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R Körfer

Publications and source records attributed to R Körfer.

At least 55 records · Page 3Linked to original sources
PubMed2000

[Congenital tubular supravalvular aortic stenosis with massive coronary artery dilatation in a 35-year-old man].

Supravalvular aortic stenosis is a rare cause of left ventricular outflow obstruction in adults. It occurs as an isolated defect sporadically or on a hereditary basis with an autosomal dominant trait without further phenotypical anomalies, or as part of the Williams syndrome with mental retardation and multiple other anomalies. This lesion was proved to result from a defect of the elastin coding gene. Supravalvular aortic stenosis is frequently associated with cardiovascular defects, particularly of the peripheral pulmonary arteries, thoracic aorta, carotid, subclavian, and coronary arteries and the aortic valve. The coronary arteries are subject to an increased perfusion pressure leading to dilatation, tortuosity and accelerated arteriosclerosis. We give details of a 35-year-old patient in whom a previously asymptomatic supravalvular aortic stenosis is associated with an excessive dilatation of the right coronary artery and the left anterior descending coronary artery as well as an ostium stenosis of the left common carotid artery. The patient did not present any phenotypical anomalies of the Williams syndrome.

Adult↗
PubMed2000

[Aortic isthmus stenosis with open ductus Botalli as etiology of severe heart failure in a 36-year-old patient--case report of successful surgical treatment].

We report on the history of a 36-year-old woman with untreated coarctation of the aorta and patent ductus arteriosus who developed refractory heart failure due to severely impaired left ventricular function. After coarctation repair and duct resection, left ventricular function improved to normal. Even in the presence of longstanding left ventricular pressure and volume overload, subsequent severe myocardial failure may be reversible by surgical repair.

Aortic Coarctation↗
PubMed2000

Novacor left ventricular assist system versus Heartmate vented electric left ventricular assist system as a long-term mechanical circulatory support device in bridging patients: a prospective study.

OBJECTIVE: Long-term mechanical circulatory support as a bridge-to-transplantation procedure and bridge to recovery is of increasing importance. The implantable left ventricular assist devices, Novacor N100 left ventricular assist system (Baxter Healthcare Corporation, Berkeley, Calif) and TCI HeartMate vented electric left ventricular assist system (Thermo Cardiosystems Inc, Woburn, Mass), have proved to be efficient devices in bridge-to-transplantation settings and for prolonged support. The two systems were compared with regard to reliability and morbidity. METHODS: Between October 1996 and March 1998, a prospective, single-center study was done that included 40 patients, 20 of whom were treated with the Novacor system and 20 of whom were treated with the HeartMate device. The diseases were mainly dilated cardiomyopathy (13/9) and ischemic cardiomyopathy (6/10). There were no statistically significant differences between the two groups regarding age, sex, preoperative clinical blood chemistry values, hemodynamic data, or risk factors. RESULTS: There were no statistically significant differences between the two groups with regard to postoperative hemodynamics, organ recovery, out-of-hospital support, and survival to heart transplantation. Mean duration of support was 235.3 +/- 210 days for the Novacor group and 174.6 +/- 175 days for the HeartMate group and mean out-of-hospital support was 241 +/- 179 days and 166 +/- 152 days for the two groups, respectively. Neurologic complications occurred significantly more often among the Novacor group, whereas the HeartMate group had a higher prevalence of infections and technical problems, which was statistically significant. Survival to transplantation was 65% for the Novacor group and 60% for the HeartMate group. CONCLUSIONS: Most patients had organ recovery with left ventricular assist system support, and a considerable number of patients in both groups underwent transplantation. However, both devices need revision to address the current problems, that is, thromboembolism for the Novacor device and infection and reliability for the HeartMate device.

Female↗
PubMed2000

Single-center experience with the thoratec ventricular assist device.

