选择性冠状静脉动脉化搭桥术中不同移植物的应用疗效比较

目的:对比选择性冠状静脉动脉化(SCVBG)搭桥治疗弥漫性右冠状动脉狭窄病变中选择乳内动脉和大隐静脉作为桥血管的治疗效果。方法:选择2008年10月到2014年10月在我院行SCVBG搭桥的84例患者资料,其中选择大隐静脉作为桥血管进行冠状静脉动脉化搭桥患者46例(大隐静脉桥组),选择乳内动脉作为桥血管进行冠状静脉动脉化搭桥患者38例(乳内动脉桥组)。随访记录两组患者的生存情况、近期复查超声心动图、冠状动脉CTA及心绞痛复发率。结果:乳内动脉桥组患者总生存率(100%)明显高于大隐静脉桥组(82.6%)(P0.05)。乳内动脉桥组患者桥血管和心中静脉通畅率(100%)明显大于大隐静脉桥组(54.35%)(P0.05)。两组患者左心室射血分数(LVEF)较治疗前明显增加,左心室舒张期末内径(LVEDD)较治疗前明显减小(P0.05)。治疗后,乳内动脉桥组患者心绞痛复发率明显小于大隐静脉桥组(P0.05)。结论:SCVBG搭桥治疗弥漫性右冠状动脉狭窄病变中,选择乳内动脉桥效果优于大隐静脉桥,能明显提高桥血管和心中静脉通畅率,降低心绞痛复发率。     

The clopidogrel after surgery for coronary artery disease (CASCADE) randomized controlled trial: clopidogrel and aspirin versus aspirin alone after coronary bypass surgery [NCT00228423]

Background

Saphenous vein graft disease remains a major limitation of coronary artery bypass graft surgery. The process of saphenous vein intimal hyperplasia begins just days after surgical revascularization, setting the stage for graft atherosclerotic disease and its sequalae. Clopidogrel improves outcomes in patients with atherosclerotic disease, and is effective at reducing intimal hyperplasia in animal models of thrombosis. Therefore, the goal of this study will be to evaluate the efficacy of clopidogrel and aspirin therapy versus aspirin alone in the prevention of saphenous vein graft intimal hyperplasia following coronary artery bypass surgery.

Methods

Patients undergoing multi-vessel coronary artery bypass grafting and in whom at least two saphenous vein grafts will be used are eligible for the study. Patients will be randomized to receive daily clopidogrel 75 mg or placebo, in addition to daily aspirin 162 mg, for a one year duration starting on the day of surgery (as soon as postoperative bleeding has been excluded). At the end of one year, all patients will undergo coronary angiography and intravascular ultrasound assessment of one saphenous vein graft as selected by randomization. The trial will be powered to test the hypothesis that clopidogrel and aspirin will reduce vein graft intimal hyperplasia by 20% compared to aspirin alone at one year following bypass surgery.

Discussion

This trial is the first prospective human study that will address the question of whether clopidogrel therapy improves outcomes and reduces saphenous vein graft intimal hyperplasia following cardiac surgery. Should the combination of clopidogrel and aspirin reduce the process of vein graft intimal hyperplasia, the results of this study will help redefine modern antiplatelet management of coronary artery bypass patients.     

Endoscopic lesser saphenous vein harvesting for coronary artery bypass grafting: first reported case

Endoscopic vessel harvesting has become a widely used modality for harvesting venous and arterial conduits for coronary artery bypass grafting. Specifically, it has been used to harvest the greater saphenous vein, internal thoracic artery, and the radial artery. A case of endoscopic lesser saphenous vein harvesting for coronary artery bypass grafting is reported.     

