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Biomedical subjects

M Kawasuji

Publications and source records attributed to M Kawasuji.

At least 55 records · Page 3Linked to original sources
PubMed1997

[Clinical effect of high-flow pulsatile cardiopulmonary bypass in coronary artery bypass grafting].

The effect of high-flow pulsatile cardiopulmonary bypass was evaluated in 36 patients undergoing coronary artery bypass grafting in our unit. The patients were divided into two groups, based on cardiopulmonary bypass (CPB) flow; high (3.0 +/- 0.2 l/min/m2), or moderate (2.4 +/- 0.2 l/min/m2). Multidose cold crystalloid cardioplegia was administered for myocardial protection. Pulsatile flow during CPB was used and systemic perfusion pressure was maintained between 50 and 80 mmHg. Preoperatively, there were no differences between groups in left ventricular ejection fraction or extent of coronary artery disease. The times required for CPB and weaning from CPB were significantly shorter in high-flow group than moderate-flow group. The urinary output during CPB was significantly higher in high-flow group than moderate-flow group. Postoperatively, there were no significant differences in the incidence of myocardial infarction, stroke, or 30-day mortality between groups. In conclusion, high-flow pulsatile CPB shortens the length of CPB and does not differ significantly from moderate-flow with respect to mortality and morbidity.

Aged↗
PubMed1997

Comparison of cilostazol with warfarin as antithrombotic therapy after femoro-popliteal bypass surgery using an ePTFE graft.

BACKGROUND: Cilostazol (6-[4-(1-cyclohexyl-1H-tetrazol-5-yl)butoxy]-3,4- dihydro-2(1H)-quinolinone) is a new antiplatelet agent with a vasodilating action. The purpose of this study was comparison of cilostazol with warfarin as antithrombotic therapy after femoro-popliteal bypass surgery using an expanded polytetrafluorethylene (ePTFE) graft. EXPERIMENTAL DESIGN: This report is a retrospective study and the patients were followed up for five years. SETTING: Outpatients of university hospital. METHODS: Sixteen arteriosclerosis obliterans patients, who were diagnosed as having only superficial femoral artery stenosis or occlusion, underwent femoro-popliteal (above the knee) bypass using an ePTFE graft 6 mm in diameter. Cilostazol (150-200 mg/day) was administered to 6 cases (9 bypasses), and warfarin (prothrombin time was controlled to 15-25%.) was administered to 10 cases (14 bypasses). RESULTS: No clinically characteristic differences were found between the two groups. The cumulative 1-, 3-, and 5-year primary and secondary graft patency rates were 69% and 80%, 69% and 80%, and, 69% and 80% in the cilostazol group, vs 61% and 91%, 51% and 91%, and, 51% and 91% in the warfarin group, respectively. These differences were not significant (p < 0.05). No hemorrhage complications were observed in the cilostazol group. The management of cilostazol administration was safe and simple. CONCLUSIONS: Although the number of cases was small in this study, cilostazol was considered to be as effective as warfarin and suitable for the postoperative antithrombotic therapy after the ePTFE bypass surgery.

Aged↗
PubMed1996

Coronary artery bypass grafting in a patient with antiphospholipid syndrome.

We report a 32-year-old female patient with antiphospholipid syndrome including severe coronary artery disease and multiple arterial and venous thrombosis. The patient had occlusion of the right internal thoracic artery, diffuse stenosis of the left internal thoracic artery, and occlusion of the left saphenous vein. The patient underwent successful coronary artery bypass grafting using the right gastroepiploic artery and a segment of the right saphenous vein. Antiphospholipid syndrome should be considered in young patients with myocardial infarction.

Adult↗
PubMed1996

Internal thoracic artery graft function during exercise assessed by transthoracic Doppler echography.

