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Biomedical subjects

H Koyanagi

Publications and source records attributed to H Koyanagi.

At least 163 records · Page 9Linked to original sources
PubMed1996

Less blood damage in the impeller centrifugal pump: a comparative study with the roller pump in open heart surgery.

A centrifugal pump with an impeller (Nikkiso Centrifugal Pump, Model HPM15; Nikkiso Co. Ltd.) was applied to cardiopulmonary bypass (CPB) in 14 patients who underwent elective coronary artery bypass grafting. Serum hemoglobin level, platelet count, and serum beta-thromboglobulin (beta TG) level were measured during CPB. The results were compared with those obtained in a comparative roller pump (RP) group (n = 10). There was no difference in the time on CPB between the NP (109 min) and RP (121 min) groups. The serum beta TG level (ng/ml) was lower in the NP group than in the RP group (obtained 90 min after the initiation of CPB). The plasma-free hemoglobin level also was lower in the NP group than in the RP group (obtained 90 min after the initiation of CPB, 120 min after the initiation of CPB, immediately after the termination of CPB, 3 h after termination of CPB; p < 0.01). There was no significant difference in platelet depletion. The HPM15 pump showed excellent hemodynamic performance with less blood trauma compared with the roller pump in its clinical application to open heart surgery.

Adult↗
PubMed1996

Biventricular bypass with oxygenation for postcardiotomy ventricular failure.

Between January 1984 and March 1995, biventricular bypass (BVB) with oxygenation was used in 17 patients for postcardiotomy ventricular failure at the Heart Institute of Japan, Tokyo Women's Medical College. Of the 17 patients, 12 (70.6%) were weaned from the circulatory support, and 8 (47.1%) were discharged from the hospital. The time interval from the endo of cardiopulmonary bypass to the start of BVB was significantly shorter in weaned patients than in unweaned patients. The duration on support also has been shortened significantly in the last 6 years, compared with the earlier 6 years. Causes of death were severe heart failure or ventricular arrhythmia in 6 patients and multiple organ failure in 3 patients. These results suggest that early application and timely weaning from biventricular bypass with oxygenation might be the effective circulatory support of choice for treatment of postcardiotomy ventricular failure.

Adult↗
PubMed1996

[Emergency coronary artery bypass in an 84-year-old patient with severe left main disease and cardiogenic shock].

An 84-year-old male was admitted to pur hospital because of unstable angina. The patient presented in cardiogenic shock with a cardiac index of 1.3 l/min/m2 associated with hypotension (systolic blood pressure < 80 mmHg) and oliguria, and in ventricular fibrillation after an acute broad anterolateral infarction due to severe left main coronary disease. The patient received an intra-aortic balloon pumping (IABP) and underwent emergency CABG. After completion of CABG, left ventricular contractility was markedly diminished to maintain systemic circulation. Because the patient could not be weaned from cardio-pulmonary bypass (CPB) in spite of IABP and high-dose of catecholamines, we decided to continue CPB. It was continued for 163 minutes and the patient was successfully weaned from CPB. In spite of the high risk of operative mortality with CABG for left main shock syndrome in elderly patients, CABG could be performed safely. The patient ran an uneventful postoperative course and is now doing well.

Aged↗
PubMed1996

[A case of extra anatomical bypass grafting for coarctation of aorta associated with Turner's syndrome].

A 24-year-old woman with manifestations of Turner's syndrome was referred for detail examinations and treatment of right subclavian tumor on chest X-ray. She was short and obese (147 cm tall and weigh 65 kg). And she had hypertension at upper extremities (160/100 mmHg). Chest enhanced CT revealed right subclavian arterial aneurysm and coarctation of aorta. Aortography showed interrupted descending thoracic aorta with short atretic segment followed by distal descending aorta, aneurysmal collateral artery from right subclavian artery to abdominal aorta and other small collateral arteries. Left lateral thoracotomy was thought to have a high risk for bleeding in the short and obese patient with ample collateral arteries. Therefore, extra anatomical bypass grafting from ascending aorta to abdominal aorta was performed through median sternotomy and laparotomy. After operation recovery was uneventful without residual hypertension. In this report, we discuss about the operation of adult coarctation of aorta and usefulness of extraanatomical bypass grafting.

Adult↗
PubMed1996

[A case report of a successful Redo Bentall operation].

