Reoperation after aortocoronary bypass procedure. Results in 53 patients in a group of 1041 with consecutive first operations.

Of 1041 patients with consecutive aortocoronary bypass operations, 53 (5.1%) underwent reoperation during a mean follow-up time of three and a half years. The operative mortality of first operations was 1.2%, and of reoperations 3.8%. The anatomical reason for reoperation was failure of the bypass graft in 41 (77%) patients, which in 18 was accompanied by progression of disease. Progression alone was seen in seven (13%). When symptoms occurred within six months after the first operation, failure of the bypass graft(s) was nearly always found--in 32 out of 36 instances. Progression in non-bypassed arteries was seen only when symptoms occurred later. Late results in angina pectoris were less favourable in the group undergoing reoperation: 31 (65%) of the 48 operated on twice and 406 (46%) of the 877 patients operated on once still had angina at late follow-up. The same fraction in both groups was improved by operation: 88% versus 89%.     

Results of aortocoronary bypass grafting in patients with subendocardial infarction: late follow-up.

Twenty-eight patients with subendocardial infarction (Group A) were compared with 28 patients with unstable angina (Group B) and 28 with stable angina (Group C) matched for age and sex. The three groups did not differ in prevalence of diabetes, hypertension, old infarction or duration of disease. There were no significant differences in number of diseased vessels, coronary score, abnormal left ventricular wall motion or left ventricular end-diastolic pressure. Angiograms performed 2 weeks postoperatively revealed closure of 3 of 31 grafts (16 patients) in Group A, closure of 3 of 34 grafts (17 patients) in Group B and closure of 6 of 50 grafts (22 patients) in Group C (differences not significant). Postoperative angiograms showed improved wall motion in 37 percent of Group A, 53 percent of Group B and 36 percent of Group C (differences not significant). Postoperative new Q waves appeared in one hospital in Group A and in two patients in Groups B and C. There were no hospital or late deaths. In a mean follow-up period of 29 months, 68 percent of patients in Group A, 61 percent in Group B and 54 percent in Group C were asymptomatic. Thus, bypass grafting was performed with similarly low mortality and morbidity in patients with subendocardial infarction and in those with angina; more than one third of postoperative angiograms in the three groups showed improved wall motion; and late follow-up studies demonstrated functional improvement in the majority of patients in all three groups.     

Transient central diabetes insipidus after aortocoronary bypass operations

Three cases of transient central diabetes insipidus after cardiopulmonary bypass are presented. All 3 patients responded promptly to administration of vasopressin, and were completely recovered from polyuria 10 days after cardiac surgery. It is postulated that transient diabetes insipidus after cardiac operation occurred in some patients who had preexisting selective osmoreceptor dysfunction when cardiac standstill during extracorporeal circulation alters the left atrial nonosmotic receptor function, resulting in suppression of antidiuretic hormone release.     

Results of computerized cardio-tomography and radionuclide ventriculography in patients with aortocoronary bypass

Cardiocomputer tomography and radionuclide assessment of left ventricular function complete each other in postoperative control of patients with coronary artery bypass grafts. 70 patients with 163 coronary artery bypass grafts had 85% or total bypass graft early postoperative period, 77% after one year and 69% after two years. Sensitivity of cardiocomputer tomography was 75% and accuracy was 84%. The left ventricular functions was unchanged postoperatively.     

Results of emergency aortocoronary bypass in complicated coronary angioplasty

Sixteen out of 293 (5.4%) procedures for percutaneous transluminal coronary angioplasty, performed between 1985 and 1988, were complicated by acute closure and required emergency revascularization surgery. The injured vessel was the left anterior descending artery in 14 cases and the right coronary artery in 2 cases. All patients had persistent chest pain associated with ST-segment elevation in 14 cases and ST-segment depression in 2 cases. Two patients developed cardiogenic shock and were in cardiac arrest at the beginning of operation; one of these died immediately after the operation. Thus the overall mortality rate was 6.2%. Enzyme evidence of myocardial infarction (CPK-MB greater than 40 UI/I) occurred postoperatively in 8 patients (50%), but only the 6 patients (37.5%) with electrocardiographic evidence of myocardial necrosis (new Q-waves or loss of R-wave voltage) showed akinesis of the myocardium perfused by the occluded vessel at the echocardiographic examination performed two weeks after the operation. The occurrence of myocardial infarction was correlated with the degree of preoperative ischemia and hemodynamic deterioration. A collateral flow was present in 3 cases and none of these showed evidence of myocardial necrosis after the operation. Our results show that emergency bypass surgery for failed coronary angioplasty is less satisfactory than elective surgery, and has a higher mortality and myocardial infarction rate. Thus, the risk of emergency operation for complicated dilation must be considered when selecting of candidates for coronary angioplasty.     

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.     

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.     

The influence of obesity on perioperative morbidity: retrospective study of 502 aortocoronary bypass operations.