BACKGROUND: Noninvasive quantitative assessment of internal thoracic artery (ITA) graft function at rest and during exercise is important in patients who have undergone coronary artery bypass grafting. METHODS: Blood flow in the ITA graft was measured using transthoracic color Doppler echography before and after operation in 50 patients who underwent coronary artery grafting using an ITA to the left anterior descending artery. The patients were divided into three groups according to the degree of coronary stenosis and previous anterior myocardial infarction: Group 1 included 12 patients with severe (90% or more) coronary stenosis accompanied by anterior infarction. Group 2 included 26 patients with severe coronary stenosis without anterior infarction. Group 3 included 12 patients with moderate (75% or less) coronary stenosis without anterior infarction. Transthoracic echographic images of the ITA were obtained through the first intercostal space using a 7.5-MHz probe, and the diameter and cross-sectional area of the ITA were measured on B-mode imaging. Systolic, diastolic, and mean blood flow velocity and volume were measured by the Doppler method. RESULTS: Internal thoracic artery diameter increased significantly from 2.2 mm to 2.4 mm after operation. The ITA flow patterns in both flow velocity and volume changed from systolic-dominant to diastolic-dominant after operation. Postoperative ITA graft flow was 82 +/- 24 mL/min, 53 +/- 30 mL/min, and 31 +/- 15 mL/min (p < 0.01, group 1 versus 3; p < 0.05, group 1 versus 2) and percent diastolic fraction of ITA flow was 72%, 68%, and 62% (not significant) in groups 1, 2, and 3, respectively. Compared with intraoperative ITA flow, which was measured using an ultrasound transit-time flowmeter, postoperative ITA graft flow was increased in group 1, but not changed in group 2 or 3. The ITA graft flow was measured before and after exercise in 19 patients and was compared with ITA flow in 10 normal control subjects. The ITA graft flow increased significantly with exercise in all patients in the three groups. Percent diastolic fraction of ITA flow increased significantly with exercise in patients with severe coronary stenosis (groups 1 and 2), but decreased significantly in patients with moderate stenosis (group 3). CONCLUSIONS: Changes in native coronary artery and ITA graft may be predicted by assessing ITA flow pattern during exercise. Transthoracic color Doppler echography is a clinically useful noninvasive method of assessing ITA graft function at rest and during exercise.

Adult↗
PubMed1996

Surgical therapy for Wolff-Parkinson-White syndrome in patients with bronchial asthma.

The surgical therapy for Wolff-Parkinson-White syndrome in patients with bronchial asthma was studied. Between 1974 and 1992, 447 patients with Wolff-Parkinson-White syndrome were treated, seven of whom had associated severe bronchial asthma. Supraventricular tachyarrhythmias were induced on occasion by bronchodilating agents such as beta-receptor agonists or theophylline preparations. High-dose steroids were required for acute bronchospasm in three patients, despite possibly leading to cardiac dysfunction. Beta-blockers therapy for Wolff-Parkinson-White syndrome can induce bronchospasm; in patients with Wolff-Parkinson-White syndrome and bronchial asthma, pharmacological agents used to treat one condition may exacerbate the other. Therefore, a non-pharmacological therapy was performed, namely surgical division of the accessory conduction pathway via an endocardial approach, in all seven asthmatic patients with Wolff-Parkinson- White syndrome. In all cases, division of the accessory conduction pathway resulted in disappearance of the delta wave, and there were no further tachyarrhythmias either at rest or after administration of bronchodilators. Since surgery, bronchial asthma has been effectively controlled with standard drug therapy in all patients. Non-pharmacological therapy is recommended for patients with Wolff-Parkinson-White syndrome and bronchial asthma.

Adolescent↗
PubMed1996

Is internal thoracic artery grafting suitable for a moderately stenotic coronary artery?

