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Biomedical subjects

Y Kosakai

Publications and source records attributed to Y Kosakai.

At least 73 records · Page 4Linked to original sources
PubMed1995

[Surgical treatment and long-term results of cardiac myxoma in 38 patients].

Long-term results of thirty-eight patients with cardiac myxoma, who underwent resection at National Cardiovascular Center between May, 1978 and December, 1993, were reviewed focussing on embolism, cerebral complication, tumor recurrence and metastasis. The mean age was 49.6 years (range 0 to 74) in 20 female and 18 male. Overall follow-up were known for 35 of 38 patients (92.1%), and an average of follow-up period was 6.7 years (range 0.5 to 15.9 years). 15 of 38 patients (34.2%) had embolism (brain 10, peripheral artery 4, coronary 1) preoperatively. All patients survived operation and the hospital mortality rate was 0%. Long-term results were almost satisfactory (myxoma related-death in one patients). However, distant metastasis occurred in two patients, and tumor recurrence in one patient irrespective of a presence of preoperative embolism. Cerebral embolism occurred in one patient and cerebral arterial lesins were noticed in five patients postoperatively. Cardiac myxoma has a malignant potentiality and a close follow-up is necessary about recurrence, metastasis and cerebral artery disease.

Adolescent↗
PubMed1995

[Results of coronary artery bypass grafting in dialysis patients].

To determine the short- and medium-term results of coronary artery bypass grafting (CABG) in dialysis patients, we analyzed a group of 14 patients with chronic renal failure who underwent CABG between May 1990 and October 1994. Two patients had concomitant valve repair for mitral regurgitation. Hospital mortality was 14% (2 out of 14). These two patients died of ileus due to ischemic colitis and agranulocytosis respectively. There was one late death from stroke. The four significant postoperative complications (morbidity 29%) were composed of two sternal dehiscence, one cardiac tamponade because of bleeding, and one perioperative myocardial infarction. Graft patency rate was 97% (34 out of 35 in 13 patients) within one month. Actuarial survival was 86% at one 1 to 3 years, and 43% at 3 and a half years. This rate is not significantly different from all dialysis patients, but night be better than dialysis patients with coronary artery disease who had not undergone CABG in the previous reports. Left ventricular size is larger in patients who died or who had significant complications in hospital than in patients with uneventful postoperative course. Cardiac arrest time, cardiopulmonary bypass time, chest tube output, and the amount of transfusion might be also related to mortality and morbidity though statistically not significant.

Aged↗
PubMed1995

[Evaluation of surgical procedures based on the types of hypertrophied obstructive cardiomyopathy].

The surgical procedures were reviewed based on the types of hypertrophied obstructive cardiomyopathy in 20 patients. The patients were classified in three groups: (1) Asymmetric septal hypertrophy (ASH), (2) Atypical or diffuse concentric hypertrophy (DIF), (3) Mid ventricular obstructive hypertrophy (MID). Among 11 patients with ASH, the ventricular septal myotomy (My) or the myotomy-myectomy (Mye) were performed in 9 patients and MVR was performed in 2 patients. Among 6 patients with DIF, My or Mye were performed in 4 and MVR was performed in 2. All three patients with MID were treated with MVR. The intraventricular systolic pressure gradient greater than 40 mmHg was still existent postoperatively in one ASH patient on whom Mye was performed and in 3 DIF patients on whom My or Mye were performed. The four patients had III degree mitral regurgitation preoperatively and were successfully treated. The postoperative NYHA functional class became II or less in all patients. For ASH, the My was effective in 9 patients except one earlier patient. For DIF, further consideration of surgical procedure might be required. For MID, a MVR is recommended.

Adult↗
PubMed1994

Prediction of postoperative exercise tolerance after aortic valve replacement.

Valve size selection for aortic valve replacement is still a controversial matter, particularly in patients with small aortic annuli. To assess optimal valve size, exercise capacity, as measured by peak oxygen consumption levels, was determined in 39 patients (age range, 18 to 77 years; mean, 56 years) who underwent isolated aortic valve replacement with a St. Jude Medical valve. This assessment was carried out at a mean of 2.2 years post-operatively using ergometer exercise testing. These levels were evaluated as a measure of the percentage of predicted. At rest, there was no significant correlation between the predicted peak oxygen consumption and the pressure gradients across the prostheses, as measured by Doppler ultrasound. In 18 patients with aortic regurgitation, the preoperative dimensions of the left ventricle in end-diastole and end-systole correlated inversely (p < 0.05) with the percentage of predicted peak oxygen consumption. In 21 patients with aortic stenosis, the linear regression line (p < 0.01) was derived from the correlation between the percentage of predicted peak oxygen consumption and the valve area index (geometric valve orifice area/body surface area). We conclude that the preoperative end-systolic and end-diastolic dimensions should be less than 50 mm and 70 mm, respectively, in the setting of aortic regurgitation, and a valve area index, though it proved to be weakly correlated with the percentage of the peak oxygen uptake, should probably be more than 1.5 cm2/m2 in the setting of aortic stenosis to achieve good exercise capacity postoperatively (> 80% of predicted peak oxygen consumption).