Recurrent myocardial infarction in a patient with Prinzmetal's angina and normal coronary arteries

A 55-year-old man was referred for the evaluation of frequent chest pain and syncope. While in the hospital, he experienced severe chest pain accompanied by transient ST segment elevation and a slight elevation of cardiac enzyme levels. Multiple coronary arteriograms were recorded at various times during an interval of 2 months. On one occasion, the results were normal; on another occasion, they showed total occlusion of the left anterior descending, diagonal, and circumflex coronary arteries. The occlusion was completely relieved with sublingual nitroglycerin. Because the patient's clinical condition deteriorated rapidly, double aortocoronary saphenous vein bypass was performed to the left anterior descending and circumflex coronary arteries. During the induction of anesthesia, ventricular fibrillation occurred, and the patient died from refractory recurrent fibrillation 4 hours after surgery. Postmortem examination revealed normal coronary arteries, patent vein grafts, and multiple focal areas of recent and old myocardial fibrosis. Thus, it appears that coronary spasm, in the presence of otherwise normal coronary arteries, can produce myocardial infarction with necrosis, and that medical management may provide a more successful method of treating such patients.     

Distal embolization at the site of a stenotic distal anastomosis of a saphenous vein graft,leading to dye entrapment

This case report describes the entrapment of contrast media after recanalization of a recently occluded saphenous vein graft with balloon predilation, thrombectomy and stent implantation. Recanalization of the respective coronary artery was performed, and the entrapped contrast media within the saphenous vein graft progressed to the left circumflex artery.     

Manual pressure distension of the human saphenous vein changes its biomechanical properties-implication for coronary artery bypass grafting

Patency rates of saphenous vein grafts following coronary artery bypass grafting (CABG) depend on multiple factors. Information regarding the impact of biomechanical properties of vein grafts on patency rates is not available. The objective of the present study was to evaluate whether uncontrolled manual pressure distension during routine preparation of the saphenous vein in CABG-induced changes in the biomechanical properties of the vein. The morphometric and stress-strain properties were studied in isolated segments of the saphenous vein from 12 patients undergoing elective CABG. Six segments were manually distended without pressure control and six were not distended. The mechanical test was performed as a ramp inflation using syringe pump. The vein dimensions were obtained from digitised images at different pressures as well as at the no-load and zero-stress states. The circumferences, the wall and lumen area, the wall thickness, and the outer diameter as function of the applied pressure were largest in the segments with uncontrolled manual distension compared to those without distension (P<0.05). The opening angle and the absolute value of the residual strains were lower (P<0.01) and the circumferential stress-strain curve shifted to the left, indicating the wall became stiffer with uncontrolled manual distension compared to those without distension (P<0.05). In conclusion, manual pressure distension changed the morphometric and biomechanical properties of the saphenous vein. The perspective is that studies on biomechanical properties on the saphenous vein may guide surgeons how to handle graft material without causing major changes of the biomechanical properties during harvesting and preparation.     

Improved gene delivery to human saphenous vein cells and tissue using a peptide-modified adenoviral vector

The establishment of efficient gene delivery to target human tissue is a major obstacle for transition of gene therapy from the pre-clinical phases to the clinic. The poor long-term patency rates for coronary artery bypass grafting (CABG) is a major clinical problem that lacks an effective and proven pharmacological intervention. Late vein graft failure occurs due to neointima formation and accelerated atherosclerosis. Since CABG allows a clinical window of opportunity to genetically modify vein ex vivo prior to grafting it represents an ideal opportunity to develop gene-based therapies. Adenoviral vectors have been frequently used for gene delivery to vein ex vivo and pre-clinical studies have shown effective blockade in neointima development by overexpression of candidate therapeutic genes. However, high titers of adenovirus are required to achieve sufficient gene delivery to provide therapeutic benefit. Improvement in the uptake of adenovirus into the vessel wall would therefore be of benefit. Here we determined the ability of an adenovirus serotype 5 vector genetically-engineered with the RGD-4C integrin targeting peptide inserted into the HI loop (Ad-RGD) to improve the transduction of human saphenous vein smooth muscle cells (HSVSMC), endothelial cells (HSVEC) and intact saphenous vein compared to a non-modified virus (Ad-CTL). We exposed each cell type to virus for 10, 30 or 60 mins and measured transgene at 24 h post infection. For both HSVSMC and HSVEC Ad-RGD mediated increased transduction, with the largest increases observed in HSVSMC. When the experiments were repeated with intact human saphenous vein (the ultimate clinical target for gene therapy), again Ad-RGD mediated higher levels of transduction, at all clinically relevant exposures times (10, 30 and 60 mins tissue:virus exposure). Our study demonstrates the ability of peptide-modified Ad vectors to improve transduction to human vein graft cells and tissue and has important implications for gene therapy for CABG.     

