Biomedical subjects

M Kawasuji

Publications and source records attributed to M Kawasuji.

At least 91 records · Page 5Linked to original sources

PubMed1992

[Diabetes mellitus and coronary artery bypass surgery].

To determine the influence of diabetes mellitus on the results of coronary artery bypass surgery, a review of 163 diabetic patients operated on during 8 years, of whom 146 were receiving no drugs or receiving oral hypoglycemic agents, and 17 were receiving insulin. They were compared with 337 nondiabetic patients operated on over the same period. Higher incidences of hypertension and cerebrovascular disease for the diabetic group were found. The extent of coronary artery disease as judged angiographically was significantly greater in the diabetic group than in the nondiabetic group. Perioperative mortality was similar in the two groups. The incidence of perioperative myocardial infarction, sternotomy complication, neurological complication, and renal insufficiency was equal in the two groups. Early graft patency was comparable in the two groups. Overall 8-year actuarial angina free ratios were 88.5% for the diabetic group, 93.2% for the nondiabetic group. Overall 8-year survival rates were 95.6% for the diabetic group, 98.6% for the nondiabetic group. Results indicate that diabetic patients have quantitatively more coronary artery disease than the non-diabetic patients but have no higher perioperative morbidity and mortality than nondiabetic patients. Long-term results revealed a lower angina free rate in diabetic patients than in nondiabetic patients.

Coronary Artery Bypass↗

PubMed1992

[Coronary artery bypass surgery in patients with familial hypercholesterolemia].

Coronary artery bypass grafting (CABG) was performed in 48 patients with heterozygous familial hypercholesterolemia (FH). Seventy-nine percent of these patients had three-vessel disease or left main trunk disease. The internal thoracic artery was used for grafting in 26 patients and the right gastroepiploic artery was used in 4 patients. Although no patient died during surgery, one died subsequently from graft-versus-host disease. Graft patency at one month after CABG was 95% in vein grafts, 100% in arterial grafts, and 97% overall. Histological study revealed that arterial grafts in patients with FH had similar structures to those in non-FH patients, without evidence of atherosclerosis. All patients were prescribed anti-cholesterol drugs to control serum cholesterol levels, and 4 patients underwent LDL-apheresis because of poor control. Survival rate at 11 years after CABG was 83% without cardiac death. Cardiac event-free rate in 47 surviving patients was 53% at 10 years after CABG in vein bypass group, 93% at 5 years in the arterial graft group, and 58% at 10 years overall. Results of CABG were as good in FH as in non-FH patients, using arterial grafts and anticholesterol therapy.

Adult↗

PubMed1992

[Basic study of myocardial coagulation by intraoperative laser ablation: in the presence and absence of blood].

To investigate whether the efficacy of laser ablation therapy is affected by the color of the target organ, we irradiated 9 canine hearts through the epicardium with Nd-YAG laser (200 J, 400 J), and compared coagulated myocardial volume in the beating heart (reddish) with that in the stopped heart (whitish) infused with 0 degrees C saline (cardioplegic model) via a coronary artery. The coagulated myocardial volume of the beating heart was significantly larger than that of the arrested heart, indicating the YAG laser energy is absorbed by red myocardium to greater extent than it is by white myocardium. In conclusion, during intraoperative laser ablation, the presence or absence of blood in cardiac tissue is an important factor for safe irradiation.

Animals↗

PubMed1992

[A new vein holder for side-to-side saphenous-coronary anastomosis].

A new vein holder for a side-to-side anastomosis between a vein graft and the coronary artery is described. The holder is consisted of two nerve hooks, and those distance is adjusted. The technique for creating the diamond anastomosis is also described.

Anastomosis, Surgical↗

PubMed1992

[Pressure measurement of coronary artery bypass graft with transducer-tipped catheter].

The pressure of in situ arterial graft was measured with Fiber Optic Transducer-Tipped Pressure Monitoring System (Camino). Internal thoracic artery (ITA) and gastroepiploic artery (GEA) were prepared as in situ grafts, and the pressure at the end of each graft was recorded with ascending aortic pressure (Ao) and electrocardiogram, simultaneously. Although the peak systolic pressures of these grafts were identical, the systolic pressure of ITA and GEA formed narrow contours. While the diastolic pressures of Ao was sustained and high, the diastolic pressures of ITA and GEA showed rapid falling. Therefore, ITA and GEA had the risk of inadequate blood supply. This pressure measurement of in situ arterial graft was an easy and effective method for presumption of the ability of blood supply.

