2, Gi-3, and Gs in myocardial tissue samples of patients undergoing heart transplantation. Northern blot analysis of total RNA extracted from left ventricles with 32P-labeled cDNAs demonstrated expression of Gi alpha-2, Gi alpha-3, and Gs alpha mRNA. In contrast, Gi alpha-1 mRNA was not detectable. To investigate whether the increased ratio of Gi/Gs might be due to altered gene expression, we compared mRNA levels of Gi alpha-2, Gi alpha-3, and Gs alpha in left ventricular myocardium from failing hearts with idiopathic dilated cardiomyopathy (n = 8) and ischemic cardiomyopathy (n = 6) and from nonfailing hearts from transplant donors (n = 8). Compared with nonfailing control hearts, the Gi alpha-2 mRNA was increased by 75 +/- 26% (p less than 0.05) in idiopathic dilated cardiomyopathy hearts and 90 +/- 26% (p less than 0.05) in ischemic cardiomyopathy hearts. Gi alpha-3 and Gs alpha mRNA levels were similar in the three groups. The results suggest that as in other mammalian species, Gi alpha-2 and Gi alpha-3 mRNA are the predominant Gi alpha mRNA subtypes in human ventricular myocardium.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Clinical evaluation of transtracheal Doppler for continuous cardiac output estimation.

A newly developed transtracheal Doppler (TTD) computer for cardiac output determination was studied in nine patients after open heart surgery (coronary artery bypass grafting, n = 4; mitral valve replacement, n = 5). The measurements were compared with those simultaneously obtained by thermodilation. Doppler signals were adequate in 78% of the patients studied. Limited correlation between both methods (r = 0.248; r2 = 0.0615; mean of difference, 1.714 +/- 1.67 L/min; limits of agreement, -1.6 to 5.0 L/min) was found. The large difference in cardiac output readings between TTD and thermodilation may be due to (a) false angles of the ultrasound beam in relation to the aortic wall and blood flow or (b) misplacement of the ultrasound head and underestimation of the aortic lumen. Patients must be completely sedated and paralyzed to prohibit artifacts. Routine patient care can interfere with continuous measurements. Cardiac output determinations by TTD are limited to the period during which the trachea is intubated with the special TTD tube. We conclude that the TTD system does not offer accurate cardiac output determinations and that the routine use of this device is not practical.

Aged↗
PubMed1992

Evaluation of lung function during pulmonary rejection and infection in heart-lung transplant patients. Hannover Lung Transplant Group.

Pulmonary rejection and infection are the most important complications after lung transplantation. To evaluate the diagnostic value of pulmonary function testing for early detection and discrimination of these complications, seven heart-lung recipients were examined. The diagnosis of each complication was confirmed by clinical and laboratory findings including transbronchial biopsies and bronchoalveolar lavage. Eight episodes of rejection, ten episodes of viral infection and six episodes of bacterial pneumonia were analyzed. Pulmonary rejection was associated with a significant fall in the FEV1/IVC% and the FEF50%. In viral infection, the most impressive finding was a reduction in the DCO, whereas no obstructive or restrictive airway dynamics were observed. During bacterial pneumonia, pulmonary function measurement revealed a decrease in IVC without signs of obstructive airway dynamics. Adequate treatment resulted in reconstitution of pretreatment values. Assessment of lung function provides valuable information for the diagnosis of pulmonary complications following HLTx.

Adult↗
PubMed1992

Preoperative corticosteroids. A contraindication to lung transplantation?

Regular preoperative application of corticosteroids has been considered as a contraindication to lung transplantation for fear of an increased risk of postoperative morbidity and mortality. Recently, however, we have accepted patients for transplantation in whom treatment with steroid medication could not be terminated preoperatively. Up to February 1991, 27 unilateral and bilateral transplantations in 26 patients were analyzed. Corticosteroid therapy was discontinued at least three months prior to transplantation in 13 patients (group 1), whereas in 14 cases, the patients continued their daily corticosteroid therapy to the time of transplantation (prednisolone, 0.1 to 0.3 mg/kg/day; group 2). There were no significant differences between the groups with respect to sex, age, diagnosis, or type of transplantation. One limited bronchial dehiscence occurred; the incidence of postoperative bronchial stenosis was identical in both cohorts; one patient died in each group. In conclusion, no increased morbidity or mortality could be found following lung transplantation with regular preoperative administration of prednisolone up to 0.3 mg/kg/day. Thus, patients who cannot be weaned from their steroid medication but who otherwise are acceptable candidates should not be excluded from lung transplantation.

Adolescent↗
PubMed1992

[Lung transplantation].