OBJECTIVE: The Thoratec ventricular assist device (Thoratec Laboratories, Pleasanton, Calif) is widely accepted for univentricular and biventricular support in patients with various indications. The aim of this study is to describe our experience with implantation of the Thoratec ventricular assist device in more than 100 patients. METHODS: From March 1992 to June 1998, 114 patients (98 men and 16 women; mean age, 47.9 years) received the Thoratec ventricular assist device for a mean duration of 44.9 days. The patients were divided into 3 groups. Group 1 included 84 patients in whom the system was applied as a bridge-to-transplant procedure. Group 2 included 17 patients with postcardiotomy cardiogenic shock, and group 3 included 13 patients with cardiogenic shock of other causes. RESULTS: Sixty-eight percent of patients in group 1 survived to transplantation with a posttransplant survival of 88%. The only independent risk factor affecting survival was age more than 60 years. Survivals in groups 2 and 3 were 47% and 31%, respectively. Main complications in all groups were bleeding, multiple organ failure, liver failure, sepsis, and neurologic disorders. CONCLUSIONS: The Thoratec ventricular assist device has proved to be a reliable device for bridge to transplantation and postcardiotomy support. Further studies are required on patient selection and on patient and device management to reduce the incidence of complications in these patient populations.

Adolescent↗
PubMed2000

Predictors of survival in patients bridged to transplantation with the thoratec VAD device: a single-center retrospective study on more than 100 patients.

BACKGROUND: Careful patient selection markedly influences the outcome of patients who undergo mechanical circulatory support. Therefore, we tried to evaluate predictors of survival after implantation of the Thoratec ventricular assist device (VAD). METHODS: Between October 1992 and January 2000, 104 patients (86 men, 18 women, aged 11 to 69 years) received the Thoratec VAD as a bridge to transplant. A total of 51 patients required left ventricular support (LVAD), 50 patients required biventricular support (BVAD), and 3 patients required total artificial heart implantation. We performed univariate analysis of 25 parameters with regard to their effect on survival and then applied a multivariate analysis to evaluate those factors that turned out to be marginally significant. We performed all analysis for the total collective as well as for the LVAD and BVAD sub-group. RESULTS: The BVAD patients tended to have worse outcomes than did LVAD patients. We found no significant predictors of survival in either sub-group. In the total collective, however, we found the following pre-implant conditions were independent risk factors for survival after VAD implantation: patient age > 60 years (odds ratio [OR] 3.87, confidence interval [CI] 1.39 to 10.76), pre-implant ventilation (OR, 6.76; CI 2.42 to 18.84), and increased pre-implant total bilirubin (OR, 1.42; CL, 1.19 to 1.69). CONCLUSIONS: Transplant candidates on inotropic support should be considered for bridging to transplant as soon as bilirubin values start to increase or before respiratory function deteriorates and ventilation becomes necessary. In elderly patients, careful patient selection, particularly considering potential risk factors, might favorably affect their outcomes.

Adolescent↗
PubMed2000

Force-generating preparation from human atria as a model for studying myocardial uptake of radiopharmaceuticals.

UNLABELLED: The aim of this study was to assess whether an in vitro preparation of force-generating human atrial trabeculae driven by external electrical stimulation is a suitable model for determining myocardial uptake of cardiotropic radiopharmaceuticals. METHODS: Human atrial trabeculae were excised from specimens removed during cardiac surgery for insertion of heart-lung apparatus. Preparations were kept under physiologic conditions in a chamber continuously perfused by Tyrode's solution at 37 degrees C under permanent oxygenation. Electrical stimulation was performed at a frequency of 1 Hz. Contractile response was continuously measured by a force transducer and registered by a lineacorder. The optimum length of the trabeculae was achieved by stepwise increases of 0.1 mm muscle length. A premixed solution containing 1.92-4.06 MBq 201TI-TICI was added to the perfusate of the chamber. After 10, 30, and 60 min, respectively, of incubation with 201TI-TICI, the atrial trabeculae were removed from the chamber and their activity was measured by a gamma counter. These experiments were repeated with nonviable trabeculae pretreated by potassium cyanide (KCN). Myocardial uptake values were measured as cts/min, normalized to cts/min/mg, and expressed as percentages of cts/mL/min in the perfusate (RUP). RESULTS: Thallium uptake was found to be dependent on the functional integrity of the tissue preparations and increased over time in intact atrial trabeculae. RUP was 325% +/- 108% after 10 min of incubation and rose to 838% +/- 160% and 1196% +/- 493%, respectively, at 30 and 60 min of incubation (P < 0.01). After 30 min of incubation, RUP was significantly higher in viable than in nonviable trabeculae (838% +/- 160% versus 90% +/- 65%; P < 0.01). CONCLUSION: These preliminary results indicate that the model proposed is suitable for studying the mechanisms of uptake of cardiotropic radiopharmaceuticals by human myocardial tissue.