Computational model of blood flow in the aorto-coronary bypass graft

Background

Coronary artery bypass grafting surgery is an effective treatment modality for patients with severe coronary artery disease. The conduits used during the surgery include both the arterial and venous conduits. Long- term graft patency rate for the internal mammary arterial graft is superior, but the same is not true for the saphenous vein grafts. At 10 years, more than 50% of the vein grafts would have occluded and many of them are diseased. Why do the saphenous vein grafts fail the test of time? Many causes have been proposed for saphenous graft failure. Some are non-modifiable and the rest are modifiable. Non-modifiable causes include different histological structure of the vein compared to artery, size disparity between coronary artery and saphenous vein. However, researches are more interested in the modifiable causes, such as graft flow dynamics and wall shear stress distribution at the anastomotic sites. Formation of intimal hyperplasia at the anastomotic junction has been implicated as the root cause of long- term graft failure.Many researchers have analyzed the complex flow patterns in the distal sapheno-coronary anastomotic region, using various simulated model in an attempt to explain the site of preferential intimal hyperplasia based on the flow disturbances and differential wall stress distribution. In this paper, the geometrical bypass models (aorto-left coronary bypass graft model and aorto-right coronary bypass graft model) are based on real-life situations. In our models, the dimensions of the aorta, saphenous vein and the coronary artery simulate the actual dimensions at surgery. Both the proximal and distal anastomoses are considered at the same time, and we also take into the consideration the cross-sectional shape change of the venous conduit from circular to elliptical. Contrary to previous works, we have carried out computational fluid dynamics (CFD) study in the entire aorta-graft-perfused artery domain. The results reported here focus on (i) the complex flow patterns both at the proximal and distal anastomotic sites, and (ii) the wall shear stress distribution, which is an important factor that contributes to graft patency.

Methods

The three-dimensional coronary bypass models of the aorto-right coronary bypass and the aorto-left coronary bypass systems are constructed using computational fluid-dynamics software (Fluent 6.0.1). To have a better understanding of the flow dynamics at specific time instants of the cardiac cycle, quasi-steady flow simulations are performed, using a finite-volume approach. The data input to the models are the physiological measurements of flow-rates at (i) the aortic entrance, (ii) the ascending aorta, (iii) the left coronary artery, and (iv) the right coronary artery.

Results

The flow field and the wall shear stress are calculated throughout the cycle, but reported in this paper at two different instants of the cardiac cycle, one at the onset of ejection and the other during mid-diastole for both the right and left aorto-coronary bypass graft models. Plots of velocity-vector and the wall shear stress distributions are displayed in the aorto-graft-coronary arterial flow-field domain. We have shown (i) how the blocked coronary artery is being perfused in systole and diastole, (ii) the flow patterns at the two anastomotic junctions, proximal and distal anastomotic sites, and (iii) the shear stress distributions and their associations with arterial disease.

Conclusion

The computed results have revealed that (i) maximum perfusion of the occluded artery occurs during mid-diastole, and (ii) the maximum wall shear-stress variation is observed around the distal anastomotic region. These results can enable the clinicians to have a better understanding of vein graft disease, and hopefully we can offer a solution to alleviate or delay the occurrence of vein graft disease.