Arteries↗

PubMed1992

Exercise response assessed by continuous monitoring of ventricular function in patients with coronary bypass operations.

The response of left ventricular function during exercise and recovery after exercise was assessed in 35 patients with coronary artery bypass grafting before and after the operation by means of a continuous ventricular function monitor, which records serial beat-to-beat radionuclide data and calculates left ventricular ejection fractions every 20 seconds. The mean ejection fraction decreased with graded bicycle exercise from 48% +/- 9% to 41% +/- 11% (p less than 0.001) before operation but increased with exercise from 50% +/- 9% to 55% +/- 11% (p less than 0.001) after operation. Cardiac response was divided into four types with respect to the profiles of the ejection fractions during exercise. Type A continued to increase; type B initially increased but then decreased in late exercise stages; type C did not change significantly; type D continued to decrease. Most patients had type C or D responses before operation but type A after operation. Seven patients with occluded grafts or ungrafted coronary arteries had type B or D responses. Three patients with complete revascularization, including an internal thoracic artery and saphenous vein grafts, had type B responses. Three patients with extensive infarction and poor left ventricular function showed type C. In the early recovery period after exercise, most patients had an "overshoot" elevation of ejection fraction. The mean value increased from 59% +/- 10% before operation to 64% +/- 11% after operation (p less than 0.01). The recovery time after exercise was reduced from 2.8 minutes before operation to 1.8 minutes after operation (p less than 0.001). The continuous ventricular function monitor elucidated changes in left ventricular function both during exercise and recovery after exercise, as well as unmasking abnormalities in left ventricular function after coronary bypass operation.

Coronary Artery Bypass↗

PubMed1992

[A successful resection of recurrent right ventricular myxoma].

A successful surgical treatment of right ventricular myxoma of twenty-year-old male was presented, who healed already previous resection of left atrial myxoma two year and eight months prior to this operation. He has been followed up closely after the first resection of left atrial myxoma for the recurrence in the left atrium. Follow-up echocardiography demonstrated the development of myxoma in the free wall in the right ventricle. The resection for this myxoma was found to be relatively easy at the second operation. The tumor was removed with the stark, without any postoperative problem. According to the literature, this case seems to be the second Japanese case of surgical treatment of right ventricular myxoma following the removal of left atrial myxoma.

Adult↗

PubMed1992

Application of a continuous ventricular function monitor with miniature cadmium telluride detector to patients with coronary artery bypass grafting.

A continuous ventricular function monitor with a miniature cadmium telluride detector was evaluated and applied to patients with coronary bypass surgery (CABG). Ejection fraction (EF) at rest and change in EF from rest to exercise and postexercise (Y) measured with the device correlated with that of the gamma camera (X) (Y = 0.86x + 6.8(%), r = 0.87, n = 110, p less than 0.001, and Y = 0.96x + 0.4(%), r = 0.90, n = 37, p less than 0.001 respectively). Left ventricular function during and after supine ergometer exercise was monitored in 54 patients before and after CABG. The EF change from baseline to peak exercise improved from -5.9% +/- 8.9% before CABG to 7.2% +/- 7.9% after CABG (p less than 0.001). In all patients but two, a rapid EF increase just after exercise over baseline EF was observed. This EF "overshoot" during recovery increased from 11.5% +/- 6.5% to 16.4% +/- 6.0% (p less than 0.001) after CABG. The time from the cessation of exercise to EF overshoot decreased from 153 +/- 80 sec to 76 +/- 49 sec (p less than 0.001) after CABG. The continuous ventricular function monitor with a miniature cadmium telluride detector is able to measure EF reliably. Following successful aortocoronary bypass, EF response during exercise improved and the EF overshoot in the recovery phase became faster and higher.

Cadmium↗

PubMed1991

Long-term results of surgery for non-ischemic ventricular tachycardia.

