Chalit Cheanvechai

Acute coronary insufficiency (impending myocardial infarction and myocardial infarction): Surgical treatment by the saphenous vein graft technique

Abstract The development of direct coronary artery surgery by the saphenous vein graft technique for the first time provides a method that immediately increases the supply of oxygen to the myocardium. As a result, the area of myocardial infarction no longer depends only upon oxygen consumption. Emergency surgery was performed on 29 patients from April 1968 to May 1971; 18 operations were performed upon patients with impending myocardial infarction and 11 upon patients with acute myocardial infarction. Nineteen patients underwent coronary cineangiography before the acute episode; 9 were studied during an acute episode. Patients with impending myocardial infarction were operated upon within 24 hours of the acute episode. Nine patients with acute infarction were operated upon within 4 to 5 hours, 1 within 8 hours, and 1 within 10 hours. Three patients died after the operation; 2 in the group with impending myocardial infarction and 1 in the group with acute infarction. Twelve patients underwent repeat cineangiographic evaluation. All grafts but 1 were open. In the group with impending myocardial infarction, postoperative left ventriculography showed good function of the left ventricle. In the group with acute myocardial infarction, 4 patients showed good function of the left ventricle. In 1 the ventricle was unchanged, and in 2 impaired contraction was demonstrated. Although the present clinical experience is limited, certain conclusions can be made: (1) Emergency coronary cineangiography can be performed with minimal risk. (2) Patients with impending myocardial infarction can undergo operation with a low mortality rate and minimal complications. These patients are ideal candidates. The operation can prevent myocardial infarction. (3) When operations are performed within 6 hours of an acute myocardial infarction, most of the heart muscle can be preserved. (4) In patients with acute myocardial infarction and cardiogenic shock, assisted mechanical circulation is mandatory as the first step. The increase of well oxygenated blood supply should improve myocardial perfusion.

Surgical treatment of coronary artery disease: Pure graft operations, with a study of 741 patients followed 3–7 Yr

This report reviews the experience with bypass graft surgery in the pure form, without associated cardiac procedures, in 6828 patients operated upon from 1967 through 1974. The hospital mortality rate in this group was 1.4%. The incidence of definite perioperative myocardial infarction was 6.9% prior to 1971, and 4.1% in the past 3 yr. Graft patency in postoperative studies performed an average of over 12 mo after surgery was 83.6%, and 89% of patients had one or more functioning grafts. In a subgroup of 741 consecutive patients operated upon with pure graft techniques from 1967 through 1970, survival seemed to be improved when compared to another group of similar, but nonoperated patients. The average annual mortality rate was 3.3% per yr in the surgical group (including surgical mortality) compared to 8.8% per year in the medical group. Differences in survival were most striking in patients with isolated anterior descending, double and triple vessel involvement. In the 741-patient subgroup the incidence of new occlusions of grafted arteries was related to the severity of the lesion(s) for which the operation was performed, and unrelated to graft patency. Arteriographically demonstrated new occlusions of ungrafted arteries were infrequent, and few patients developed significant new lesions during the period of observation. Symptomatic improvement is related to completeness of revascularization as determined by postoperative arteriography.

The Structural Study of the Saphenous Vein

From November, 1971, to September, 1974, 1,179 patients received aortocoronary saphenous vein bypass grafts at the Cleveland Clinic Hospital. Segments of saphenous vein from each patient were sent for microscopical analysis. These vein segments were classified as normal or abnormal (phlebosclerotic). Four hundred ninety-six normal vein grafts in 295 patients were restudied and had a patency of 87.9%. One hundred forty-four abnormal vein grafts in 86 patients were restudied and showed 89.5% patency. This study suggests that histopathological identification of an abnormal (phlebosclerotic) vein segment does not constitute a determining factor as far as late patency is concerned in a vein segment that is not grossly sclerotic.

Internal mammary--coronary artery anastomosis. "No-touch" technique.

A simple technique for internal mammary--coronary artery anastomosis that can be applied to all branches of the coronary circulation is described. The anastomosis can be constructed in 10 to 15 minutes. This technique eliminates pinching of the internal mammary artery by forceps.

Emergency myocardial revascularization

From April 1968 to December 1972, 100 patients received emergency aortocoronary artery saphenous vein bypass grafts at the Cleveland Clinic Hospital. Thirty-seven of these 100 patients received grafts during acute myocardial infarction and 63 during impending infarction. Coronary arteriograms were obtained in all patients before operation. In the group with acute infarction, operations were performed within 12 hours after the onset of acute chest pain in 29 patients and from 3 to 14 days after infarction in 8. In the group with impending infarction, most patients received grafts within 3 to 4 hours after the onset of chest pain. Six of the 100 patients died in the postoperative period, 2 with acute and 4 with impending infarction. Thirty patients with acute infarction and 55 with impending infarction became asymptomatic. Sixteen of the 37 patients with impending infarction and 20 of the 63 patients with acute infarction were restudied. The graft patency rate in these patients was 92 percent. Coronary arteriography can be performed during acute and impending myocardial infarction with minimal risk. Aortocoronary saphenous vein bypass grafting can prevent the development of acute infarction when properly performed during the stage of impending infarction. It may also prevent the extension of acute infarction when , performed during the early phase of this lesion.

