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Biomedical subjects

A Haverich

Publications and source records attributed to A Haverich.

At least 163 records · Page 9Linked to original sources
PubMed1999

[Coronary vasculopathy after heart transplantation--effect of temporal onset, severity and progression on long-term prognosis].

Despite considerable progress in the knowledge about pathophysiology of cardiac allograft vascular disease (CAVD), only few systematic studies are available, characterizing the natural course during long-term follow-up after heart transplantation (HTX). Therefore, we analyzed in 354 heart transplant recipients (305 male, 45.9 +/- 11.2 years, mean observation period 5.8 +/- 3.0 years, range 0.9-12.4 years) the results of 1129 coronary angiograms under the aspects of development, severity, localization, and progression of disease related to the prognosis of patients. As expected an increasing prevalence was found over time with a luminal obstruction > or = 30% in 83% of all patients more than 10 years after HTX. Coronary artery stenosis (> or = 50%) at initial diagnosis was predominantly localized in the LAD (46%) followed by RCX (31%) and RCA (23%). Angiographic risk profiles with an impaired prognosis could be identified in the form of an early development (< 4 years post HTX) of disease (p = 0.03), luminal obstruction > 50% (p = 0.001), and multivessel appearance at first diagnosis (p = 0.02) as well as in progressive forms of CAVD (p = 0.001). Summarizing, CAVD is a frequent finding in HTX recipients. Especially in patients with early onset, progressive, and advanced stages of disease it represents a prognostically limiting complication following HTX. Identification of the natural course is of major importance defining the need and efficacy of future palliative therapeutical approaches.

Adolescent↗
PubMed1999

Attitude of patients toward transplantation of xenogeneic organs.

BACKGROUND: The prospect of xenotransplantation has stimulated considerable hopes as well as major concerns. The question of whether or not patients accept xenografts is influenced not only by scientific facts but also by psychological factors. It was the aim of this study to analyze the attitudes of patients toward transplantation of xenogeneic organs and evaluate factors influencing these attitudes. METHODS: To this end, attitudes toward xenogeneic compared with allogeneic organ grafts were evaluated by means of detailed questionnaires in 1049 patients in Germany, who either had received transplants (n=722) or were on the waiting list for various organ grafts (n=327). Answers were correlated to demographic data as well as to the physical and mental conditions of the patients. RESULTS: The survey indicates that 77% of patients would accept xenografts while 7% would refuse them if results of xenotransplantation were comparable with those of allotransplantation. If xenotransplantation were associated with increased risks due to more intensive medication 58% would still basically accept xenografts. Acceptance of xenografts was significantly higher in patients who had received transplants and among males. Age, religion, waiting time, and type of organ were not found to influence acceptance rates. Xenografts were thought to be associated with considerable or severe emotional stress by 23% of patients, versus 3% for allografts. The pig was the preferred donor animal, and gene therapeutic manipulation for improvement of results would be accepted by 84%. Inadequate graft function/increased risk of rejection and risk of disease transmission were the major concerns for 60% and 52% of patients, respectively; emotional concerns were the major concerns for 24% and animal-rights concerns for 15%. CONCLUSIONS: These findings show that the potential acceptance rate of xenografts would be quite high, with a more positive attitude in transplanted patients than in waiting-list patients; there was no major difference in acceptance rate for various types of organs. Major concerns about xenotransplantation currently are functional inferiority and transmission of diseases.

Adult↗
PubMed1999

Progression of steroid-associated osteoporosis after heart transplantation.

BACKGROUND: Osteoporosis has been recognized as an important side effect of long-term and of pulsed steroid application after heart transplantation. METHODS: In June 1989 a prospective clinical trial was started to study bone demineralization by quantitative computed tomographic scan. All patients received vitamin D and calcium. In group I (n = 30) synthetic calcitonin (40 Medical Research Council Standard Units subcutaneously per day was administered in 14-day cycles, whereas group II patients (n = 31) received a placebo preparation. Repeat trabecular and cortical quantitative computed tomographic scans of the thoracic (T12) and lumbar spine (L1, L2, L3) were obtained within 48 weeks after heart transplantation. RESULTS: Expressed as the means of T12, L1, L2, and L3, trabecular bone density decreased significantly from 100+/-24 to 79+/-29 mg/mL within 3 weeks after heart transplantation, followed by a further reduction to 67+/-29 mg/mL after 3 months in the calcitonin group. The values for cortical bone density decreased significantly from 229+/-37 to 202+/-40 mg/mL (calcitonin) 3 weeks after heart transplantation. Comparable results were obtained in the placebo group. In both groups bone density remained stable thereafter. Intergroup differences were not of statistical significance. CONCLUSIONS: In heart transplant recipients progressive trabecular bone demineralization is limited to the first 3 postoperative months. Thereafter, bone density remained stable. A positive effect of synthetic calcitonin in addition to prophylactic calcium and vitamin D application could not be proved by repeat quantitative computed tomography.

