Improvement of aortocoronary bypass patency by antiplatelet drug administration. Preliminary communication

Patients with aortocoronary bypass whose peroperatively measured blood flow amounted to 40 ml/min or less were divided into two groups. The treated group was from postoperative day 0 given 2 X 500 mg acetylsalicylic acid and 3 X 75 mg dipyridamole per day; the control group was without this medication. One month and one year after surgery the patients were examined by coronarography. The first follow-up examination revealed in the treated group 34 patent and 7 occluded bypasses, in the control group 17 patent and 20 occluded bypasses. On late follow-up examination there were in the treated group 24 patent and 13 occluded and in the control group 8 patent and 30 occluded bypasses (p less than 0.001).     

Complete and incomplete revascularization at aortocoronary bypass surgery: experience with 392 consecutive patients

This report presents our experience with “complete” and “incomplete” revascularization in 392 consecutive patients undergoing aortocoronary artery bypass surgery. Patients were considered to have had “complete” revascularization only if all major coronary arteries with 70 per cent occlusion received at least one bypass graft. Patients were considered “incompletely” revascularized if any vessel with a 70 per cent or more occlusion did not receive at least one bypass graft. The “completely” revascularized cohort contained 186 patients and the “incompletely” revascularized cohort contained 206 patients. The survival of the “completely” and “incompletely” revascularized cohorts was compared postoperatively and at 6, 12, and 24 months using the Chi-square test. Relief of anginal pain rates were compared at 6, 12, and 24 months using the Chi-square test. Analyses were repeated after stratifying for number of vessels diseased. The subgroup with one vessel diseased was, by definition, “completely” revascularized. No significant difference in survival or relief of anginal pain was demonstrated in the total group or in subgroups with 2 and with 3 vessels diseased. The data indicate that “complete” revascularization is not closely coupled to two-year survival or relief of anginal pain.     

Angina following aortocoronary bypass surgery.

43 patients (group A) who had a recurrence of angina after aortocoronary bypass surgery were compared with 93 (group AF) who remained symptom free for at least 1 yr in order to assess the effects of pre- and intraoperative factors on the outcome of surgery. Age and sex distribution, severity and duration of preoperative angina, incidence of preoperative infarction, known coronary risk factors and severity of coronary artery disease assessed angiographically, were similar in the 2 groups. Group A had a lower preoperative exercise tolerance (434 V, 517 ppm/min; P less than 0.05) and a greater proportion of patients with cardiac enlargement (33% V, 14%; P less than 0.05). Fewer grafts were implanted in this group (1.65 V, 2.05; P less than 0.01) which consequently had a higher postoperative coronary score (2.47 V, 1.69; P less than 0.05). It appears that the extent of myocardial revascularization may influence the symptomatic result of aortocoronary bypass surgery.     

Myocardial protection during aortocoronary bypass.

The authors analyze the results of 220 applications of internal cold cardioplegia in 136 patients with ischaemic heart disease, treated surgically by aortocoronary bypass. The operation was performed under neuroleptanalgesia and artificial circulation with hypothermia (27.9 +/- 0.2 degrees C) and haemodilution (24.9 +/- 0.3%). On the basis of clinical examination, electron microscopy of the myocardial ultrastructure, and investigation of the myocardial metabolism (contents of glucose, lactate, pyruvate, free fatty acids, catecholamines, and oxygen in arterial and venous blood flowing out of the myocardium), they come to the conclusion that internal cold cardioplegia efficiently protects the myocardium during aortocoronary bypass and secures favourable conditions for the development of anastomoses between coronary arteries and venous shunts.     

Non-invasive study of the patency of aortocoronary bypass with pulsed Doppler technic. Preliminary studies]

The pulsed Doppler effect is a non-invasive investigation technique based on the fact that the blood cells moving in a vessel on which ultrasound is incident cause a rebound of different frequency, according to their rate. This technique allows us to measure flow in a "measuring volume", whose size and depth are regulable. It is also possible to collect the signal from one or several aorto-coronary grafts, and to distinguish these from the sorrounding vasculature by their diastolic perfusion. This preliminary study (11 cases) is an attempt to formulate strict procedural criteria by comparison with follow-up arteriography of the grafts. The ease of performance of this investigation should, eventually, make it unnecessary to have to carry out repeated arteriography.     