The Free Internal Mammary Artery Bypass Graft: Use of the IMA in the Aorta-to-Coronary Artery Position

Abstract Transposition of the internal mammary artery (IMA) into the aorta-to-coronary artery position is described, and 4 patients who underwent this operation are reported. Currently, this type of bypass graft is reserved for those patients who have unsuitable or stripped saphenous veins. The free IMA grafts can be connected to any of the major coronary vessels, and in most instances optical assistance is not necessary. There was no significant difference in recorded blood flow between these free grafts and a large group of in situ IMA-to-coronary artery bypass grafts.

Aortocoronary Artery Graft During Early and Late Phases of Acute Myocardial Infarction

Abstract From April, 1968, to August, 1972, 30 patients received one to three emergency saphenous vein grafts during acute myocardial infarction. In all but 1 patient, acute myocardial infarction occurred while the patients were in the hospital awaiting coronary angiography or myocardial revascularization. The patients were divided into two groups: those in the early and those in the late phases of acute myocardial infarction, depending on the time interval between the onset of chest pain and operation. Twenty-four patients (early phase) received grafts within 10 hours after the onset of infarction, and 18 of these 24 patients underwent operation within 4 hours after infarction. Two patients included in this group sustained myocardial infarctions in the operating room during elective myocardial revascularization procedures; another patient was brought to the operating room following cardiac arrest and was supported by internal cardiac massage throughout the opening of the chest and cardiac cannulation. Six patients (late phase) received grafts from three to fourteen days after acute infarction because of postinfarction angina. Only 1 patient was in cardiogenic shock prior to operation. Two patients, both from the early phase group, died in the postoperative period; and 1 patient died seven months postoperatively from a noncardiac cause. Twenty-five of 27 surviving patients became asymptomatic, and 2 patients continue to have mild angina (Functional Class II). Sixteen patients with 24 grafts were restudied in the postoperative period, and 22 of the grafts were found to be patent. This experience suggests that early operative intervention in acute myocardial infarction by the saphenous vein graft technique is beneficial to the patient. The rationale of revascularization in the early phase of acute myocardial infarction is to minimize the area of muscle necrosis by increasing perfusion to the ischemic myocardium around the infarct.

A metal ring marker for the proximal end of an aorta-to-coronary artery graft.

Abstract A metal ring encircling an aorta-to-coronary artery saphenous vein graft can facilitate the assessment of graft patency at postoperative cardiac catheterization.

Triple Bypass Graft for the Treatment of Severe Triple Coronary Vessel Disease

Abstract In a 3-year period (January, 1970, to January, 1973) three or more bypass grafts were placed in 397 patients who had severe triple coronary vessel disease. Ten patients (2.5%) died in the hospital postoperatively. Fifteen patients (4%) had postoperative myocardial infarctions. Late myocardial infarction occurred in 11 patients (2.8%), and in 6 of these the infarctions were fatal. Late deaths occurred in 11 patients; 7 of the deaths were of cardiac origin. Three patients were lost to follow-up. The remaining 373 patients were followed from 10 to 46 months. Three hundred sixty-one patients (96.7%) improved, 295 (79%) of these becoming asymptomatic. Two hundred twenty-one patients (672 grafts) were restudied from 6 weeks to 31 months after operation. The overall patency rate was 81.5%. There was a direct correlation between relief of angina and completeness of the revascularization. With one functioning graft, 9 patients (42.8%) became asymptomatic; with two functioning grafts, 52 patients (74.2%) became asymptomatic; and with three functioning grafts, 108 patients (87.8%) became asymptomatic. This experience suggests that three or more bypass grafts can be placed with a low operative risk in selected patients. Total or complete revascularization should be attempted in patients with severe triple-vessel disease.

Aorta-to-Circumflex Artery Saphenous Vein Bypass Graft: Operative Technique

Abstract Atherosclerosis of the circumflex artery is less common than that of the right and anterior descending arteries. It is also more difficult to perform saphenous vein bypass grafting on the circumflex artery because of its location and exposure, especially a graft to the main circumflex artery in the atrioventricular groove. This report describes in detail the technique for performing grafting to the circumflex artery. It also illustrates variation of the circumflex artery on cineangiographic pictures.