Homograft aortic root replacement for destructive prosthetic endocarditis.

Prosthetic aortic valve endocarditis with extensive destruction of the aortic root, annular abscess formation, and left ventriculoaortic discontinuity was seen in 3 patients, with aorta to left atrial fistula formation in 2. Homograft aortic root replacement with use of the anterior mitral leaflet of the aortic root to repair the fistula was used successfully in all 3 patients. Their case reports are discussed to highlight the use of the homograft aortic root in these complicated cases, and to report the occurrence of aorto-left atrial fistula in prosthetic valve endocarditis.

Left atrial reduction for chronic atrial fibrillation associated with mitral valve disease.

Currently available surgical procedures to control chronic atrial fibrillation associated with mitral valvar disease are not always successful. The size of the left atrium is a major factor in the initiation and maintenance of atrial fibrillation. Here we describe a case of ablation of atrial fibrillation with left atrial reduction and pulmonary vein isolation in a patient with mitral valve disease.

Effects of PEEP on cardiovascular dynamics after open-heart surgery: a new postoperative monitoring technique.

The circulatory effects of incremental increases in positive end-expiratory pressure ventilation (PEEP) were assessed on 11 occasions in post-operative cardiac surgical patients by phasic aortic blood flow measurements and high-fidelity pressure recordings from which flow and pressure-flow derivatives of cardiac performance were calculated. At 15 cm H2O PEEP, mean arterial blood pressure was decreased by 10%, stroke volume and cardiac output by 15%, and peak left ventricular power by 21%. Although these indices promptly returned to control levels when PEEP was discontinued, levels of PEEP above 10 cm H2O should be used with caution for this group of patients.

Homograft aortic root replacement to correct infective endocarditis requiring seven open cardiac procedures.

Infective endocarditis, presumably from a septic dental focus, affecting the aortic valve was seen as acute aortic regurgitation in a 20-year-old woman. Seven open cardiac procedures for replacement of the aortic valve and left ventricular outflow tract were performed over the subsequent 6 years. Aortic root replacement using a fresh antibiotic-sterilized homograft was performed as the last definitive operative procedure. This article is presented to highlight (1) the use of homograft aortic root replacement for extensive involvement of aortic valve and left ventricular outflow tract in cases of infective endocarditis and (2) the feasibility of multiple sternal reentries when indicated.

A monitor for the continuous assessment of left ventricular performance after open-heart operations.

A cardiac monitoring system has been developed that incorporated phasic aortic blood flow measurement by an extractable electromagnetic flow probe and high-fidelity arterial blood pressure recordings. Cardiac output, stroke volume, and peak aortic blood flow are measured continuously; using logarithmic amplifiers, the pressure-flow derivatives of left ventricular function, such as cardiac power and stroke work, are obtained beat by beat. This monitor is used to follow the postoperative course of patients undergoing cardiac operations and to evaluate the hemodynamic effect of therapeutic agents.

Effects of low-dose cyclosporine A on toxicity and rejection in cardiac transplantation.

In conclusion, the low doses of CsA have significantly reduced nephrotoxicity and infectious complications. The patient survival has been acceptable, but there has been a disappointing incidence of rejection and graft loss in patients who have survived the first 3 months. We feel our experience would indicate that by targeting our CsA dosages to such low serum levels some of our patients receive suboptimal immunosuppression. Perhaps the best way of overcoming this is add a third maintenance immunosuppressive agent such as azathioprine to supplement immunosuppression. In fact, we have now changed our immunosuppressive protocol to include azathioprine while maintaining our CsA therapy at its current level.

The Bentall procedure: a surgical option in Ehlers-Danlos syndrome.

The Ehlers-Danlos syndrome (EDs) is one of the most frequently encountered inherited disorders of connective tissue. The arterial-ecchymotic type IV is notorious for large vessel involvement associated with spontaneous catastrophic bleeding. Most of these patients who require cardiovascular surgical procedures have a poor prognosis. Our experience of two patients, with aneurysmal dilatation of the ascending aorta is presented. The first patient presented with an aortic dissection extending from the ascending aorta to the common iliac arteries. The second patient presented with asymptomatic but progressive aneurysmal dilatation of the aortic root. Both patients underwent the Bentall procedure using a 25 mm St. Jude composite valved conduit. Despite increased vascular friability, both of these patients tolerated the operative procedure without complication and are doing well on early follow-up. This experience suggests that the Bentall procedure may be used to decrease the risks of dissection and rupture of the ascending aorta in patients with Ehlers-Danlos syndrome.

