Dire consequence of a patent ductus arteriosus.
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Adult↗
Biomedical subjects
W Harringer
Publications and source records attributed to W Harringer.
Early postoperative flow rates after internal thoracic artery grafting for the left coronary artery system.
OBJECTIVE: The low perioperative flow rates of internal thoracic artery (ITA) conduits have been regarded as a limitation of their use in critical coronary situations with a high myocardial blood demand. To clarify whether these restrictions are justified, early postoperative flow rates were determined. METHODS: Following bilateral ITA grafting, 48 of 106 patients (April 1993-September 1994) underwent recatheterization. Subsequent to control angiography between days 8 and 12, 20 of these patients were studied by intravascular Doppler techniques applied for ITA grafts supplying the left anterior descending artery (LAD) and branches of the circumflex system (CX) (n = 20). Doppler spectral analysis allowed for determination of the average peak velocity and diastolic-systolic velocity ratio. Vascular diameters were assessed by simultaneously performed quantitative angiography and mean flow rates were calculated. All parameters were recorded at rest and following selective stimulation with nitroglycerin (0.2 mg) and papaverine (12.5 mg) to evaluate the graft flow capacity. RESULTS: Baseline values of average peak velocity at rest were 24.6 +/- 11.5 cm/s for ITA-LAD conduits and 21.9 +/- 6.8 cm/s for ITA-CX pedicles. Following dilative stimulation with papaverine, a significant increase in average peak velocities were obtained for both locations (ITA-LAD: 47.3 +/- 17.1 cm/s, ITA-CX: 42.3 +/- 11.8 cm/s). The application of nitroglycerin had a similar effect (ITA-LAD: 42.6 +/- 15.3 cm/s, ITA-CX: 40.3 +/- 10.7 cm/s). The vascular diameters of ITA conduits remained unchanged on nitroglycerin stimulation, whereas papaverine effected significant dilatation in both locations. Flow rates at rest were not significantly different (ITA-LAD: 51.0 +/- 34.2 ml/min, ITA-CX: 44.7 +/- 16.4 ml/min) and maximal flow increase was observed following papaverine stimulation of the LAD conduits (116.1 +/- 90.6 ml/min). Dilative stimulation effected an increase in diastolic-systolic velocity ratios from average values at rest in a range between 34% and 41.7% for both groups and substances. CONCLUSIONS: The basic blood flow in functioning ITA grafts appears to be similar in conduits supplying the LAD and marginal branches. Flow rates between 50 and 60 ml/min at rest should meet myocardial demands, even in the LAD position. Increased flow rates were predominantly based on higher flow velocities with an increased diastolic flow proportion. Enlargement of the graft diameter may exert additional effects, at least following papaverine stimulation at a particular concentration.
Blood Flow Velocity↗
[MR diagnosis after a Ross operation].
PURPOSE: To determine the ability of MRI to diagnose morphological and functional changes in patients after Ross procedure. MATERIAL AND METHODS: During one year, 5 patients after Ross procedure were studied by MRI. T1-weighted spin-echo sequences in different orientations as well as cine sequences and a VENC sequence were used. RESULTS: In all patients the morphology including the postoperative changes could be visualised by MRI. The cine sequences provided functional information on valvular and ventricular function. VENC-MR yielded an exact quantification of the regurgitant fraction. CONCLUSION: MRI is capable of providing all important diagnostic information in patients after Ross procedure such as valvular and ventricular function and valvular and outflow tract morphology in a single examination.
Adolescent↗
[Coronary heart disease and impaired left ventricular function in patients over 80 years of age--is bypass operation justified?].
Between April 1988 and February 1995, 35 patients aged 80 years or older underwent elective coronary artery bypass grafting. Concomitant aortic valve replacement was performed in eight patients. Fifteen patients with moderate to severe left ventricular dysfunction (left ventricular ejection fraction (EF) 20 to 45%) (group I) were compared to 20 patients with an EF > 45% (group II). There were no differences according to age, NYHA classification and associated diseases. Group I patients had significantly more myocardial infarctions compared to group II (1.3 +/- 1.1 vs. 0.5 +/- 0.8; p < 0.05). Also more bypass grafts per patient were used in group I (3.1 +/- 0.9 vs. 2.3 +/- 0.9; p < 0.01). No differences between the groups were observed in the postoperative course. One patient of group II died from multiorgan failure (hospital mortality 2.2%). A follow-up could be performed in 32 of 34 hospital survivors (94%) 12.0 +/- 11.2 months (1-41 months) postoperatively. There was one non-cardiac death in each group. All hospital survivors improved by at least one NYHA functional class. Actuarial survival at 3 years is 91% in both groups. In patients aged 80 years or older with or without left ventricular dysfunction coronary artery bypass surgery can be performed with an acceptable risk and a functional benefit. Thus, elective operations should be performed in this age group despite left ventricular dysfunction.
