Biomedical subjects

M Kawasuji

Publications and source records attributed to M Kawasuji.

At least 109 records · Page 6Linked to original sources

PubMed1991

[Assessment of myocardial viability by 24-hour imaging after stress thallium-201 scintigraphy].

Twenty-four-hour delayed imaging after stress thallium-201 scintigraphy was assessed for more accurate detection of viable myocardium. Thirty-two patients with coronary artery disease who showed fixed perfusion abnormality (FPA) at 3 hr imaging after stress Tl study were evaluated with 24 hr delayed imaging. Of 37 areas with FPA, 19 areas (51%) showed redistribution (RD) at 24 hr imaging. After successful coronary artery bypass grafting (n = 19) or transluminal coronary angioplasty (n = 3), stress Tl scintigraphy was performed. Of 13 areas with RD at 24 hr imaging, 12 revealed improvement of Tl uptake after revascularization. On the other hand, of 12 areas with FPA until 24 hr, 8 showed no improvement. In conclusion, conventional stress Tl-201 scintigraphy underestimates myocardial viability, and additional 24 hr imaging permits more accurate assessment of myocardial viability.

Adult↗

PubMed1991

[Assessment of coronary bypass surgery by continuous ventricular function monitoring].

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.

Adult↗

PubMed1991

[Cardiac function during exercise in patients with coronary bypass surgery assessed by continuous ventricular function monitoring].

The response of left ventricular function during exercise and recovery after exercise was assessed in 52 patients with coronary artery bypass surgery by means of a radionuclide continuous ventricular function monitor. This system consists of 2 radionuclide detectors, recorder and a computer. After the equilibration of 20 mCi technetium 99m-labeled autologaous red blood cells into the intravascular space, the beat by beat radionuclide data were summed for 20-sec intervals to measure left ventricular ejection fraction (EF). Before surgery, the mean EF decreased with exercise from 51 +/- 9% to 45 +/- 11% (p less than 0.001). Cardiac response was divided into 4 types according to the profiles of the EFs during exercise. In 6 patients, EF continued to increase until maximal exercise (type A). In 10 patients, EF initially increased and then decreased in late exercise stages (type B). In 9 patients, EF did not change significantly during exercise (type C). In 27 patients, EF decreased throughout exercise (type D). After surgery, the mean EF increased with exercise from 53 +/- 10% to 60 +/- 13% (p less than 0.001). Thirty-five patients showed type A, 9 type B, 5 type C, and 3 type D. Two type D and 5 type B patients had occluded grafts or ungrafted coronary arteries. Four patients with complete revascularization including an internal thoracic artery and saphenous vein grafts showed type B. Three patients with extensive infarction and poor left ventricular function showed type C.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

[Coronary bypass surgery for solitary stenosis of the left main coronary artery].

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.

Adult↗

PubMed1990

[Surgical treatment of ischemic heart disease combined with hypothyroidism].

Treatment for patients with ischemic heart disease and hypothyroidism contains many difficulties, such as a dilemma that thyroid hormone to hypothyroid patients may worsen angina. The purpose of this study is to propose an appropriate control of thyroid function in these patients before coronary artery bypass grafting (CABG), and to clarify the change of thyroid function during postoperative period. Because of progressive angina pectoris, five hypothyroidism patients underwent CABG. Preoperatively, minimal dose of L-Thyroxine (0-75 micrograms, daily) was administered orally to keep thyroid function at slightly low level before CABG. Ten consecutive CABG patients with normal thyroid function were selected as control group. Between both groups, there was no significant difference in age, coronary artery disease, and the number of bypass grafts. Serum T4, free-T4, T3, free-T3, and TSH were measured at 1st, 2nd, 3rd, and 7th P.O.D. In control group, pituitary-thyroid function was suppressed transiently. In hypothyroid group, T4 revealed no change and was kept at slightly low level during observed period. There was no significant difference in postoperative hemodynamics between both groups. Postoperatively all of hypothyroid patients got free from angina and received an adequate thyroid hormone replacement therapy without complications. It is concluded that CABG for patients with angina and hypothyroidism can be performed safely by keeping preoperative thyroid function at slightly low level.

Aged↗

PubMed1990

[Transesophageal echocardiography during coronary bypass surgery].

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.

Coronary Artery Bypass↗

PubMed1990

Evaluation of postoperative flow capacity of internal mammary artery.

