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Biomedical subjects

Y Yokote

Publications and source records attributed to Y Yokote.

At least 37 records · Page 2Linked to original sources
PubMed2000

Clinical experience of milrinone as a pharmacological bridge to heart transplantation.

A 19-year-old man with idiopathic dilated cardiomyopathy developed cardiogenic shock. A HeartMate left ventricular assist device was inserted as an emergency procedure, but removed after 189 days due to sepsis related to the device. Intravenous milrinone was administered because of recurrence of heart failure, and as a result the symptoms disappeared and the urinary output increased. Echocardiography showed improvement in the left ventricular ejection fraction. Subsequently, the patient successfully underwent heart transplantation. Milrinone was effective as a pharmacological bridge to heart transplantation in this patient with terminal and critical heart failure after removal of a left ventricular assist device.

Adult↗
PubMed2000

Development and clinical application of minimally invasive cardiac surgery using percutaneous cardiopulmonary support.

OBJECTIVES: Optimal cardiopulmonary support during minimally invasive cardiac surgery remains controversial. We developed cardiopulmonary bypass for minimally invasive cardiac surgery using percutaneous peripheral cannulation. METHODS: Subjects were 34 patients (age: 58 +/- 13 years; range: 17-73) undergoing minimally invasive cardiac surgery using percutaneous cardiopulmonary support between June 1997 and March 1999. Procedures included atrial septal defect closure (n = 14), partial atrioventricular septal defect closure (n = 1), mitral valve replacement (n = 8), mitral valve repair (n = 3), aortic valve replacement (n = 6), coronary artery bypass grafting (n = 1), and right atrial myxoma extirpation (n = 1). Bicaval venous drainage from the right internal jugular vein and the femoral vein and arterial return to the femoral artery were instituted by percutaneous cannulation. Venous drainage was implemented by negative pressure (-20 to -40 mmHg) and arterial return was by conventional roller pump. All procedures were conducted through a skin incision 8 +/- 1 cm, from 6 to 10 cm and partial sternotomy. Aortic cross clamping and cardioplegic solution were administered in the surgical field. RESULTS: The operation lasted 224 +/- 45 min., cardiopulmonary bypass 104 +/- 32 min., and aortic clamping 77 +/- 23 min.. No deaths occurred. One patient with residual atrial septal defect required reoperation through the same skin incision. Only 1 patient required homologous blood transfusion. The average postoperative hospital stay was 15 +/- 5 days. CONCLUSIONS: Minimally invasive cardiac surgery using percutaneous cardiopulmonary support is safe and an excellent option for selected patients affected by single valve lesion, simple cardiac anomalies, and coronary artery bypass grafting.

Adolescent↗
PubMed2000

Ventricular energetics in Fontan circulation: evaluation with a theoretical model.

BACKGROUND: Both pulmonary and systemic circulation must be maintained by a single pump in Fontan circulation. This unique property of Fontan circulation may be related to decreased exercise tolerance or increased instantaneous postoperative mortality rate, often observed in patients with this circulation. To better understand Fontan physiology, the present study theoretically investigated cardiac performance of Fontan circulation by using ventricular-vascular coupling framework analysis. METHODS: End-systolic volume elastance (Ees), as a chamber contractile property, and effective arterial elastance (Ea), a lumped measure of ventricular afterload, were estimated both in normal left ventricular systemic circulation and in Fontan circulation. RESULTS: End-systolic volume elastance was decreased and Ea was increased in Fontan circulation. Both ventricular external stroke work (SW) and mechanical efficiency (EFF) under Fontan circulation were lower compared with those under normal circulation. Furthermore, the Ees-Ea relationship in Fontan circulation predicted limited cardiac reserve in terms of SW and EFF. Such cardiac performance in Fontan circulation stemmed from increased impedance due to the additional connection of the pulmonary vascular bed to the systemic vasculature and from the lack of a compensatory increase in contractility for increased afterload. CONCLUSIONS: Thus, it was inferred that Fontan circulation had intrinsic disadvantages and this may explain, in part, abnormal functional status and decline in survival following this procedure.

