ISSN:0268-4705    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Vein graft atherosclerosis and myointimal hyperplasia can result in critical stenosis and subsequent graft failure. Injury to the vein wall and the healing response to this injury appear to underlie the formation of these graft lesions. Although the exact nature of the injury remains controversial, loss of endothelial integrity with exposure of the subendothelial intima are believed to stimulate cellular adhesion with smooth muscle migration, proliferation, and phenotypic transformation. Recent progress has been made in understanding the molecular and cellular events involved in this process. The roles of endothelial cells, smooth muscle cells, macrophages, and T lymphocytes continue to be defined as does the role of peptide growth factors such as platelet-derived growth factor, fibroblast growth factor, transforming growth factor, and insulin-like growth factor. Additional regulation by cytokines, adhesion molecules, proteoglycans of the extracellular matrix, and hemodynamic flow patterns helps determine the response of the vein wall to injury. A thorough understanding of this multifactorial process will permit molecular techniques to genetically modify vascular cells in order to deliver appropriate peptides or pharmacologic agents, thereby improving the function of vein bypass grafts.

ISSN:0268-4705    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Occlusion of saphenous vein coronary artery bypass grafts remains a significant clinical problem. Early occlusion can be minimized by optimizing surgical techniques and by antithrombotic treatments. Unfortunately, no modification of surgical technique or drug therapy has been shown to reduce late vein graft occlusion. This results from excessive proliferation of vascular smooth muscle cells and the superimposition of atheroma on the resulting thickened intima. Understanding the basic mechanisms underlying this response may be helpful in developing strategies to reduce vein graft occlusion.

ISSN:0268-4705    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

This review analyzes the role of coronary artery bypass grafting in ventricular arrhythmia associated with exertion, problematic sustained ventricular tachycardia, and sudden cardiac death associated with documented ventricular arrhythmia, or first manifestation of coronary artery disease. Specifically discussed is the role of acute ischemia in initiating and perpetuating ventricular arrhythmia. Coronary artery bypass grafting is indicated as a curative intervention for ventricular arrhythmia, but in only one rare instance: exercise-induced ischemia associated with problematic sustained ventricular arrhythmia, when the tachycardia is documented as being induced by acute ischemia. In other instances, indications for coronary artery bypass grafting follow the current guidelines based on clinical trials. Patients with the most severely damaged coronary artery anatomy associated with impaired left ventricular dysfunction have their life expectancy significantly prolonged after coronary artery bypass grafting. These results have been presented as evidence that coronary artery bypass grafting prevents ventricular arrhythmia and sudden cardiac death by modifying the two most powerful predicting factors of sudden cardiac death: coronary artery anatomy and left ventricular function.

ISSN:0268-4705    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

This paper reviews the morbidity and mortality of preoperative risk factors for patients undergoing myocardial revascularization surgery for coronary artery disease and reviews a clinical severity scoring system for risk factors. Risk factors include severe ventricular dysfunction, congestive heart failure, prior myocardial infarction, urgent and emergency surgery, repeat surgery, vascular disease, renal dysfunction, combined coronary artery bypass grafting and valve procedures, diabetes, age, sex and body weight, preoperative anemia, respiratory function, surgical volume, and so forth.

ISSN:0268-4705    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Three clinical techniques providing significant changes in the approach to myocardial protection have been reported recently. These techniques deviate from conventional practice, and they infer that normothermia is superior to hypothermia, retrograde cardioplegia is more advantageous than antegrade administration, and continuous cardioplegic delivery is preferable to intermittent dosage. Encouraging preliminary clinical results with warm-blood cardioplegia are reported, but rigid clinical and experimental testing against conventional methods is not yet available for evaluation. The ideal cardioprotective strategy has yet to be determined, but these preliminary data suggest strongly that incorporation of these techniques with conventional methods will improve intraoperative myocardial protection and provide the cardiac surgeon with an augmented arsenal of strategies that can be employed to provide increased flexibility.

ISSN:0268-4705    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Accurate evaluation of left ventricular function during and after cardiac surgery is essential for a successful outcome. Intraoperative and postoperative evaluation of left ventricular function is still most commonly accomplished with data obtained from a pulmonary artery catheter. Newer techniques are being introduced in the operating room. For example, two-dimensional transesophageal echocardiography is commonly utilized intraoperatively to detect myocardial ischemia and may be used to estimate left ventricular volume and ejection fraction. Recent studies suggest that it may also have a role in the determination of left ventricular contractility. The Doppler capabilities of transesophageal echocardiography provide information about regurgitant flow after mitral valve repair and may be able to measure cardiac output. Other techniques used intraoperatively include determination of myocardial lactate production to detect ischemia and the use of conductance catheters to measure contractility. Postoperatively, a much wider variety of methods is available for evaluation of left ventricular function and includes echocardiography, scintigraphy, positron emission tomography, and magnetic resonance imaging.

ISSN:0268-4705    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

This paper reviews literature from the past year on mortality and on cardiac, neurologic, gastrointestinal, hematologic, and endocrine morbidity after coronary artery bypass grafting.

ISSN:0268-4705    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Appropriate operative techniques are crucial to ensure safety and achieve satisfactory outcome for the increasing number of reoperations for coronary disease. Recent emphasis has been placed on the key role of atherosclerotic vein grafts in causing operative complications. Minimal handling of patent vein conduits and retrograde cardioplegia are advocated. Use of the internal mammary artery at initial operation has been shown to both reduce the need for reoperation and to increase its safety when progression of disease makes further surgery necessary.

ISSN:0268-4705    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Coronary artery bypass grafting has been an established procedure for more than 20 years. This article summarizes recently published information regarding the long-term results of coronary artery bypass grafting, including several analyses of large data bases that extend over periods of 15 to 20 years. Other research pertinent to the etiology of conduit occlusion and information regarding the management of patients with recurrent ischemia following coronary artery bypass grafting is discussed. The studies reviewed for the present article confirmed the beneficial effect of internal mammary artery grafting on long-term survival and defined the factors influencing long-term survival in patients with saphenous vein grafts. Other studies determined the effect of initiating aspirin postoperatively on graft patency, evaluated novel conduits for grafting, and elucidated the remodeling of saphenous vein that occurs over time in the arterial circulation.

ISSN:0268-4705    

出版商:OVID    

年代:1992

数据来源: OVID