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Biomedical subjects

Y Sasako

Publications and source records attributed to Y Sasako.

At least 73 records · Page 4Linked to original sources
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

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↗
PubMed1994

[Clinical analysis of second CABG].

We performed 1,560 coronary artery bypass grafting (CABG) at National Cardiovascular Center between November 1977 and August 1993. Of those, 41 patients received second CABG, 2 pts. received third CABG and 97 pts. received percutaneous transluminal coronary angioplasties (PTCA). We conducted a retrospective analysis of these patients to determine whether a previous CABG or CABGs affects the results. The hospital death rate was 10% (4/41) for re CABG, 50% (1/2) for third CABG and 0% for PTCA. In second CABG, 3-year cardiac event free rate was 58-68%, and early graft patent rate for new native lesion was high (97%, 28/29). However, the rate was low in graft to the site of the vessel which had occluded within 3 months after first CABG (59%, 7/12). Emergent or urgent operations performed in 14 cases (34%). In PTCA for SVG lesion (33 pts.), 14 (42%) patients received re PTCA and 6 (18%) had second CABG. These data indicated that the results of second CABG were affected by timing of the operation and the site of grafting. We believed that re operation to early occlusion site within 3 months should be performed carefully and further investigation is warranted.

Angina Pectoris↗
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↗
PubMed1992

Clinical experience of mitral valve reconstruction with artificial chordae implantation.

To expand the application of mitral valve reconstruction for pure mitral regurgitation due to diffuse leaflet prolapse, we have employed artificial chordae implantation using GPEP strips in 9 patients and 4-0 PTFE sutures in 20 patients since November 1986. The total number of GPEP strips implanted was 20 with a range from 1 to 4 (average 2.2 per patient) and 45 pairs of PTFE sutures with a range from 1 to 6 (average 2.3 per patient). There was one hospital death (3.4%). All other patients survived operation without valve-related complications except 1 patient who required reoperation for failure of mitral valve reconstruction. In 27 survivors free from reoperation, the amount of mitral regurgitation assessed postoperatively was none or trivial in 19 patients, mild in 7 and moderate in 1. All 27 patients improved to NYHA functional class I or II. So far, our results were no less acceptable than those with conventional procedures for mitral valve prolapse.

Adolescent↗
PubMed1992

[Mitral valve surgery for patients after undergoing percutaneous transvenous mitral commissurotomy (PTMC)--investigation on indication of PTMC based on the intraoperative findings].

Ten patients underwent open heart surgery for mitral valve after PTMC because of post PTMC MS (n = 4) and MR (n = 6) out of 150 patients undergoing PTMC in our hospital between June 1987 and October 1991. Intraoperative findings of 4 patients with residual mitral stenosis included severe thickening, stiffening and calcification on anterior and posterior leaflets, commissures and subvalvular apparatus. Mitral valve repair was possible in 2 and mitral valve replacement (MVR) was necessary in the other 2. In all 6 cases who massive mitral regurgitation after PTMC, in repairable tears in the mitral leaflets necessitated MVR. Since in these cases changes in the leaflets were less severe than those of the commissures or subvalvular apparatus, surgical repair could have been possible if open mitral commissurotomy (OMC) was done primarily. Patients selection for PTMC versus OMC based on precise morphological evaluation of mitral valve would reduce occurrence of massive MR resulting in surgical replacement.

Adult↗
PubMed1992

Determination of optimal perfusion flow rate for deep hypothermic cardiopulmonary bypass in the adult based on distributions of blood flow and oxygen consumption.

To determine the optimal perfusion flow in deep hypothermic cardiopulmonary bypass at 20 degrees C in human beings, we studied the relationship of perfusion flow to the whole body and to regional oxygen consumption. In adult patients (n = 11, average age 54 years) with valvular or coronary heart disease, the distributions of perfusion flow rate and oxygen consumption were analyzed by dividing into the superior and inferior vena caval areas. Measurements (n = 39) were made at various perfusion flow rates (perfusion flow rate in the superior vena caval area plus that in the inferior vena caval area equals whole-body perfusion flow rate: 0.4 to 2.2 L/min/m2) in a setting of average hemoglobin levels of 8.1 gm/dl. Between whole-body perfusion flow rate and oxygen consumption (total oxygen consumption equals superior plus inferior vena caval oxygen consumption), there was a hyperbolic correlation (r = 0.73; p less than 0.001; asymptote = 29.0 ml/min/m2). A positive linear correlation was found between whole-body perfusion flow rate and inferior vena caval oxygen consumption (r = 0.75; p less than 0.001), whereas no significant relation was seen between whole-body perfusion flow rate and superior vena caval oxygen consumption. For distributional changes in inferior vena caval perfusion flow rate/whole body perfusion flow rate and inferior vena caval oxygen consumption/whole body oxygen consumption, the broken-line regression analysis showed respective critical points where both parameters started to drop when whole-body perfusion flow rate was gradually reduced: 1.2 L/min/m2 for inferior vena caval perfusion flow rate/whole-body perfusion flow rate and 0.8 L/min/m2 for inferior vena caval oxygen consumption/whole-body oxygen consumption. The results indicate that (1) the oxygen consumption to the superior vena caval area was maintained independent of the perfusion in a relatively wide range in contrast to that for the inferior vena caval area and (2) when the redistribution of oxygen consumption is considered as undesirable under low-flow perfusion, the optimal perfusion flow for 20 degrees C deep hypothermic cardiopulmonary bypass appeared to be 0.8 L/min/m2.