Grafting an internal thoracic artery to a coronary artery with moderate stenosis remains controversial. Competitive flow from the native coronary artery has been proposed as the cause of distal narrowing and ultimate failure of the internal thoracic artery graft. We investigated intraoperative phasic blood flow in internal thoracic arteries grafted to coronary arteries with various degrees of stenosis and the influence of stenosis on postoperative angiographic findings. One hundred patients who underwent coronary artery bypass grafting of an internal thoracic artery to the left anterior descending coronary artery were divided into three groups according to degree of coronary stenosis. Group 1 included 39 patients who had 75% or less stenosis, group 2 included 34 patients with stenosis from 76% to 90%, and group 3 included 27 patients with stenosis greater than 90%. Mean flow and peak systolic flow of internal thoracic artery graft in group 1 were lower than those in group 2 (p < 0.01, p < 0.05). Peak diastolic flow in group 1 showed no difference from flows in groups 2 and 3. In eight patients in group 1, internal thoracic artery flow showed a predominant diastolic peak with characteristic systolic reversal as a result of competitive flow from the native coronary artery. Angiography at 1 month showed that the internal thoracic artery graft was patent in every case. Relative contributions of native coronary artery and internal thoracic artery flow to distal perfusion differed among the three groups (p < 0.001). In group 1, 15% of patients showed native-dominant flow, 62% showed balanced flow, and 23% showed internal thoracic artery-dependent flow. In group 2, 9% of patients showed native-dominant flow, 29% showed balanced flow, and 62% showed internal thoracic artery-dependent flow. In group 3, 96% of patients showed internal thoracic artery-dependent flow. String sign of the internal thoracic artery graft developed in only three patients; in two of these patients internal thoracic arteries were grafted to coronary arteries with stenosis of 50% or less and in the other patient there was competitive flow from a diagonal vein graft. Eleven of 13 internal thoracic arteries grafted to coronary arteries with stenosis of 50% or less did not show string sign. Competitive flow from a moderately stenotic coronary artery did not predispose the patient toward string sign of the internal thoracic artery graft in the presence of substantial diastolic internal thoracic artery flow. We conclude that internal thoracic artery grafting is acceptable for a moderately stenotic coronary artery.

Adult↗
PubMed1996

A new contact probe for intraoperative laser ablation.

Several clinical factors decrease the accuracy of intraoperative laser ablation. The distance to the target, the irradiation angle, and the media are reported among these factors. We developed a new laser probe to resolve these problems. This probe has a hollow conical tube with a tip covered by a thin film. Zero-degree centigrade saline was fed into this probe. Results from using the new probe were compared with those from the conventional noncontact irradiation method with cooling by sprinkled cooling water. In beating canine hearts, ventricles were irradiated with neodymium:yttrium aluminum garnet (Nd:YAG) lasers at 50-200 J/mm2. There was no difference in the mean volume of irradiated tissue between the new and the noncontact method. However, the distribution of volume values in the new method was smaller than that in the noncontact method (P < 0.05). In conclusion, results obtained indicate that this new probe could perform more accurate intraoperative ablation than the conventional method. Problems of stabilizing the distance to the target, the irradiation angle, and the media were resolved.

Animals↗
PubMed1996

[Simultaneous operation of aortic valve replacement and renal artery reconstruction in a patient of aortitis syndrome: a case report].

A 27-year-old female underwent concomitant aortic valve replacement and reconstruction of the right renal artery. She was diagnosed as aortitis syndrome with AR and 90% stenosis of the right renal artery by angiography. PRA were high, Ccr value was low, and renogram showed non-functioning pattern in the right kidney though normal pattern in the left. After CRP value was decreased by predonisolone, the operation was done in the inactive stage. Postoperative angiography showed good aortic valve function and patent renal artery graft. Postoperative PRA and Ccr became normal and the renogram was improved. Based on the result we recommended simultaneous operation can be done with minimal risk.

Adult↗
PubMed1995

Efficacy of a skeletal muscle-powered dynamic patch: Part 1. Left ventricular assistance.

