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Biomedical subjects

B Reichart

Publications and source records attributed to B Reichart.

At least 145 records · Page 8Linked to original sources
PubMed1998

Minimally invasive coronary artery bypass grafting: port-access approach versus off-pump techniques.

BACKGROUND: Within the past 5 years several surgical techniques have been developed for less invasive surgical treatment of coronary artery disease. The aim of this study was to define specific indications for the various minimally invasive coronary artery surgical procedures. METHODS: Minimally invasive direct coronary artery bypass grafting through a minithoracotomy was performed in 67 patients. The left internal mammary artery was anastomosed on the beating heart with the use of a pressure or suction stabilizer without the use of extracorporeal circulation. In 58 other patients with multivessel disease, the off-pump coronary artery bypass grafting technique through a sternotomy was applied with a left internal mammary artery to left anterior descending artery and additional vein grafts without extracorporeal circulation. In a third group, Port-Access (Heartport Inc, Redwood City, CA) coronary artery bypass grafting was performed through a left minithoracotomy with the use of an endovascular extracorporeal circulation system and cardioplegic arrest. Angiographic follow-up was complete in 64% of the patients. RESULTS: There was minimal perioperative or postoperative mortality (0.5%). The medium surgical procedure time for all minimally invasive and off-pump procedures was 2.5 hours; it was 4.5 hours for Port-Access procedures. The median postoperative intensive care unit stay was 1.0 days, and the median hospitalization was 5.0 days. Overall graft patency was 97.3%; in 8 patients (4.1%) a stenosis either at or distal to the graft anastomosis was dilated with coronary angioplasty. CONCLUSIONS: For single-vessel disease of the left anterior descending artery, the minimally invasive coronary artery bypass grafting procedure can be performed safely without the use of extracorporeal circulation. In case of hemodynamic instability or anatomic variation, the Port-Access procedure can be applied without additional necessity for sternotomy. For multivessel disease, the off-pump bypass grafting procedure with sternotomy can be recommended depending on the coronary arteries involved. In case of necessary grafts to the lateral marginal or circumflex branches, Port-Access grafting can be recommended and may play an important role in the future for the development of fully endoscopic robot-assisted coronary artery bypass grafting.

Adult↗
PubMed1998

Reduction of wound healing problems after median sternotomy by use of retention sutures.

Obese people have a higher risk of sternal wound dehiscence resulting from traction of suprasternal tissue. In such patients we recommend the use of retention sutures with extracorporeal plates to improve tissue connection and to disburden fascia and skin sutures. This augmented closure is simple and effective and, since 1996, has prevented wound healing problems in more than 50 patients with a body mass index greater than 27.

Body Mass Index↗
PubMed1998

Nitric oxide and endothelin in the development of cardiac allograft vasculopathy. Potential targets for therapeutic interventions.

Extensive research has been carried out in recent years to discover the potential risk factors contributing to cardiac allograft atherogenesis. Injury to endothelial cells has been regarded as an important early mechanism in the development of transplant atherosclerosis; it leads to the manifestation of epicardial and microvascular endothelial dysfunction and development of intimal hyperplasia. Moreover, continuous minor endothelial cell damage contributes to endothelial dysfunction which reflects one of the first measurable steps in the cascade of atherogenesis without macroscopic evidence of vascular lesions. The discovery of two important vasoactive substances nitric oxide (NO) and endothelin (ET) has brought new insights but also new unsolved questions regarding the mechanisms leading to atherosclerosis. To date it is known that both substances play a major role in both prevention and development of atherosclerosis. NO appears to be protective in low concentrations by inhibiting leukocyte and platelet activation/adherence and smooth muscle cell proliferation. Impaired endothelial NO production, as one cause of endothelial dysfunction may occur in early stages of atherosclerosis before macroscopic lesions are evident. In addition, increased endothelin release also results in endothelial dysfunction by inducing vasoconstriction; it promotes vascular lesion formation due to endothelial- and vascular smooth muscle cell proliferation. Direct and indirect manipulation of both the NO and ET signal transduction systems may provide novel preventive and therapeutic approaches for limiting transplant atherogenesis and to treat native atherosclerosis. This review summarizes important experimental and clinical evidence which points to nitric oxide and endothelin as potential therapeutic targets in the process of cardiac allograft vasculopathy.