Dysfunction of aortocoronary bypass. Prognosis]

From 1978 to 1988, 108 patients with at least one occluded or stenosed aorto-coronary bypass graft (over 75% stenosis) underwent coronary angiography on average 31 months after the initial coronary bypass surgery. The occluded or stenosed coronary graft was either a saphenous vein (n = 126 including 9 sequentials) or internal mammary artery (n = 5). The bypassed artery was the left anterior descending (n = 66), right coronary (n = 40), left marginal (n = 25) or diagonal (n = 9). The number of occluded or stenosed grafts by patient was 1.2. The left ventricular ejection fraction was 55% (range 25 to 77%). During a mean follow-up period of 60 months after coronary angiography, there were 14 cardiac deaths and 15 non-lethal myocardial infarctions. Treatment comprised 12 angioplasties, 26 new bypass grafts and 3 cardiac transplantations. The 8 year actuarial survival was 84%. The survival without infarction at 8 years was 69%. Survival was significantly decreased to 72% when the occluded or stenosed graft was located on the left anterior descending artery. The survival without infarction at 8 years was 52% in the patients with dysfunction of left anterior descending artery grafts and 89% when the diseased graft was located on another artery (right coronary, left marginal, diagonal). Therefore, the data of this retrospective study show that coronary graft dysfunction on the right coronary, left marginal or diagonal arteries do not greatly influence life expectancy in the medium term after coronary bypass surgery.(ABSTRACT TRUNCATED AT 250 WORDS)     

Noninvasive Doppler ultrasound evaluation of aortocoronary bypass.

Using ultrasound method, aortocoronary bypass patency was determined by means of bidirectional Doppler's flowmeter. In 8 (3%) of 302 subjects without aortocoronary bypass was recorded diastolic signal which might distort the results of postoperative evaluation of graft patency. Two-hundred and ninety-seven patients with 330 aortocoronary bypasses were studied at the mean time of 8 months after operation. The graft patency was 84.5%. Comparison of 89 ultrasound findings with angiographic results established considerable specificity (90%) and sufficient sensitivity (77%). Reproducibility of this method was also good. The method is inexpensive and not time consuming. The advantages are also its safety and convenience for the patient. In the present level of development it can be used mainly as screening test at long-term follow-up of aortocoronary graft patency.     

Elective aortocoronary bypass grafting in the elderly

Operative mortality, postoperative morbidity and follow up data were analyzed retrospectively from 122 consecutive patients, over 65 years old undergoing elective aortocoronary bypass grafting for symptomatic relief of angina pectoris at the Plains Health Centre, Regina, Saskatchewan, from January 1980 to December 1985. There were two in-hospital deaths (operative mortality 1.6%). Definite perioperative myocardial infarction occurred in 12 patients (9.8%). The 120 survivors were followed for a mean of 32 months. There were three deaths during follow-up, giving a five-year probability of survival of 93%. Twenty-three clinical events (including deaths) occurred during follow-up, giving a five-year probability of event free survival of 72%. Ninety percent of patients say they are pleased with their operation. Seventy-eight percent are currently angina free. These data illustrate the effectiveness of aortocoronary bypass grafting in low risk elderly patients with symptomatic coronary artery disease.     

主动脉手术体外循环的初步体会

10例主动脉手术在体外循环下进行。降主动脉手术4例,升主动脉手术5例,主动脉弓离断(B型)手术1例。根据不同手术分别采用低温体外循环,深低温停循环或左心转流。本组死亡3例。本文讨论了左心转流的方法,深低温停循环的安全时限,B型主动脉弓离断手术的体外循环管理,及防止人工血管渗血的问题。     

Results of aortocoronary bypass operations. Follow-up in 343 patients.

Three hundred and forty-three patients who had aortocoronary bypass graft operations for disabling angina were followed up for from 6 months to 5 years (average 2 years). 80 per cent had multiple grafts and 20 per cent had additional endarterectomy. The overall mortality within one month of operation was 5 per cent, and in those who had vein graft procedures only was 4 per cent. 11 per cent had a postoperative myocardial infarction (6% perioperative) and there were 3 per cent late deaths. At 3 years 90 per cent are surviving. 80 per cent are asymptomatic without treatment. The mean angina grade was 0.3 at the latest follow-up, compared with 2.5 before operation; maximum exercise tolerance was also significantly improved (P less than 0.001). When angina recurred, it did so in 80 per cent of the cases within 12 months of operation and was usually attributable to inadequate revascularisation. Ventricular function as assessed by preoperative ventriculography was the factor most clearly related to survival rate and the early excellent results of coronary bypass operations seem to be maintained up to 5 years. It is, therefore, reasonable to continue to advise operation if only for relief of angina.     