The incidence of perioperative complications after coronary artery surgery was investigated by a retrospective study of all 502 patients undergoing coronary artery bypass graft (CABG) surgery in our Department between January 1st and December 31st of last year (1990). Furthermore, the influence of obesity on the early results of surgery was assessed and the effect of preoperative weight reduction on perioperative complication rates examined. Obese patients had a greater incidence of left-stem coronary artery stenosis (p less than 0.001), hyperlipidaemia (p less than 0.05), hypertension (p less than 0.05), diabetes mellitus (p less than 0.02), and were in general younger at the time of operation (57.9 +/- 8.4 vs. 60.8 +/- 8.5 years). There were no differences in the surgery performed and in operative mortality, but there were some in perioperative morbidity. Obese patients had higher rates of infection (p less than 0.02), sternal dehiscence (p less than 0.02), arrhythmias (p less than 0.02) and myocardial infarction (p less than 0.02). No significant differences were identified in obese patients with or without preoperative weight reduction, although there was a trend of better postoperative recovery and results in patients having undergone preoperative weight reduction. Analysis of our results demonstrated obesity to be an independent risk factor for perioperative complications, hospital morbidity, and length of hospitalization.     

Increased oxygen free radical activity in patients on cardiopulmonary bypass undergoing aortocoronary bypass surgery.

Cardiac dysfunction after cardiopulmonary bypass (CPB) has been reported by various investigators. Oxygen free radicals have been shown to depress cardiac function and contractility. To evaluate the possible role of oxygen free radicals (OFR) in post-pump cardiac dysfunction, measurements of cardiac function, OFR producing activity of polymorphonuclear (PMN) leukocytes (PMN chemiluminescence) and malondialdehyde (MDA), a lipid peroxidation product, in blood were made at induction of anesthesia (T1), before cross clamping of the aorta (T2), after closure of the chest (T3), and 24 hours postoperatively (T4) in 21 patients undergoing aortocoronary bypass surgery. The total OFR-derived chemiluminescence at T1, T2, T3, and T4 was 1590 +/- 156, 3169 +/- 338, 1972 +/- 214, and 2614 +/- 366 mv.min.10(6) PMN-1, respectively. Superoxide dismutase (SOD)-inhibitable chemiluminescence at T1, T2, T3, and T4 was 1214 +/- 129, 2674 +/- 328, 1752 +/- 215, and 2139 +/- 292 mv.min.10(6) PMN-1, respectively. Superoxide anion at T1, T2, T3, and T4 was 0.99 +/- 0.14, 1.30 +/- 0.17, 1.07 +/- 0.14, and 1.19 +/- 0.12 nmol.10(6) PMN-1.30 min-1, respectively. Blood MDA at T1, T2, T3, and T4 was 0.17 +/- 0.02, 0.25 +/- 0.03, 0.20 +/- 0.03, and 0.23 +/- 0.02 nmol/ml, respectively. OFR-derived and SOD inhibitable chemiluminescence, superoxide anion, and blood MDA increased significantly during CPB and postoperatively. There were decreases in the blood pressure and stroke volume, and increases in the central venous pressure, capillary wedge pressure, and heart rate during CPB and postoperatively. Cardiac output remained unchanged during this procedure. There was leukopenia during CPB.(ABSTRACT TRUNCATED AT 250 WORDS)     

A time-saving technique in angiography of aortocoronary bypass patients

We have used the sidewinder catheter for selective cattwterization and anglography of aortocoronary bypass grafts and have been Impressed by the usefulness of this catheter. Selective anglography of vein grafts can be done easily and quickly wtth this catheter, with a very high success rate.     

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.     

Risk factors and mortality in patients with aortocoronary vein bypass operation.

Patients who died one or more years after aortocoronary bypass surgery showed, at the time of the operation, higher prevalence of hypertension, and history of smoking and had higher plasma lipid levels than the patients who survived the operation for similar periods of time. No such differences in risk factors were seen between patients who survived or have died during the first 30 days after the operation. These findings suggest that pateints with abnormal risk factors have a poorer long-term prognosis.     

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)     

Selection of appropriate patients with heart failure for aortocoronary bypass surgery.

There is a slowly increasing amount of information on surgical revascularization of high-risk patients with lower ejection fractions. Many of these patients, formerly thought to be best treated by transplantation, can undergo safe and effective revascularization with excellent medium-term results. Factors that are important in predicting the success of surgical revascularization include left ventricular dilitation, elevated left ventricular end-diastolic pressure, redo coronary surgery, depressed white ventricular function, the presence of mitral regurgitation, and the presence of associated systemic diseases, among others. The management of patients with low ejection fraction around the time of coronary surgery is of critical importance; a period of pre-operative "tune-up" in the hospital on intravenous pressures, intra-aortic balloon, counter pulsation, and the use of transesophageal echocardiography, and improved intra-operative myocardial protection techniques have all contributed to improved results. The improvement in mechanical cardiac systems has also contributed toward improved surgical outcomes in this high-risk patient group.     

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.