Blood Circulation↗
PubMed2000

Global myocardial ischemia as a complication of an acute type A aortic dissection--rapid diagnosis of a case by transesophageal echocardiography.

A 36-year-old female was admitted for severe chest pain followed by profound shock. Electrocardiography showed severe ST segment depression (0.5-0.7 mV) in all leads except aVR and aVL. Echocardiography revealed an intimal flap in the ascending aorta and coexisting grade 3 aortic regurgitation. She was immediately intubated and transferred to the intensive care unit. Transesophageal echocardiography (TEE) demonstrated an intimal tear at 2 cm above the sinotubular junction, and the ostium of the left main trunk was oppressed by the intimal flap during diastole. Emergency graft replacement of the ascending aorta and aortic hemiarch concomitant with aortic valve resuspension was performed successfully. The ECG changes reversed to normal immediately after the operation. The patient was extubated 2 days postoperatively and discharged from the hospital 14 days postoperatively. TEE is useful for the rapid evaluation of coronary malperfusion as a complication of acute aortic dissection, especially in patients with hemodynamic instability.

Acute Disease↗
PubMed2000

Influence of age (body size) on the Fontan circulation--analysis by a theoretical model.

Among the original selection criteria for the Fontan operation, the recommended age at the time of surgery has been 4 years or older, but recent clinical data have indicated the feasibility of this procedure in younger patients. Because age may influence the properties of the systemic vascular bed, changes in systemic vascular resistance (Rs) and systemic vascular compliance (Cs) associated with physical development were quantified in 86 pediatric patients without known abnormalities of the systemic circulation, and the effects of age (body size) on Fontan circulation were then analyzed using an analytical model of the cardiovascular system. As the body surface area (BSA) of the patient decreased, Cs also decreased significantly (r=0.81, p<0.001). Based upon this relationship between BSA and Cs, the analytical model showed that the impedance (ventricular afterload) of the Fontan circulation significantly increased as Cs decreased with the decrease in BSA. Moreover, the increase in impedance in response to changes in heart rate or Rs was inversely proportional to the BSA. However, these findings were significant only when the BSA was below 0.3 m2. Small BSA, or a lower age, has minimal effects on the Fontan circulation until it comes close to the infant value, and thus the Fontan procedure may be feasible much earlier than formerly recommended when the hemodynamics are otherwise acceptable.

Age Factors↗
PubMed2000

Reversible thermal transition of soluble branched chains from slightly acid-treated potato starch.

The reversible thermal transition of soluble branched starch chains prepared from slightly acid-treated potato starch granules (ATS) was investigated. Potato starch was immersed in 15% sulfuric acid to obtain ATS with a 1% hydrolysis rate. About half of the molecules of ATS, which spontaneously formed large aggregates with a mass of a few million daltons in aqueous solution, was fractionated and soluble branched starch chains with a relative molecular weight (Mr) of 8.91 x 10(4) were obtained. Structural analysis indicated that the soluble branched starch chains consisted of three unit chains with Mr 7,900 and 21 unit chains with Mr 2,700. DSC and FT-IR measurements showed that the soluble branched starch chains underwent a reversible thermal transition, which is considered to be a helix-coil transition, during heating and cooling, but a debranched sample and beta-limit dextrins showed substantially different thermal behavior, indicating the contribution of the ordered structure of the branched chains.

Acids↗
PubMed1999

Does intensive perioperative dialysis improve the results of coronary artery bypass grafting in haemodialysed patients?

