Clinical manifestation of heparin-induced thrombocytopenia type II.
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Aged↗
Biomedical subjects
R Hetzer
Publications and source records attributed to R Hetzer.
Coronary artery bypass grafting after orthotopic heart transplantation.
OBJECTIVE: Graft coronary disease (GCD) remains the major determinant of long-term survival after heart transplantation. Therapeutic strategies for the prevention or retardation of GCD in the cardiac allograft are limited, and palliative surgical coronary revascularization has been attempted. The aim of this report was to retrospectively analyze our results of coronary artery bypass grafting after cardiac transplantation. This paper correlates the outcome of patients with the pathohistological and angiographic type of lesion in order to identify transplant recipients who may profit from surgical myocardial revascularization. METHODS: Seven patients with a mean age of 55 years (range 45-61 years) underwent coronary artery bypass grafting as a result of GCD at a mean of 67 months (range 6-128 months) after cardiac transplantation. By the inclusion of the clinical history and the angiographic pattern of GCD lesions, the primary indications for surgical revascularization, operative results, pathohistological studies and follow-ups were examined. RESULTS: Elective surgery was performed in two patients with proximal, severe triple vessel disease (Type A lesion) and in one patient in whom the primary reason for cardiac surgery was severe tricuspid regurgitation. This patient electively received a tricuspid valve replacement and concomitant single vessel bypass surgery for proximal GCD (Type A lesion). Emergency surgery was performed in four patients: preoperatively three patients post-infarction developed worsening congestive heart failure, which resulted in low cardiac output syndrome. One patient with combined Types A and B/C lesions required emergency surgery for dissection of the right coronary artery (RCA) after an angioplasty procedure. Angiographically all these patients showed diffuse, distal arteriopathy (combined Type B/C lesions). The electively operated patients (n = 3) and the patient with dissection of the RCA (n = 1) had successful operations and survived beyond hospital discharge (overall survival for coronary artery bypass graft (CABG) in GCD patients 4 out of 7; 57%). All three patients with distal arteriopathy, who underwent emergency surgery, died in hospital from left ventricular failure (43%). The four patients discharged from hospital with a mean follow-up of 10 months (range 2-32 months) are all in good clinical condition. CONCLUSIONS: Coronary artery bypass grafting can be successfully performed in a subgroup of cardiac transplant patients with Type A lesions. However, the state of diffusely diseased distal arteries (Type B/C lesions), which is prevalent in this group of patients, limits the use of bypass surgery.
Biopsy↗
Pulmonary artery stenosis 5 years after single lung transplantation in primary pulmonary hypertension.
This is a case report about a 56-year-old female patient with primary pulmonary hypertension who underwent single, right lung transplantation. Five years postoperatively she developed signs of right heart failure. History and physical examination suggested pulmonary artery stenosis. Diagnosis was confirmed by pulmonary angiography. Percutaneous placement of a balloon expandable stent normalized pulmonary artery pressure.
Blood Pressure↗
A novel perfusion system for the endothelialisation of PTFE grafts under defined flow.
OBJECTIVES: to develop a perfusion system for culturing human endothelial cells on small-diameter PTFE grafts under defined pulsatile shear stress. METHODS: to benefit from a stronger adhesion of endothelial cells to the substrate, we developed a perfusion system which enables culture of endothelial cells on PTFE grafts to confluence under a wide range of shear stress. We also developed an in situ staining method for the determination of the endothelialisation stage by upper light microscopy. RESULTS: the application of pulsatile flow with high shear stress (6.6 dyn/cm2, 5 min) to a graft endothelialised under perfusion did not lead to a disruption of the confluent cell layer. In contrast, a shear stress of 3 dyn/cm2 applied for 5 min was sufficient to wash more than 50% of endothelial cells off the PTFE graft when cultured to confluence under static conditions. CONCLUSIONS: this technique induces a stronger cell adherence of endothelial cells to a PTFE graft in comparison with grafts endothelialised under static conditions. Endothelialised vascular grafts can be pre-conditioned to defined shear stress values.
Blood Vessel Prosthesis↗
[The value of magnetic resonance tomography (MRT) for evaluating ventricular and anastomotic functions in patients with an extra- or intracardiac total cavopulmonary connection (TCPC)-modified Fontan operation].