In this study, we examined the capability of a skeletal muscle-powered, dynamic patch to provide left ventricular assistance. An actuator was developed that used linear traction power furnished by the latissimus dorsi muscle and liquid as the medium for power transfer. The proximal portion of the muscle was dissected and was reattached to the actuator. The left ventricular apex was excised, and the dynamic patch lined with autologous pericardium was implanted during cardiopulmonary bypass. Hemodynamic studies were performed in 8 dogs after weaning from cardiopulmonary bypass. Muscle stimulation was found to significantly increase the systolic aortic pressure (91.6 versus 112.1 mm Hg; p < 0.01), the mean aortic pressure (65.2 versus 73.0 mm Hg; p < 0.01), and aortic blood flow (0.77 versus 0.92 L/min; p < 0.01). The left atrial pressure decreased from 17.9 to 16.6 mm Hg (p < 0.01). This "hybrid" left ventricular assist device possesses notable clinical advantages because of its remarkable efficacy in assisting circulation. Further experimental studies using preconditioned skeletal muscle are necessary to assess the long-term effects of this technique.

Animals↗
PubMed1995

Pressure characteristics in arterial grafts for coronary bypass surgery.

The haemodynamic properties of arterial grafts were studied by measuring the pressure waveform at the tip of the grafts in 28 patients who underwent coronary artery bypass surgery (CABG). The internal thoracic and gastroepiploic arteries were harvested as pedicles for CABG. Pressure wave of the ascending aorta and arterial grafts were simultaneously recorded with an electrocardiogram under stable haemodynamic conditions before cardiopulmonary bypass. Systolic, diastolic and mean pressures were measured, and mean systolic and diastolic pressures calculated for systolic and diastolic areas divided by time. The ascending aorta showed high sustained diastolic pressure that decreased gradually. Pressures in the internal thoracic and gastroepiploic artery grafts had narrow contours and decreased rapidly. Pressure waveforms in the internal thoracic and gastroepiploic artery grafts had a notch between the systolic and diastolic contours. There was no difference in systolic pressure between the ascending aorta and internal thoracic and gastroepiploic artery grafts. Diastolic pressures were 64(9), 55(7), and 51(6) mmHg in the ascending aorta and internal thoracic and gastroepiploic artery, respectively. Mean(s.d.) pressures were 75(9), 65(9) and 59(7) mmHg in the ascending aorta and internal thoracic and gastroepiploic artery grafts, respectively. Diastolic and mean pressures in the internal thoracic artery grafts were significantly lower than in the ascending aorta but significantly higher than in the gastroepiploic artery grafts. The mean(s.d.) calculated diastolic pressure in the internal thoracic artery grafts was significantly lower than in the ascending aorta but significantly higher than in the gastroepiploic artery grafts. The inferior capacity of flow through the arterial grafts may be mainly attributable to reduced diastolic pressure, which is caused by anatomical characteristics.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Coronary artery bypass grafting in familial hypercholesterolemia.

Familial hypercholesterolemia is an autosomal dominant disorder caused by a mutation of the gene for the low-density lipoprotein receptor and is characterized by rapidly progressing coronary atherosclerosis. We assessed the long-term results of coronary artery bypass grafting performed during the past 13 years in 62 patients with heterozygous familial hypercholesterolemia, whose mean plasma total and low-density lipoprotein cholesterol level was 327 mg/dl, respectively. The patients had severe coronary atherosclerosis, with coronary stenosis index of 19.7, and the prevalence of extracoronary atherosclerotic lesions was 27%. Sixty-one patients underwent successful coronary artery bypass operation, with an average of 2.5 grafts, and the coronary stenosis index decreased to 7.1. After operation, all patients consumed a cholesterol-lowering diet and received drug therapy with pravastatin, probucol, or cholestyramine. Seven patients who were resistant to drug therapy were treated with plasma low-density lipoprotein apheresis. The cholesterol-lowering therapy reduced plasma total cholesterol level by 37%, low-density lipoprotein cholesterol level by 42%, and low-density lipoprotein/high-density lipoprotein cholesterol ratio by 37% (p < 0.001). During the follow-up period (mean, 52 months; range, 10 to 157 months), there was no cardiac death, but three patients died of malignant disease. The actuarial survival rate was 95% at 5 years and 89% at 12 years after operation. The actuarial freedom from recurrent angina was 90% at 5 years and 53% at 11 years after operation. Four patients underwent reoperation, an average of 8 years postoperatively, because of vein graft atherosclerosis. In spite of severe coronary atherosclerosis, these patients with familial hypercholesterolemia showed good long-term outcome after coronary artery bypass operation. The present findings suggest that aggressive use of arterial grafts, intensive cholesterol-lowering drug therapy, and low-density lipoprotein apheresis may be useful in patients with familial hypercholesterolemia.

