Aortocoronary Artery Bypass Graft Research Articles

Thallium-201 imaging in assessment of aortocoronary artery bypass graft patency.

Fifteen patients with significant coronary artery disease confirmed by cardiac catheterisation were studied before and after aortocoronary artery bypass graft surgery by rest and exercise 201Tl myocardial scintigraphy in an attempt to predict graft status non-invasively. Segmental myocardial perfusion comparisons in pre- and postoperative exercise images allowed correct predictions of high (greater than or equal to 67%) or low (less than or equal to 50%) graft patency rates in 10 of 15 patients, while similar comparisons in postoperative rest and exercise images yielded 13 of 15 correct predictions. Furthermore, 20 of 21 myocardial segments with increased postoperative perfusion when compared with corresponding segments in preoperative exercise studies were supplied by patent grafts. Regional graft occlusion, however, was difficult to predict. It was also difficult to predict graft status when myocardial segments were shown to have unchanged perfusion postoperatively as compared with the preoperative segmental assessment. Despite these limitations, the non-invasive technique of 201Tl imaging can provide useful information regarding coronary artery bypass graft patency.

Aortocoronary bypass surgery: a 7-year follow-up.

Follow-up of 748 consecutive patients who underwent aortocoronary artery bypass grafts was obtained for 5 to 94 months (average, 59 months). Operative mortality of 2.5% did not vary with number of vessels bypassed. There was a linear 3.5% annual recurrence rate of angina, and average annual late infarction rate of 1.4%. The cumulative survival rates did not differ for the number of grafts performed or for men and women, but did differ for left main coronary stenosis and impaired ejection fractions. The late cumulative survival rates for the entire group approached those of the general U.S. population.

Aortocoronary-Artery Bypass

DURING the past ten years, as aortocoronary-arterybypass operation has received wider application, the procedure has been subjected to possibly the most intensive scrutiny of any operation in the history of surgery. The recent preliminary report of a Veterans Administration Cooperative Study, 1 highly publicized in the lay press, has not only created considerable controversy within the medical profession, but has also caused confusion and concern cmong patients. Unfortunately, an editorial accompanying this report has been erroneously interpreted as a total condemnation of the surgical treatment of coronary arterial disease. 2 That the preliminary study of a small, highly selective group of patients operated on by surgeons with variable experience and observed for a mean interval of only 21 months should have received such enormous attention indicates the passion and partisanship that have enveloped this subject. In the 13 years since the first successful aortocoronary-artery—bypass graft was performed for coronary atherosclerosis,

Coronary-Artery Surgery at the Crossroads

The surgical treatment of coronary-artery disease began early in this century when surgical sympathectomy was reported as a successful treatment for angina pectoris. Since then a variety of procedures have been tried, all of which were greeted with initial enthusiasm, which then rapidly waned. However, aortocoronary-artery bypass graft (CABG) is qualitatively superior to the earlier operations because it is associated with marked and sustained relief of angina pectoris in most patients. Since the delivery of substantial quantities of blood to previously ischemic myocardium can be accomplished with relatively low mortality by a skilled, experienced surgical team, the indications for this . . .

Relation of intraoperative or early postoperative transmural myocardial infarction to patency of aortocoronary bypass grafts and to diseased ungrafted coronary arteries

Serial preoperative and postoperative electrocardiograms and vectorcardiograms were obtained in 500 patients undergoing saphenous vein aortocoronary artery bypass graft surgery. Evidence of transmural myocardial infarction was found early postoperatively in 67 patients (13 percent). Age and sex distributions, number of vessels diseased or vessels grafted, and preoperative and postoperative New York Heart Association functional classification (mean follow-up, 26 months) did not differ in the groups with and without infarction. Increased duration of cardiopulmonary bypass time (more than 120 minutes) was slightly greater in the group with infarction ( P < 0.05). Multivariate analysis revealed that 60 percent of patients in the group with infarction were identified by a 1st day serum glutamic oxaloacetic transaminase value greater than 100 U/liter; however, for each such patient identified, there was approximately one false positive result. Use of other values (creatine phosphokinase, cardiopulmonary bypass time and total anoxic rest time) did not improve discrimination. Twenty-five percent of all transmural infarctions occurred within the zone of myocardium supplied by a diseased ungrafted artery. In 32 patients with early evidence of transmural myocardial infarction in a zone of myocardium supplied by a grafted artery, postoperative angiography showed as many with patent as with occluded grafts. Of 154 patients in the group without infarction who had early postoperative graft angiograms, 30 (19 percent) had one graft occluded and yet no evidence of transmural infarction by our criteria. Therefore, early postoperative evidence of transmural myocardial infarction as defined in this study is an unreliable indicator of the status of the graft supplying the zone of infarction.

Disposable membrane oxygenator support during emergency coronary angiography and during surgery for acute myocardial infarction or chronic myocardial ischemia.

Forty-two patients received successful total cardiopulmonary support with the effective, easy to use, completely disposable, Lande-Edwards Membrane Oxygenator.In 4 patients, partial cardiopulmonary support was provided with the Membrane Oxygenator and/or intra-aortic baloon pump during emergency coronary arteriography and corrective cardiac surgery for shock, following myocardial infarction.Two Lande—Edwards membrane oxygenators, 3 m2, were connected in parallel and joined in either a recirculation circuit or, more recently, a simplified gravity circuit. Three oxygenators were used for patients 80 kg to 103 kg body weight.Effective gas exchange was documented by the normal range of arterial and venous oxygen and carbon dioxide levels during flow rates of 50 cc/kg/min at 30°C. Safety of perfusion was demonstrated by 25 of 26 patients being discharged improved after complex aortocoronary artery by-pass graft operations. Minimal side effects were observed including plasma hemoglobin under 100 mg%, platelet c...

Emergency aortocoronary bypass. Treatment of ventricular tachycardia due to ischemic heart disease

Seven weeks after onset of chest pain, diagnosed as subendocardial infarction, a 49-year-old woman developed frequent ventricular tachycardia and loss of consciousness. An emergency coronary cineangiography revealed significant constriction of the left main coronary artery. Aortocoronary artery bypass graft was performed. Ventricular tachycardia completely disappeared and the patient was discharged from the hospital.

Emergency Aortocoronary Bypass

Seven weeks after onset of chest pain, diagnosed as subendocardial infarction, a 49-year-old woman developed frequent ventricular tachycardia and loss of consciousness. An emergency coronary cineangiography revealed significant constriction of the left main coronary artery. Aortocoronary artery bypass graft was performed. Ventricular tachycardia completely disappeared and the patient was discharged from the hospital.

Coronary Artery Bypass in Totally Obstructed Major Coronary Arteries

Of 278 patients undergoing aorto-coronary artery bypass grafts through July 1970, a total of 167 (62.2%) had 220 complete occlusions of one or more major coronary arteries. The right coronary artery (RCA) was occluded in 61%, the left anterior descending (LAD) in 28%, the left circumflex (LCA) in 10%, and the left main (LM) in less than 1%. Previous myocardial infarctions, congestive heart failure, incapacitation, and elevated left ventricular end diastolic pressure were more common in this group than in those with stenotic lesions. The RCA was most often suitable for bypass graft, followed by the LAD, and lastly the LCA. In the small group without demonstrable distal collaterals on arteriograms, distal bypasses were done successfully beyond 70% of the occluded RCAs, 51% of the LADs, and none of the LCAs. Operative mortality (30 days) was only 3% higher in the occluded than in the stenotic group. Postoperative angiographic patency rates were the same.