The internal mammary artery has been advocated for use in coronary artery bypass grafting because of its excellent long-term patency. We compared the flow capacities of internal mammary artery and saphenous vein grafts under exercise conditions by means of radionuclide angiocardiography. Fifty-two patients were divided according to the type of bypass graft done to the left anterior descending artery: group 1 comprised 27 patients with the internal mammary artery graft, and group 2 included 25 patients with the saphenous vein graft. Saphenous vein grafts were placed into the right and circumflex systems. Before the operation, global and regional ejection fractions decreased similarly in both groups with exercise. After the operation, the global ejection fraction measured in groups 1 and 2 increased significantly from 54% +/- 2% to 57% +/- 2% and from 54% +/- 1% to 60% +/- 2%, respectively, the anteroseptal ejection fraction from 29% +/- 1% to 32% +/- 2% and from 29% +/- 1% to 35% +/- 1%, respectively, and the apical ejection fraction from 75% +/- 3% to 82% +/- 2% and from 77% +/- 2% to 86% +/- 2%, respectively. There were no differences in exercise-induced increases in the global and regional ejection fractions between groups 1 and 2. Six patients in group 1 had exercise-induced wall motion abnormalities at the anteroseptal and/or apical segments. In contrast, patients in group 2 had no exercise-induced wall motion abnormalities at these segments (p less than 0.05, group 1 versus group 2). Results of this study show that internal mammary artery grafts respond to the increased blood flow demand of exercise in essentially the same way as saphenous vein grafts. However, there seems to be a slightly greater potential for inadequate flow in patients with the internal mammary artery graft, as evidenced by the small group of patients with exercise-induced wall motion abnormalities.

Coronary Artery Bypass↗

PubMed1990

[Surgical management of aneurysm of the ascending aorta with aortic insufficiency].

Twelve patients had elective surgical treatment for the aneurysm of the ascending aorta with aortic insufficiency at the Kanazawa University School of Medicine between 1976 and 1987. There were 9 men and 3 women aged from 26 to 39 years (mean, 33.0 years). Seven patients had a Marfan's syndrome and 6 of these patients also had aortic dissection. Three patients had aortic valve replacement plus supracoronary tube graft (Wheat's operation) and the other 9 patients underwent composite tube graft, with Bentall's operation in 3, Cabrol's operation in 2, and the modified Bentall's operation in which prosthetic valve was offset inside the tube graft in 4. Early deaths accounted for an operative mortality of 16.7%. The mean aortic cross-clamp time and the amount of bleeding were less with the modified Bentall's operation than with the other composite tube graft procedures. This modification seems to decrease the morbidity and to simplify the procedure in treatment of aneurysm of the ascending aorta with aortic insufficiency. There were 2 late deaths of patients with Marfan's syndrome associated with type I aortic dissection. Regular periodic examinations of the patients is needed, especially when Marfan's syndrome is present, in order to detect and surgically correct residual lesions.

Adult↗

PubMed1990

[A case of complex cardiac anomalies with high pulmonary blood flow treated successfully by PDA banding].

A patient with complex cardiac anomalies who developed severe respiratory insufficiency due to high pulmonary blood flow from a giant PDA was treated successfully by PDA banding. PDA-dependent heart disease causes a reduction in pulmonary blood flow in many patients and is often treated by palliative shunt operation. Although the present patient had PDA-dependent heart disease, heart failure occurred due to increased pulmonary blood flow through PDA and required surgical treatment. We performed PDA banding, because it is technically simple and allows adjustment of the postoperative pulmonary blood flow according to the degree of constriction. The degree of constriction was determined according to the PaO2 value. SO2 levels of 60-70% have been used as an index of the extent of banding, but PaO2 is considered to be equally appropriate.

Constriction↗

PubMed1989

Cardiac phaeochromocytoma of the interatrial septum.

A patient with a phaeochromocytoma arising from the interatrial septum is reported. A 131I-metaiodobenzylguanidine scan and magnetic resonance imaging were useful for tumour localization. Complete removal of the tumour in the right atrium was performed on cardiopulmonary bypass. The right atrial wall and the interatrial septum were reconstructed with two patches. This is the first successful operation for an intracardiac phaeochromocytoma arising from the interatrial septum.

Heart Neoplasms↗

PubMed1989

Intraarterial digital subtraction angiography for evaluation of internal mammary artery graft in coronary bypass surgery.