Biological Transport↗
PubMed2000

Implantation of the Biomedicus centrifugal pump in post-transplant right heart failure.

BACKGROUND: Right heart failure after heart transplantation represents a life-threatening complication. When conventional therapy including NO-inhalation fails the only choice to reach sufficient haemodynamic conditions may be the implantation of a right ventricular support system. METHODS: In all cases the Biomedicus centrifugal pump was implanted by cannulation of the right atrium and pulmonary artery. RESULTS: Since March 1989 950 heart transplant procedures were performed at our center. In nine cases (7 male, 2 female, mean age 52 years) implantation of a right ventricular support system was necessary because of deterioration of right ventricular function. The implantation was carried out in 7 cases immediately after transplantation, in 2 cases after 2 days. The support time ranged from 4-348 hours. Six patients could be weaned, 2 patients underwent retransplantation and died and 1 patient died on the support system. Three of the six weaned patients died in the further course because of multiorgan failure. CONCLUSIONS: Mechanical right ventricular support is often the only therapeutical tool to reach adequate haemodynamic conditions in post-transplant right heart failure. The Biomedicus centrifugal pump provides good conditions in these cases. Weaning is often possible after short-term support. The mortality rate is determined by multiorgan failure in immuno-suppressed patients. Retransplantation seems not to be successful despite maximal treatment.

Extracorporeal Circulation↗
PubMed1999

[Post-traumatic pyoderma gangrenosum: combination therapy with intravenous immunoglobulins and systemic corticosteroids].

Pyoderma gangraenosum is a rare, chronic type of skin ulceration of unknown aetiology. It occasionally appears following trauma. There are no set standards for the treatment of pyoderma gangraenosum. It is essential to consider acuteness of progression as well as underlying systemic diseases and possible drug side effects before initiating a therapy. Immunosuppressive as well as immunomodulating agents are most often used with varying degrees of success. We report a 45-year-old patient who suffered from an extensive posttraumatic pyoderma gangraenosum after cardiac bypass operation. With short-term combination therapy consisting of high dose intravenous immunoglobulins and systemic corticosteroids, the progression of the disease could be stopped within a few days.

Anti-Inflammatory Agents↗
PubMed1999

Thoracic and cardiovascular interventions after orthotopic heart transplantation.

BACKGROUND: The long-term outcome of orthotopic heart transplantation is limited by the development of cardiac allograft vasculopathy, rejection, infection, and malignancy. METHODS: After heart transplantation, we treated patients with thoracic and cardiovascular diseases: preexisting coronary artery sclerosis in 2 patients, cardiac allograft vasculopathy in 19, valvular disease in 3, mycotic ascending aortic aneurysm in 2, superior vena cava stenosis in 2, and lung neoplasm in 10 patients. RESULTS: We successfully performed coronary artery bypass grafting for preexisting coronary artery sclerosis, valve replacement for valvular disease, and patch enlargement for superior vena cava stenosis. Percutaneous transluminal coronary angioplasty for cardiac allograft vasculopathy achieved excellent initial results, but the incidence of restenosis was high (67%). One patient who underwent coronary artery bypass grafting for cardiac allograft vasculopathy died immediately after operation. Graft replacement was performed for mycotic aortic aneurysm, but 1 patient required reoperation because of recurrent aneurysm. The long-term survival rate in patients undergoing surgical resection for lung neoplasm was poor (50%). CONCLUSIONS: The need for thoracic and cardiovascular interventions in patients after heart transplantation was low (4.7%). Use of the appropriate procedures can improve the long-term survival after heart transplantation.