Structural features of cell death in atherosclerotic lesions affecting long-term aortocoronary saphenous vein bypass grafts.

Aortocoronary saphenous vein bypass grafts fail because of structural pathologies (thrombosis, intimal hyperplasia and atherosclerosis) within the 'arterialized' vein leading to graft stenosis. This study examined structural characteristics of atherosclerotic alterations in long-term aortocoronary artery saphenous vein bypass grafts with particular attention to the features of cell death in atherosclerotic lesions. Stenotic vein grafts were obtained from 10 patients at redo coronary artery bypass grafting operations. All the grafts were affected by histological abnormalities, with eight out of ten grafts showing evidence of atherosclerotic alterations in the intimal hyperplastic layer. Areas containing foam cells were examined by electron microscopy. Cells with cytoplasmic lipid accumulations were characterized by varying degrees of chromatin condensation, fragmentation or dispersion, by focal areas of oedema and vacuolisation of their cytoplasm, and by plasmalemmal destruction. Some lipid-filled cells exhibiting signs of destruction contained myofilaments and basal membrane fragments, allowing them to be identified as smooth muscle cells. Macrophage foam cells were found to have undergone similar destruction. No cells showing nuclear degeneration were observed to have intact cytoplasmic organelles. Neither were apoptotic bodies identified, but necrotic remnants were frequently seen. The results suggest that cell death in atherosclerotic lesions affecting aortocoronary artery saphenous vein bypass grafts occurs through oncosis rather than by apoptosis.

Electron-microscopic detection of apoptotic and necrotic cell death in non-atherosclerotic areas of stenotic aortocoronary saphenous vein bypass grafts.

Aortocoronary saphenous vein bypass grafts undergo structural alterations within the arterialized vein, resulting in graft stenosis and failure. Areas of the acellular intima contribute to fissuring, cracking and ulceration, while areas of the media become highly vascular but thinned. This study aimed to examine the ultrastructural features of cell death, including apoptosis and necrosis, in non-atherosclerotic areas of the stenotic aortocoronary saphenous vein bypass grafts. Thirteen stenotic vein grafts were obtained at redo coronary artery bypass grafting. The ultrastructural features of cell death were analysed by electron microscopy. Typical features of necrosis, including focal areas of cytoplasmic oedema, plasmalemmal destruction and nuclear condensation with cytoplasmic organelle destruction, were observed throughout the intima and media. Features of apoptosis, including the presence of apoptotic bodies, were also identified in the hyperplastic intima and its adjacent media. Our observations suggest that both apoptosis and necrosis occur in non-atherosclerotic areas of stenotic aortocoronary saphenous vein bypass grafts.

Expression of vascular endothelial growth factor in aortocoronary saphenous vein bypass grafts.

Neovascularisation is a prominent feature of long-term aortocoronary saphenous vein bypass grafts but mechanisms involved in the formation of neovessels have not been previously studied. Vascular Endothelial Growth Factor (VEGF) is an important angiogenic factor that induces migration and proliferation of endothelial cells, enhances permeability and modulates thrombogenecity. This study investigated the expression of VEGF in aortocoronary saphenous vein bypass grafts. Aortocoronary saphenous vein bypass grafts with angiographic luminal stenosis of >75% were explanted from 14 patients at redo coronary artery bypass grafting. The grafts demonstrated two distinct forms of graft occlusion: four out of the 14 graft occlusions (29%) resulted from severe hyperplastic transformation of the intima complicated by thrombi attached to the degenerating liminal endothelium; the remaining graft occlusions (71%) were due to the development of atherosclerotic lesions associated with mural thrombosis. Hiperplastically altered intimal segments were practically free of neovascularisation while atherosclerotic-like lesions contained neovessels irregularly distributed throughout. Intimal neovessels were located exclusively in microzones enriched with VEGF-expressing cells and, furthermore, neovascular endothelial cells themselves also displayed VEGF immunopositivity. Double-immunostaining revealed that in areas of neovascularisation, the vast majority macrophages (CD68+) expressed VEGF. Some CD68+ foam cells that surrounded branches of neovascularisation were also VEGF-positive. These findings suggest that VEGF expressed by neovascular endothelial cells and by macrophages may act as a local regulator of endothelial cells functions and may induce intimal neovascularisation in aortocoronary saphenous vein bypass grafts affected by atherosclerosis.

