Search PubMed⌕ Search

Biomedical subjects

A Haverich

Publications and source records attributed to A Haverich.

At least 289 records · Page 16Linked to original sources
PubMed1994

Cyclosporin A and transplant coronary disease after heart transplantation: facts and fiction.

From published data in the currently available literature on animal experiments, it can be concluded that CyA may be involved in the development of hypertension and renal dysfunction. These side effects are probably related to a disturbed vasomotor tone and a pathologic reaction to physiologic vasoconstrictive and vasodilative agents following administration of high doses of CyA. These effects are dose related and reversible and were undetected at clinically applied levels of immunosuppression. It therefore appears to be unlikely that this pathologic response is operative in precipitating or promoting TCD, which is supported by findings of in vivo and in vitro studies on human coronary arteries as well as by comparison of immunosuppressive protocols comparing series with and without application of CyA. Chronic graft dysfunction, as depicted by late mortality in heart and isolated lung transplant recipients and by loss of kidney allograft survival, yields an annual rate of between 4 and 6% per year. It is only in heart transplantation that TCD has been tried to be associated with CyA application. If CyA-related damage were to occur in coronary arteries independent from immunologic factors, the incidence of coronary disease should be similar in heart, lung, liver, and kidney transplants. This is not the case. Although continuous investigation on the side effects of immunosuppressive agents is definitely necessary, we should concentrate our research activities on potential prophylactic and therapeutic measures to overcome the single most important risk factor of long-term surviving patients after solid organ transplantation: chronic rejection.

Animals↗
PubMed1994

Pulmonary retransplantation for obliterative bronchiolitis. Intermediate-term results of a North American-European series.

An international series of pulmonary retransplantation was updated to identify the predictors of survival in the intermediate-term after reoperation for obliterative bronchiolitis. The study cohort included 32 patients with end-stage obliterative bronchiolitis who underwent retransplantation in 15 North American and European centers between 1988 and 1992. Five types of retransplantation procedures were done, including repeat ipsilateral single lung transplantation (7 patients), repeat contralateral single lung transplantation (8 patients), repeat double lung transplantation (3 patients), double lung transplantation after a previous single lung transplantation (3 patients), and single lung transplantation after a previous double lung or heart-lung transplantation (11 patients). The mean interval between transplants was 564 +/- 51 days (range 187 to 1589 days). Postoperative follow-up was 100% complete and the average follow-up in surviving patients was 678 +/- 63 days. Actuarial survival was 72%, 53%, 50%, 41%, and 33% at 1, 3, 6, 12, and 24 months, respectively. Survival did not differ according to the age, preoperative diagnosis, ambulatory or ventilator status, or cytomegalovirus serologic status of the recipient before reoperation. Life-table and Cox proportional hazards analysis identified the type of retransplantation procedure and the year of reoperation as significant (p < 0.05) predictors of postoperative survival. Actuarial survival was significantly better in patients without an old, retained contralateral graft after retransplantation and in patients who underwent reoperation between 1990 and 1992, as opposed to between 1988 and 1989. Infection was the most common cause of death at all time intervals after retransplantation, although all deaths beyond 2 years resulted from obliterative bronchiolitis of the second graft. Most surviving patients are in a satisfactory clinical condition, with a mean forced expired volume in 1 second of 59% +/- 13% of predicted (repeat double lung transplant recipients) or 41% +/- 6% of predicted (repeat single lung transplant recipients). We conclude that pulmonary retransplantation for obliterative bronchiolitis is associated with significantly worse survival than after primary lung transplantation. The absence of an old contralateral graft after retransplantation and reoperation after 1989 are important predictors of survival. Additional data and follow-up are required to determine the merit of pulmonary retransplantation for obliterative bronchiolitis.

Actuarial Analysis↗
PubMed1994

[Heart and lung transplantation in acute organ failure].

Heart and lung transplantation represent a realistic therapeutical option in endstage cardiac and pulmonary diseases. Transplantation for acute organ failure, however, is limited due to the scarcity of suitable donors with respect to the shortage of time. Aside from pharmacological means a number of mechanical assist devices are available for bridging of those patients in acute myocardial or respiratory failure. Indications for acute organ transplantation are primary graft failure following heart or lung transplantation and acute myocardial insufficiency due to extensive myocardial infarction or after open heart surgery, respectively acute respiratory distress syndrome in selected cases. Initiation of mechanical support requires previous detailed patient evaluation with respect to indication and possible contraindication for the bridging procedure and a subsequent transplantation as well.