Animals↗
PubMed1998

Long-term prognosis of surgically-treated aortic aneurysms and dissections in patients with and without Marfan syndrome.

OBJECTIVE: Aortic aneurysms and dissections are the leading causes of premature death in Marfan syndrome (MfS). This study aims to compare long-term results of surgically treated aortic aneurysms and dissections in patients with and without MfS in respect to early and late prognosis. METHODS: From March 1975 to August 1994, 33 patients with classic MfS (group A, age 34.2 +/- 9 years) and 298 patients with non-fibrillinopathic aortic disease (group B, age 54 +/- 13 years) underwent aortic surgery. Acute dissections occurred in 57.6 (A) versus 37.9% (B). A total of 54.6% of patients in group A were treated with a composite graft versus 16.4% in B. The aortic arch and the descending aorta was replaced in 30.4% of MfS patients and 24.9% of patients without MfS. RESULTS: We observed 7 (25.0%, A) versus 35 (14.2%, B) late deaths among the 28 (A) versus 247 (B) early survivors. In 5 patients (17.9%) of A and 8 patients (3.2%) of B, late death was caused by redissection or recurrent aneurysm (P < 0.001). Long-term survival after 5, 10 and 15 years in group A was 82 +/- 7, 60 +/- 11 and 30 +/- 22%, and 75 +/- 3, 69 +/- 3 and 64 +/- 4% in group B. A total of 22 reoperations were performed in 11 MfS patients, 17 reoperations were due to recurrent aortic diseases. Three of the 8 patients underwent reoperation after Wheat procedure because of sinus valsalva aneurysm. None of the patients with composite graft replacement needed reoperation in this segment, but 3 patients suffered from redissection at the proximal aortic arch. In group B, reoperations were significantly less frequent (10.7%) compared to MfS patients (66.7%; P < 0.001). CONCLUSIONS: Surgical treatment of aortic disease in MfS patients is associated with a high risk of redissection and recurrent aneurysm. If the ascending aorta needs to be replaced, we recommend the composite graft technique and a more aggressive approach to reduce the frequency of distal reoperations. In order to reduce the high reoperation rate in MfS patients, frequent clinical follow-up may contribute to improve life expectancy in MfS patients.

Adult↗
PubMed1998

Central venous pressure, pulmonary capillary wedge pressure and intrathoracic blood volumes as preload indicators in cardiac surgery patients.

OBJECTIVE: Monitoring of cardiac preload is mainly performed by measurement of central venous and pulmonary capillary wedge pressure in combination with assessment of cardiac output, applying the pulmonary arterial thermal dilution technique. However, the filling pressures are negatively influenced by mechanical ventilation and the pulmonary artery catheter is criticized because of its inherent risks. Measurement of right atria, right ventricular, global end diastolic and intrathoracic blood volume index by arterial thermal dye dilution utilizing the COLD-system may represent an alternative. METHODS: In 30 CABG patients with an uncomplicated postoperative course the mentioned parameters were measured 1, 3, 6, 12 and 24 h postoperatively to prove their qualification as preload indicators: As patients received no inotropic support, changes of cardiac index and stroke volume index must correlate to changes of presumably preload indicating parameters. RESULTS: When arterial and pulmonary arterial thermal dilution were compared, no differences were found; the correlation coefficient being 0.96, the bias 0.16 l/min per m2 (2.4%) and coefficients of variation did not exceed 7%. Changes of central venous pressure, capillary wedge pressure, right atrial end diastolic volume index and right ventricular end diastolic volume index did not correlate at all to changes of cardiac and stroke volume index (coefficients ranged from -0.01 to 0.28). In contrast, intrathoracic and global end diastolic blood volume indices with coefficients from 0.76 to 0.87, did show a good correlation to cardiac and stroke volume index. CONCLUSION: Central venous pressure, capillary wedge pressure, right atrial and right ventricular end diastolic volumes are no suitable preload parameters in cardiac surgery intensive care, compared to intrathoracic and global end diastolic blood volumes. The latter show a higher clinical value and can be obtained by less invasive methods, as no pulmonary artery catheter is required.

