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Biomedical subjects

Y Kosakai

Publications and source records attributed to Y Kosakai.

At least 109 records · Page 6Linked to original sources
PubMed1990

[Late results of coronary bypass grafting in patients with concomitant multifocal arteriosclerotic vascular diseases].

Late results of coronary bypass graftings (CABG) in the patients with multifocal arteriosclerotic vascular diseases were reviewed. Between September 1978 and July 1989, 819 consecutive patients underwent CABG. There were 693 males and 126 females, mean ages 58 +/- 8.5 years. Of 819 consecutive patients underwent CABG, 95 patients had the coexistence of multifocal atherosclerosis (Group A). Seventy two patients had aortoiliac or femoropopliteal disease, and 29 patients had aortic aneurysm. The remaining 724 patients had no coexistence of multifocal atherosclerosis (Group B). The mean follow-up periods was 4.0 +/- 2.1 years, and the follow-up ratio was 99.4%. The 5- and 10-year survival rates were 80% and 52% in group A, and 92% and 82% in Group B, respectively. The 5- and 10-year free ratio from cardiac events were 79% and 42% in Group A, and 85% and 61% in Group B, respectively. The 5- and 10-year free ratio from noncardiac events were 53% and 38% in Group A, and 85% and 76% in Group B, respectively. The results showed that the coexistence of multifocal atherosclerotic vascular disease in patients underwent CABG significantly increase the ratio of noncardiac and cardiac events, and decreased life expectancy.

Aged↗
PubMed1990

[Clinical results of open heart surgery within 2 weeks after cardiogenic embolic stroke].

Fourteen patients, 5 with infective valvular disease (IVD), 7 with non-infective valvular disease (NVD) and 3 with LA myxoma, underwent open heart surgery within 2 weeks after cardiogenic embolic stroke because of uncontrolled heart failure or recurrent embolism. Fifty percent of patients experienced a second embolism within 2 weeks of the initial stroke. Preoperative brain CT revealed no hemorrhagic infarction in all patients. However, in 3 of 5 patients with IVD, who had large brain infarction, one patient died from massive brain edema and two patients from severe brain hemorrhage. The other 2 patients with IVD, who had small infarction, and the remaining 7 patients with NVD and LA myxoma, even having large or small infarction, recovered without any complications. From these results, we concluded that 1) Open heart surgery within 2 weeks after initial stroke was safe in patients with no brain infarction and small non-hemorrhagic infarction, 2) Patients with IVD should be treated surgically before embolic stroke, because mortality rate was so high even in patients with non-hemorrhagic infarction.

Adult↗
PubMed1990

[Influences of intra-aortic balloon pumping on superior mesenteric flow dynamics].

The influences of intra-aortic balloon pumping (IABP) on arterial flow of the superior mesenteric artery were assessed by Doppler echocardiography. The subjects were 13 patients postoperatively, requiring IABP support to control low cardiac output state, in which distal aspects of balloons were distal to the superior mesenteric artery. Superior mesenteric flow velocity integral in systole (IntS) and that in diastole (IntD) were measured from superior mesenteric flow pattern, and the sum of IntS and IntD (IntS + IntD) was calculated ON and OFF balloon pumping (IABP ON-OFF test). The same parameters were obtained with balloon inflating on every other beat (IABP 1:2 test); the cardic cycle with balloon assist was defined as "1:2 ON", and that without balloon assist was defined as "1:2 OFF". 1) IABP ON-OFF test. IABP increased IntS from 7.07 +/- 2.56 cm to 9.20 +/- 3.19 cm (p less than 0.05), IntD from 3.00 +/- 1.18 cm to 3.62 +/- 1.40 cm (p less than 0.05), and IntS + IntD from 10.07 +/- 3.48 cm to 12.82 +/- 4.04 cm. Cardiac output increased from 3.89 +/- 1.34 l/min to 4.24 +/- 1.64 l/min with IABP support. The increments in IntS, IntD and IntS + IntD with IABP are attributed, to a large extent, to an increase in cardiac output. 2) IABP 1:2 test. Without balloon inflation, IntS increased (1:2 ON; 7.16 +/- 2.91 cm, 1:2 OFF; 8.41 +/- 3.30 cm, p less than 0.05), and IntD decreased (1:2 ON; 3.51 +/- 1.60 cm, 1:2 OFF; 2.33 +/- 1.25 cm, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Vitamin A protects the small intestine from methotrexate-induced damage in rats.