Aged↗
[Is heart surgery in over 80-year-old patients justified?].
Coronary artery bypass grafting and/or aortic valve replacement was performed in 68 patients aged 80 or older. These patients were compared to 743 patients younger than 80 years. In octogenerians cardiac surgery can be performed with an acceptable risk and a functional benefit.
Aged↗
[Simultaneous operations of the carotid bifurcation and coronary vessels in moderate systemic hypothermia].
Comorbidity of coronary heart disease and carotid stenosis raises the question of surgical stratification. A simultaneous approach of carotid endarterectomy and coronary revascularization, both under conditions of moderate hypothermic extracorporeal circulation, was applied in 48 patients. Considering the complexity of the procedures required the 30-day mortality (2.1%) and perioperative incidence of permanent stroke (2.1%) or myocardial infarction (0%) appeared to be comparably low.
Aged↗
Aortic valve replacement: is the stentless xenograft an alternative to the homograft? Early results of a randomized study.
From November 1992 to October 1993 we randomized 101 patients over 60 years of age undergoing elective aortic valve replacement, with or without concomitant coronary artery bypass grafting, to receive either a cryopreserved aortic or pulmonary homograft (n = 38) or a stentless porcine aortic valve xenograft (Edwards Prima 2500) (n = 63). The majority of all valves (92%) were inserted freehand in the subcoronary position. Six homografts (16%) were implanted as a free-root replacement and two xenografts (3%) were used as a mini root. There were four in-hospital deaths (4%), three in the homograft group and one in the xenograft group (homograft, 7.9% versus xenograft, 1.6%; p = not significant). Forty-one patients were followed at 3- to 6-month intervals for 9 +/- 2 months (3 to 14 months) and valve pathology was assessed routinely by means of color flow Doppler echocardiography. Two patients in the homograft group developed new aortic insufficiency grade II; all others remained with trivial or no valve incompetence. The mean gradient remained unchanged to immediate postoperative measurements (homograft, 5 +/- 1 mm Hg versus xenograft, 11 +/- 4 mm Hg; p < 0.001). Despite a slightly higher transvalvular gradient, xenografts achieved excellent initial results when compared to homografts. Ease of implantation and freedom from thromboembolism indicate that xenografts can be an acceptable alternative to homografts, particularly in older patients with small aortic annuli. Long-term studies assessing the durability of the xenograft are necessary for final evaluation.
Aged↗
Aortic valve replacement with cryopreserved pulmonary allografts: five years' follow-up.
Excellent clinical results with pulmonary autografts and experimental evidence that pulmonary valves can withstand the higher stress in the systemic circulation led us to use the cryopreserved pulmonary allograft for aortic valve replacement. From September 1988 until March 1993, 126 consecutive patients (61 +/- 10 years; 74 men and 52 women) underwent aortic valve replacement with a cryopreserved pulmonary allograft. All allografts were inserted freehand in the subcoronary position. There were four in-hospital deaths (3.2%), and 1 patient had severe valvular incompetence immediately postoperatively, requiring reoperation after 4 weeks. One hundred twenty-one patients were followed up in 3- to 6-month intervals for 25.3 +/- 16.3 months (range, 6 to 66 months), and valve performance was assessed routinely by means of color-flow Doppler echocardiography. Nine patients (7.1%) died during follow-up. Two patients died of multiple septic emboli during bacterial endocarditis, and 1 patient died of a massive stroke. The other 6 patients died of myocardial infarction (4), respiratory insufficiency due to chronic obstructive lung disease (1), and carcinoma (1). Ninety-four patients (78%) had absent or trivial aortic valve regurgitation. Valvular incompetence class II was present in 3 patients (2.5%), whereas 5 others (4%) demonstrated class II to III. Severe aortic regurgitation (class III or IV) could be detected in 10 patients (8.3%). All underwent reoperation and replacement of the valve with a prosthetic device. Bacterial endocarditis caused graft incompetence in 3 patients, valve degeneration was detected in another 3, and technical mistakes at valve implantation caused valve failure in the other 4.(ABSTRACT TRUNCATED AT 250 WORDS)
Actuarial Analysis↗
Nebulized synthetic surfactant in reperfusion injury after single lung transplantation.
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Adult↗
[Prevention and therapy of prosthesis infections in the thoracic area].