     

CD68 expression in aortocoronary saphenous vein bypass grafts

Atherosclerosis commonly affects the arteries harvested from patients 70 years of age or older. Saphenous vein grafts appear to maintain a higher patency rate after coronary artery bypass grafting in these subjects. The infiltration of macrophages is an early step in saphenous vein graft atherosclerosis; however, little is known regarding the underlying mechanisms of infiltration. The objective of the present report is to evaluate the presence of CD68-positive cells in the saphenous vein wall and correlate initial CD68-positive infiltration to specific clinical and biochemical parameters and the graft patency rate as estimated in patients undergoing coronary artery bypass grafting. A total of 309 patients were allocated into two groups: A1 patients, who were between 50 and 70 years of age, and A2 patients, who were 70 years or older at the time of vein harvesting. CD68 expression was evaluated by immunohistochemistry. There were no significant differences between A1 and A2 patients regarding macrophage expression within any of the analyzed vascular regions. Saphenous vein macrophages were never present in the tunica intima unless they were also expressed in the media or the adventitia. The patients with CD68-positive cells in the tunica intima had a significantly higher number of bypass stenoses when compared with the subjects who did not have CD68-positive cells in this layer. These findings suggest that the CD68-positive cells (those that have not yet developed into foam cells) present in the intima of saphenous vein grafts might serve as a very early marker of graft occlusion.     

27-Hydroxycholesterol causes remodeling in endothelial cell membrane lipid composition comparable to remodeling in the failed vein grafts of CABG patients

Our objective is to determine if vascular remodeling in CABG patients is related to oxysterols, therefore, we compared failed vein grafts from 18 patients, available after a second coronary artery bypass grafting (CABG), with human endothelial cells (ECs). The ECs were cultured in minimum essential medium (MEM) with or without 27-hydroxycholesterol (27OHC), one of the oxysterol products of oxidatively modified low density lipoproteins (ox-LDL), as an agent to alter molecular mechanisms in vascular cells. Significant changes in phospholipid composition, in fatty acid profile and in calcium concentration were found in the failed vein compared to the native saphenous vein from the same (CABG) patient. The failed vein contained significantly less phosphatidylethanolamine, more sphingomyelin, less arachidonic acid, more linoleic acid and more calcium than the native saphenous vein. Comparable changes in phospholipid composition, in fatty acid profile and increased calcium influx were reproduced in ECs cultured in medium containing 27OHC indicating that an oxysterol is an agent that can alter the lipid composition of vascular cell membranes. Our study indicates that a lipid agent, as well as protein agents that have previously been linked to the process of vascular remodeling, may be fundamental to many vascular diseases.     

MYOCARDIAL INFARCTION FOLLOWING CAROTID ENDARTERECTOMY

Myocardial infarction has been the major cause of mortality following operation for cerebrovascular insufficiency. In our institution, a clinical diagnosis of coronary artery disease was made in 37 of 125 (29.6%) consecutive male patients having carotid endarterectomy. Six of these 37 patients developed postoperative myocardial infarction. In contrast, none of the 88 patients without coronary artery disease developed myocardial infarction. A more recently treated group of 20 patients who had undergone carotid artery surgery and had previously undergone coronary artery bypass for angina did not develop postoperative myocardial infarction. These data suggest that in patients with both coronary artery and carotid artery disease, prior or concomitant coronary artery bypass should be considered. Myocardial infarction has been the leading cause of early and late death following operation for cerebrovascular insufficiency.(1) DeBakey(2) found operative mortality in patients having surgery for cerebrovascular insufficiency directly related to the incidence of coronary artery disease. An increased operative mortality due to reinfarction has been found in patients recovering from recent myocardial infarction.(3) Cooley(4) found that in patients having aortocoronary bypass there was no increased operative mortality 30 days after myocardial infarction and this may apply to patients having carotid endarterectomy. Subendocardial postoperative infarction associated with minor T wave changes and slight enzyme elevation had a better prognosis than did transmural infarction causing significant Q waves, sequential ST and T wave changes and marked enzyme elevations.(5) The purpose of this study was to document our experience with myocardial infarction in patients undergoing carotid artery operation for clinical coronary artery disease. Consideration of the role of saphenous vein bypass in those patients with coronary artery disease was the background for this review even though the evidence that myocardial infarction can be prevented with saphenous vein bypass operation is only preliminary at the present time.(6)     