Pheochromocytoma and aortocoronary bypass. Double surgical procedure

Based on a personal case of a 47 year old woman with an adrenal medullary pheochromocytoma and stenosis of the left anterior descending artery treated by aorto-coronary bypass grafting after ablation of the pheochromocytoma, the authors illustrate the frequency and precocity of organic coronary artery disease in 27 cases in the literature. Chest pain and electrocardiographic changes are often attributed to functional ischaemia but the high incidence of organic coronary artery disease in the series analysed confirms the need for coronary angiography in doubtful cases. It is reasonable to start by removing the pheochromocytoma and, only then, consider coronary angiography with a view to coronary bypass surgery: the risks of a hypertensive crisis seem to be reduced when this protocol is followed.     

Successful aortocoronary bypass in osteogenesis imperfecta

Cardiovascular abnormalities are infrequently documented in osteogenesis imperfecta, one of a group of hereditary, generalized connective tissue disorders. A patient with osteogenesis imperfecta is described with mitral valve prolapse, significant coronary artery disease and a coronary artery aneurysm. The latter two cardiac defects are apparently rare in this disease. The option of surgery was carefully considered with regard to technical feasibility and potential deterioration of the graft anastomoses. Although successful aortocoronary bypass surgery had not been previously reported in osteogenesis imperfecta, this patient received such surgery with therapeutic benefit. Therefore, coronary artery vascularization should be considered as a safe and effective treatment modality for patients with osteogenesis imperfecta and coexisting coronary atherosclerosis.     

Percutaneous transluminal angioplasty of stenosed aortocoronary bypass grafts.

During the period between October 1980 and December 1982, percutaneous transluminal angioplasty of stenosed aortocoronary bypass grafts was attempted 44 times in 31 patients who had developed disabling angina pectoris four months to seven years after coronary bypass surgery. The primary success rate was 93%. Two (4.5%) patients developed myocardial infarction related to the procedure. No emergency aortocoronary bypass surgery was required and there was no mortality. Although the primary success rate was high, the incidence of recurrence after one or more angioplasties was 50%. Despite this recurrence rate the condition of 10 of the first 16 (62%) patients was clinically improved after a mean follow up of 26 months.     

Heart disease indicators in patients with aortocoronary bypass operation.

The incidence of cardiovascular disease risk factors and other indicators of cardiac impairment were studied in 478 patients prior to their aortocoronary vein bypass operation and 194 patients who had angiographic examination but did not undergo the operation because the clinical and coronary angiographic findings were not considered serious enough to warrant the bypass procedure. The patients referred for surgery had higher plasma cholesterol and triglyceride levels (259 and 219 vs 233 and 180 mg/100 ml), tended to be older (53 vs 49 years) and had more extensive occlusive disease (occlusion score 200 vs 70) than the group without the operation. There was little difference in the proportion of smokers (81 vs 83%) or prevalence of hypertension (33 vs 30%). In comparison with 9,964 participants of a local health screening program, both patient groups had markedly higher prevalence of smoking, hypertension, chest pain and previous myocardial infarcts.     

Changes in saphenous veins used as aortocoronary bypass grafts.

This report describes morphologic changes in saphenous veins used as aortocoronary bypass conduits, and discusses the relative contribution of various factors to these changes. The three primary changes are: (1) medial fibrous replacement, (2) adventitial fibrous proliferation, and (3) intimal fibrous proliferation. Medial fibrous replacement is caused by vein wall ischemia with loss of smooth muscle cells; adventitial fibrous proliferation is the result of organization of fibrin deposits and repair of ischemic injury; and intimal fibrous proliferation results from some stimulus, probably fibrin deposition on injured intima, which causes stimulation of smooth muscle cells to become fibroblasts or "myointimal cells". Although all grafts show some changes, the degree and severity of these three changes is variable along the length of the grafts and among separate grafts in the same patient.