Adult↗
PubMed1992

[Long-term follow-up of exercise tolerance after coronary bypass grafting].

Six hundred forty-eight serial graded exercise tests were performed on 400 patients up to 10 years after coronary bypass graftings (CABG). The maximal attained exercise tolerance, over 10 METS, were observed in 60% of patients and the negative response to exercise test in 43% of patients. The positive response in various parameters were observed at the following rates: graft occlusion-30% vs graft patent-46% (p less than 0.01); incomplete revascularization-39% vs complete revascularization-22% (p less than 0.01); and less than or equal to 8 METS 4-45% vs greater than or equal to 10 METS-28% (p less than 0.01), respectively. However, no significant difference was observed among number of vessels diseased, number of graftings, and presence of old myocardial infarction. The maximal attained stage of exercise, over 10 METS, in various parameters were at the following rates: less than or equal to 59 years old-70% vs greater than or equal to 60 years old-44% (p less than 0.01); male-63% vs female-32% (p less than 0.01); and graft patent-63% vs graft occlusion-50% (p less than 0.05), respectively. The serial analysis of exercise test demonstrated that improved exercise tolerance appears to persist for at least 5 years after CABG. However, the patients in complete revascularization had a tendency to increase the rate of positive response. In conclusion, the completeness of revascularization as well as graft patency was the main factor limiting exercise tolerance, and correlates with the extent and the duration of improvement after CABG.

Coronary Artery Bypass↗
PubMed1991

[Invasive treatment in patients with prior coronary artery bypass grafting].

In eight hundred eighty three patients with prior coronary bypass grafting (CABG), cardiac symptoms were recurred in 179 patients in late follow-up period (mean 5 +/- 2.8 years). Of 179 patients, 43 patients had PTCA eventually. In these, 57 times of angioplasties were attempted. Twenty-one lesions in venous bypass grafts and 50 in native coronary arteries were performed, respectively. The initial success rate per bypass graft and per stenosis of native coronary artery were 68% and 74%, respectively. Five patients had elective CABG following failed PTCA. There were no emergency CABG procedures required after unsuccessful PTCA. Intracoronary thrombolysis (ICT) were performed in 13 patients. In these, 15 ICT attempts were made. Nine lesions in venous bypass grafts, 9 for native coronary arteries, and 3 for both were attempted. The primary success rate per occlusion was 67%. Twenty reoperation were done. There was one hospital death and one late death due to congestive heart failure 4 years after the reoperation. In conclusion, invasive treatments in patients with prior CABG can be performed with satisfactory safety and good results. Therefore, invasive treatment should be considered in the patients with CABG if cardiac symptoms are disabling and angiographically suitable lesions are present in the native coronary arteries or vein grafts.

Aged↗
PubMed1990

[Optimal perfusion criteria for deep hypothermic selective cerebral perfusion in patients with aortic aneurysm involving aortic arch].

Although selective cerebral perfusion (SCP) might be an useful supportive method for aortic arch surgery, its optimal perfusion criteria has not been established. We studied the relationship between the oxygen saturation of superior vena cava or internal jugular vein (SvO2) and the perfusion hemodynamics during deep hypothermic (DH) SCP in twenty patients (pts) (type A dissection; 10, arch aneurysm; 10). SCP was accomplished by perfusion to the brachiocephalic trunk (BCT) and the left common carotid artery (LCC) using separate pumps. Cardiopulmonary bypass and DHSCP time were 128-312 (222 +/- 43, mean +/- SD) minutes and 25-214 (122 +/- 49) minutes, respectively. The cerebral perfusion pressures (CPP) monitored at the bilateral temporal arteries were 20-60 (47 +/- 9) mmHg and cerebral perfusion flow (CPF) was 0.28-0.7 (0.43 +/- 0.10) L/min/m2. The cerebral perfusion score (CPS) defined as CPP X CPF was 7-39 (20 +/- 8). SvO2 ranged from 79 to 99 (94 +/- 7)%. Two operative deaths were encountered from unrelated causes to SCP in both cases. Cerebral infarction occurred in one patient possibly form prolonged low perfusion with low SvO2. When the safety range of SvO2 in DHSCP was defined as greater than 90%, essential criteria to keep this range was CPP greater than 40 mmHg. In 13 out of 15 pts with SvO2 greater than 90%, CPS were above 15. In conclusion, optimal perfusion criteria for DHSCP was defined as CPP greater than 40 mmHg and CPS(CPP X CPF) greater than 15 considering adequate cerebral oxygen consumption.

Adult↗