Predictive Factors of Late Venous Aortocoronary Graft Failure: Ultrastructural Studies

Background

Venous aortocoronary graft arterialization may precede a preterm occlusion in some coronary artery bypass grafting (CABG) patients. The aim of the present study was to identify ultrastructural variations in the saphenous vein wall that may have an impact on the development of venous graft disease in CABG patients.

Methods

The study involved 365 consecutive patients with a mean age of 62.9±9.4 years who underwent isolated CABG. The thickness and area of the whole venous wall, the tunica intima, the tunica media and the adventitia and the number and shape (length, thickness and length/thickness ratio) of the nuclei in the medial smooth muscle cells nuclei in the distal saphenous vein segments were evaluated by ultrastructural studies. Patients were followed up for 41 to 50 months (mean 45.1±5.1). Saphenous vein graft patency was assessed by follow-up coronary angiography. Logistic regression models were used to identify independent risk factors for late graft failure.

Results

In 71 patients significant lesions in the saphenous vein grafts were observed. The whole venous wall thickness (437.5 µm vs. 405.5 µm), tunica media thickness (257.2 µm vs. 211.5 µm), whole venous wall area (2.23 mm² vs. 2.02 mm²) and tunica media area (1.09 mm² vs. 0.93 mm²) were significantly larger for this group of patients than for those without graft disease. In the latter group more elongated smooth muscle cell nuclei (higher length/thickness ratio) were found in the tunica media of the saphenous vein segments. Thickening of the saphenous vein tunica media and chunky smooth muscle cell nuclei were identified as independent risk factors for graft disease development.

Conclusions

Saphenous vein tunica media hypertrophy (resulting in wall thickening) and chunky smooth muscle cell nuclei might predict the development of venous graft disease.     

Clinical outcomes of long coronary stents: a single-center experience

BACKGROUND: Coronary artery stenting is particularly useful during percutaneous coronary intervention for long lesions previously associated with a low procedural success rate and a high complication rate of dissection and occlusion. Current treatment options include implantation of a single long stent, multiple contiguous stents, or 'spot' stenting. However, multiple stent implantation may result in sections of overlapping stent or gaps of unstented segments and is an independent predictor of restenosis. The early and intermediate clinical outcome of single and multiple long stent (>/= 30 mm) implantation is not established. METHODS AND RESULTS: The authors retrospectively identified 123 consecutive patients who had undergone stenting using one or more long coronary stents. Baseline clinical data, procedural outcomes and completed clinical follow-up to 52 weeks were obtained by case-note review. The majority (69%) required intervention for stable coronary disease. Seventy-seven per cent of lesions were either type B2 or C and only 2% were in saphenous vein grafts. The procedural success rate was 94%. A total of 15 major events occurred in 13 patients (11%). Ten acute events occurred and five events were during the follow-up period from 30 days to 52 weeks. Two patients died, one from uncontrolled bleeding secondary to the use of antithrombotic agents and one at four weeks due to sudden death. One patient had a postprocedural infarct. Two patients required in-hospital repeat revascularization for acute vessel closure and eight required revascularization during follow-up (three cases of occlusion/thrombosis and five cases of restenosis). CONCLUSIONS: The use of long coronary stents (>/= 30 mm) for the treatment of long diffuse native vessel disease, saphenous vein graft disease and long coronary dissections is associated with a reasonable procedural success rate and acceptable early and intermediate-term clinical outcomes.     