Adult↗
PubMed1998

Bicarbon valve -- European multicenter clinical evaluation.

OBJECTIVE: Fifteen collaborating centers in eight countries present their pooled experience with the new Bicarbon bileaflet valve. METHODS: Between 4/90 and 4/96, 1351 patients, 806 males and 545 females, aged 10 to 83, mean 58.4 +/- 12.4, underwent valve implantation. OPERATIONS: aortic valve replacement (AVR), 726; mitral valve replacement (MVR), 475; double valve replacement (DVR), 150. Additional procedures: CABG, 211; TV repair, 64; other, 152. RESULTS: Mortality: 67 early (seven valve related) and 56 late (40 valve related). Valve thrombosis: six obstructive, three non-obstructive; embolism: nine major cerebral, 37 other. Major bleeding: 29. Hemolysis: two clinically significant. Non-structural dysfunction: 24 paravalvular leaks, one leaflet interference. No structural failure! Endocarditis: 24. Reoperation 48: 22 non-structural dysfunctions, 14 endocarditis, seven thrombosis and embolism, five other. Estimated 5-year freedom from valve-related deaths is 97.2% for AVR and 92.4% for MVR; 4-year freedom from valve related deaths for DVR is 90.5%. Mean calculated NYHA improvement is 1.24. CONCLUSIONS: The Bicarbon mechanical prosthesis is well designed, durable, has good hemodynamic features and an acceptably low incidence of complications.

Adolescent↗
PubMed1998

Asymptomatic right atrial leiomyosarcoma with tricuspid valve obstruction in a young female patient.

Primary cardiac leiomyosarcomas of the heart are rare tumors usually diagnosed post-mortem. Like other sarcomas located in the heart, it causes symptoms by obstruction or occlusion of cardiac cavities, local invasion, embolization or by systemic manifestations. We present an unusual case of a previously healthy young female patient who was accidentally diagnosed with a cardiac tumor of unknown origin during routine physical examination in May 1997. Until a few days prior to elective cardiac surgery for diagnostic purposes in June 1997, no clinical symptoms were present. To our surprise, a primary right atrial leiomyosarcoma was found which almost completely occluded the right atrium and destroyed the tricuspid valve. Despite the combination of surgical removal and adjuvant chemotherapy the patient died 3 weeks after the operation due to progressive tumor disease and development of congestive heart failure and lung embolism.

Adult↗
PubMed1998

Continuous, less invasive, hemodynamic monitoring in intensive care after cardiac surgery.

A pulse-contour-based method for continuous measurement of cardiac output (CO) and systemic vascular resistance (SVR) was tested and arterial thermodilution, used for calibration, was compared to pulmonary artery thermodilution. In 30 patients CO and SVR were measured by pulse contour analysis (COpc, SVRpc) 270 times in 24 h and compared to arterial (COart, SVRart) and pulmonary arterial (COpa, SVRpa) thermodilution measurements. The mean difference between COpa and COart was 0.26 L/min (3.6%) with a standard deviation (SD) of 0.7 L/min, the correlation coefficient was 0.96, and the coefficient of variation was 5.0% and 5.9% respectively. COpc did differ from COpa by 0.11 L/min (1.5%, SD = 0.6 L/min) and from COart by 0.15 L/min (2.1%, SD = 0.7 L/min). Correlation of COpc with COpa was 0.91, correlation of COpc with COart was 0.90. SVRpc did correlate with SVRpa, a coefficient of 0.94, and with SVRart, a coefficient of 0.92. Mean COpc and SVRpc did not differ significantly from COpa or COart and SVRpa or SVRart during the 24 h study period. It is concluded that COart correlates well with COpa and can be used to calibrate COpc. COpc and SVRpc agree with thermodilution-based CO and SVR without recalibration for 24 hours.

Adult↗
PubMed1998

The effect of factor XIII on bleeding in coronary surgery.