PURPOSE: To evaluate different MR methods (ventricle and flow measurements) for the postoperative follow-up of hemodynamics in patients with extra- or intracardial TCPC. MATERIALS AND METHODS: Twenty-eight consecutive patients (14 female, 14 male) within the ages of two to thirty-eight years were examined using a 1.5 T Gyroscan ACS-NT scanner (Philips, Best, Netherlands). 7 patients had an extracardial (eTCPC), and 21 an intracardial (iTCPC) tunnel. The calculation of the ventricular function and muscle mass was performed using "multislice-multiphase" technique by summing up the end-diastolic and end-systolic areas; the flow measurements were evaluated by phase shift velocity mapping in the superior vena cava (SVC), inferior vena cava (IVC), right (RPA) and left (LPA) pulmonary artery. Besides peak and mean velocity, the mean and maximal flow volumes (ml/min) were calculated. RESULTS: Ejection fraction (EF) of the functionally single ventricle was within the normal range (mean 57%) in 22/28 patients while mean muscle mass was elevated in the group with eTCPC (mean 121 g/m2). The mean flow volumes and the peak velocities in all vessels were higher in the group with iTCPC as compared to the one with eTCPC. Clinically relevant retrograde flows in the IVC were only found in the group with iTCPC (7/21), as well as a significant predominant flow distribution towards the RPA (p < 0.05; Wilcoxon signed-rank test); in the group with eTCPC towards the LPA (n.s.). CONCLUSIONS: MRI is a useful method for the assessment of ventricular function and muscle mass in the follow-up after the modified Fontan operation. MRI flow measurements additionally provided clinically relevant information about the hemodynamics in Fontan patients.
Adolescent↗
Thoracic transposition of the greater omentum as an adjunct in the treatment of mediastinitis--pros and cons within the context of a randomised study.
Mediastinitis after cardiac surgery is a rare but life-threatening complication. The omentum is particularly well-suited for the treatment of severe sternal wound infections, because it contains large numbers of immunologically active cells that seem to be responsible for the high anti-infective activity of the omentum. The additional transposition of parts of the greater omentum into the thorax was discussed in the development of a protocol for the planned ATMI study, which will investigate the effectiveness of immunoglobulins in the treatment of severe sternal wound infections that require reoperation. We present two different points of view about whether omentopexy should be allowed within the study design.
Cardiac Surgical Procedures↗
Ventricular assistance for recovery of cardiac failure.
Mechanical assist devices have been used increasingly to support patients who await heart transplantation. The initial goal was to provide sufficient circulatory function to keep these patients alive and to allow them to recover from secondary organ dysfunction. A recent observation showed an improvement in native heart performance in some transplant candidates who receive support with mechanical assist devices. Under these conditions, myocardial recovery has been mostly restricted to patients with primary dilated cardiomyopathy and with extended periods of ventricular support. Also, the exact mechanisms that lead to substantial myocardial recovery remain unknown. Several investigations have demonstrated improved myocyte performance, reduced fibrosis, reduced cytokine levels, and reduced autoantibodies during long-term mechanical support; therefore, the observation of cardiac recovery during mechanical support is in accordance with currently discussed models of end-stage heart failure.
Heart Diseases↗
Radiologic anatomy of ventricular assist devices.
Ventricular assist devices (VAD) allow for long-term circulatory support of patients with end-stage heart failure. With the increasing duration of circulatory support, diagnostic imaging plays an important role in the management of patients on a VAD. The aim of our review was to analyze the radiologic features of different VADs. From 1987 to 1996, 319 patients (mean age 42 years, range 3 to 74 years) were treated with a VAD. A Berlin Heart VAD was implanted in 263 of the patients, the univentricular Baxtor Novacor was implanted in three patients, and the univentricular CI Heartmate was implanted in 19 patients. All patients were studied by serial chest radiographs. In addition, 70 patients underwent computed tomography (CT), and five patients underwent electron beam CT. The Berlin Heart VAD was used as a biventricular support system in 218 patients. In all cases, the position of the wire-directed cannulae was identified on the chest radiographs, while the exact position of the cannula tip could be visualized by CT only. The plastic cannulae of both the Novacor and the Heartmate were not discernible on radiographs, but required CT for evaluation. Computed tomography also resolved the metal components of the pumps. The titanium-made pump housing of the Heartmate caused beam-hardening artefacts that might conceal fluid accumulations in the pump pocket. Computed tomography is the standard of reference for examinations of cannula position, pump position, and pump components of ventricular assist devices.