Acute Disease↗
PubMed1994

[Lung and heart-lung transplantation: indications, complications and prognosis].

Lung- and heart-lung transplantation has become a serious therapeutic option for terminally ill patients with chronic pulmonary failure. Due to the still rather high risk of acute rejection, severe pulmonary or systemic infection, and the relatively demanding postoperative care, this treatment can only be considered for patients where inspite exhausted conservative options for therapy quality of life and prognosis are not acceptable. Not only due to lack of donors single-lung transplantation has developed to be the favorite treatment for patients with interstitial lung disease (idiopathic, sarcoidosis, asbestosis etc.) and even for pulmonary hypertension unless irreversible damage to the myocardium is present. Double-lung transplantation is the treatment of choice for patients with emphysema and cystic fibrosis. Heart-lung transplantation is mainly limited to patients with a high degree of right ventricular or valve dysfunction as in Eisenmenger-Syndrome. Midterm clinical results have evolved to be very satisfactory while on the longterm basis chronic transplant dysfunction not responding to any kind of therapy causes a lot of concern. One- and two-year survival rates are 85 and 82% resp. in our program and thus are in the same range as those after heart transplantation.

Contraindications↗
PubMed1994

Surgical treatment of airway complications after lung transplantation.

The treatment of dehiscence or stenosis of the bronchus after lung transplantation has to date consisted of endobronchial stenting or balloon dilation. Operative intervention has been limited to retransplantation with all its limitations. In our series of 121 anastomoses at risk, severe bronchial stenosis occurred in 11 (9%). In five instances the airway complications were treated surgically: two patients underwent retransplantation, one patient had a bilobectomy, and two required sleeve resection of the stenotic segment. All these procedures successfully removed the stenosis. This experience demonstrates that options other than bronchial anastomotic stenting and dilation may be successfully used to overcome posttransplantation anastomotic complications. Conventional resections may result in superior long-term graft function compared with retransplantation, avoiding the immunologically adverse effects of the latter procedure.

Bronchi↗
PubMed1994

Surgical treatment of active infective endocarditis with paravalvular involvement.

Aortic root infection remains a challenging problem in the surgical treatment of both native and prosthetic valve endocarditis. Between 1980 and 1991, 73 patients with active aortic valve endocarditis and paravalvular infection underwent operation. Indications for operation included congestive heart failure and uncontrolled sepsis. Aortic root abscesses were located in the noncoronary anulus or in the aorticomitral junction in 45% of cases, followed by the subannular interventricular septum in 23%. Two patients had an aorticoatrial fistula, seven an interventricular septal defect. Total or partial left ventricular-aortic dehiscence was observed in 27 patients. All patients underwent aortic valve replacement, nine with simultaneous mitral valve operations. Two of the latter required patch reconstruction of the destroyed aorticomitral septum with double valve replacement. Reconstruction of the aortic base was possible in 16 patients, whereas in 12 total replacement of the aortic root was necessary. In one patient, supracoronary aortic valve replacement was used. Recently, topical application of antibiotics in fibrin sealant was used in 25 patients. The operative mortality rate was 21% and correlated to preoperative uncontrolled sepsis and the presence of extensive root destruction. Operation for active endocarditis of the aortic root requires radical, individualized techniques and results in an acceptable operative and long-term risk. The use of an antibiotic fibrin compound appears to be a useful prophylactic tool to prevent postoperative residual endocarditis.

Abscess↗
PubMed1994

[Use of inferior epigastric artery for coronary artery bypass grafting].

Between 3/91 and 3/93 twenty-nine patients (pts.) with a mean age of 55 years (30-68) underwent CABG (including 3 reoperation) using inferior epigastric artery (IEA) in addition to internal thoracic artery and saphenous vein graft. IEAs were harvested as pedicles with a mean length of 12.2 cm (7.5-17). Overall distal anastomoses were performed 3.2 per patients. And a mean of 2.3 anastomoses were completed as an arterial graft. IEA grafts were applied to left anterior descending artery in 10, diagonal branch in 15, in marginal branches in 2 and right coronary artery in 2. Mean cardiopulmonary bypass time amounted to 103 minutes and operation procedures were completed in 258 minutes (mean). Aortic cross clamp time of 48 minutes were required. One patient was died of cerebral accident 23 days postoperatively. Except for two abdominal wall infection no wound healing problems occurred. One reexploration for bleeding were necessary. Postoperative angiography revealed patent IEA grafts in 12 of 13 patients (92%). We concluded that the application of IEAs for CABG is available as a third arterial graft and with respect to intraoperative management and perioperative complications use of IEA combined with ITAs appears suited or superior to the use of the right gastroepiploic artery.