Adolescent↗
PubMed1994

[A case of aortitis operated twice Bentall's operation due to valve (graft) detachment].

A 40-year-old man had received emergency Bentall's operation due to acute aortic regurgitation (AR) of aortitis in October, 24, 1990. On out patient clinic, the CRP had been kept from 0.5 to 1.5 mg/dl in dose of 10 mg of prednisolone. In the midnight of November, 17, 1992, his condition deteriorated to circulatory shock and echocardiography revealed massive AR due to para-annular graft detachment with large pseudoaneurysm of 50 mm. He was transferred for emergency operation. The composite graft shifted 2-3 cm above the annulus and detached in three quarter of the annulus. Distal anastomosis was also detached in half of anastomosis and coronary anastomosis almost detached. He was operated on modified Bentall's operation employing Piehler's technique and he is now followed in dose of 10 mg of prednisolone. There are some cases of aortitis showing recurrent valve or graft detachment like this case, even if modified Bentall's operation have been done to decrease the mechanical stress to the annulus and the inflammation have been controlled under the dosage of steroid.

Adult↗
PubMed1994

Comparison of repair techniques for mitral valve prolapse.

Between January 1978 and September 1992, 127 patients with isolated mitral regurgitation due to prolapse underwent mitral valve reconstruction. There were 74 men and 53 women whose mean age was 49.7 years, ranging from 16 to 74 years. Follow up was 99.2% complete and totaled 483.0 patient-years (mean: 3.8 years). One hundred and forty-eight procedures were carried out to repair the prolapses using four types of techniques: (1) leaflet plication in 97 patients; (2) artificial chordal replacement with polytetrafluoroethylene sutures in 30 patients; (3) chordal shortening in 16 patients; and (4) commissural imbrication in five patients. In order to repair the annular dilation, commissural plications were done in 75 and ring prostheses were implanted in 15 patients. There were one hospital and eight late deaths. One (cerebral infarction) of all deaths was related to the reconstructed mitral valve. There were 14 reoperations (11.0%) for recurrent mitral incompetence with a freedom from reoperation of 89.0% at five, and 81.1% at 10 years. There were four cases of thromboembolism (one fatal, three non-fatal) with freedom from thromboembolism of 96.7% at five, and 93.3% at 10 years. No endocarditis or hemorrhagic complications were noted. Linearized incidence of recurrent mitral regurgitation according to repair technique for the prolapse was 1.44%/pty in the leaflet plication series, 1.45%/pty with chordal replacement, 4.37%/pty after chordal shortening and 8.67%/pty following commissural imbrication. The linearized rate of failure in annuloplasty was 2.91%/pty after commissural plication and 1.74%/pty after ring annuloplasty. Statistically significant difference was confirmed only between leaflet plication and chordal shortening.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Cox maze procedure for chronic atrial fibrillation associated with mitral valve disease.

Between April 1992 and October 1993, we combined a modified maze procedure with mitral valve repair (n = 26) or replacement (n = 36) in 62 patients with atrial fibrillation, including 16 patients undergoing reoperation. Associated procedures included aortic valve operation (n = 22), tricuspid annuloplasty (n = 28), atrial plication (n = 10), and others (n = 3). Duration of atrial fibrillation varied from 0.1 to 23 years (average 8.3 +/- 6.4 years), the f-wave voltage ranged from 0 to 0.45 mV (0.16 +/- 0.09 mV), and cardiothoracic ratio varied from 46% to 85% (64% +/- 9%). We modified the maze atriotomies to preserve the sinus node artery and used cryoablation to simplify procedures. Aortic crossclamp time was 142 +/- 25 minutes and cardiopulmonary bypass time 226 +/- 34 minutes. No early or late deaths occurred in a total of 783 patient-months of follow-up. In 52 patients (84%) who regained atrial rhythm, an atrial A-wave was detected in 84% for transtricuspid flow and in 71% for transmitral flow. One patient with sinus rhythm had an episode of transient neurologic ischemia 4 months after mechanical valve implantation. The 10 patients who remained in atrial fibrillation had preoperative fibrillation for a significantly longer time than the rest of the patients with atrial rhythm (14.8 versus 7.2 years p < 0.001) and a larger left atrial dimension (70 versus 58 mm, p < 0.01). Nonetheless, no variable alone could have predicted postoperative rhythm for individual patients. The results suggest that the maze procedure is safe and effective and therefore should be considered for patients with chronic atrial fibrillation undergoing mitral valve operations.