Comparative effects of endothelin (ET-1) and U46619 on human saphenous vein and gastroepiploic artery,sources of human autologous grafts

The effects of endothelin (ET-1) on smooth muscle contractile activity were investigated and compared in human saphenous vein and gastroepiploic artery, vessels frequently used in revascularization procedures. ET-1 contracted saphenous vein and gastroepiploic artery in a concentration-dependent manner. The peptide produced a greater maximal effect in the vein than in the artery and, in both preparations, ET-1 was less efficacious than U46619, an agent which mimics the actions of thromboxane A₂ at the thromboxane A₂/prostaglandin HZ receptor. The contractile response to ET-1 declined spontaneously at a more rapid rate in the artery than in the vein. The present data indicate that ET-1 has significant contractile activity in both vessels which are used for coronary arterial bypass surgery and suggest that although, a weaker vasoconstrictor than U46619, the peptide could induce vasospasm in both graft vessels.     

Simultaneous endoscopic radial artery and great saphenous vein harvesting for redo coronary artery bypass grafting. A report of two cases

Aim: An ageing population and increase in patient co-morbidities are forcing cardiac surgeons to meticulously consider the benefits and risks of respective conduits and their harvesting techniques. Case reports: Two cases of simultaneous endoscopic radial artery and great saphenous vein harvesting, for redo coronary artery bypass grafting, are presented. A shortage of venous conduits after previous bypass grafting, as well as the presentation of several risk factors of wound-healing complications, favoured simultaneous utilisation of both endoscopic techniques. Conclusion: Endoscopic vessel harvesting together with the pre-harvesting duplex study is able to gain not only high-quality conduits but also minimize the risk of wound-healing and neurological disturbances associated the saphenous vein and radial artery harvesting.     

Troglitazone has no effect on K(ATP) channel opener induced-relaxations in rat aorta and in human saphenous veins from patients with type 2 diabetes

Troglitazone, a thiazolidinedione derivative, is an oral antidiabetic agent that enhances insulin sensitivity in insulin-resistant states. K(ATP) channels, on the other hand, have important roles protecting cardiovascular system in ischemic and/or hypoxic states. They are also important in the control of vascular tone, and therefore of blood pressure. We tested whether troglitazone can directly affect vascular K(ATP) channel opener-induced relaxations in vitro. 1, 10 or 100 microM troglitazone incubations for 30 min did not alter cromakalim (a K(ATP) channel opener)--induced relaxations in endothelium-denuded aortas from rat, saphenous veins from type 2 diabetic and nondiabetic patients. In addition, we compared the sensitivity to cromakalim in diabetic saphenous veins with that of nondiabetic veins. The concentration-response curve for cromakalim was shifted to the right in diabetic vein. pD2 values for cromakalim were 6.85+/-0.08 vs. 6.61+/-0.04 (p<0.05) in nondiabetic (n:10) and diabetic (n:7) veins respectively. % maximum response of cromakalim was also significantly decreased by 24+/-3% in diabetic veins. However, responsiveness of veins to phenylephrine or sodium nitroprusside were similar in both groups. The results obtained may be clinically useful 1. suggesting that in ischaemic and/or hypoxic insults troglitazone may not worsen vascular dilatation, through K(ATP) channel, in diabetic patients who are more prone to these conditions than healthy people, 2. providing an evidence that diabetes causes an impaired dilatation of human saphenous vein through K(ATP) channels. This may partly be related with diabetes-induced vascular complications, such as vasospasm and even hypertension. Accordingly, since saphenous veins are used as conduit vessels in coronary by-pass graft surgery, the results also suggest that the defective dilatation through K(ATP) channels may play a role on the performance of saphenous vein grafts in type 2 diabetes.     