Adult↗
PubMed1999

Experience with lung transplantation.

BACKGROUND: On the basis of a 5-year experience with heart transplantation and long-term animal experimentation, a lung transplantation program was instituted in 1987. After 10 years of experience, the entire patient population was reviewed. METHODS: Hospital records were reviewed to evaluate the underlying diagnosis, year of transplantation, type of procedure, and long-term follow-up. The changing scope of indications, procedures performed, and donor criteria, as well as survival data for various subgroups of high-risk candidates, were also examined. RESULTS: A total of 283 heart-lung (n = 46), single-lung (n = 94), and bilateral lung transplantation procedures (n = 143) were performed, with 22 patients undergoing 24 retransplantation procedures. The overall 5-year survival rate was 63%, with no difference between types of operations. Patients with cystic fibrosis, emphysema, pulmonary fibrosis, and secondary pulmonary hypertension showed similar survival rates; primary pulmonary hypertension was associated with a lower long-term survival. In all groups, the bronchiolitis obliterans syndrome occurred at a rate of approximately 15%/year. CONCLUSIONS: Acceptable long-term results can be obtained with lung transplantation. Because of expanded indications, no survival benefit was gained in the overall population over a 10-year period. The major obstacle to true long-term survival remains the bronchiolitis obliterans syndrome.

Adult↗
PubMed1999

Different approaches for minimally invasive closure of atrial septal defects.

BACKGROUND: To improve the acceptance of cosmetic results after closure of atrial septal defects, anterior or lateral thoracotomies are preferred rather than median sternotomies. Along with the availability of minimally invasive techniques, a further reduction in incision length appeared feasible while preserving thoracic stability. METHODS: Various minimally invasive approaches differing in the type of incision and mode of cannulation have been applied under conditions of normothermic ventricular fibrillation. In technique 1 (n = 5), a right parasternal mini-incision was combined with a central aortic and bicaval cannulation. Technique 2 (n = 2) was composed of an anterior submammary mini-incision with femoral arterial and central bicaval cannulation. To optimize the surgical access, the transincisional cannulation of the superior vena cava was replaced by a percutaneous cervical cannulation (technique 3, n = 17). RESULTS: Effective atrial septal defect closure assessed by intraoperative echocardiography was achieved in all patients. Central neurologic complications were completely absent. Besides temporary atrial fibrillation in one case, no other cardiac complications occurred. There were no cases with complicated wound healing. CONCLUSIONS: Along with modified cannulation techniques and intraoperative echocardiography, minimally invasive techniques can be safely applied for atrial septal defect closure. Submammary incisions were highly accepted and allowed for adequate surgical exposure.

Adolescent↗
PubMed1999

Coronary revascularization without cardiopulmonary bypass in patients with pectus excavatum.

BACKGROUND: Coronary revascularization in patients with pectus excavatum is technically difficult through a median sternotomy secondary to the posterior displacement of the sternum and the asymmetric angulation that it produces. The role of minimally invasive coronary artery bypass grafting (MIDCABG) in this subset of patients was evaluated. METHODS: In 1998, four patients with pectus excavatum underwent revascularization of the left anterior descending artery without cardiopulmonary bypass through a left anterior minithoracotomy. RESULTS: All patients underwent the procedure without intraoperative complications and postoperative angiography demonstrated adequate graft patency. CONCLUSIONS: The advantages of MIDCABG in patients with pectus excavatum is the superior exposure to the LAD and LIMA and avoidance of a median sternotomy and cardiopulmonary bypass. This procedure is deemed safe and effective in patients with such deformities of the chest wall.

Cardiopulmonary Bypass↗
PubMed1999

Human cytokine responses to coronary artery bypass grafting with and without cardiopulmonary bypass.