Drug resistant, non-ischemic ventricular tachycardia (VT) was treated in 43 patients by direct surgery based on electrophysiological data. Two main surgical techniques were employed: myocardium was resected followed by cryocoagulation with a special probe in 23 patients with VT originating from the right ventricle. The myocardium was incised followed by cryocoagulation in 10 patients with VT from the left ventricle. The follow-up period ranged from 1 week to 10 years, 4 weeks (mean 3 years, 8 months). After operation, 36 patients (83%) showed complete disappearance of VT without antiarrhythmic therapy. Of these 2 patients died of congestive heart failure not related to VT in the postoperative period at 1 year 4 months, and 2 years 4 months, respectively. In 7 patients, VT remained. In 2, VT disappeared after catheter ablation. In 3 patients, VT became controllable with antiarrhythmic therapy. Operation was not successful in 2 patients (5%); 1 with a giant left ventricular aneurysm died of low cardiac output syndrome due to VT 1 week after operation; the other with arrhythmogenic right ventricular dysplasia originating from both ventricles died suddenly 5 months after operation. The 10-year survival is 89%, and the 10-year freedom from recurrent VT is 83%. These results indicate that surgical management for non-ischemic VT is safe and effective with a high chance of cure.

Adolescent↗

PubMed1991

Silent left ventricular dysfunction during exercise after coronary artery bypass surgery.

Serial changes in left ventricular function during exercise were assessed by radionuclide continuous ventricular function monitoring in 80 patients undergoing coronary artery bypass surgery before and after operation. This monitor records serial beat by beat radionuclide and electrocardiographic data and calculates the left ventricular ejection fraction every 20s. The profiles of ejection fractions during graded bicycle exercise were divided into 4 types. In type A, the ejection fraction continued to increase. In type B, the ejection fraction initially increased but decreased in late exercise. In type C, the ejection fraction did not change. In type D, the ejection fraction continued to decrease. Type A is considered to be the normal response to exercise and types B, C and, D are considered to be abnormal responses. Before operation, 8 patients showed type A, 21 type B, 13 type C, and 38 type D. After operation, 53 patients showed type A, 16 type B, 8 type C, and 3 type D. The mean ejection fraction decreased with exercise from 53% +/- 11% to 47% +/- 11% before surgery, but increased with exercise from 55% +/- 10% to 64% +/- 14% after surgery. During postoperative exercise, no patient developed chest pain but 19 patients showed a decrease in the ejection fraction in early or late exercise. A decrease in the ejection fraction is an earlier indicator of myocardial ischaemia than angina or electrocardiographic changes. Silent left ventricular dysfunction during postoperative exercise was considered to reflect myocardial ischaemia resulting from occluded grafts, ungrafted coronary arteries, or inadequate perfusion by arterial grafts. The radionuclide continuous ventricular function monitor can detect silent left ventricular dysfunction after coronary artery bypass surgery.

Adult↗

PubMed1991

Coronary artery bypass surgery in patients with angina pectoris and hypothyroidism.

The treatment of hypothyroidism in patients undergoing coronary artery bypass surgery is a difficult clinical problem. To determine perioperative thyroid replacement therapy in patients with hypothyroidism, plasma total thyroxine (T4), total triiodothyroxine (T3), free T4, free T3 and thyroid-stimulating hormone levels were measured preoperatively and at 1, 2, 3, 7, and 14 days after operation in 9 patients with hypothyroidism and were compared with levels in 14 patients with normal thyroid function who underwent coronary bypass surgery. In the normal control group, total T4 decreased to its lowest level on the 1st postoperative day and then increased gradually to the preoperative level at 7 days. Total T4 remained within the normal range throughout the entire postoperative course. In 6 patients with hypothyroidism who were treated with thyroid hormone before surgery, total T4 decreased immediately after operation and only increased after starting thyroid replacement therapy. In 3 hypothyroid patients without prior thyroid replacement, total T4 showed a change similar to patients in the control group but remained below the normal range until starting thyroid replacement therapy. Coronary bypass surgery was performed safely in patients with hypothyroidism. Preoperative thyroid replacement with suboptimal doses was safe in patients with severe hypothyroidism. Adequate postoperative thyroid replacement was achieved in all patients without complications.

Adult↗

PubMed1991

Ventricular assistance by right free wall dynamic cardiomyoplasty following acute right heart failure in canines.