Changes in the phospholipid composition of the arterial cell can result in severe atherosclerotic lesions

The oxysterol concentration in the plasma and the phospholipid composition of vascular tissue obtained by coronary artery bypass grafting (CABG) were compared with plasma and vascular tissue from age and sex matched controls. The plasma from CABG patients had a higher concentration of oxysterols than was present in the controls. Human endothelial cells were cultured for 72 hours in a medium containing plasma obtained from CABG patients, from controls or from the same controls to which 5 oxysterols were added to make the total oxysterol level equivalent to that in the CABG plasma and then pulsed with calcium (45Ca(2+)) for one hr. A significantly higher influx of 45Ca(2+) was noted in the endothelial cells cultured in the plasma obtained from CABG patients and from the controls with 5 added oxysterols, but not in those cultured without added oxysterols indicating that oxysterols increased calcium influx into endothelial cells. A phospholipid analysis indicated that the arterial tissue from CABG patients had 48.2% sphingomyelin in its phospholipid fraction compared to 10% in arterial tissue from umbilical cords. The saphenous vein obtained during CABG surgery from the same patient had only 24% sphingomyelin in its phospholipid fraction and unlike the coronary arteries had no atherosclerotic lesions. The higher level of oxysterol in the plasma of patients suffering from severe atherosclerosis could increase the concentration of sphingomyelin in the arterial cell membrane and thereby increase calcium influx required for producing the calcific type VII lesions in the coronary arteries.     

ASCENDING AORTIC ANEURYSM RESECTION EIGHT MONTHS AFTER TRIPLE CORONARY ARTERY BYPASS: CASE REPORT

This report involves the surgical treatment of a patient who underwent saphenous vein triple coronary artery bypass and subsequently developed an ascending aortic aneurysm and aortic insufficiency. Although the implantation of vascular structures into synthetic grafts is commonplace, this case is unique in that it involves the successful implantation of an aortic island containing the origin of the coronary arteries.     

Management of dyslipidemia after coronary artery bypass grafting

The results of serial angiographic studies and intervention trials in patients after coronary artery bypass artery grafting have provided ample evidence that abnormalities of the plasma lipoprotein system are one of the most significant risk factors for a rapid atherosclerotic attrition of saphenous vein grafts. In addition to confirming the well recognized role and contribution of cholesterol-rich LDL or lipoprotein B particles to the progression of atherosclerotic lesions, intervention trials have also provided strong evidence for the atherogenic capacity of some intact and partly delipidized triglyceride-rich very low density lipoprotein and intermediate density lipoprotein (lipoprotein B complex) particles, and the protective effect of some (high density lipoprotein 3) but not all high density lipoprotein particles. Most importantly, those studies have emphasized the need for an early, aggressive treatment of dyslipoproteinemias with pharmacological agents as the most efficient therapeutic approach to delaying, if not preventing, the detrimental effect of atherosclerosis on saphenous vein grafts.     

PERFUSION FOR MYOCARDIAL REVASCULARIZATION WITHOUT AN ARTIFICIAL OXYGENATOR (New Method to Reduce Surgical Morbidity)

Thirteen patients were submitted to direct myocardial revascularization (saphenous vein graft) without the use of an artificial oxygenator. The perfusion was done by a left ventricle-to-aorta bypass and autogenous oxygenation. Most patients had three grafts implanted plus endarterectomy of the distal right coronary artery. There was one hospital death that was apparently not related to the method used. Perfusion time ranged from 45 minutes to 4 hours. Body temperature during perfusion was kept between 25 and 30 degrees C. Perfusion flow was maintained between 25 to 50 ml per kg of body weight per minute. Ischemic, hypothermic cardiac arrest was employed. We demonstrated for the first time that perfusion for this kind of heart surgery could be done with no artificial oxygenators and, apparently, is safer for the patients. There were no bleeding problems even in perfusions as long as 4 hours. There was no respiratory dysfunction, and artificial respiration was used for only 6 to 12 hours. The patients awoke at the end of surgery with no signs or symptoms of central nervous system damage, and vasopressor drugs were rarely used after surgery. Although the experience is very small, it suggests that many postoperative problems, especially those related to bleeding and respiratory dysfunction may be reduced or eliminated by this new method.