BACKGROUND: One cause of diffuse bleeding after cardiac operations may be a low plasma concentration of Factor XIII, which is essential for coagulation, but is not covered by standard coagulation monitoring. METHODS: In a prospective pilot study, Factor XIII levels before and after extracorporeal circulation were investigated, and drain volumes and blood transfusions of a control group of 11 patients were compared with a group of 11 patients who received 2500 units Factor XIII postoperatively. RESULTS: Factor XIII fell significantly from preoperative values of 96.1% and 88.7% (control) to 55.7% and 51.8% (control) postoperatively. By administration of Factor XIII, plasma level rose significantly from 55.7% to 103.1%; in the control group the value remained low. Drain volumes on the first and second postoperative day were significantly lower in the Factor XIII group. In the control group 1.9 units of red blood cells and 1.6 units fresh frozen plasma were administered, in the Factor XIII group 0.9 and 0.6 units were necessary. CONCLUSIONS: Factor XIII influences bleeding after coronary surgery and can reduce the need for blood transfusions. In patients with prolonged diffuse bleeding, we therefore recommend substitution of Factor XIII.

Aged↗
PubMed1998

Aerosol bolus dispersion in patients with bronchiolitis obliterans after heart-lung and double-lung transplantation. The Munich Lung Transplantation Group.

Bronchiolitis obliterans (BO) is one of the main late complications in patients after lung transplantation. Because BO is located in small airways, conventional lung function tests are supposed to be rather insensitive to detect early stages of this disease. In this study, the capability of the aerosol bolus dispersion test to detect BO was tested in 12 subjects with heart-lung and double-lung transplantation. Four of these patients had histological evidence of BO. The broadening (dispersion) of inhaled boluses consisting of monodispersed inert test particles during respiration was repeatedly measured in each subject. Additional measurements of spirometric and bodyplethysmographic measurements were performed. Patients with evidence of BO showed significantly increased aerosol bolus dispersion and significantly reduced maximal airflow parameters. Calculation of receiver operating characteristics (ROCs) revealed that from all lung function parameters under consideration, aerosol bolus dispersion divided by the maximum expiratory flow rate at 50% of vital capacity (MEF50) and MEI50 had the highest sensitivity and specificity for the detection of BO. Both parameters showed a sensitivity and specificity of 100%. Therefore, it may be speculated that even in early stages of disease, the combination of MEF50 measurement with aerosol bolus dispersion measurements may be a powerful tool for the detection of BO in patients with lung transplantation.

Adolescent↗
PubMed1998

Port-Access cardiac surgery using endovascular cardiopulmonary bypass: theory, practice, and results.

BACKGROUND: Reduction of surgical trauma is the aim of minimally invasive cardiac surgery. This can be achieved by reducing the size of the incision or by eliminating or changing the cardiopulmonary bypass system. However, certain cardiac surgical procedures, such as valvular surgery and complex multivessel coronary artery surgery, are not feasible without the use of cardiopulmonary bypass. Therefore endovascular cardiopulmonary bypass may allow reduction of surgical trauma for these patients. METHODS: Since its first application in April 1995, more than 1100 procedures have been performed worldwide using the EndoCPB endovascular cardiopulmonary bypass system. The authors' experience consists of 60 Port-Access coronary artery bypass grafting procedures, 34 Port-Access mitral valve procedures (18 replacements, 16 repairs), 5 atrial septal defect closures, and 3 atrial myxoma removals. RESULTS: The patient survival rate was 99%, the incidence of perioperative stroke was 1%, and the incidence of aortic dissection was 1%. In the Port-Access mitral valve and atrial septal defect patients, the survival rate was 100% with no peri- or postoperative complications. Peri- and postoperative transesophageal echocardiography revealed no perivalvular leak or remaining mitral insufficiency after valve repair. CONCLUSIONS: The EndoCPB endovascular cardiopulmonary bypass system allows the application of true Port-Access minimally invasive cardiac surgery in procedures that require the use of cardiopulmonary bypass and cardioplegic arrest. Sternotomy and its potential complications can be avoided, and the surgical procedures can be performed safely on an empty, arrested heart with adequate myocardial protection.

Adult↗