The efficacy of right ventricular assistance provided by electrically conditioned skeletal muscle was studied in 17 canines. The right ventricular free wall was made ischemic and akinetic by ligating all coronary branches supplying it. The latter procedure led to deterioration of hemodynamic parameters. After that, 14 canines were divided into two groups: group 1 (n = 8) was observed without cardiomyoplasty for 2 hours; group 2 (n = 6) underwent right ventricular dynamic cardiomyoplasty with the conditioned left latissimus dorsi. The deterioration in hemodynamic parameters in group 1 showed no further significant change during the period of observation. In group 2, right ventricular function was augmented by cardiomyoplasty, as shown by a significant increase in right ventricular and pulmonary artery pressures. In addition, decreased CVP suggested improved right ventricle (RV) filling. Right ventricular function curves obtained by volume loading in a further group of three canines, group 3, also demonstrated improved right ventricular function. Thus right ventricular dynamic cardiomyoplasty appears to contribute significantly to right ventricular function in a model of acute right heart failure.

Acute Disease↗

PubMed1991

Ex vivo performance of muscle powered cardiac assist device: potential for right ventricular support.

The present study addressed the filling sensitivity and power output of the TOYOBO VAD (TVAD) and Utah soft artificial ventricle (USAV) to evaluate these pumps as a muscle powered cardiac assist device (MCAD). Two pumps were assembled with three different types of driving chambers placed underneath the latissimus dorsi (LD) muscle: the soft spindle (SS) type, elastic spindle (ES) type and bellows (B) type. The USAV required a filling time of greater than 1000 msec at any preload with any driving chamber, although the TVAD allowed this only with the ES-type chamber assembly. In an ex vivo mock study, the ES- and SS-type chamber assembly demonstrated a maximum stroke volume (SV) of 7.7 mL (39% stroke) by the USAV and 12 mL (17% stroke) by the TVAD at an afterload below 20 mmHg. On the other hand, the B-type chamber increased SV according to afterload in both pumps, resulting in a maximum SV of 25 mL (36% stroke) by the TVAD and 7.6 mL (38% stroke) by the USAV at a 30 mmHg afterload. The maximum stroke work (SW) achieved was 1.3 x 10(6) erg by the TVAD and 0.5 x 10(6) erg by the USAV, which exceeds that of the canine right ventricle. In conclusion, the ES-type chamber provided best pump filling and the B-type chamber best pump ejection, but back pressure at the chamber diaphragm determined performance efficiency. An active filling mechanism for the driving chamber will be necessary to offset the low preload requirements of a VAD, and provide the maximum power output necessary for right ventricular support.

Back↗

PubMed1991

Transesophageal echocardiographic monitoring during coronary artery bypass surgery.

To demonstrate serial changes of left ventricular (LV) function during coronary artery bypass grafting surgery, transesophageal echocardiography (TEE) was used in 17 patients. The cross-sectional image of the left ventricle at the level of the papillary muscles was monitored, and was analyzed immediately in the operating room using a computer-assisted cine-memory function. Global LV function was evaluated by measuring LV end-diastolic and end-systolic area and computing the fractional area change (FAC). Segmental wall motion abnormalities (SWMA) were graded according to a scoring system. During the operative procedure before sternal closure, 5 patients showed SWMA with a simultaneous decrease in FAC to under 40%, and 9 patients showed SWMA without FAC depression. Two-thirds of new SWMA improved after myocardial revascularization. All 17 patients showed a change of interventricular septal movement at the end of the operation. FAC improved from a mean value (+/- SD) after intubation of 47.6 +/- 10.7% to a mean value after revascularization of 58.5 +/- 13.0% (p less than 0.05) and to a mean value at the end of the operation of 55.9 +/- 12.2% (p less than 0.05). Thus: 1) global and regional LV function improved immediately after myocardial revascularization with administration of inotropic agents; 2) a significant change of interventricular septal movement occurred after sternal closure; and 3) intraoperative TEE monitoring is a safe, simple, and effective method for evaluating LV global and regional function.

Adult↗

PubMed1991

Diagnosis and treatment of left ventricular false aneurysm.

Three patients are presented in whom a false aneurysm of the left ventricle was surgically treated. False aneurysm of the left ventricle is an unusual consequence of ventricular wall rupture with containment of the resulting hematoma. Most false aneurysms of the left ventricle develop following myocardial infarction. The false aneurysm wall contains no myocardium. The false aneurysm has a great tendency to rupture, regardless of its size. One patient developed progressive congestive heart failure following a myocardial infarction. The other two patients were asymptomatic following myocardial infarction. Preoperative magnetic resonance imaging showed characteristics of a false aneurysm. These included a distinct discontinuance of the myocardium at the neck of the aneurysm and a narrow neck relative to the diameter of the aneurysm. Two patients underwent successful closure of the orifice of the false aneurysms. One patient underwent emergency surgery because of acute rupture while awaiting surgery but died of cerebral damage. Surgical correction of a false aneurysm is clearly advisable even in the absence of symptoms.