An initial Bentall operation was performed on a patient aged 38 years with annuloaortic ectasia and aortic regurgitation. An echocardiogram and RI angiogram revealed a perigraft aortic aneurysm on the same patient aged 45 years. The aneurysm gradually developed and the maximum diameter reached 90 mm in size. The Redo-Bentall operation (Piehler modification) was successfully done once again on the same patient aged 56 years. The anastmosis between the right coronary orifice and the graft was detached on all sides. The anastmosis between the left coronary orifice and the graft was detached two thirds of all sides.

Aneurysm, False↗
PubMed1996

[Cardiac surgery in patients on chronic hemodialysis].

From March 1993 to February 1993, 36 patients with chronic renal failure underwent cardiac surgery with intraoperative hemodialysis (HD). We examined and compared the medium term results of those patients cased upon the time periods of operation and types of heart disease. With respect to the time periods of operation, the 1st term (n = 12) was between March 1985 and February 1989, and the 2nd term (n = 24) was between March 1989 and February 1993. Concerning types of disease, Group A was comprised of 24 patients with ischemic heart disease, and Group B was comprised of 12 patients with valvular or congenital heart disease. Only one early death was observed in the 1st term (8.3%: LOS). As for late death, 5 cases were observed in the 1st term (45.3%), and 2 cases were observed in the 2nd term (8.3%). The actuarial survival rate (post 3 years) was 72.7% in the 1st term and 91.3% in the 2nd term. In each case, the survival rate of the 2nd term was significantly better than the that of the 1st term (p < 0.025). When compared cased upon the types of disease, the actuarial survival rate (post 6 years) was 84.6% in Group A, and 45.5% in Group B, respectively. This difference was statistically significant (p < 0.05). Causes of late death were cerebral hemorrhage in 5 cases, sudden and unknown in one and DIC in the remaining one patient. There were many postoperative complications in this series in addition to the above stated fatal ones. The majority of them, however, were successfully treated, if early diagnosis of them was obtained. During the perioperative period through the long-term period, incidents of fatal hemorrhage among patients on chronic dialysis were reduced by 1) strict management of hypertension; 2) HD without use of Heparin; and 3) with respect to patients who required Warfarin after valve replacement, through the careful anti-coagulant therapy which maintained the thrombo-test (TT) value at precise levels.

Adult↗
PubMed1996

[A surgical case report of an atrial septal defect combined with stenosis of the left main coronary artery caused by a dilated pulmonary artery in adult].

We encountered a 40-year-old male patient diagnosed to have an atrial septal defect combined with pulmonary hypertension and left main coronary artery stenosis of 50% caused by a dilated pulmonary artery. Preoperative Trazoline tolerance test revealed an increase in pulmonary artery pressure from 77/22(40) to 85/24(42), and a decrease in pulmonary vascular resistance from 4.2 U.m2 to 3.6 U.m2. Moreover, his treadmill exercise test was positive. We performed only a patch closure of the atrial septal defect. The postoperative catheterization examination showed normal pulmonary artery pressure, mild mitral valve regurgitation, and improvement of the left main coronary artery stenosis from 50% to 41%. After 6 months, his treadmill exercise test was negative. We believe that it is important to estimate preoperatively for the possible reversibility of pulmonary hypertension in a patient with an atrial septal defect combined with a left main coronary artery stenosis caused by a dilated pulmonary artery.

Adult↗
PubMed1996

[Perforation and localized dissection of the left common iliac artery during the modified Bentall procedure: a case report].

We performed the modified Bentall procedure for annuloaortic ectasia in a 41-year-old man with Marfan's syndrome. Approximately 15 minutes after initiation of cardiopulmonary bypass with an arterial delivery via the left common femoral artery, perfusion volume gradually decreased and the abdomen of the patient was distended. Retrograde dissection was strongly suggested. Perforation and localized dissection of the left common iliac artery were recognized. Following repair of the lesion, the modified Bentall operation was carried out. Postoperative course was uneventful. The patient has been well for 22 months after the operation.

Adult↗
PubMed1996

Coronary artery bypass grafting with both internal thoracic arteries and the right gastroepiploic artery.