BACKGROUND: Coronary artery bypass grafting (CABG) is associated with a systemic inflammatory response. This has been attributed to cytokine release caused by extracorporeal circulation and myocardial ischemia. This study compares the inflammatory response after CABG with cardiopulmonary bypass and after minimally invasive direct coronary artery bypass grafting (MIDCABG) without cardiopulmonary bypass. METHODS: Cytokine release and complement activation (interleukin-6 and interleukin-8, soluble tumor necrosis factor receptors 1 and 2, complement factor C3a, and C1 esterase inhibitor) were determined in 24 patients before and after CABG or MIDCABG. The maximum body temperature, chest drainage, and fluid balance were recorded for 24 hours after operation. RESULTS: Release of interleukin-6, interleukin-8, and tumor necrosis factor receptors 1 and 2 was significantly higher (p < or = 0.005) in the CABG group than the MIDCABG group just after operation. After 24 hours, a significant increase in interleukin-6 was also found in the MIDCABG group (p = 0.001) compared with preoperative value. Body temperature and fluid balance were significantly higher after CABG (p < or = 0.001). CONCLUSIONS: Minimally invasive direct coronary artery bypass grafting represents a less traumatizing technique of surgical revascularization. The reduction in the inflammatory response may be advantageous for patients with a high degree of comorbidity.

Aged↗
PubMed1999

Transthoracic fistula with erosion of the ascending aorta along an IMA-protecting graft.

Internal mammary artery (IMA) graft protection with nonbiodegradable material, such as polytetrafluorethylene (PTFE), is recognized as an effective means for preventing overexuberant adhesion development as well as injury of retrosternally crossing arterial grafts in the event of resternotomy and should enable better identification of the IMA graft. It is still uncertain whether the use of PTFE material is suitable for diabetic patients with complete arterial revascularization due to potential infectious complications. We report on a young diabetic patient after arterial T-grafting due to severe coronary disease and readmission with wound infection and retrosternal fistula formation 8 months after operation.

Adult↗
PubMed1999

Volumetric remodeling of the proximal left coronary artery: early versus late after heart transplantation.

OBJECTIVES: The aim of this study was to characterize progression of cardiac allograft vasculopathy (CAV) with special respect to coronary artery geometry. BACKGROUND: As previously shown by intravascular ultrasound (IVUS), CAV is characterized by a multifocal intimal hyperplasia. Little is known, however, about vascular remodeling processes influencing vessel geometry and luminal narrowing. METHODS: In 30 heart transplant recipients serial IVUS studies were performed at baseline (BL) and after a mean follow-up period of 12.5+/-2.5 months. Changes in plaque, lumen and vessel volume were assessed in the proximal left anterior descending artery. Pattern of remodeling was analyzed in patients "early" (n = 15, BL study 1.4+/-0.7 months after heart transplantation [HTX]) compared with "late" after HTX (n = 15, BL 46.1+/-29.1 months). RESULTS: Plaque volume was found to increase by a mean of 23.8+/-25.9 mm3, not significantly different within and beyond the 1st year after HTX. Significant differences, however, were observed in changes in vessel volume with a mean decrease of -52.8+/-70.9 mm3 in the early group, whereas late follow-up group presented with an enlargement of 32.3+/-46.0 mm3. Based on these changes, lumen volume decreased by -73.2+/-69.8 mm3 early, in contrast to a slight increase of 5.2+/-32.6 mm3 in the late group. CONCLUSIONS: Progression of CAV is a complex process, modified by changes in the vascular geometry. Especially within the 1st year after HTX, luminal loss is influenced not only by an increase in plaque area but by a decrease in total vessel volume as well.

Adult↗
PubMed1999

Early angiographic results after revascularization by minimally invasive direct coronary artery bypass (MIDCAB).

OBJECTIVE: Anastomosing the left anterior descending artery (LAD) by use of the internal mammary artery (IMA) via an anterior minithoracotomy represents the most commonly performed minimally invasive direct coronary artery bypass (MIDCAB). However, little is known about angiographic results beyond patency rates. METHODS: Therefore, a retrospective analysis of 205 consecutive control angiographies was performed evaluating anastomototic patency as well as the angiographic morphology of the left IMA and the LAD. RESULTS: The overall anastomotic patency rate was 98.0%. As a result of incomplete IMA preparation (6-15 cm) large side branches (n = 4), or an IMA course under tension (n = 6) were occasionally observed. Despite a tension-free course, the IMA appeared fixed to the chest wall without functional compromise in 21 cases. A restrictive thrombus formation occurred once, IMA dissection was not seen. Two of the grafts developed spasms. A distal IMA stenosis >50% was seen in five cases. Stenosis of the anastomosis (>50%) itself was found once, as well as unexpected malinsertation to diagonal branches (n = 4). Compared with preoperative angiograms, de novo stenoses of the LAD were assessed proximal (14< or =50%, 2>50%) and distal (15< or =50%, 2>50%) to the anastomosis. Elevation of the LAD out of the vascular bed was an additional finding (n = 12) in a few cases. CONCLUSIONS: The overall patency of MIDCAB-LAD-grafting appears to be equivalent to conventional IMA grafting to the LAD. Particular angiographic findings, however, may be directly associated to the applied surgical technique.