Adolescent↗
Children may survive severe myocarditis with prolonged use of biventricular assist devices.
The outcome of acute myocarditis with cardiogenic shock is poor. In some children in whom aggressive medical treatment fails, artificial replacement of heart function may offer lifesaving support until the myocardium has recovered. Four previously healthy children (three boys aged 4, 6, and 1 years; one girl aged 5) developed acute myocarditis with ventricular failure and multiorgan dysfunction caused by low cardiac output. Biventricular assist devices (BVAD) were implanted for prolonged support. In three children cardiac function improved and after up to 21 days mechanical support could be withdrawn. They had full recovery of heart function. In the fourth patient there was no myocardial recovery after a period of 20 days. He underwent orthotopic heart transplantation with an uneventful postoperative course. Prolonged circulatory support with BVAD is an effective method for bridging until cardiac recovery or transplantation in children.
Child↗
Ventilatory and diffusion abnormalities in long-term survivors after orthotopic heart transplantation.
OBJECTIVE: To investigate the long-term development of pulmonary diffusion abnormalities after orthotopic heart transplantation (oHT). DESIGN: Retrospective analysis of pulmonary function test results of different patient groups at different time intervals after oHT was performed. PATIENTS: This investigation included 642 patients who had undergone oHT for chronic heart failure. Patients were grouped according to the time elapsed after transplantation (group 1: n = 164; age, 47 +/- 14 years; days after oHT, 324 +/- 101; group 2: n = 100; age, 48 +/- 15 years; days after oHT, 723 +/- 104; group 3: n = 106; age, 52 +/- 12 years; days after oHT, 1,092 +/- 98; group 4: n = 84; age, 51 +/- 13 years; days after oHT, 1,442 +/- 99; group 5: n = 61; age, 50 +/- 14 years; days after oHT, 1,819 +/- 105; group 6: n = 101; age, 53 +/- 12 years; days after oHT, 2,463 +/- 303; and group 7: n = 26; age, 54 +/- 14 years; days after oHT, 3,478 +/- 246). In 56 (group 8) of the 642 patients, follow-up measurements were performed with tests before and at two time points after oHT (6.5 +/- 1.7 and 12.5 +/- 9.3 months). RESULTS: Of all patients, 39% showed restrictive and obstructive abnormalities with no differences between the groups. No significant differences in lung transfer factor for carbon monoxide (DLCO) were observed (61.2 vs 63.7 vs 65.5 vs 65.6 vs 64.5 vs 65.7 vs 67.6% predicted). Differences in transfer coefficient for carbon monoxide (Kco) were significant between group 1 and 4 (58.7 vs 64.1% predicted), and group 1 and 6 (58.7 vs 63.4% predicted). No differences occurred in the rate with which patients exhibited pathologic abnormalities for DLCO and KCO. After oHT, a marked reduction in diffusion capacity occurred in group 8. On follow-up, these measurements were only slightly restored in terms of the predicted DLCO percentage. No such improvement was observed in KCO or in the rate of pathologic changes for both DLCO and KCO. We conclude, therefore, that the impairment of diffusion does not improve even after a significant period has passed after the oHT. Whether this has any effect on symptoms and/or the prognosis for these patients is extremely unclear.
Carbon Monoxide↗
Motion artifacts in cardiac CT. The Novacor left ventricular assist device and its implications for clinical imaging.
PURPOSE: Cardiovascular applications of CT are primarily limited by temporal resolution of the scanner. Recent development in scanner technology has greatly increased temporal resolution. We here describe a standardized method of assessing temporal properties of various CT techniques. MATERIAL AND METHODS: The Novacor left ventricular assist device was mounted in a water-filled circulation phantom and scanned at different pump rates with a spiral CT unit and an electron beam unit. We also evaluated the use of ECG-triggered subsecond scanning on a spiral CT unit. RESULTS: Using the fastest conventional scanning protocol, severe motion artifacts occurred. These artifacts could not be reproduced from image to image, even if the pump rate was adjusted to scan rate (l/s). Electron beam tomography (EBT) reproducibly yielded few artifacts at 100 ms and practically no artifacts at 50 ms scanning time. Even without ECG-triggering, pump motion could be reproduced as a cine-cycle. With the ECG-triggered partial scanning CT technique, limited motion artifacts could be reproduced during diastole at a heart rate of 70-80 beats/min. CONCLUSION: The Novacor ventricular assist device may serve as a benchmark test in the evaluation of new scanning techniques for cardiovascular CT. While EBT presently remains the only CT technique to freeze cardiac motion throughout its cycle, ECG-triggered subsecond scans may, under certain conditions, capture cardiac anatomy in diastole.