Echocardiography↗

PubMed1991

[Cardiac response to exercise before and after coronary artery bypass grafting: evaluation by continuous ventricular function monitor].

Cardiac response to exercise was evaluated with continuous ventricular function monitor (VEST) with cadmium telluride detector. Thirty-nine patients (30 male and 9 female, aged 57 +/- 8, 23 had old myocardial infarction) were monitored with VEST during and after supine ergometer exercise before and 4 weeks after coronary artery bypass grafting (CABG). Left ventricular ejection fraction (EF) responses were classified into 4 types; type A showed EF increase greater than 5% till end of exercise, type B demonstrated initial increase followed by decrease in EF, type C revealed no significant EF change, type D showed continuous EF decrease. Before CABG, each EF response type A, B, C, and D consisted of 4, 2, 12, 21 patients respectively and after CABG each type included 18, 10, 9, 2. The EF change from rest to peak exercise (delta EF-Ex) improved from -6.4 +/- 8.8% to 5.0 +/- 7.4% (p less than 0.001) after CABG. All patients showed rapid EF increase after exercise or "EF overshoot" (EF-OS). After CABG, the EF change from rest to EF-OS (delta EF-OS) and time to EF-OS (T-OS) were improved from 9.9 +/- 5.2% to 14.9 +/- 5.3% (p less than 0.001) and 162 +/- 86 sec to 80 +/- 48 sec (p less than 0.001) respectively. Type A, B patients showed higher delta EF-OS and shorter T-OS than type C, D patients, suggesting EF overshoot was contingent upon cardiac function during exercise. After CABG, in patients with myocardial infarction, T-OS shortened but delta EF-OS showed less improvement than patients without infarction, suggesting loss of myocardium hampered EF-OS.

Aged↗

PubMed1991

[Transesophageal echocardiography during coronary bypass surgery].

The early diagnosis of intraoperative myocardial ischemia is important because such ischemia can lead to myocardial infarction. Clinical effectiveness of transesophageal echocardiography (TEE) was evaluated for detecting intraoperative myocardial ischemia and for observing the recovery of cardial motion at the end of cardiopulmonary bypass (CPB) in 20 patients who had undergone CABG. After endotracheal intubation, the TEE transducer was introduced into the esophagus to obtain a short axis cross-sectional view of the left ventricle at the level of the papillary muscles. Global LV function was assessed by measuring end-diastolic and end-systolic areas, which were calculated automatically, and the fractional area change (FAC). Regional endocardial wall motion was also analyzed by subdivision into four anatomical segments. The mean FACs were 48% after intubation, 47% after skin incision and 48% after sternotomy. Thereafter it increased significantly to 59% 30 minutes after CPB and 56% at the end of the operation. Thus, global LV function was improved significantly by revascularization. TEE could detect myocardial ischemia more sensitively than ECG. In 9 patients, FAC decreased significantly and new regional wall motion abnormality (RWMA) appeared around the time of sternotomy, but no ECG changes were detected. In another 7 patients, new RWMAs were detected without either a decrease in the FAC or ECG changes. It was found that myocardial ischemia took place more frequently before the initiation of CPB than expected. The recovery of left ventricular wall motion from cardioplegic arrest was able to be monitored visually during the period of weaning from CPB and the TEE could facilitated prompt and exact judgement of weaning from CPB.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

[The use of Doty's extended aortoplasty in binovular twins with congenital supravalvular aortic stenosis].

Binovular twins with congenital supravalvular aortic stenosis underwent Doty's extended aortoplasty. Neither twins displayed signs of Williams syndrome. Peak systolic pressure gradients of 65 and 70 mmHg, respectively, were measured across the stenotic portion at the ascending aortae. After surgery, the pressure gradients were reduced to 15 and 20 mmHg, respectively, at the aortic valves. No new aortic regurgitation was observed postoperatively. It is important that the ascending aorta, including the stenotic part, is symmetrically incised into the noncoronary and the right coronary sinus of Valsalva. The fibrous ring should be removed as completely as possible. Doty's extended aortoplasty is a safe and effective procedure for supravalvular aortic stenosis.

Aorta↗