Adolescent↗
PubMed1999

Temporary pulsatile ventricular assist devices and biventricular assist devices.

BACKGROUND: During the past years several systems for mechanical circulatory support have become available. In this study we describe our experience with short-term and mid-term application of the ABIOMED and Thoratec device. METHODS: Since 1990 the ABIOMED BVS and since 1992 the Thoratec VAD have been applied to 75 and 103 patients, respectively, with postcardiotomy heart failure, as a bridge-to-transplant procedure, and with different other indications. RESULTS: In the ABIOMED collective 25 of 50 patients (50%) with postcardiotomy heart failure and 1 of 4 patients with miscellaneous other indications could be discharged from hospital, 7 of 14 bridge-to-transplant patients (50%) underwent transplantation with a posttransplant survival of 86%. In the Thoratec collective 6 of 10 patients (60%) with postcardiotomy heart failure and 4 of 8 patients (50%) with miscellaneous indications could be discharged from hospital, 48 bridge-to-transplant patients (74%) underwent transplantation with a posttransplant survival of 90%. CONCLUSIONS: The results show the versatility of the Thoratec VAD for short-term and mid-term application in patients with postcardiotomy heart failure and as a bridge-to-transplant procedure. The use of the ABIOMED device is not indicated for bridging patients to transplantation. Although in case of postcardiotomy heart failure, Thoratec is also superior to ABIOMED, the high costs of the Thoratec VAD limits its wide acceptance in this patient cohort.

Adult↗
PubMed1999

New technique for the outflow cannulation of right ventricular assist device.

Cannulating the outflow cannula of a right ventricular assist device (RVAD) through the main pulmonary artery is often troublesome because of extensive dissecting adhesion. We implanted RVADs using the new technique for outflow cannulating through the right pulmonary artery between the ascending aorta and the superior vena cava. With this technique, we needed only a little dissection and no cardiopulmonary bypass. This technique could make RVAD implantation simple, quick, and safe.

Aorta↗
PubMed1999

Results after Norwood procedure and subsequent cavopulmonary anastomoses for typical hypoplastic left heart syndrome and similar complex cardiovascular malformations.

OBJECTIVE: From October 1989 to June 1998, 60 patients have undergone the Norwood procedure (stage I) at our institution. The results of the staged surgical reconstruction and risk factors were analysed. Typical hypoplastic left heart syndrome (HLHS) and complex lesions with aortic hypoplasia were compared with each other. PATIENTS: Typical HLHS: N = 48, median age 15 days (5-190 days), median weight 3.6 kg (2.6-5.3 kg). Complex lesions (dominant left ventricle): N = 12, median age 59 days (10-884 days), median weight 3.4 kg (2.4-12 kg). RESULTS: Typical HLHS: The stage-I hospital survival was 73% (35/48). It improved from 60% (95% confidence interval: 49-71%) during 1989-1994 to 91% (95% CI: 81-100%) during 1997-1998. Seven patients were lost late. The right ventricular end diastolic diameter (P = 0.015), shortening fraction (P = 0.027), and the presence of an obstructed pulmonary venous return (P = 0.0032) were significant risk factors. 23 children underwent stage-II operation with four (17%) deaths. All survivors experienced an improvement of their statomotoric development. Stage-III operation was performed in 13 patients with no hospital death. Follow up after stage-III procedure was 7 months to 7 years. 4 year actuarial survival, including hospital mortality and deaths at subsequent stages, improved from 28% (95% CI: 18-38%) during 1989-1994 to 58% (95% CI: 48-68%) during 1994-1997. No patient had signs of myocardial insufficiency. Complex lesions: Stage-I hospital survival was 83% (10/12) with no late death. Stage-II was performed in 8 and stage-III in 6 patients with no death respectively. CONCLUSION: In typical HLHS the results have improved over time. Both size and function of the right ventricle determined significantly stage-I survival. An early operation prevents the natural progression of pulmonary blood flow and may weaken all three risk factors. Patients with complex lesions seemed to have better chances of surviving the early postoperative period. The multistage reconstructions have become a realistic option for patients with HLHS and similar lesions, regardless of the morphologic subtype or diminutiveness of the aorta, and lead to an acceptable quality of life.