A protective effect of vitamin A (VA) against cytotoxic antitumor drug-induced damage of rat small intestine was found. Oral administration of methotrexate (MTX) for the small intestinal mucosa of rats resulted in a severe histological change, whereas rats coadministered VA with MTX showed a histological status similar to that of control rats. The p.o. administration of MTX led to a decrease in the amounts of membrane proteins and lipids in rat small intestine and its brush border membrane. When administered p.o. with VA, this decrease failed to occur. The brush border membrane of MTX plus VA-treated rats, when monitored by the fluorescence of cationic safranin O and anionic 8-anilino-1-naphthalenesulfonic acid, was found to resemble that from control rats rather than that from MTX-treated rats. The in vitro permeation of MTX in the small intestine of MTX plus VA-treated rats was enhanced, in contrast with the decrease noted for MTX-treated rats. However, that of untreated rats was not affected by the presence of VA. Thus, VA is unlikely to affect the transport process of MTX directly. When administered p.o. with VA, MTX was absorbed effectively to the same or a slightly greater extent than when administered by itself. Consequently, it has been shown histologically, biochemically, physicochemically and physiologically that VA protects the small intestine from the damage induced by MTX.

Administration, Oral↗
PubMed1990

[Middle term follow-up and comparative study of valve replacement with four kinds of new model bovine pericardial xenografts].

Our early clinical experience (up to 4 year's follow-up) with four new pericardial xenografts were reviewed. During the period July 1983 to December 1986, 148 Ionescu-Shiley Pericardial Xenografts (ISL) in 130 patients, 68 Carpentier-Edwards pericardial xenografts (CEP) in 65, 32 Mitroflow pericardial xenografts (MF) in 29 and 36 Hancock pericardial xenografts (HP) in 29 have been implanted. The actuarial survival rates at 3.3 years are 89.9 +/- 2.7% for ISL, 92.3 +/- 3.3% for CEP, 93.1 +/- 4.7% for MF and 93.1 +/- 4.7% for HP. Fifteen cases of primary tissue failure (PTF) were caused in all groups but CEP. The actuarial free rates from PTF at 3.3 years were 92.9 +/- 2.4% for ISL, 100% for CEP, 95.5 +/- 4.4% for MF, 82.6 +/- 7.9% for HP. All bioprostheses explanted because of PTF showed commissural tears occurred at the top of the stent posts or at the edge of the stent. In this respect, it is the reason why the cases with CEP were free from PTF that CEP has been achieved to be improved its frame design. The incidences of prosthetic valve endocarditis were not different among these kinds of bioprosthetic valves. The free rates from thromboembolism at 3.3 years were 97.5 +/- 1.5% for ISL, 98.3 +/- 1.7% for CEP, 96.0 +/- 3.9% for MF and 88.7 +/- 6.1% for HP. There was no patient with CEP and MF suffered from thromboembolism with sinus rhythm. In comparison of these 4 valves, we conclude that CEP is useful clinically because of its satisfactory durability and antithrombogenicity.

Adult↗
PubMed1989

Change in small intestinal brush border membranes of rats following methotrexate administration.

Change in small intestinal brush border membranes of rats following methotrexate administration was monitored by the fluorescence spectra and polarization of the cationic fluorescent probe, safranin 0. Total protein content of brush border membranes of treated rats was less than that of control rats, whereas no significant difference in total sialic acid content of brush border membranes was observed between them. Thus, an apparent increase in the electronegative charge of brush border membrane vesicles per unit of membrane protein following methotrexate administration may possibly cause the change in fluorescence spectra and polarization of safranin 0.