Infections of vascular prostheses following replacement of the thoracic aorta remain a rare complication, fortunately. The incidence of prosthetic infection amounts to approximately 1.6%, however, there is only limited information from single center studies, and linearized actuarial data for more exact estimations are not available. Experience with prophylaxis and treatment of bacterial endocarditis as well as data available from peripheral vascular reconstruction nevertheless allow the development of treatment strategies concerning this complication. Experimentally, there is clear evidence that pretreatment of Dacron-grafts using the fibrin sealant-antibiotic compound results in a significant protection from infection, created by artificial contamination with staphylococcus aureus. This concept could clearly be confirmed in clinical series involving treatment of prosthetic valve endocarditis. Currently, the concept of implantation of cryopreserved human vascular allografts is studied clinically. Its efficiency in infected areas and following prosthetic replacement of the thoracic aorta has not been proven. Some preliminary results as well as studies on treatment for bacterial endocarditis would suggest a clear advantage of this strategy, however statistically significant improvements have not been published. Currently available data, however, appear to be sufficient to advocate potentially successful techniques as a prophylaxis in routine thoracic aortic replacement as well as for treatment in case of a vascular prosthetic infection following such procedures.
Animals↗
Mycotic aneurysms of the thoracic aorta.
Between February 1982 and December 1992 we operated on five patients (three men, two women; aged 40 to 70 years) with mycotic aneurysms of the thoracic aorta. One patient had an aneurysm of the ascending aorta, once the aortic arch and in three cases the descending thoracic aorta were involved. In four of the five patients, excision of the aneurysm and in situ reconstruction of the aorta with a Dacron graft was performed, one patient required a Dacron graft repair and aortic valve replacement. We employed deep hypothermia with circulatory arrest (2), extracorporeal circulation (1), an axillofemoral shunt (1) and a centrifugal pump (1) for cerebral and spinal cord protection. One patient died 4 months postoperatively, the other four patients were without recurrent graft infection and are free of symptoms between 20 months and 5 years postoperatively.
Adult↗
Comparison of the effects of aprotinin and tranexamic acid on blood loss and related variables after cardiopulmonary bypass.
Aprotinin reduces blood loss after cardiopulmonary bypass, but may sensitize recipients and is expensive. Tranexamic acid, a synthetic antifibrinolytic, has less disadvantages, but opinions differ regarding its efficacy. We studied three groups of patients undergoing cardiopulmonary bypass for coronary disease: recipients of aprotinin (total dose 4.2 x 10(6) kallikrein inhibiting units, n = 14), recipients of tranexamic acid (total dose 20 mg/kg body weight, n = 15), and nonmedicated controls (n = 14) during 24 hours after cardiopulmonary bypass. Compared with controls, aprotinin reduced blood loss, the number of patients requiring transfusions, and the mean number of transfused red cell units (all with p < 0.05), whereas the recipients of tranexamic acid did not differ either from aprotinin recipients or from controls. Aprotinin and tranexamic acid both mitigated the early postoperative reduction of adenosine diphosphate-induced platelet aggregation seen in the controls (p < 0.05). Postoperative increases of plasma concentrations of the prothrombin activation fragment F1 + 2 and the thrombin-antithrombin III complex showed an activation of intravascular coagulation, without any intergroup differences. The balance between concentrations of tissue plasminogen activator and the type 1 plasminogen activator inhibitor disclosed an activation of fibrinolysis, without differences between the groups. The concentrations of D-dimer, a breakdown product of cross-linked fibrin, remained at baseline in the recipients of aprotinin and tranexamic acid but tripled in the controls (p < 0.05). By contrast, the plasma antiplasmin activity was equally depressed in the tranexamic acid and the control groups but decreased less in the recipients of aprotinin (p < 0.05). This discrepancy may reflect the different modes of action of the two agents, which may make aprotinin more efficacious than tranexamic acid in the "nonfibrinolytic" act of protecting platelet function against attack by plasmin during cardiopulmonary bypass.
Aged↗
Coronary disease and tracheal stenosis with tracheo-oesophageal fistula: a combined surgical procedure.
A patient with coronary disease class III of the New York Heart Association and tracheal stenosis with a tracheo-oesophageal fistula, which developed after long-term intubation, is described. As both conditions were symptomatic, an aortocoronary double bypass was combined with resection of the trachea and closure of the fistula. Postoperative recovery was uneventful and the patient is symptom-free after 3 years.
Adult↗
Prevention of postoperative pericardial adhesions with a hyaluronic acid coating solution. Experimental safety and efficacy studies.