Adult↗
PubMed1999

Celsior solution for improvement of currently used clinical standards of lung preservation in an ex vivo rat model.

OBJECTIVE: The introduction of Euro-Collins solution with its intracellular electrolyte composition has allowed for clinically accepted pulmonary preservation for up to 7 h of ischemic time. In recent years several alternative solutions have been developed for the improvement of pulmonary preservation. Celsior is an extracellular solution which has significantly reduced the ischemia/reperfusion (IR)-induced pulmonary damage in animal studies. So far, no larger experimental studies exist concerning the influence of Celsior on pulmonary gas exchange following IR. METHODS: In an extracorporeal rat lung model ten lungs, were each preserved with Celsior (CE) and Celsior/ prostacycline (CEPC, 6 mg/100 ml) at 4 degrees C and compared with preservation with low-potassium-Euro-Collins solution (LPEC, 40 mmol/l of potassium). After 2 h of ischemia the lungs were re-ventilated and reperfused using a roller-pump. Relative oxygenation capacity (ROC), pulmonary vascular resistance (PVR), peak inspiratory pressure (PIP) and wet/dry ratio were monitored for 50 min. Statistical analysis was performed using ANOVA. RESULTS: ROC was increased in all Celsior preserved organs compared with the EC group (P < 0.032). Though the CEPC group was found to have the lowest PIP and the least amount of lung water as assessed by wet/dry ratio, PVR was highest after 30-50 min. The significantly lowest PVR was determined in the CE group (P < 0.02). CONCLUSIONS: Celsior provides better lung preservation than LPEC solution, as demonstrated by a significantly increased oxygenation ability, a lower PVR and a decreased wet/ dry ratio. In vivo experiments and additional histological analysis are warranted for further evaluation of Celsior in lung preservation.

Analysis of Variance↗
PubMed1999

The use of gelatin-resorcin-formalin glue in acute aortic dissection type A.

OBJECTIVES: The Gelatin-resorcin-formalin (GRF) glue is widely used in the surgical treatment of dissecting aneurysms. This paper is focused on our experience with the GRF glue in cases, operated for acute aortic dissection type A. METHODS: Between September 1990 and December 1997, 164 patients were operated on for acute aortic dissection type A. In 148 patients GRF was used to reinforce the dissected layers proximal (n = 106) or distal (n = 144) of the grafted aortic segment. An intervention at the aortic valve was necessary in 93 instances. In 111 patients, an open distal anastomosis for replacement of the proximal aortic arch was performed. Thirty-seven additional patients underwent subtotal or total aortic arch replacement. RESULTS: Early postoperative mortality was 26.2% (43/164 patients). Another 16 patients died late postoperatively. Actuarial survival rates are 69.9% at 1 year, 62.5% at 3 years, 59.4% at 5 years and 56.1% at 7 years, post-operatively. Twenty-two reoperations were performed in 20 patients (16.5%). Nine of these patients had developed complications in aortic segments that underwent reconstruction by use of GRF during the primary intervention. Aortic root redissection was found in 7/9 patients intraoperatively, whereas 1/9 patients presented with a rupture near the distal graft to aortic anastomosis. CONCLUSIONS: The introduction of GRF glue has greatly facilitated the reconstruction of dissected aortic wall layers adjacent to the vascular graft. However, the use of the adhesive for aortic root reconstruction in acute aortic dissection type A may bear a significant risk of late postoperative proximal aortic redissection. Complications associated with the GRF glue are likely to be due to the toxic effects of the formalin component. Therefore, care should be taken that the amount of formalin administered to the glue components remains as low as possible.

Acute Disease↗
PubMed1999

Replacement of ascending aorta with aortic valve reimplantation: midterm results.