From July 1989 to March 1995, 83 patients (79 men, 4 women, mean age 58.3 years, range 35 to 76 years) underwent coronary artery bypass grafting with the both internal thoracic arteries (ITAs) and the right gastroepiploic artery (RGEA). Postoperative follow-up ranged from one to 69 months with a mean of 31 months. Seventy-eight patients (94%) had either triple vessel disease or left main disease. A total of 264 distal anastomoses with arterial grafts were constructed; 90 with the left ITA, 73 with the right ITA, 90 with the RGEA and 1 with the inferior epigastric artery (IEA). An additional saphenous vein graft was constructed in 13 patients including 4 sequential bypass grafting. The mean number of distal anastomoses was 3.4. Postoperative angiography was performed in 80 patients (96%) 3 to 4 weeks after the operation. There were no operative deaths or hospital deaths. No patients developed perioperative myocardial infarction. Graft patency in arterial grafts was 96% (242/253), 95% (80/84) in the left ITA, 100% (82/82) in the right ITA and IEA (1/1), and 93% (80/86) in the RGEA. Graft patency in vein grafts was 99% (84/85) and overall patency rate was 96% (326/338). Four patients (5%) died during follow-up period but all were non-cardiac deaths. Six postoperative percutaneous transluminal coronary angioplasties (PTCA) (7%) and two reoperations (re-CABG) (2%) were required, but no patients developed myocardial infarction (MI). The 5-year actuarial survival rate and cardiac event (cardiac death, MI, PTCA, and re-CABG) free rate was 90.1% and 86.6% respectively. In conclusion, the clinical outcome of the coronary artery bypass grafting with the both ITAs and RGEA was satisfactory in terms of low operative risk, high patency rate, and excellent long-term results.

Abdominal Muscles↗
PubMed1996

Aortic valve replacement in small aortic annulus with or without annular enlargement.

BACKGROUND AND AIMS OF THE STUDY: Surgical treatments for aortic valve disease in the presence of a small aortic annulus need appropriate indications for operative procedures and precise selection of valve prostheses. The objective of this study was to compare long term results after aortic annular enlargement with those after operation using a small valve prosthesis. MATERIALS AND METHODS: Since 1980, 45 patients with small aortic annulus underwent operation at our institution. There were six men and 39 women, and their ages ranged from 16 to 69 with a mean of 45.6 years. Of these patients, 28 underwent aortic annular enlargements (Nicks' procedure in 13, Manouguian's in 12 and apico-aortic bypass in three patients) and 17 patients received standard aortic valve replacement with a small valve prosthesis (19 mm Standard St. Jude Medical). Mean follow up was 8.6 years in the enlargement group and 4.9 years in the standard group. RESULTS: Early mortality was 3.6% (1/28) in the enlargement group and 5.9% (1/17) in the standard group (NS). The 10-year actuarial survival including all deaths was 85.7% in the enlargement group and 62.7% in the standard group (p < 0.10). The rate of freedom from reoperation at 10 years was 90.7% in the enlargement group and 93.8% in the standard group (NS). The 10-year freedom from all valve-related events was 81.0% in the enlargement group and 58.8% in the standard group (p < 0.05). CONCLUSIONS: The above results suggest that long term mortality and morbidity after aortic annular enlargement might be superior to those after standard AVR with a small valve prosthesis.

Adolescent↗
PubMed1996

[Long-term results of cardiac valve replacement with a Delrin-disk model of the Björk-Shiley valve prosthesis--comparative analysis with the Spherical-disk model].

Records from 99 patients who received the Delrin-disk model (Group D) of the Björk-Shiley (BS) prosthesis between December, 1971 and November, 1974 were reviewed and compared to those from 248 patients who received the Spherical-disk model BS between January, 1975 and June, 1981 (Group S). Complete follow-up was obtained in 98.8% of the patients. The follow-up was over 1302.3 patient-years (mean 13.2 years per patient) in Group D and 2967.5 patient-years (mean 12.0 years per patient) in Group S. Early mortality was not significantly different (Group D: 18.2%, Group S: 10.5%). Of 15 late deaths in Group D, 12 (60%) were valve related and of 58 late deaths in Group S, 34 (58.6%) were valve related. The survival proportion based on Kaplan-Meier analysis, and which included early deaths, was equivalent in both groups (Group D: 65.7% at 21 years, Group S: 64.8% at 18 years). The freedom from reoperation was 74.3% at 21 years for Group D and 95% at 18 years for Group S (p < 0.005). The incidence of prosthetic valve dysfunction in Group D was significantly higher than that in Group S during 15 years after insertion of the valve. The freedoms from thromboembolism and valve-related events were not significant in both groups. Gross examination of the explanted Delrin disk found wear indentations and excessive clearance between the disk and the prosthetic ring. Therefore, disk wear was the primary cause of prosthetic valve dysfunction for the Delrin model. These results suggest that patients with the Delrin-disk model of the Björk-Shiley prosthesis should receive close follow-up for structural integrity of the valve. Further, reoperation might be needed due to significant valve dysfunction in this group of patients.