Abdominal Muscles↗
PubMed1993

University of Wisconsin versus St. Thomas' Hospital solution for human donor heart preservation.

Prolongation of the safe period of ischemia of the heart is an efficient way to overcome donor organ shortage, as demonstrated in renal and hepatic transplantation. We present the results of a prospective, randomized study comparing preservation with University of Wisconsin solution (UWS) versus St. Thomas' Hospital solution (STS) in clinical heart transplantation. A total of 39 patients were enrolled in the study (n = 20 for UWS and n = 19 for STS). Hemodynamic, electron microscopic, and biochemical evaluation did not reveal any significant differences in postoperative myocardial performance. Only the number of intraoperative defibrillations (0.82 for UWS versus 1.7 for STS) and the rhythm stability after reperfusion (13/20 UWS hearts versus 6/19 STS hearts in sinus rhythm) were significantly different. Heart preservation with UWS and STS appears to be of comparable efficacy at mean ischemic times of less than 4 hours.

Adenosine↗
PubMed1993

Biophysical properties of the gelatin-resorcin-formaldehyde/glutaraldehyde adhesive.

Refixation of dissected aortic layers with gelatin-resorcin-formaldehyde/glutaraldehyde (GRFG) adhesive represents a new option in the surgical treatment of aortic dissection. Because of its ability to reinforce the delicate structures of the acutely dissected aortic wall, GRFG has been used increasingly in recent years. However, the biomechanical properties of the adhesive are still unclear, and little is known regarding the optimal mode of its application. In an ex vivo study, aortic specimens from sheep were glued with warm (45 degrees C) adhesive under wet and dry conditions and submitted to defined degrees of compression (5 Newtons [N], 20 N). Bonded specimens were retracted to assess tensile strength and elasticity compared with two reference adhesives: cyanoacrylate gel and fibrin glue. Gelatin-resorcin-formaldehyde/glutaraldehyde and cyanoacrylate gel showed similar results at 5 N. Both provided better adhesion when applied under dry conditions (GRFG 5 N: dry, 3.5 +/- 1.6 N/cm2; wet, 1.4 +/- 1.0 N/cm2; cyanoacrylate gel 5 N: dry, 4.8 +/- 1.8 N/cm2; wet, 3.2 +/- 1.3 N/cm2). At 20 N, GRFG tensile strength was significantly increased for either condition compared with values at 5 N (GRFG 20 N: dry, 17.1 +/- 4.2 N/cm2; wet, 4.8 +/- 1.8 N/cm2). Fibrin glue demonstrated only weak adhesive properties even under dry conditions (fibrin glue 5 N: dry, 0.8 +/- 0.3 N/cm2). Gelatin-resorcin-formaldehyde/glutaraldehyde has good adhesive properties both in wet and dry tissue. Bonding capacity can be substantially increased when applied on dry surfaces and at increased pressures.

Adhesiveness↗
PubMed1993

Effect of methylprednisolone and prostacyclin on bronchial perfusion in lung transplantation.

In an experimental investigation using modified unilateral lung transplantation in pigs, the effects of systemic administration of methylprednisolone and prostacyclin on bronchial mucosal blood flow were assessed. Laser Doppler velocimetry (LDV) and radioisotope studies using radiolabeled erythrocytes (RI) were employed to measure blood flow at the donor main carina and upper lobe carina after 3 hours of reperfusion. The recipient carina was used as a reference point. Five groups of 6 animals each were studied. Group I served as control. In group II, methylprednisolone (20 mg/kg) was administered to the recipient. In group III, prostacyclin (4 ng.kg-1.min-1) was given to the recipient, and in group IV, prostacyclin (100 micrograms intravenously) was administered to the donor. In group V, prostacyclin was given to the recipient and the donor animals as in groups III and IV, respectively. In group I, bronchial blood flow at the donor main carina was 37.6% +/- 2.2% (LDV) and 44.1% +/- 14.8% (RI) of reference blood flow. No significant differences were found between the controls and groups II, III, and IV. In group V, bronchial blood flow was markedly increased both at the donor main carina (LDV, 39.8% +/- 6.2%, p = 0.12; RI, 55.7% +/- 11.4%, p < 0.2) and the donor upper lobe carina (LDV, 65.8% +/- 5.4%, p < 0.05; RI, 76.8% +/- 21.3%, p < 0.2). We conclude that systemic administration of prostacyclin to the donor and recipient results in marked improvement of bronchial blood flow and may reduce the incidence of bronchial complications after lung transplantation.