OBJECTIVE: Aneurysms of the aortic root lead to aortic valve incompetence due to dilatation of the sinotubular junction and annuloaortic ectasia. Reimplantation of the native, structurally intact aortic valve within a Dacron tube graft corrects annular ectasia as well as dilatation of sinotubular junction and aortic sinuses. Durability of this valve repair with respect to increased mechanical stress on valve cusps is discussed controversially and is yet unknown. METHODS: Since 7/93, replacement of the ascending aorta with repair of the aortic valve was performed in 48 patients (34 male, 14 female; 47+/-20 years) with aortic insufficiency and aneurysm of the aortic root. Fifteen patients (31%) had Marfan's syndrome and five patients (10%) had an aortic dissection type A (two acute, three chronic). In 11 patients (23%), concomitant replacement of the aortic arch was necessary utilizing elephant trunk technique in two patients. Additionally, one patient required mitral valve repair and two other patients coronary artery bypass grafts. Clinical and echocardiographic follow-up was performed in 6-12 month intervals for a cumulative study period of 100 patient years. RESULTS: There were no operative deaths. Two patients (4%) died 5 and 20 months postoperatively. One additional patient experienced a TIA within the first postoperative week. Three patients (6%) with an early postoperative aortic insufficiency (AI) > 1 required aortic valve replacement after 9, 11, and 14 months due to progressive AI. In these patients, distortion of the aortic root geometry led to valve incompetence. All other patients have no or mild aortic insufficiency. The repair now remains stable for up to 63 months (mean 25+/-18 months). Other valve related complications did not occur. CONCLUSIONS: Our results demonstrate that this type of aortic valve repair achieves excellent results in selected patients. Perfect coaptation of valve cusps during the repair with no or only trace AI at initial echocardiography seems to be essential for durability.

Adolescent↗
PubMed1999

Two-stage repair of a combined aneurysm of the descending aorta and the aberrant right subclavian artery.

In cases of combined aneurysms of the descending aorta and the aberrant right subclavian artery a common surgical strategy has not been clearly elaborated. In this report the case of a 76-year-old male patient with this rare combination of aneurysms is presented. The surgical strategy consisted of a two-stage approach for repairing both aneurysms maintaining the perfusion of the right subclavian and vertebral artery, finally providing an excellent postoperative result even in a patient of this advanced age.

Aged↗
PubMed1999

Lung transplantation--10-year experience.

OBJECTIVE: The experience at our institution with various forms of lung transplantation (heart-lung, double lung and single lung) from December 1987 to September 1998 is reviewed and discussed. METHODS: During this decade, 282 procedures (46 heart-lungs (HLTx), 142 double lungs (DLTx) and 94 single lungs (SLTx)) have been performed in 258 patients (140 male, 118 female; age: 38 +/- 13 years). Major indications included pulmonary fibrosis (n = 73), obstructive lung disease (n = 55), cystic fibrosis (n = 48), primary pulmonary hypertension (n = 36), secondary pulmonary hypertension (majority Eisenmenger's syndrome) (n = 30), and retransplantation (n = 24). RESULTS: Early postoperative mortality (<90 days) was 13.9% (n = 36). The 1-, 3-, and 5-year survival rates in all recipients was 77, 70 and 63%, respectively. There was no significant difference in 1-year survival rates between the different procedures (HLTx: 78%, DLTx: 77%, SLTx: 77%). Significantly better 1-year survival was achieved in patients with cystic fibrosis (89%), pulmonary fibrosis (81%), obstructive lung disease (74%), and Eisenmenger's syndrome (83%) when compared to patients with primary pulmonary hypertension (55%). Survival rates remained unchanged during this period despite expanding indications during the last years. Causes of death in 90 recipients (HLTx: n = 19, DLTx: n = 37, SLTx: n = 34) included sepsis (n = 42), obliterative bronchiolitis (n = 28), cardiac failure (n = 5), and early allograft dysfunction (n = 2). Freedom from bronchiolitis obliterans syndrome (BOS) (>stage I ISHLT) was 80% at 1 year and 45% at 5 years. CONCLUSIONS: Lung transplantation offers a true therapeutic option with good early and midterm results. Yet, chronic graft dysfunction represents a major obstacle for long-term benefit of this procedure.

Adolescent↗
PubMed1999

Influenza vaccination in heart transplant recipients.

Seventy-nine heart transplant recipients were vaccinated with a trivalent influenza virus vaccine 1996/97 containing the strains A/Singapore/6/86 (H1N1), A/Wuhan/395/95 (H3N2), and B/Beijing/184/93. The proportions of patients with protective levels of antibody (HI > or = 40) after vaccination ranged from 100% (A/Singapore [H1N1]) to 31.6% (B/Beijing) and their mean fold titer increases were lower than those recorded for vaccination of 109 healthy subjects with the same batch of vaccine. The vaccinations were tolerated well and did not result in serious side effects, such as graft rejections. Our findings indicate that influenza vaccination can induce protective antibody levels in a substantial proportion of heart transplant recipients and lend support to the recommendation to vaccinate such patients annually against influenza.

Antibodies, Viral↗