Dendritic cells in aortocoronary saphenous vein bypass grafts.

Dendritic cells are specialised leucocytes responsible for capturing and presenting antigens to T lymphocytes, which in turn mediate immune responses in various pathological conditions. The observations in this study demonstrate that dendritic cells are present in stenotic aortocoronary saphenous vein bypass grafts, which suggest that these cells may be involved in inflammatory actions which may subsequently contribute to graft failure.

Measurement of the circulatory effects of dobutamine, a new inotropic agent, in patients following cardiac surgery.

The use of an extractable aortic electromagnetic flow probe to provide a continuous on-line display of ascending aortic flow and cardiac output following open heart surgery is described. Utilizing this equipment, the hemodynamic actions of dobutamine and isoprenaline are compared in 14 patients immediately following cardiac surgery. The study confirmed an inotropic action produced by dobutamine at a heart rate 10 to 15 per cent lower than isoprenaline, with less peripheral vascular action. Arterial and coronary sinus blood analyses revealed little difference in the myocardial metabolic actions of either drug. Because inotropic drugs produce only relatively small increases in stroke volume in this group of patients, the rise in cardiac output caused by these agents is more dependent on the effects upon heart rate rather than improved myocardial contractile state and consequently dobutamine has little advantage over isoprenaline in this situation.

Ascending aortic aneurysms associated with aortic valve regurgitation: St Vincent's Hospital's experience.

This report represents a retrospective analysis of the St Vincent's Hospital experience with combined replacement of the aortic valve and ascending aorta using a composite conduit and coronary artery reimplantation, in 44 patients, from 1 January 1981 to 30 June 1988. The mean age at operation was 48 years. Annuloaortic ectasia was the most common indication for operation in 24 patients (54%). There were three hospital deaths (7%). Forty-one patients were discharged from hospital and were followed up for a total of 1,106 patient months (mean = 26.5 months). There were three late deaths (7%). One death was due to a new dissection, one to a cerebrovascular accident and one to a drug overdose. So far, no patients have required reoperation. Of the 36 surviving patients available for follow-up, 28 are in New York Heart Association class I, seven patients are in class II and one in class III. Composite graft replacement reduces the risk of recurrent dissection and aneurysm formation and of periprosthetic leak. In the present experience, it is the method of choice in patients with degenerative lesions in the ascending aorta and aortic valve and particularly for annuloaortic ectasia. The exact surgical technique currently used has been the result of an evolution of different techniques.

Effectiveness of minimal dosage cyclosporine in limiting toxicity and rejection.

The optimal dose of cyclosporine to achieve minimal toxicity and adequate control of rejection remains undetermined. We initiated our program with an immunosuppressive protocol designed to reduce drug toxicity, to reduce early severe rejection, and to provide adequate long-term immunosuppression. Because of increasing reports of nephrotoxicity associated with cyclosporine, we adopted a protocol of low-dose cyclosporine combined with steroids and equine antithymocyte globulin. The mean preoperative creatinine was 0.12 +/- 0.08 mmol/L and by 1 year after transplant was 0.13 +/- 0.04 mmol/L. Cyclosporine dose at 1 year was 5 +/- 2 mg/kg/day, and the serum cyclosporine level was 120 +/- 40 ng/ml. However, at 1 year 85% of the patients were hypertensive. The incidence of rejection in the first year after transplantation was 1.46 episodes per patient. Incidence of infection was 0.85 episodes per patient. The 3-month survival was 91%, and the actuarial 1-year survival was 76%. Seventy percent of our mortality was due to rejection, and four patients suffered significant graft damage in the period 3 months to 1 year, two requiring retransplantation. Although these low doses of cyclosporine have reduced nephrotoxicity and infectious complications, hypertension remains a significant problem. Moreover, although survival is acceptable, the incidence of graft rejection causing death or loss of function is of concern. This may indicate that cyclosporine at this dosage needs supplementation by a third immunosuppressive agent such as azathioprine.

Rationale for simultaneous carotid endarterectomy and aortocoronary bypass.