BACKGROUND: Between January 1996 and April 1998, 17 chronic haemodialysed patients underwent coronary artery bypass grafting (CABG). Two of them simultaneously had valve replacement. METHODS: Except for two cases in which CABG was performed in an emergency, 15 patients (CRF group) received 3 consecutive days of haemodialysis in the preoperative period, intraoperative haemodialysis connected to cardiac pulmonary bypass (CPB) and continuous hemodiafiltration in the early postoperative period. The perioperative clinical parameters of the CRF group were compared with those of 17 age-matched patients with normal renal function undergoing CABG as the control (NRF group). RESULTS: When the perioperative variables were compared, no significant differences were seen in total operation time and CPB time, but we noted significant increases in the mean volume of transfused blood in the 6 perioperative days, postoperative intubation time, postoperative fasting time, and time spent in the intensive care unit. Levels of central venous pressure, systolic blood pressure, respiratory index (PaO2/FiO2) and daily fluid balance of the CRF group were the same as the control group in the early postoperative period. In addition, the levels of serum creatinine, urea nitrogen, potassium and hematocrit of CRF group remained almost constant in the early postoperative period. After all, the hospital morbidity of the CRF group was not more serious than that of the NRF group, and hospital mortality of the CRF and NRF groups was 0%. CONCLUSIONS: Our intensive perioperative dialysis programme could successfully manage the perioperative clinical course of haemodialysed patients undergoing CABG.

Coronary Artery Bypass↗
PubMed1999

[Single-dose and high-volume Bretschneider cardioplegic solution for congenital heart surgery].

Bretschneider cardioplegic solution is used widely in Europe. The aim of this study is to investigate the efficacy of Bretschneider cardioplegic solution for open heart surgery of congenital heart disease in comparison with blood cardioplegia. From June 1995 to July 1997, we treated 32 congenital heart disease patients using Bretschneider cardioplegic solution and 20 patients using blood cardioplegia. Hospital mortality, water balance during operation, percentage of arrhythmia, and intubation time were not significant in both group. Also CPK and CPK-MB were not significant in both group. Bretschneider cardioplegic solution had preserved the heart as same as blood cardioplegia. This is a very convenient method so that we can use only one time infusion.

Cardiac Surgical Procedures↗
PubMed1999

[Report of three cases of emergency operation for acute pulmonary embolism].

Three successful surgical cases of acute pulmonary embolism with severe cardiopulmonary impairment were reported. Currently, thrombolysis is widely accepted as the front-line treatment for most patients with pulmonary embolism. However, treatment failure is high and can lead to death in the most severe cases. If these patients have severe cardiopulmonary impairment, pulmonary embolectomy should be done immediately.

Acute Disease↗
PubMed1999

[The effect of milrinone for the shock patients after cardiac surgery].

The effect of milrinone in the 16 postoperative shock patients of cardiovascular surgery was studied. The preoperative hemodynamic status were 12 of cardiogenic shock, 2 cases of chronic heart failure and 2 cases of unstable angina pectoris. The operative procedure were 8 cases of coronary artery bypass grafting, 4 cases of valvular surgery, 2 cases of closure of ventricular septal perforation, 2 cases of Bentall operation and 1 case of ascending aortic replacement. The postoperative hemodynamic status were 15 cases of cardiogenic shock, 10 cases of hemorrhagic shock and 1 case of septic shock. Continuous intravenous infusion of 0.5 microgram/kg/min without initial bolus loading was administered immediately after the entrance of the intensive care unit. Significant increase in the maximum blood pressure 3 hours after the infusion were observed (84 +/- 17 mmHg vs 94 +/- 12, p = 0.033). The maximum blood pressure was increased gradually until 24 hours after the infusion. Significant increase in the peripheral body temperature 3 hours after the infusion were observed (32.5 +/- 2.0 degrees C vs 35.9 +/- 1.1 degrees C, p = 0.001). The difference between the peripheral temperature and the central body temperature diminished until 24 hours after the infusion. No significant change in the central venous pressure, pulmonary arterial pressure, pulmonary and cardiac index wedge pressure were observed. No significant change in the platelet number was observed until 3 days after the infusion. Twenty patients (75%) were discharged. Four hospital deaths included 1 cardiac and 3 septic cause were seen. These data suggest that the administration of milrinone for the shock patients after cardiac surgery showed safe and that the continuous intravenous infusion of 0.5 microgram/kg/min without bolus loading showed effective for the recovery of the peripheral circulation.