Animals↗
PubMed1993

The efficacy of controlled antibiotic release for prevention of polyethyleneterephthalate- (Dacron-) related infection in cardiovascular surgery.

Infection of prostheses containing polyethyleneterephthalate (Dacron) remains a dreaded complication in cardiovascular surgery despite perioperative antibiotic (AB) prophylaxis. Dacron, which is widely applied as a fabric for manufacturing vascular prostheses and also the sewing rings of artificial heart valves, remains a source for infection once implanted in the body. In order to increase the AB concentration in Dacron, 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 three weeks. In a subsequent animal study, four Dacron rings with different pretreatments were implanted in the descending aorta of ten pigs after direct contamination with 10 8 Staph. 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 one week, the Dacron rings and their corresponding implantation sites were asserved for measurement of AB content and for culture. The AB content of AB/F rings was 24.99 +/- 7.16 mug/g wet weight, while Dacron rings pretreated with the AB alone contained no measurable drug amounts, with the exception of one specimen (0.5 mug/g)(AB/F versus AB rings: P less than 0.0005).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMed1993

Impaired coronary dilator responses to substance P and impaired flow-dependent dilator responses in heart transplant patients with graft vasculopathy.

OBJECTIVES: Because pathologic mechanisms for transplant vasculopathy are still uncertain, we tested the hypothesis that endothelial function, in terms of the release of endothelium-derived relaxing factor (EDRF), is impaired in patients with evidence of angiographic transplant vasculopathy. BACKGROUND: The long-term prognosis after heart transplantation is mainly determined by the development of transplant vasculopathy. METHODS: The study included 23 patients undergoing diagnostic cardiac catheterization approximately 40 months after heart transplantation. Patients were classified into those with (n = 8) and those without (n = 15) angiographic evidence of transplant vasculopathy. Coronary flow velocity (by intravascular Doppler echocardiography) and epicardial coronary diameter (by quantitative angiography) were determined after intracoronary bolus injections (1 ml) of the endothelium-dependent dilator substance P (20 pmol) and the endothelium-independent dilators nitroglycerin (0.1 mg) and papaverine (8 mg). Substances were injected through the lumen of the Doppler catheter, which was placed into the midportion of the left anterior descending artery. RESULTS: Increases in blood flow velocity in response to substance P were significantly less in patients with than in patients without evidence of transplant vasculopathy. In addition, flow-mediated dilation of epicardial coronary arteries in response to papaverine was abolished in patients with such evidence. Vasodilation of epicardial coronary arteries in response to nitroglycerin and increases in flow velocity in response to papaverine were similar in both groups. CONCLUSIONS: These results suggest that transplant vasculopathy in heart transplant patients is associated with endothelial dysfunction (that is, impaired EDRF-mediated vasodilation). Furthermore, responsiveness of epicardial arteries to increased flow appears to be abolished in patients with evidence of transplant vasculopathy. These abnormal vascular functions may contribute to the pathogenesis of transplant vasculopathy and its vascular complications.

Adult↗
PubMed1993

The inferior epigastric artery for coronary bypass grafting. Functional assessment and clinical results.

The use of the internal thoracic artery (ITA) for coronary bypass grafting (CBG) has resulted in superior long-term function. Other autologous arteries have been investigated also, but the role of the inferior epigastric artery (IEA) for CBG has not yet been defined. From March 91 to August 92, IEA grafts were used in 50 male patients aged 30-68 years/mean 54.9) combined with 1 (n = 40) or 2 (n = 8) ITA grafts. Pedicled grafts were dissected (length: 8.5-16.5, 13.1 cm) but left in situ covered by sponges soaked with papaverine solution until going on bypass. There was no mechanical or pharmacological intraluminal manipulation. Distal free flow (in situ) was 41.8 ml/min (16-95 ml/min). A total of 146 grafts were constructed (2.9/patient), including free IEA-CBG performed to the LAD (n = 28) or its diagonal branches (n = 22). The operative mortality was 2.0%, there were no sternal wound complications but superficial abdominal infections in 5 patients. Recatheterization (1-6 months postoperatively) revealed an 82.6% patency rate (19/23) in IEA, compared to 100% in ITA, grafts. In vitro stimulation of arterial segments by endothelium- or muscular-dependent relaxation revealed a response (% of the maximum) of 92.4% in IEA and 74.6% in ITA to acethylcholine, while the response to nitroglycerin was 92.7% and 98.6%, respectively. Our clinical results would support the concept of combining IEA and ITA for arterial revascularization in CBG. Inferior epigastric artery grafts should provide adequate blood flow and good long-term patency due to preservation of their endothelial function.