Digital subtraction angiography (DSA) was performed to evaluate graft patency in 60 patients who had undergone coronary artery bypass grafting with the internal mammary artery (IMA). Sixty IMA grafts with 62 distal anastomoses, and 84 saphenous vein grafts with 85 distal anastomoses were evaluated by intraarterial DSA with an image frequency of 4 frames/sec. A No. 4 Fr. angiography catheter was introduced percutaneously into the left brachial artery and contrast medium was injected both into the subclavian artery for opacification of the IMA grafts and into the ascending aorta for opacification of aortocoronary saphenous vein grafts. Bypass grafts were defined as patent when grafts were opacified through their entire course, including anastomotic sites. Fifty-nine IMA grafts with 61 distal anastomoses (98%) and 76 saphenous vein grafts with 77 distal anastomoses (91%) were patent. The overall patency rate for total grafts was 94%. In 4 patients, DSA showed a "string sign" in the IMA graft which was patent but narrowed at its distal segment. In 5 patients, large first intercostal branches were opacified. Intraarterial DSA with the retrograde brachial approach is not difficult, and is an excellent low risk method of evaluating the patency of IMA and saphenous vein grafts. DSA provided information about functional patency as well as anatomical patency of the IMA graft.

Adult↗

PubMed1989

[Pulmonary embolectomy for a patient of chronic pulmonary embolism].

Chronic pulmonary embolism is resistant to medicinal treatment. This is a report of the successful operation for chronic pulmonary embolism. A 29-year-old man suffered from dyspnea attack twice half a year in spite of intensive anticoagulant therapy. Cardiac catheterization showed pulmonary hypertension of 72/25 mmHg, mean 42 mmHg. Pulmonary angiogram demonstrated emboli in the right pulmonary artery and pulmonary perfusion scintigram revealed large perfusion defect in the right lung. The patient underwent pulmonary embolectomy after the total cardiopulmonary bypass. After surgery, blood gas showed an increased PaO2 from 65 to 77 mmHg. Pulmonary artery pressure decreased to 39/12 mmHg, mean 23 mmHg. Pulmonary arteriogram showed increased pulmonary vascular beds and pulmonary scintigram showed an increased perfusion in the right lung. The patient has been free from symptom and a half year after surgery.

Adult↗

PubMed1989

[Mitral regurgitation due to anomalous attachment of chordae tendineae to the left atrial wall].

A 47-year-old female admitted to our hospital with exertional dyspnea and cerebral thromboembolism. There was no history of rheumatic fever. The chest roentgenogram showed marked cardiomegaly with pulmonary congestion. Ultrasound cardiogram showed mitral valve incompetence and abnormal echo shadow in the left atrium. Left ventriculogram revealed grade 3 mitral regurgitation. At operation, a 5-cm anomalous chordae tendineae was attached to the left atrial wall through the mitral orifice. The mitral valve showed thickening of the leaflets and fusion of the posterior commissure. The mitral valve was replaced with a mechanical prosthesis. The patient has been doing well after her surgery.

Chordae Tendineae↗

PubMed1989

[Left ventricular performance before and after left ventriculotomy and removal of a left ventricular aneurysm].

The effects of left ventriculotomy on left ventricular performance were studied in seven patients with ventricular tachyarrhythmia (VT) and nine patients with left ventricular aneurysm (LVA). Hemodynamic and left ventriculographic findings were evaluated before and after operations. In VT the non-contracting areas, measured at end-diastole, as mean 10.8 +/- 7.1% of the left ventricular internal surface area. There was no significant fall in left ventricular ejection fractions (EF), cardiac indexes (CI) and left ventricular end-diastolic volume indexes (LVEDVI) after left ventriculotomy. In LVA, the non-contracting areas decreased from 31.0 +/- 7.4% to 13.7 +/- 13.5% (p less than 0.01) in association with a reflex decrease in LVEDVI from 117 +/- 31.8 ml/m2 to 90.4 +/- 24.7 ml/m2 (p less than 0.05). EF increased from 40.8 +/- 7.00% to 54.6 +/- 10.7% (p less than 0.01). There was no significant change in CI and left ventricular stroke volume index after left ventricular aneurysmectomy. The observations indicate that left ventriculotomy of limited size is an acceptable and a safety approach to the ventricular tachyarrhythmias and another cardiac operations.