Animals↗
PubMed1989

[Surgical treatment of rheumatic tricuspid valve disease].

The rheumatic tricuspid valve is relatively rare in this country. We report the study on surgical treatment of 27 patients with rheumatic tricuspid valve. Surgical procedure on 7 cases out of them was tricuspid valve replacement (TVR) with bioprosthesis and tricuspid valvuloplasty (TVP) was performed in the remaining 20 cases. There were two operative deaths in TVR group, however, there were no major complications, such as thrombosed valve, the valve dysfunction or prosthetic valve endocarditis in the remaining five cases after the operation. The method of TVP in twenty cases consisted of two Kay's TAPs, six tricuspid commissurotomies (OTC), ten OTC with Key's TAPs and two OTC with DeVega's TAPs. Doppler cardiography (DCG) revealed residual tricuspid regurgitation (TR) more than 3/4 degrees in 7 cases of TVP group immediately after operation. Moreover, the increment of residual TR was seen in 7 cases during the following period and TVR was performed in 3 cases out of these 7 cases. In conclusion, it is suggested that TVR may be preferred to TVP for the rheumatic tricuspid valve because of severe residual TR in many cases of TVP group.

Bioprosthesis↗
PubMed1989

[Comparative analysis of long-term results with porcine-aortic, bovine pericardial and tilting disc valves].

The three series with the first-generation valve prostheses were reviewed for long-term clinical evaluation in isolated aortic and mitral valve replacement. Hancock porcine xenograft was implanted in 71 patients from 1977 to 1979, ionescu-Shiley pericardial xenograft (standard model) in 271 patients from 1979 to 1983, and Bjork-Shiley tilting disc valve in 194 from 1978 to 1986. In aortic position, no any significant difference among three valve types could be demonstrated in the actuarial survival and freedom from thromboembolism and valve infection, while the actuarial freedom from valve dysfunction in lonescu-Shiley valve was significantly lower than that in other two valves. Björk-Shiley valve in mitral position showed satisfactory clinical performance in terms of valve-related complications and survival in comparison with two types of bioprosthetic valves. In our conclusion at present time, Björk-Shiley valve is suitable for the first choice of both aortic and mitral valve prostheses. In case of valve replacement with a bioprosthesis, however, porcine aortic valve is a better choice for aortic, and bovine pericardial valve likely for mitral replacement.

Aortic Valve↗
PubMed1989

[Results of tricuspid valve replacement using xenograft bioprostheses].

Thirty-two cases of tricuspid valve replacement were done with bioprostheses during the period from 1979 to 1986 at our institution. In these cases there were 19 cases of acquired valvular diseases, 10 cases of congenital types of heart diseases and other 2 cases were another genesis. Seven different kinds of bioprostheses were utilized: 30 were bovine pericardial xenografts and 2 were porcine xenografts. In postoperative hemodynamic study, right ventricular end-diastolic pressure and right atrial pressure significantly decreased after tricuspid valve replacement. RV ejection fraction were reduced but there was no statistic significance when compared to the preoperative data. There were 5 patients who showed postoperative atrio-ventricular block and two of them needed permanent pacemaker implantation. Six patients died in postoperative period and other 3 died in late follow-up period. However, these was no mortality directly related to prosthetic valvular failure. In follow-up study, there was no episode of valve thrombosis nor pulmonary embolism. Prosthetic endocarditis was not encountered during this observation period. One patient showed mild degree of tricuspid regurgitation who had severe pulmonary hypertension even after the operation. Based on our experience, we concluded that the bovine pericardial xenograft may be the best choice for the TVR because of its anti-thrombogenicity. However, mechanical valve will be better choice for the patients who are complicated with severe pulmonary hypertension.

Adult↗
PubMed1989

[Late onset of angina pectoris after coronary bypass surgery].