Actuarial Analysis↗
PubMed1995

[Continuous measurement of myocardial oxygen saturation using near-infrared spectroscopy during warm blood cardioplegia].

Continuous infusion of warm blood cardioplegic solution is often interrupted during coronary artery bypass grafting to obtain a bloodless operating field. We measured myocardial oxygen saturation continuously using near-infrared spectroscopy to determine myocardial oxygen metabolism during intermittent warm blood cardioplegia (IWBC). In 7 adult mongrel dogs undergoing cardiopulmonary bypass IWBC was administered using the Buckberg-Shiley system. Cardiac arrest was induced by a warm blood cardioplegic infusion of 100 ml/min for 5 minutes followed by a maintenance infusion of 40 ml/min for 5 minutes. The infusion of warm blood cardioplegia was then stopped for 15 minutes. Measurement of myocardial oxygen saturation was performed continuously throughout cardiopulmonary bypass. IWBC produced an increase in myocardial oxygen saturation for the first 5 minutes and a slight decrease for the second 5 minutes. After the termination of IWBC, myocardial oxygen saturation showed a marked reduction for 3 minutes and plateaued after 5 minutes. Measurement of myocardial oxygen saturation revealed myocardial oxygen metabolism during IWBC. This procedure may be a useful way to monitor myocardial oxygen metabolism during open heart surgery.

Animals↗
PubMed1995

[Surgical treatment of coronary artery fistulas].

Coronary artery fistula is one of the most common coronary malformations and is being diagnosed with increasing frequency with widespread use of selective coronary arteriography. Twenty-one patients with coronary artery fistulas underwent surgical treatment at our institute between 1973 and 1994. The left coronary artery was most commonly involved, and the fistula communicated primarily with the pulmonary artery. Associated cardiovascular disease include: mitral stenosis (1), mitral insufficiency (1), partial anomalous pulmonary venous return (1), ventricular tachycardia (1), atrial septal defect (1), aortitis syndrome (1), and coronary arteriosclerotic narrowing (1). In five patients, the coronary artery fistulas were selectively ligated without CPB. In sixteen patients, in addition to selective ligation, the fistula ostia were closed from inside using CPB. There were no operative or late deaths in the patients who underwent operations. Thus, the risks of surgical correction appear to be considerably less than the potential development of serious and possibly fatal complications, even in asymptomatic patients.

Adult↗
PubMed1995

[Left ventricular systolic and diastolic function after mitral valve replacement with preservation of posterior chordae tendineae].