Adolescent↗
PubMed1996

[Cerebral oxygen desaturation during rewarming in retrograde cerebral perfusion with total circulatory arrest].

To evaluate cerebral oxygen desaturation during retrograde cerebral perfusion with total circulatory arrest (RCP), we measured cerebral oxygen extraction (O2 Ext), and arterio-venous oxygen differences (AV DO2) during and after RCP and compared the results with usual cardiopulmonary bypass (CPB) using continuous jugular blood saturation (SjO2) monitoring. In the RCP group, 7 patients underwent aortic arch replacement with RCP and in the CPB group, 4 patients underwent valvular surgery with CPB. A 5.5 Fr oximetric catheter was placed in the jugular bulb and cerebral venous and radial arterial blood were sampled. Oxygen partial pressure and saturation were measured at six intervals from cerebral venous and radial arterial blood. Measurements were taken at the following phases: phase I: before ECC was established, phase II: immediately after ECC started; phase III: at hypothermia (18 degrees C in the RCP group and 28 degrees C in the CPB group), phase IV: during rewarming (30 degrees C), phase V: after rewarming (36 degrees C), phase IV: immediately after weaning from ECC. All 11 patients survived without neurological complications. The minimum SjO2 of continuous monitoring during rewarming in the RCP group was significantly lower than in the CPB group. AVDO2 in the RCP group was also significantly higher than in the CPB group during rewarming. O2 Ext in the RCP group was significantly higher than in the CPB group during and after rewarming. Differences in glucose utilization during and after rewarming were also detected. Moreover, to determine factors that influence SjO2 during and after rewarming, we evaluated correlations with arterial PaCO2, arterial pH, and rewarming duration. There were significant (p < 0.05) correlations between SjO2 and PaCO2 in phase IV and phase V, between SjO2 and pH, and between SjO2 and rewarming duration. In conclusion, continuous SjO2 measurements reflected cerebral oxygen desaturation during and after rewarming in RCP. In RCP, significantly greater desaturation during and after rewarming was detected than in CPB. Therefore we suggest that relatively slow rewarming, higher PaCO2, and more acidic pH strategies were advantageous for preventing desaturation during and after rewarming in RCP.

Adult↗
PubMed1996

[Current status and future prospect of organ transplant network in Japan].

Transplant network plays a indispensable role in the organ transplantation, which consists of the registration of patients, collection of donor information, recipient selection and shipping of the organs, retrieval of transplant data and their analysis. Since 1977 the cadaveric kidney transplantation have had been done in the kidney transplant network, which was run by National Sakura Hospital as the transplant center and 14 subcenters. As the number of cadaveric kidney transplantation, however, was decreased year by year since 1989, there raised some problems, such as allocation policy of kidney grafts, lack of standardized HLA examination and review system, management within each administrative district and so on. Based upon the report of ad hoc committee of the Multiorgan Transplant Network, there substituted the new kidney transplant network system, Japan Kidney Transplant Network for the former kidney transplant network since 1995. The new system is operated not only by transplant surgeon, but by transplant coordinators, nephrologists, doctors in charge of dialysis therapy, representatives of kidney bank and other organizations/associations, and others. After the legislation of the transplant act, the network will be reorganized into the network system for multiorgan sharing. To establish the multiorgan sharing network, uniform protocol of multiorgan procurement, insurance of informed consent, propagation of donor cards for multiorgan donation, registration for waiting lists, allocation system for other organs than kidney, and education of transplant coordinator for multiorgan procurement are required.

Forecasting↗
PubMed1995

Role of ADF/TRX and its inhibitor on the release of major basic protein from human eosinophils.