Aged↗
PubMed1999

[Clinical practice in nursing, and "re establishment of daily routines"--the nurse's role in inter-professional collaboration].

Clinical practice in adult nursing is given during the 4th year at the School of Health Sciences, Sapporo Medical University. In this paper, we report the achievements in this training on one theme. The theme chosen was the nursing of patients and support of their families particularly their caregivers, for whom re-establishment of daily routines was indispensable. A total of 51 students underwent this nursing practice at a neurological hospital on 26 occasions, over 3 years from 1996. We found that the students learned inter-professional collaboration in their relationships with other students, skilled nurses and other professionals in the hospital and other organizations. We also analyzed the nurses' roles learned through the inter-professional collaboration, which could be summarized as follows: 1. Understanding patients' and their families' living conditions and mental state, as affected by the patient's disease or disability. 2. Supporting the safe care at home of patients helping them to re-establish living routines. 3. Educating caregivers on how to attend to patients and develop better attendance skills. 4. Making sure the patients' and their families' living needs are reflected in the support system. 5. Providing nursing information for the coordination process of the support system, as well as respecting patients' and their families' individuality and lives as a whole.

Aged↗
PubMed1998

[Aortic regurgitation caused by the proximal dissecting flap invagination to the left ventricle].

A 68-year-old male with sudden back pain and cardiogenic shock status transferred to our ward. Transthoracic echocardiography revealed that the abnormal round shape string was in the left ventricular outflow tract. The continuity from the staring to the aortic valve was unclear. Intimal flap could not be detected at the level of the ascending aorta. Color Doppler flow imaging showed that the severe AR jet extended into the round string. TEE showed that the intimal tear and flap was seen just above the left subclavian artery. Preoperative diagnosis was acute Stanford type A dissection and acute severe AR due to the inversion of the proximal intimal flap to the left ventricular outflow tract through the aortic valve. At operation, the proximal intimal flap was dissected circumferentially and was cut all the way around 8 cm above the aortic valve ring and was inverted to the left ventricular outflow tract. The aortic valve was preserved because of its normal character after exclusion of the proximal intimal flap. Ascending and arch replacement was carried out. Postoperative TEE and TTE slowed no findings of AR. The patient's postoperative course was uneventful. To our knowledge, this is the first reported case that severe AR caused by the proximal intimal invagination to the left ventricle.

Acute Disease↗
PubMed1998

[A surgical case of quadricuspid aortic valve associated aortic regurgitation and severe mitral regurgitation due to infective endocarditis].

We report a case of rare anomaly of quadricuspid aortic valve associated aortic regurgitation and severe mitral regurgitation due to infective endocarditis. A 50-year-old man was admitted to our hospital for fever and dyspnea. The transesophageal echocardiography showed severe aortic regurgitation due to four equal aortic cusps and severe mitral regurgitation due to infective endocarditis. At the operation, aortic valve and mitral valve were replaced with 23 mm and 29 mm SJM valves. His postoperative course was uneventful.

Aortic Valve↗
PubMed1997

Usefulness of transesophageal echocardiography in detecting changes in flow dynamics responsible for malperfusion phenomena observed during surgery of aortic dissection.

Intraoperative transesophageal echocardiography (TEE) was performed in order to study the flow dynamics in the descending aorta during surgery of aortic dissection Stanford A. TEE was seen to be a sensitive and accurate method to promptly detect severe decrease in retrograde pump flow and to clarify some of the mechanisms that can result in malperfusion during cardiopulmonary bypass.

Adult↗