Left ventricular function was compared in 14 patients who underwent mitral valve replacement with preservation of the posterior leaflet, chordae tendineae and papillary muscle (preserved group) and 14 patients who underwent conventional mitral valve replacement (non-preserved group). 99mTc radionuclide ventriculography was performed before surgery and one month after surgery. The early diastolic filling rate, an indicator of the efficiency of diastolic function, was measured. The patients in the non-preserved group showed an anteroseptal ejection fraction of 28 +/- 10% before surgery and 32 +/- 10% after surgery, an apical ejection fraction (71 +/- 10% vs 73 +/- 16%), and an inferolateral ejection fraction (56 +/- 16% vs 53 +/- 16%). The global ejection fraction tended to decrease from 56 +/- 9% to 52 +/- 10%. The patients in the preserved group showed an anteroseptal ejection fraction of 37 +/- 13% before surgery and 43 +/- 19% after surgery, an apical ejection fraction (74 +/- 20% vs 77 +/- 17%) and an inferolateral ejection fraction (53 +/- 11% vs 68 +/- 16%). The global ejection fraction, reflecting improvement in the inferolateral ejection fraction, tended to increase from 53 +/- 11% to 58 +/- 11%. The early diastolic filling rate for the preserved group was 1.73 +/- 0.43 before surgery and 1.05 +/- 0.61 after surgery, while that for the nonpreserved group was 1.59 +/- 0.24 vs 0.97 +/- 0.48. Although the early diastolic filling rate normalized in both groups, there was no significant difference between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Chordae Tendineae↗
PubMed1995

[Effect of tepid cardiopulmonary bypass in coronary artery bypass operation].

The effect of systemic temperature during cardiopulmonary bypass (CPB) surgery was evaluated in 100 patients. The patients were divided into three groups, based on systemic temperature during CPB; 28 degrees C, 30 degrees C, or 32 degrees C (tepid). Multidose cold crystalloid cardioplegia was administered for myocardial protection. Pump flow was maintained at 75 ml/kg/min. Methoxamine hydrochloride and phenothiazine were used to maintain systemic perfusion pressures between 60 and 80 mmHg. Preoperatively, there were no differences between groups in left ventricular ejection fraction or extent of coronary artery disease. The time required for CPB and weaning from CPB were significantly shorter in the 32 degrees C group than in either the 28 degrees C or the 30 degrees C group. There were significant differences in the doses of methoxamine hydrochloride and phenothiazine required in each group. Postoperatively, there were no significant differences in the incidence of myocardial infarction, stroke, or 30-day mortality between groups. In conclusion, tepid systemic perfusion shortens the length of CPB and does not differ significantly from cold perfusion with respect to mortality and morbidity.

Aged↗
PubMed1994

Twenty-four-hour quantitative thallium imaging for predicting beneficial revascularization.

To determine the utility of 24-h thallium single-photon emission tomographic imaging for the assessment of myocardial viability, 40 patients with persistently decreased uptake on 3-h delayed imaging after exercise were studied before and after bypass surgery (n = 34) or coronary angioplasty (n = 6). Wall motion improvement after revascularization was also analysed in 23 patients with respect to the segments with and without 24-h redistribution. Of a total of 113 segments without redistribution at 3-h imaging after exercise, 62 (55%) demonstrated redistribution at 24 h. After revascularization 57 (92%) of these 62 segments revealed improvement of thallium uptake. On the other hand 40 (78%) of the 51 segments with persistently decreased thallium uptake until 24 h did not show improvement of uptake after revascularization. Of the 15 segments with > 50% relative thallium uptake and without redistribution on 24-h images, ten showed improvement of thallium uptake after revascularization. Hence higher uptake even without 24-h redistribution may indicate viability. Regional wall motion improved in 22 of 23 segments with redistribution on 24-h images, and did not improve after revascularization in 19 of 22 segments without redistribution at 24 h. These data suggest that 24-h late imaging with quantitative analysis may provide reliable information about reversible myocardial ischaemia in segments that demonstrate a fixed perfusion abnormality on conventional 3-h delayed imaging.

Angioplasty, Balloon, Coronary↗
PubMed1994

Coronary steal caused by a right gastroepiploic artery graft.

We report a patient with coronary artery steal after gastroepiploic artery grafting to the right coronary artery. The coronary artery steal syndrome involves reversed flow in the gastroepiploic artery, which siphons blood from the heart and results in myocardial ischemia.

Adult↗