Artifacts↗
Saccular aneurysm of the aortic arch.
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Aged↗
Contrast media radiography in patients with retrosternal irrigation drainage for severe sternal wound infection.
Severe wound infection after open-heart surgery is a potentially life-threatening complication, which is mostly treated by re-operation with debridement, and insertion of closed irrigation drainage. Until now there is no consensus about the appropriate duration of irrigation therapy. Since the retrosternal irrigation cavity is likely to become continually smaller as the infection heals, this study was intended to answer the question, as to whether this process can be made visible by the use of contrast media radiography, and whether this information could be used to determine when an irrigation therapy can safely be discontinued. In 1997, 34 patients suffered from sternal wound healing disturbances which required re-operation at our institution (incidence = 0.97%). During the re-operation, a closed retrosternal irrigation drainage was inserted. Of the 34 patients contrast media radiography examinations were carried out on the first, 4th and 12th postoperative day (POD), which consisted of an antero-posterior x-ray of the chest after contrast media injection through each inlet tube. At POD 4 and 12 in the majority of cases, the retrosternal irrigation cavity became smaller when compared with the previous x-ray examination. Only in three of the non-survivors there was a huge irrigation cavity visible at the 12th POD, which sometimes even included the pleural cavity. We conclude that in patients with mediastinitis treated by insertion of a closed irrigation drainage, the retrosternally irrigated cavity seems to become smaller over the therapeutic course of treatment. This process can be visualized by contrast media radiography. Results from this examination should be included in decision making about the best time for discontinuation of the irrigation therapy.
Anti-Infective Agents, Local↗
Mitral valve reconstruction and replacement for ischemic mitral insufficiency: seven years' follow up.
BACKGROUND AND AIMS OF THE STUDY: Patients with ischemic mitral incompetence have a high operative risk whether the valve is repaired or replaced. The advantage of repair over replacement is unclear in this subgroup of patients. METHODS: Between April 1986 and December 1998, 337 patients underwent surgery for ischemic mitral valve insufficiency. Coronary artery bypass grafting (CABG) was carried out concomitantly in 314 cases (93.2%). Valve repair was performed in 140 patients (operative mortality rate 12.1%). The surgical risk in patients with a left ventricular ejection fraction (LVEF) of 10-30% was higher (operative mortality rate 33.3%) than in those with LVEF >30% (operative mortality rate 8.4%). Actuarial survival rates were 75.4%, 66.8% and 61.7% after 2, 5 and 7 years, respectively. Mitral valve replacement was performed in 197 patients (operative mortality rate 14.2%). The surgical risk in patients with a LVEF of 10-30% (operative mortality rate 30.3%) was greater than in those with a LVEF of >30% (operative mortality rate 11.0%).Actuarial survival rates after replacement were 78.6%, 73.4% 67.2% after 2, 5 and 7 years, respectively. RESULTS: Our initial analysis showed that, after mitral valve repair, mortality during follow up was greater in patients with residual mitral valve insufficiency of more than grade I. Subsequent outcome was superior when repair was evaluated perioperatively with transesophageal echocardiography. When mitral insufficiency was persistently more than grade I after repair, mitral replacement was performed. A total of 105 patients was analyzed with no or maximum grade I mitral insufficiency following valve repair; actuarial survival rates were 81%, 78.4% and 77.2% after 2, 5 and 7 years' follow up. CONCLUSIONS: Patients with highly impaired LV function and ischemic mitral insufficiency are at high risk during valve repair or replacement, and cardiac transplantation should be considered for this group. However, patients with ischemic mitral insufficiency and moderately impaired LV function can undergo valve repair or replacement with an acceptable prognosis. The goal of mitral valve repair should be to reduce valvular insufficiency to at least grade I. If this is not the case, then the prognosis of repair is worse than after valve replacement. Thus, the surgeon should replace the valve during the same operation.
Adult↗
Screening the human bradykinin B2 receptor gene in patients with cardiovascular diseases: identification of a functional mutation in the promoter and a new coding variant (T21M).