Postoperative pericardial adhesions complicate reoperative cardiac procedures. Topical application of solutions containing hyaluronic acid have been shown to reduce adhesions after abdominal and orthopedic surgery. The mechanism by which hyaluronic acid solutions prevent adhesion formation is unknown but may be due to a cytoprotective effect on mesothelial surfaces, which would limit intraoperative injury. In this study, we tested the efficacy and safety of hyaluronic acid coating solutions for the prevention of postoperative intrapericardial adhesion formation. Eighteen mongrel dogs underwent median sternotomy and pericardiotomy followed by a standardized 2-hour protocol of forced warm air desiccation and abrasion of the pericardial and epicardial surfaces. Group 1 (n = 6) served as untreated control animals. Group 2 (n = 6) received topical administration of 0.4% hyaluronic acid in phosphate-buffered saline solution at the time of pericardiotomy, at 20-minute intervals during the desiccation/abrasion protocol, and at pericardial closure. The total test dose was less than 1% of the circulating blood volume. Group 3 (n = 6) served as a vehicle control, receiving phosphate-buffered saline solution as a topical agent in a fashion identical to that used in group 2. At resternotomy 8 weeks after the initial operation, the intrapericardial adhesions were graded on a 0 to 4 severity scale at seven different areas covering the ventricular, atrial, and great vessel surfaces. In both the untreated control (group 1, mean score 3.2 +/- 0.4) and vehicle control (group 3, mean score 3.3 +/- 0.2) animals, dense adhesions were encountered. In contrast, animals treated with the hyaluronic acid solution (group 2, mean score 0.8 +/- 0.3) characteristically had no adhesions or filmy, transparent adhesions graded significantly less severe than either the untreated control (group 2 versus group 1, p < 0.001) or vehicle control (group 2 versus group 3, p < 0.001) animals. In separate experiments, six baboons were infused with 0.4% hyaluronic acid in phosphate-buffered saline solution in volumes equivalent to 2.5%, 5%, and 10% of the measured circulating blood volume. The 2.5% and 5% infusions had no effect on the parameters measured; infusion of the 10% volume produced transient hemodynamic, coagulation, and gas exchange abnormalities. Hyaluronic acid solutions are efficacious in the prevention of pericardial adhesions in this model, and they appear safe in doses five times the amount needed to prevent adhesions. Further studies investigating the mechanism by which these solutions prevent adhesions, their optimal dose and method of application, and documentation of their safe use in humans are warranted.
Animals↗
Homograft replacement of the aortic valve after liver transplantation.
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Aortic Valve↗
Evaluation and validation of microsphere technique for determination of pancreatic blood flow.
The purpose of this study was to evaluate the radiolabeled microsphere technique for pancreatic blood flow measurements. Using a canine model with an isolated pancreatic circulation, we assessed the shunting of 11- and 15-microns-diam microspheres in the pancreas, correlated pancreatic blood flow measurements obtained with the microsphere technique with those made with an ultrasonic flow probe, and determined the effects of high doses of microspheres on pancreatic blood flow and its measurement. Microspheres of 11 microns demonstrate significant shunting through the pancreatic microcirculation with underestimation of pancreatic blood flow of approximately 10% compared with results obtained with 15-microns microspheres. There is a close linear relationship between flow results obtained with 15-microns microspheres and with an ultrasonic flow probe for both the resting (r = 0.85) and the secretin-stimulated pancreas (r = 0.97). Left atrial injections of very large doses of 15-microns microspheres (50 x 10(6)) caused an acute transient reduction of pancreatic blood flow (to 39% of baseline flow) with a return to baseline values within 2 min. The accuracy of flow results and absence of physiological changes after repeated injections support the use of 15-microns microspheres for pancreatic blood flow measurements.
Animals↗
Cardiac angiosarcoma--a diagnostic dilemma.
A 25-year-old man suffering from sudden onset of haemoptysis after 1 week of orthopnoea, fatigue and general weakness was admitted to a cardiology department in Vienna. No diagnosis was made. Four weeks later cardiopulmonary resuscitation and pericardiocentesis were necessary because of cardiac tamponade. Although all modern imaging procedures were performed, a diagnosis of rapidly progressive primary cardiac angiosarcoma could not be established. Definitive diagnosis was established only after exploratory median sternotomy. The patient exhibited no response to chemotherapy. He died 5 days after surgery as a result of respiratory failure.
Adult↗
[Surgical management of coronary heart disease and simultaneous carotid artery stenosis].
Simultaneous carotid endarterectomy and open-heart procedures (bypass, aortic and mitral valve replacement, arterial myxoma) were performed on 89 patients. The indication for carotid endarterectomy were either preoperative neurological symptoms (n = 36) or radiologically verified, hämodynamically relevant stenosis of more than 50-60% (n = 53). The postoperative course was uneventful in 80 patients (90%). Neurological complications occurred in 5 patients; 4 had required surgery for pre-operative neurological symptomatology and 1 of these patients died from postoperative stroke. Cardiac complications occurred in 4 patients, one of whom died because of bypass thrombosis with subsequent myocardial infarction. Many authors have different opinions regarding indication, technical procedures and optimum time of operation. We consider the simultaneous operative procedure of carotid endarterectomy and open heart procedures justified in view of the neurological complication rate of approximately 5% in our group of patients.
Aged↗