Biomedical subjects

E B Diethrich

Publications and source records attributed to E B Diethrich.

159 records · Page 9Linked to original sources

PubMedDate not supplied

A symposium on surgery for coronary artery disease. Pre-infarction syndrome--surgical indications.

Although the atherosclerotic process does not penetrate the coronary circulation at subendocardial levesl, the hemodynamic effects of coronary arterial narrowing occur at the endocardial and myocardial cellular levels. Theee resultant deprivation of blood supply to these tissue areas eventually leads to myocardial infarction. In certain clinical situations, a sudden increase in symptoms signifies and impending acute ischemic process. Three parameters have clinically been used to evaluate the changes that lead progressively to myocardial infarction: symptoms, electrocardiogram, and serum enzyme levels. The typical preinfarction patient experiences episodes of acute angina pectoris, sometimes intense and prolonged, and often unresponsive to nitroglycerin. Physical examination is usually not remarkable, serum enzyme levels are normal if tissue damage has not occurred, and the electrocardiogram is variable with pain. Th pathologic process in the preinfarction patient is frequently confined to the proximal arterial segment of one or more of the coronary arteries, usually in the form of a high-grade (in excess of 95 per cent) atherosclerotic lesion. This pathologic condition presents a satisfactory distal arterial segment suitable for bypass, and these patients are ideal candidates for urgent myocardial revascularization.

Coronary Angiography↗

PubMedDate not supplied

Surgical correction of coronary arterial disease associated with lesions of the aorta ad its major branches.

When a candidate for aortocoronary bypass has an associated lesion of the aorta orone of its major branches, a single operation may be indicated for correction of both problems. Three typical cases illustrate the concept of the combined approach to surgical management of coronary arterial lesions and associated carotid arterial disease, abdominal aortic aneurysm, and superficial-femoral arterial disease. An aortocoronary bypass candidate with carotid stenosis may be in imminent danger of both myocardial infarction and stroke. The selection of the proper sequence of operations under these circumstances is extremely important because any form of hypotension might produce a stroke. Cardiopulmonary bypass usually results in at least a transient reduction of the systemic pressure which would further compromise the blood flow across the tight stenosis of the carotid artery. Therefore, we recommended repair of the carotid lesion before aortocoronary bypass is attempted in order to avoid the possibility of postoperative stroke. The combined presence of coronary arterial disease and abdominal aortic aneurysm is indication for operation, but resection of the aneurysm involves cross-clamping of the aorta, and subsequent changes in arterial pressure might impair the coronary circulation and lead to myocardial infarction. On the other hand, the systemic heparinization required for the establishment of cardiopulmonary bypass and arterial pressure changes could affect the integrity of aneurysm. Unless the abdominal aneurysm is expanding, however, we elect to perform coronay revascularization first, with resection and graft replacement of the aneurysm immediately after heparin reversal. Occlusive disease of the superficial femoral artery can be corrected immediately following aortocoronary bypass. Since the femoral and upper leg incisions have been performed, in certain cases it is convenient to complete the femoral popliteal bypass while the chest is being closed, thus saving a separate operation to correct the femoral occlusive disease.

Aortic Diseases↗

PubMedDate not supplied

Aortocoronary bypass-classification and results.

Technical, physiologic, metabolic, and pathologic factors combine to determine the long-term patency of aortocoronary bypass grafts. Numerous variables are present in each of these categories, and the results of the operation cannot be determined unless comparable groups of patients are studied objectively. The classification proposed in this paper takes into account many of the factors that can effect graft patency. The available results of direct coronary arterial surgery are stated and used as the basis for five-year projections in the context of the proposed classification system.

Adult↗

PubMedDate not supplied

Gas endarterectomy with distal bypass of the coronary arteries.

Carbon dioxide gas endarterectomy was first applied in cases of total occlusion of the right coronary artery. The early technique involved removal of the disease core along the entire length of the vessel. At follow-up, progressive changes were observed to cause segmental stenosis within the proximal and middle portions of the vessel which led to complete reocclusion of the artery at 36 months. In every case, however, the distal branches of the endarterectomized arteries appeared unaffected. On the basis of these results, we have modified our technique. The present treatment involves distal endarterectomy with aortocoronary bypass to the endarterectomized segment. This surgical approach is appropriated only in cases of diffuse atherosclerotic involvement of the distal arterial branches. It can be applied to any one of the three main coronary artery branches and has therefore broadened the range of patient selection for direct myocardial revascularization. The operative mortality in our series of 58 patients was 6.9 per cent (4 patients), but all deaths were associated with such aggravating factors as anerurysm formation, valve disease, and the preoperative evolution of myocardial infarction. The associated morbidity rate was 6.8 per cent; two patients had disruption of the sternal wound, and one suffered uncomplicated myocardial infarction. The fourth patient had a myocardial infarction followed by development of conduction defect and required operation for the insertion of a permanent transvenous pacemaker. To date, follow-up indicates a high patency rate among the surviving 54 patients.

Arizona↗

PubMedDate not supplied