Abdominal Muscles↗
PubMed1993

Chronic rejection following lung transplantation. Incidence, time pattern and consequences.

UNLABELLED: The long-term prognosis following lung transplantation (LTX) depends mainly on the development of chronic rejection which appears clinically as deterioration of the lung function while, histologically, obliterative bronchiolitis (OB) is found. However, it still remains questionable whether heart-lung (HL), double or single lung (DL/SL) transplants behave similarly with regard to incidence and time pattern. Eighty-two patients, transplanted until August 92, were analyzed. Early and late deaths within 180 days postoperatively were excluded. A total of 64 patients at risk could be evaluated. By repeated lung function tests, obstructive airway disease was defined by a drop of 25% or more of the forced expiratory volume in one second (FEV1) in percent of the inspiratory vital capacity. RESULTS: The functional optimum after transplantation was reached after a comparable time-span postoperatively in all groups. Chronic deterioration of the lung function developed earlier following DLTX compared to HLTX and SLTX. Obstructive airway disease was diagnosed in 9/20 (45%) HL, 7/19 (37%) DL, and 7/25 (28%) SL patients. Of these, 4 died and 4 had to be retransplanted for the disease while an additional 15 patients are currently under investigation. It is concluded that the development of obstructive airway disease represents a serious problem in all types of lung transplantation. There is a tendency to earlier development following DLTX--perhaps caused by the greatest immunological potential in this group of patients.

Adult↗
PubMed1993

The impact of early postoperative cyclosporine serum levels on the incidence of cardiac allograft rejection.

The introduction of cyclosporine A (CyA) into the immunosuppressive therapy has significantly improved the results of heart transplantation (HTX). Its nephrotoxicity and hepatotoxicity, however, often limit the perioperative and postoperative use of this drug. The purpose of this retrospective study was to evaluate the effect of early postoperative CyA blood levels on the incidence of early as well as late cardiac rejection and patients' survival. Between October 1985 and June 1991, HTX was performed in 311 patients. Standard immunosuppression consisted of azathioprine (1-2 mg/kg), prednisolone (0.5 to 0.1 mg/kg) and CyA. Rabbit-antithymocyte-globulin (RATG - 1.5 mg/kg) was administered for the first 4 days postoperatively. Moderate rejection was treated with 3 x 500 mg methylprednisolone, severe rejection with RATG (1.5 mg/kg three times a day). Patients were excluded from this study because of a positive cross-matching, early death unrelated to rejection or alternate forms of immunosuppression (n = 111). Follow-up was complete in 200 patients (mean age 44 +/- 11; 18 female, 182 male; 204,233 patient days) with a total of 5380 biopsies. The cohort was divided into group I (no CyA for day 0 to 2; n = 108) and group II (CyA during day 0 to 2; n = 92) according to the onset of CyA therapy. In 101 patients (group A) the mean CyA blood level was less than 150 ng/ml from day 0 to 14 and in 99 patients more than 150 ng/ml (group B).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Supraventricular bradycardia after heart transplantation--orciprenaline or pacemaker implantation?

Supraventricular bradycardia is an occasional complication after orthotopic heart transplantation. This study was undertaken to analyze the effectiveness of orciprenaline to increase heart rate and thus to avoid pacemaker implantation. Between January 1989 and December 1990, 109 patients underwent orthotopic heart transplantation at our institution, of whom 80 patients were included in the study (66 male, 14 female; age 9 to 62 years). Within the early postoperative period (< 14 days) 29 of 80 patients (36%) developed supraventricular bradycardia. Two patients underwent immediate pacemaker implantation, 27 patients were treated with oral orciprenaline (4-6 x 20 mg). 9 of the 27 patients (33%) showed an increase of the heart rate from 57 to 76/min, which remained sufficiently high after discontinuation of the drug. 18 patients (67%) did not respond to the drug (mean heart rate 45/min) and were scheduled for pacemaker implantation, which was performed in all except two. The period of orciprenaline application in both subsets of patients were comparable (postoperative day after HTX = POD 4.6-19.6 vs POD 5.9-23.2, Student's t-test: not significant). During the follow-up period of 6 months, none of the patients developed further bradycardia. However, 11 out the 18 patients with pacemaker implantation (61%) regained sufficient supraventricular rhythm (mean heart rate 96/min). In summary, orciprenaline application is able to prevent pacemaker implantation in one third of patients with sinus dysrhythmia after heart transplantation.

Adolescent↗