血液性心筋保護液による開心術中心筋保護の研究

取得学位 : 博士（医学）, 学位授与番号 : 医博乙第1102号, 学位授与年月日：平成2年11月7日,学位授与年：199

左冠動脈主幹部単独病変の外科治療

Ten patients with solitary stenosis of the left main coronary artery underwent coronary artery bypass grafting. All patients suffered from unstable angina and were in NYHA class III or IV. Two of them required intravenous infusion of nitroglycerin preoperatively. The degree of stenosis of the left main coronary artery was 75% in 3 patients, 90% in 5, 95% in one and total obstruction in the other one. Five patients received saphenous vein grafts to the LAD and circumflex artery and the other 5 patients received IMA grafts to the LAD and saphenous vein grafts to the circumflex arteries. In 2 patients with 75% stenosis of the left main coronary artery we found narrow internal mammary artery grafts, the so called "string sign", on postoperative angiography. Although several causes of string sign were proposed previously, we supposed that the main cause of the "string sign" was the competition for flow between the IMA graft and the native coronary artery or grafted coronary artery. Postoperatively, all patients showed improvements in cardiac function and were in NYHA class I. No evidence of ischemic findings was found in postoperative exercise stress tests

経食道心臓超音波検査による冠動脈バイパス手術時の連続的心機能評価

Transesophageal two-dimensional echocardiography (TEE) was evaluated in 14 patients who underwent coronary bypass surgery. The TEE transducer was positioned to view the left ventricular short axis at the level of the papillary muscle. Global left ventricular function was assessed by measuring left ventricular end-diastolic and end-systolic area and computing the fractional area change (FAC). Regional left ventricular function was analyzed after dividing the short axis view of the left ventricle into four anatomic segments. The mean FAC was 48% after intubation, 48% after skin incision, 47% after sternotomy, and 51% after pericardiotomy. The mean FAC increased significantly to 55% 0 to 30 minutes after cardiopulmonary bypass, and was 53% at the end of the operation. In 5 patients, FAC decreased and regional wall motion abnormalities appeared around sternotomy. These abnormalities was considered due to transient myocardial ischemia. In 7 patients, a paradoxical motion of the ventricular septum occurred at closing of the sternum. TEE was performed without complication and found to be a good method for assessing global and regional left ventricular function

携帯用持続心機能モニターによる冠動脈バイパス術の評価

The sequential change of left ventricular function during exercise and recovery after exercise was assessed in 50 patients who had undergone coronary bypass surgery before and after the operation by means of continuous ventricular function monitoring system (VEST). Cardiac response was divided into 4 types with respect to the profiles of the left ventricular ejection fraction during exercise. Type A continued to increase; type B initially increased but decreased in severe exercise stages; type C did not change during exercise; type D continued to decrease. Most patients showed type C or D before surgery but showed type A after surgery. 9 patients with occluded grafts or ungrafted coronary arteries showed type B, C or D. Two patients with extended infarction and poor left ventricular function showed type C after surgery. In recovery period after exercise, the ejection fraction showed an overshoot. The mean ratio of peak ejection fraction during recovery to ejection fraction at rest increased from +62 +/- 12% before operation to +68 +/- 16% after operation (p less than 0.05). The recovery time after exercise was decreased from 195 sec before operation to 98 sec after operation (p less than 0.01). VEST revealed response of left ventricular function during exercise and recovery after exercise as far as detail abnormalities

High-risk患者の腹部大動脈瘤手術: 粥状動脈硬化性疾患と腹部大動脈瘤

金沢大学医薬保健研究域医学