Abnormalities, Multiple↗
PubMed1999

Bridging to cardiac transplantation with the Thoratec Ventricular Assist Device.

Mechanical circulatory support has become an established procedure for bridging patients to cardiac transplantation. One of the devices available is the Thoratec VAD, which can be applied for univentricular or biventricular support. Between March 1992 and June 1997, 74 patients were bridged with Thoratec VAD to cardiac transplantation. In 67 patients the system was applied exclusively (26 LVAD, 38 BVAD, 3 TAH), in 7 patients subsequently or in combination with another MCS device. 71.6% with exclusive Thoratec application underwent transplantation with a post-transplant survival rate of 90%, 4 patients are still waiting. Transplant rate in LVAD and BVAD patients was 84% and 71.4%, respectively, posttransplant survival 95.2% and 88%, respectively. 28.6% with a combined application of Thoratec and another MCS device survived to be discharged from hospital. Main complications were bleeding, liver failure, multiple organ failure, and infections. In terms of reliability and efficacy the Thoratec VAD is the system of choice for mid-term application in patients bridged to cardiac transplantation.

Equipment Design↗
PubMed1999

Altered levels of mRNA of apoptosis-mediating genes after mid-term mechanical ventricular support in dilative cardiomyopathy--first results of the Halle Assist Induced Recovery Study (HAIR).

BACKGROUND: Ventricular assist devices (VADs) lead to an immediate unloading of the failing heart. Although VADs are used as a bridge to transplant, in some cases patients suffering from dilated cardiomyopathy have been weaned from the VAD without transplantation after a recovery process initiated by the cardiac support. Myocardial apoptosis is associated with inadequate myocardium and might be reverted during VAD support of the failing heart. Therefore we measured transcription of apoptosis-associated genes FasExo6 Del, Fas-receptor, and Bcl-xL as markers of a putative recovery. METHODS: Fas-receptor, its soluble isoform FasExo6Del, and Bcl-xL mRNA were quantified by standard calibrated competitive reverse-transcription polymerase chain reaction (PCR) in 6 patients suffering from dilated cardiomyopathy. RNA standards were prepared by introducing 100 bp deletions into the native cDNA, resulting in truncated PCR products with identical primer-binding sites. Standards were transcribed in vitro and the resulting RNA was quantified. RESULTS: Transcription of apoptosis-inhibiting genes FasExo6 Del and Bcl-xL were upregulated in patients supported for more than 6 weeks. Fas receptor mRNA remained unaffected by VAD support. CONCLUSIONS: Transcriptional upregulation of apoptosis-inhibiting genes might be caused by a desensitization to apoptotic stimuli and might indicate a relaxation of the diseased status of the myocardium. These data outline the first biochemical evidence of a remodelling process occurring in supported ventricular myocardium.

Apoptosis↗
PubMed1998

Aortic valve surgery following previous coronary artery bypass grafting. Impact of calcification and leaflet movement.

We reviewed the reports of 27 patients who had an aortic valve replacement after previous coronary artery bypass grafting. The aortic valve disease -- mainly aortic stenosis -- showed a rapid rate of progression. In the time interval between coronary artery bypass grafting and aortic valve replacement of 4.6+/-2.2 years the peak-to-peak pressure gradient of the aortic valve rose from 20.2+/-14.3 to 63.0+/-22.7 mmHg. As there is a great interest to identify the patients with a high risk of a rapid progression because of a high mortality of an aortic valve replacement as the second cardiac operation following a coronary artery bypass grafting we also reviewed the cardiac catheterisation films and found a high incidence of calcification and impaired aortic valve motion (81.5% of the patients had already calcified aortic valves and 81.5% had a impaired valve motion) at the time of coronary artery bypass grafting. We concluded that if a patient has to be operated for coronary artery disease an aortic valve replacement should be considered not only according to hemodynamic criteria but also when the aortic valve is calcified or its leaflets' motion is impaired.

Aged↗