In the past 10 years, three different types of lung transplantation were introduced into clinical practice, the combined transplantation of the heart and both lungs (HLTx), unilateral single lung transplantation (SLTx), and bilateral sequential lung transplantation (DLTx). At present, the indications for the various procedures have not been ultimately defined. Through 1991, a total of about 1,100 HLTx, 460 SLTx, and 160 DLTx was performed worldwide. One- und 3-year survival rates amount to 75-60% resp. in HLTx, to 80-70% resp. in SLTx, and to 70-60% resp. in DLTx. In our own experience with 24 HLTx, 32 SLTx, and 18 DLTx patients, global survival rates at one and 3 years are 85 and 80%, resp. The vast majority of surviving patients is able to lead a near normal life both physically and socially.

Actuarial Analysis↗
PubMed1992

[Complex progressive palliation for univentricular circulation].

The type of palliative procedures (PP) for complex univentricular circulation (UC) changed significantly during the 80ies. Between 07/86 and 02/91 77 patients (pts) presented with UC to eventually undergo a modified Fontan-Kreutzer-type-operation (MFKTO). 33 pts had been previously palliated, 22 of whom were accepted for MFKTO as well as an additional 9 not palliated pts (group A: 31 pts; 20 PP). 11 previously palliated pts and 35 new pts required new palliations (group B: 46 pts; 89 PP), 34 of which resulted in 13 MFKTO. Prerequisites to be met for MFKTO are: undistorted PA-anatomy; absence of subaortic stenosis (SAS); Qp greater than 2.5 l/min/m2; PAP less than 20 mm Hg; Rp less than 3 Wood Units. All earlier PP in group A (31 BTS, 3 PAB, 2 PA-valvotomy/dil.) merely prolonged survival by only adjusting Qp. In group B PP comprise reconstruction of pulmonary arteries, aortic arch and isthmus as well as bypass or resection of SAS or atrial septectomy. Mortality for complex PP (group B) was 32.5% (15/46). 9 of these pts were neonates, 7 after modified Norwood procedures. In an attempt to plan a MFKTO for all pts presenting with UC (group B), complex PP was necessary. The high mortality is due to lesions in pts who would not have survived if only closed PP were applied.

Child↗
PubMed1992

Imaging of pulmonary artery and vein anastomoses by transesophageal echocardiography after lung transplantation.

BACKGROUND: In patients after isolated lung transplantation, the postoperative course may be complicated by dysfunction of the pulmonary artery and vein anastomoses. METHODS AND RESULTS: Pulmonary artery and vein anastomoses in 11 transplanted lungs (four left, four right, and three bilateral lungs) in 10 patients were studied 1 day to 11 months after operation by transesophageal echocardiography (TEE). All 14 pulmonary vein anastomoses, all seven right (100%) and five of seven (71%) left pulmonary artery anastomoses could be visualized by TEE. Thrombosis of a left pulmonary vein anastomosis could be identified by TEE and successfully treated by thrombolysis. TEE detected a significant stenosis in one right and one left pulmonary artery anastomosis; anastomoses dysfunction were confirmed by cardiac catheterization and pulmonary angiography and successfully treated by surgical correction in both cases. CONCLUSIONS: Function and morphology of pulmonary artery and vein anastomoses in patients after isolated lung transplantation can reliably be assessed by TEE. In patients with suspected dysfunction of an anastomosis, TEE may be considered the diagnostic technique of choice.

Adult↗
PubMed1992

Future horizons of lung preservation by application of a platelet-activating factor antagonist compared with current clinical standards. Euro-Collins flush perfusion versus donor core cooling.

With the introduction of platelet-activating factor antagonists, a direct inhibition of ischemia-induced reperfusion injury can be achieved by prevention of platelet activation, reduction of microvascular leakage, and platelet-activating factor-induced bronchoconstriction. At present, two preservation methods are established for clinical lung preservation: (1) donor core cooling by extracorporeal circulation and (2) pulmonary artery flush with Euro-Collins solution and prostacyclin. We compared the quality of organ preservation obtained with these methods to the application of a platelet-activating factor antagonist (WEB 2170; 0.3 mg/kg) for the donor, perfusion solution, and throughout the first 6 hours of reperfusion in combination with prostacyclin (20 ng/kg/min) and Euro-Collins solution (60 ml/kg). Eighteen heterotopic heart and orthotopic left lung transplants were performed in three groups of six dogs each after 6 hours of cold ischemia (group I, donor core cooling; group II, Euro-Collins flush and prostacyclin; group III, Euro-Collins flush, prostacyclin, and WEB 2170). Myocardial preservation was achieved with St. Thomas' Hospital solution (20 ml/kg) in all groups. After transplantation, cardiorespiratory function was assessed at an inspired oxygen fraction of 0.4. After transplantation, superior results were observed in group III, as expressed by significantly improved oxygenation, while cardiac output and pulmonary artery pressures were similar in all groups. We concluded that the use of the platelet-activating factor antagonist WEB 2170 resulted in better lung preservation than current clinical standards.

Animals↗