Seventy-eight patients were treated for coexistent carotid and coronary stenosis by simultaneous reconstructions. Five patients died (6.4%), one from a stroke contralateral to the carotid reconstruction. Four others suffered a perioperative stroke (total stroke incidence 6.4%). Three myocardial infarctions occurred (3.8%) including one fatal infarct. Analysis of the most recent 36 combined reconstructions indicates that the extramorbidity in this group increased the stroke or death rate for all carotid endarterectomies carried out in the same period by only 1%. Alternatively if these patients had been operated upon by aortocoronary grafting alone the mortality would have increased by 0.1% assuming no neurologic complications. Since these 36 patients had severe carotid stenosis and would have been refused carotid endarterectomy as an isolated procedure the results seem better than would have been achieved by staged operations.

Psychological adjustment after cardiac transplantation.

Cardiac transplantation is viable therapeutic alternative for patients with end-stage heart disease, which offers a favourable short- and medium-term prognosis. The survival has improved from 20% of patients who survived at one year after transplantation in the 1960s to the present figures of 80%-85% of patients who are alive at one year, and 50%-70% of patients who are alive at five years, after transplantation. Therefore, it seems timely to focus attention on the psychological well-being of cardiac-transplant recipients. The medical literature is scant in regard to the psychiatric and the psychosocial impact of cardiac transplantation on recipients, and a systematic and prospective study of the psychosocial adaptation of recipients is lacking. Since 1984, we have been studying the emotional impact of cardiac transplantation on recipients and their families. This article presents the results for a group of recipients who have been assessed before transplantation, then followed-up at discharge from hospital and at four, eight and 12 months after transplantation. The study attempted to quantitate the recipients' anxiety, depression, body image and subjective quality of life by way of standardized self-assessment questionnaires. The recipients' satisfaction with relationships or their marital situation also was reported, as were their degree of rehabilitation at 12 months and their attitudes to various aspects of treatment after the transplantation. Before the transplantation, 53% of patients reported an increase in anxiety and 34% of patients recorded scores that indicated mild-to-moderate levels of depression. Thirty-seven per cent of patients showed a deterioration in the quality of their lives and 34% of patients had a negative body image. After the transplantation, significant improvements occurred in all parameters, which were maintained at follow-up.

Right ventricular assist and prostacyclin infusion for allograft failure in the presence of high pulmonary vascular resistance.

The presence of high pulmonary vascular resistance (PVR) greater than 4 Wood units contributes to significant early posttransplant mortality, and remains a negative predictor of long-term survival. Current trends have been toward exclusion of the recipient with high PVR from the orthotopic procedure; elective heterotopic allograft placement is increasingly advocated. A patient with a PVR of 6 Wood units underwent orthotopic transplantation; the cardiac allograft from a 12 kg heavier donor was implanted after an ischemic time of 115 minutes. Early graft failure at 4 hours and subsequent cardiac arrest were followed by reinstitution of cardiopulmonary bypass, during which time optimal pharmacologic manipulation of the pulmonary vasculature was undertaken, including the use of high-dose prostacyclin. Refractory right heart failure indicated the requirement for right ventricular assistance (RVA) for patient survival. RVA with a Bio-Medicus pump was instituted in association with high-dose prostacyclin; an intraaortic balloon pump was inserted 12 hours later. Maintenance immunosuppression consisted of cyclosporine and azathioprine alone. RVA was maintained for 3 days; during this time the patient was totally pump dependent. Over an 18-hour period the patient was weaned and successfully withdrawn from RVA. Intraaortic balloon pump counterpulsation and the prostacyclin infusion were continued for 6 and 10 days, respectively. The clinical implications of the various interventions that resulted in the patient's survival are discussed.

Repeat myocardial revascularization surgery: an analysis of 169 cases.

One hundred and sixty-nine patients who underwent repeated myocardial revascularization surgery between 1982 and 1987 were studied. The mean interval between operations was 91.6 +/- 7.3 months. The indications for repeated surgery were graft failure in 37.2% of patients, progressive coronary atherosclerosis in 40.2% of patients and a combination of the two causes in 22.5% of patients. The mean number of grafts that were inserted was 2.74 +/- 0.61 grafts per patient at the second operation. Coronary endarterectomy as an adjunctive procedure was necessary in 17.1% of patients. The hospital mortality rate was 4.1%, with a 1.8% incidence of perioperative myocardial infarctions. Of the surviving patients, 96.3% were available for follow-up at a mean of 19 +/- 6.4 months. Of these patients, 68.5% were well and could be categorized into the New York Heart Association's functional class I. We conclude that both progression of coronary atherosclerosis in native vessels and obstruction of venous grafts cause recurrent angina and that repeated myocardial revascularization surgery is a feasible treatment option in these patients.