The repeat of angina pectoris of 598 patients with undergoing coronary bypass surgery during the years Jan. 1978 to Aug. 1987 was analyzed. The 5-year and 8-year survival rate was 88% and 84%, respectively. The 5-year and 8-year cardiac event free ratio was 91% and 83%, respectively. The 5-year and 8-year angina free ratio was 73% and 64%, respectively. The causes of repeat angina were graft occlusion in 42%, incomplete revascularization in 16%, progression of native coronary lesions in 28% and unknown in 14%, respectively. PTCR in 4 patients, PTCA in 8 patients and re-CABG in 8 patients were performed to relief from angina pectoris.

Adult↗
PubMed1989

[Late cardiac events of coronary bypass surgery].

The cardiac events of 598 patients undergoing coronary bypass surgery were analyzed. The hospital and late death was 4.9% and 3.8%, respectively. The late death were caused by cardiac events in 7 patients and non-cardiac events in 16 patients. Of 7 cardiac death, 5 patients were died of acute myocardial infarction (AMI), and 2 patients were died of congestive heart failure. 5-year survival rate, 5-year event free ratio, and 5-year non-cardiac event free ratio were 88%, 70% and 91%, respectively. Of 18 patients who suffered from AMI after operation, 5 patients died. The causes of AMI were grafts occlusion in 9 patients, progression of coronary lesions in 5 patients and unknown in 4 patients. PTCR, PTCA and rebypass surgery were performed in 4, 9 and 8 patients, respectively.

Adult↗
PubMed1989

[Surgical management of concomitant diseases of coronary and cerebral arteries--indication and late results].

Among 632 patients with isolated coronary artery bypass graftings (CABG), 77 patients had coexisting symptomatic or asymptomatic cerebrovascular diseases (group A). The other 555 patients had not concomitant cerebrovascular diseases (group B). Surgical and late mortality rate in group A and group B were 7.8%, 5.2%, and 6.4%, 3.6%, respectively. The late mortality rate in group A was significantly higher than those in group B. The cerebrovascular accident (CVA) rate in group A and group B were 5.2% and 1.3% in perioperative period, and 18.2% and 3.6% in late stage, respectively. The complication ratio of CVA after CABG were significantly higher in group A than those in groups B. In conclusion, the best surgical approach to the patients with combined coronary artery and cerebrovascular diseases who indicated CABG and extracranial to intracranial bypass graftinges (ECICG) were suggested as follows: 1) CABG is the first staged operation, if cerebrovascular disease is clinically stable. 2) ECICG for cerebrovascular disease is the first staged operation, if angina pectoris is clinically stable. 3) ECICG should be started in the first stage under the assist with IABP if both diseases in the crisis, and wait few days to perform CABG in the second stage, if possible. The simultaneous approach of CABG and ECICG should be the last of choice.

Cerebral Revascularization↗
PubMed1988

[Orthopedic local treatment of metastatic bone tumor].

Since 1971, we have treated 76 patients with metastatic bone tumor. Forty-eight of 76 cases were treated surgically. In 34 cases, removal of metastatic foci of the spine was attempted from the anterior and/or posterior approach. In the remaining 14 cases, resection of the tumor with or without prosthetic replacement, osteosynthesis, or amputation was performed according to the site of bone metastasis. In cases of spinal metastasis, if foci were located anteriorly, resection and replacement of vertebral body by ceramic spacer and/or bone cement was effective for both relief of pain and reduction of paralysis. If foci were located posteriorly, however, the results of simple laminectomy were poor, and those of spinal instrumentation in addition to laminectomy were satisfactory. In the treatment of metastatic foci of pelvis, scapula and long bone, the results of orthopedic surgery were satisfactory, because relief of pain and maintenance of function were achieved in almost all cases. From the standpoint of prolongation of life, 15 out of 76 cases (20%) were alive with or without disease; 13 of them were treated not only surgically but also by radiation and/or chemotherapy.

Adult↗