Adult↗
PubMed1993

The clinical significance of reactivity to individual epitopes of the hepatitis C viral genome.

In order to analyze the clinical significance of the various HCV epitopes, we compared the results of different HCV specific assays with HCV-RNA, determined in serum by RT-PCR method using primers to the 5' untranslated region of HCV-RNA. Among 73 patients with chronic NANB liver disease, 93% were positive for C22-3, 96% for C33C, 81% for C100-3 and 91% for RT-PCR. Positivity rates for 537 healthy subjects were 1.7% for C100-3 and 2.9% for second generation anti-HCV. A total of 6 persons were positive for C22-3 but not C100-3; all were negative for HCV-RNA. In 11 of 30 patients treated with interferon and HCV-RNA became negative and remained so for more than 24 months. In these 11 sustained responders, C100-3 and C33C antibody declined progressively, but C22-3 antibody showed a little change after treatment by quantitative analysis. The discrepancy of changes to NS region and core region after interferon treatment is consistent with a different clinical significance of reactivities to these HCV epitopes. Thus negative reactivity to NS region but positive for core region among healthy subjects may indicate past infection with HCV. Presence of antibodies to NS epitopes is implicated in HCV replication, while core epitopes indicate both present and past HCV infection.

Antigens, Viral↗
PubMed1993

[A case of modified maze operation for atrial fibrillation accompanied by mitral stenosis].

A 45-year-old man suffering from mitral stenosis and atrial fibrillation underwent a mitral commissurotomy and received a modified maze operation. In order to preserve the sinus node artery, we used a new incision line differing from that of Cox and introduced a cryosurgery. After the operation, atrial fibrillation disappeared. The atrial kick was also clearly observed by the echocardiogram. We think that combined operations have advantage both to cure atrial fibrillation and to deal with the mitral valve easily.

Atrial Fibrillation↗
PubMed1993

[A case of primary cardiac hemangiosarcoma].

A case of primary hemangiosarcoma of right atrium was reported. The patient was 43 years old female. She had the symptoms of tamponade due to massive bloody pericardial effusion. Echocardiography, computed tomography, NMR imaging and angiography revealed the precise delineation and extension of tumor, and also allowed diagnosis of hemangiosarcoma. Extirpation of tumor was performed under the cardiopulmonary bypass. The patient was died 3 months later after the operation for liver metastasis. The bloody pericardial effusion seems to be an important symptom of the primary malignant cardiac tumor, and early and precise diagnosis may allow successful operation and long survival of the patients.

Adult↗
PubMed1993

[Clinical application of recombinant human SOD for the protection of ischemia reperfusion injury during open heart surgery].

We have applied recombinant human superoxide dismutase (RH-SOD) to prevent ischemia reperfusion injury in the patients who received open heart surgery. Twenty-four patients were divided into 2 groups; group A had no treatment as control and group B received bolus injection of RH-SOD (35,000 IU/kg) into cardiopulmonary bypass 5 minutes before reperfusion. Arterial and coronary sinus blood was collected to measure chemiluminescence (ChL) value, SOD activity, lactate and pyruvate level, and several parameters of myocardial oxygen metabolism after reperfusion. Arterio-venous difference of ChL value showed the tendency of less ChL generation of the heart in group B compared with those in group A. But no other parameters showed significant difference between the two groups. Our data suggested that this way of the administration of RH-SOD failed to improve the myocardial protection during open heart surgery. Further investigation, such as dose response study, might be required to determine whether RH-SOD possess beneficial effects or not in the clinical setting.

Heart Arrest, Induced↗
PubMed1992

Effects of intraaortic balloon pumping on mitral flow dynamics in patients with coronary artery bypass operations.

We evaluated the improvement in left ventricular function in 26 patients after coronary artery bypass grafting who were treated with intraaortic balloon pumping (IABP). Mitral flow velocity-time integral in the rapid filling phase (IntR) and that in the atrial contraction phase (IntA), the sum of IntR and IntA (IntR+IntA), and the ratio of IntA to IntR (IntA/IntR) were calculated with patients on and off balloon pumping (IABP ON-OFF test). IABP increased IntR and IntR+IntA, decreased IntA/IntR, and did not change IntA, suggesting that a decreased afterload or augmented coronary perfusion improves left ventricular relaxation. When the balloon inflated on every other beat (IABP 1:2 test), IntR and IntR+IntA increased without balloon assist, IntA/IntR decreased off IABP, and IntA did not change. The afterload reduction or augmented coronary perfusion on the previous beat with IABP might help ventricular filling on the next beat without balloon assist. A drastic decrease in IntR after IABP stopped indicated the need to continue IABP. Since the change in IntR during IABP ON-OFF test was significantly correlated with that in IntR during IABP 1:2 test, the change in IntR during IABP 1:2 test could help to predict the optimal time of weaning.

Aged↗