Adolescent↗

PubMed1989

[Surgical management of infective endocarditis].

We reviewed fourty-six patients who had undergone surgery for infective endocarditis in the past fifteen years and identified risk factors affecting the outcome. Twenty-nine patients had infection of the native valve only, 11 had infective endocarditis associated with congenital heart disease, and 6 had prosthetic valve endocarditis. Overall hospital mortality was 6.5%. Prosthetic valve endocarditis carried a higher mortality (33%) than native valve endocarditis (3.4% or congenital heart disease with infective endocarditis (0%). For the patients with active endocarditis, the early mortality rate was higher (13%) than with inactive endocarditis (3.2%). Staphylococcal infections were more likely to cause severe valve destruction and residual infection than streptococcal infection. Our results indicated that surgical management of infective endocarditis should be done after the completion of adequate antibiotic therapy. Early diagnosis should reduce the mortality, prevent fatal complications, and lead to qualitative improvement of infective endocarditis.

Adolescent↗

PubMed1989

[Application of a lung stapler to reduce tension on the internal mammary artery].

In-situ internal mammary artery (IMA) grafts have a better patency rate than free IMA grafts. Every effort is made to leave the IMA as an in-situ graft attached to the subclavian artery. A 56-year-old patient underwent reoperation because of occlusion of the vein graft to the left anterior descending coronary artery (LAD). At the second operation, the left IMA was anastomosed to the segment of the LAD distal to the first anastomotic site. The hyperinflated lung crossed the midline and stretched the IMA graft. The herniated portion of the left lung which stretched the IMA graft was resected with a 9-cm long linear stapler along the course of the IMA graft. No harmful effects were observed. This is a simple and safe method to reduce the tension on the IMA graft due to the hyperinflated lung.

Hernia↗

PubMed1989

[Evaluation of internal mammary artery graft patency by intraarterial digital subtraction angiography].

Intraarterial digital subtraction angiography (DSA) was performed to evaluate graft patency in 45 patients undergoing coronary artery bypass grafting with the use of internal mammary artery (IMA). Fourty-five IMA grafts and 59 saphenous vein grafts were evaluated using a DSA equipment with a pulse mode of 2 frames per second. A 4F catheter was introduced percutaneously into the left brachial artery. Nonionic contrast medium was nonselectively injected into the left subclavian artery for visualization of IMA grafts and also into the aortic root for visualization of vein grafts. No serious complications occurred. Forty-four IMA grafts and 53 vein grafts were patent. The patency rate was 97.8% for IMA grafts, 89.8% for vein grafts, and 93.3% for all grafts. In 11 patients (24%), intercostal or pericardial branches were visualized. Two patients showed a string sign of the IMA. Intraarterial DSA with nonselective injection of contrast medium into the subclavian artery is a new method for evaluation of IMA graft patency with a low risk.

Adult↗

PubMed1988

Intraoperative evaluation of coronary bypass grafts by measuring myocardial blood flow using the electrolytic hydrogen clearance method.

The regional myocardial blood flow (MBF) was measured in 33 patients who underwent coronary bypass graft surgery in order to evaluate the efficiency of coronary bypass grafts in restoring MBF. MBF was measured by the electrolytic hydrogen clearance method during the coronary bypass surgery. The mean prebypass MBF was 161 +/- 19, 162 +/- 12, 80 +/- 12, 43 +/- 14, 104 +/- 18 ml/min/100 g in segments supplied by the left anterior descending coronary artery (LAD) showing less than or equal to 50 per cent, 75 per cent, 90 per cent, 99 per cent, and 100 per cent stenosis with collaterals, respectively. After bypass grafting of the LAD, the mean MBF increased from 70 +/- 13 and 126 +/- 12 ml/min/100 g to 133 +/- 14 and 163 +/- 9 ml/min/100 g in the segments with and without infarction, respectively. The mean postbypass MBF was 149 +/- 10 and 152 +/- 14 ml/min/100 g in the segments supplied by the LAD bypassed with saphenous vein grafts and mammary artery grafts, respectively. Postbypass MBF was dependent upon the magnitude of myocardial infarction. Measurement of MBF by the electrolytic hydrogen clearance method made it possible to quantitatively evaluate myocardial perfusion at the time of operation. It also provided direct information about the effectiveness of myocardial revascularization.

Blood Flow Velocity↗