To elucidate if genetic variants in the bradykinin B2 receptor (B2) gene occur that could affect receptor expression and function, we screened for mutations in the promoter and in the coding region of the human B2 gene. In our initial study we analyzed 92 consecutive, unrelated subjects (including 25 patients with hypertrophic cardiomyopathy, 18 patients with dilated cardiomyopathy (DCM), 25 patients with hypertension, 18 patients with coronary heart disease, and 6 patients with valvular heart disease) using nonradioactive polymerase chain reaction-single-strand conformation polymorphism analysis as mutation screening method. We detected eight as yet unknown polymorphic sites in the promoter region of the B2 gene (-845 C/T, -704 C/T, -649 insG, -640 T/C, -536 C/T, -412 C/G, -143 C/T and -78 C/T) with allele frequencies between 0.5 and 13%. One of them (-412 C/G) destroys a Sp1 binding site and abolishes protein binding to this Sp1 site in human umbilical vein endothelial cells and human vascular smooth muscle cells. In the protein-coding region one new coding variant (T21M) with the potential to create a truncated receptor isoform was detected. We determined the frequency of the promoter variant at position -412 (C --> G) and the newly identified coding variant (T21M) in extended samples of 69 patients with HCM, 163 patients with DCM, 109 patients with hypertension, and 173 healthy anonymous blood donors. The promoter variant (-412 C/G) was found in one blood donor and the T21M mutation was not found in the control population. Therefore, it appears that these mutations are rare events and the determination of clinical significance will be a demanding task in the future.
Cardiovascular Diseases↗
Images in cardiovascular medicine. Myocardial complications of acute mitral valve endocarditis.
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Acute Disease↗
[Electron-beam computed tomography in heart surgery].
PURPOSE: Electron beam CT (EBCT) has been devised to improve the imaging of the heart and the great vessels. Therefore, this method is expected to facilitate the imaging workup of patients referred for cardiothoracic surgery. We set out to review the most important surgical issues that can be addressed with this method. METHODS: From June, 1997 until July, 1998, more than 300 patients were referred from cardiothoracic surgery. In a retrospective analysis, diagnostic results were reviewed and compared with surgical findings and the clinical course. RESULTS: Aortocoronary bypass graft occlusions were detected with a sensitivity of 100% and a specificity of 95%. Calcifications of the aorta, pericardium and intracardiac tumors were surgically confirmed in all instances. There was a significant association of the degree of coronary artery calcification and the progression of cardiac allograft vasculopathy in 50 heart transplant recipients. In EBCT of the aorta, a high degree of diagnostic confidence was found for aortic dissection, aortic wall hematoma or aortic perforation. CONCLUSIONS: We conclude that EBCT represents an important diagnostic tool both for surgical planning and postoperative surveillance in cardiothoracic surgery.
Adult↗
Soluble L-selectin plasma concentrations in infants undergoing heart surgery: no association with capillary leak syndrome or need for respiratory support.
OBJECTIVE: In critical care patients at risk of developing the acute respiratory distress syndrome (ARDS), low soluble L-selectin (sCD62L) plasma concentrations have been shown to be associated with progression to ARDS and prolonged subsequent mechanical ventilation. This study aimed to determine the usefulness of sCD62L plasma concentrations to identify infants undergoing cardiovascular surgery who are at risk for postoperative pulmonary dysfunction and capillary leaks. DESIGN: Serial measurements of sCD62L plasma concentrations in a cohort of infants with congenital heart disease before, during, and after surgery for 4 consecutive days. SETTING AND PATIENTS: Infants aged 3-337 days undergoing cardiovascular surgery with (N = 27) or without (N = 12) cardiopulmonary bypass in a tertiary care center. RESULTS: sCD62L concentrations before surgery showed a strong correlation with the infant's age (r = 0.77, p < 0.001). During surgery, sCD62L levels dropped from 9.0 +/- 0.7 to 5.6 +/- 0.4 nmol/l (mean +/- SEM; p < 0.001). The minimum sCD62L concentration during and after surgery did not differ between infants operated upon with or without cardiopulmonary bypass (p > 0.1) or in infants who did (N = 10) or did not (N = 29) develop capillary leak syndrome. Whereas capillary leak syndrome was associated with prolonged mechanical ventilation (p < 0.01), there was no relationship between sCD62L concentrations at baseline or at any time thereafter and number of hours on the ventilator(p > 0.1). CONCLUSION: sCD62L concentrations before or after surgery are not apt to identify infants at increased risk of prolonged mechanical ventilation.
Age Factors↗