Adult T cell leukemia-derived factor (ADF)/Thioredoxin (TRX), originally defined as an IL-2 receptor alpha-chain/p55 inducer, has many cytokine-like activities. We reported that the release of major basic protein (MBP) from mature eosinophils stimulated with cytochalasin B and C5a were augmented after preincubation with recombinant ADF/TRX. The addition of a TRX specific inhibitor, BE40644, suppressed the augmentation of MBP release from mature eosinophils. It is suggested that BE40644 is applicable in allergic diseases associated with eosinophils.

Benzoquinones↗
PubMed1995

Do isolated gastric mucosal surface cells from rabbits secrete HCO3-?

Only indirect observations suggest that gastric surface cells secrete HCOH3-, which, if the case, should result in an alteration of intracellular pH. This study attempts to determine if HCO3- transport is notable in intracellular pH regulation by isolated surface cells. Maintenance of cellular pH during perfusion with HCO3(-)-free Ringer's solution is unaffected by either the absence of Cl- or the presence of an inhibitor of HCO3- transport, 4,4'-diisothiocyanostilbene-2-2'-disulfonate (DIDS). This implies the absence of Cl-/HCO3- exchange and HCO3- transport related to Na+. Addition of HCO3-/CO2 to the perfusate results in acidification due to CO2. The pH then drifts upward, which is prevented by amiloride, an inhibitor of Na+/H+ exchange. Calculated H+ efflux is not significantly affected by HCO3-/CO2. Removal of HCO3-/CO2 results in alkalinization, which is unaffected by the absence of Cl-. Alkalinization following HCO3-/CO2 removal is significantly impaired by acetazolamide. Once alkalinization occurs, the pH declines slowly and is unaffected by a Cl(-)-free perfusate or amiloride or conductance but is markedly accelerated by a Na(+)-free perfusate. The latter is prevented by amiloride but not by DIDS. Thus, under isolated conditions, gastric mucosal surface cells do not appear to be a major source of HCO3- secretion. Alkalinization of the cells can occur as a result of carbonic anhydrase activity, but the alkalinization is maintained by an extracellular Na+ gradient that prevents exchange of intracellular Na+ with extracellular H+.

Amiloride↗
PubMed1995

Long-term results of aortic valve translocation for mycotic periannular abscess: comparative study of Danielson's original method and our threadless method.

Between June, 1983, and October, 1992, we performed Danielson's original translocation method in four patients (group I) and our translocation method in seven patients (group II), for the treatment of active periannular abscess. There were no perioperative or hospital deaths in either group. The long-term results of these two groups are compared in this report. There were four late deaths (mortality rate 100%) in group I, and three late deaths (mortality rate 43%) in group II. The causes of death were cardiac in six patients and noncardiac in one patient. Vein graft failure occurred in one group I patient (25%) and in two group II patients (28%). Rupture or aortic pseudoaneurysm formation occurred in three group I patients (75%). These findings suggest that our threadless method may be superior to Danielson's original translocation method. Therefore, with close observation, especially of saphenons vein great (SVG) failure, arterial graft use could be acceptable for translocation.

Abscess↗
PubMed1995

Operation for type A aortic dissection: introduction of retrograde cerebral perfusion.

Circulatory support during operation for type A aortic dissection is controversial among many medical centers. In the last 21 years, 100 patients with type A aortic dissection underwent 102 operations including 2 reoperations, and 29 patients showed Marfan's syndrome. During operation, no cerebral perfusion technique was used through February 1985 (period I), antegrade cerebral perfusion was applied since March 1985 (period II), and retrograde cerebral perfusion was introduced in November 1990 (period III). Surgical results were compared among these subgroups. Operative mortality was 12.1% in 33 chronic and 57.1% in 7 acute patients in period I, 11.1% in 27 chronic and 54.5% in 11 acute patients in period II, and 6.7% in 15 chronic and 0% in 9 acute patients in period III (period II versus III; p = 0.04). Retrograde cerebral perfusion decreased permanent brain complications. The 5-year actuarial survival was 59.7% in period I and 63.2% in period II (not significant), and the 3-year survival of period III was 91.7%. Actuarial survival of period III was significantly higher than those of periods I and II (p < 0.05). Surgical repair of aortic arch with cerebral perfusion techniques reduced the residual aneurysms. These results show that surgical results of type A aortic dissection in this series improved with the introduction of retrograde cerebral perfusion and extended surgical procedures.

Adult↗