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Biomedical subjects

Y Shimazaki

Publications and source records attributed to Y Shimazaki.

At least 217 records · Page 12Linked to original sources
PubMed1984

Transaortic closure of ventricular septal defect in atrioventricular discordance with pulmonary stenosis or atresia. Results in five patients.

In five patients (aged 5 to 11 years) with atrioventricular discordance, pulmonary stenosis or atresia, and origin of the aorta from the right ventricle, transaortic closure of the ventricular septal defect was performed. Double-outlet right ventricle was confirmed in four patients. All patients underwent placement of an extracardiac valved conduit from the anatomic left ventricle to the pulmonary artery. Neither operative death nor postoperative complete heart block resulted. Postoperative follow-up periods were from 3 months to 4 years (average 35 months), and one patient who had no evidence of complete heart block died suddenly 2 years postoperatively. Aortic regurgitation developed in two patients from possible trauma during the operation: Regurgitation was mild (causing symptoms) in one patient who had had poor surgical exposure with a subpulmonic ventricular septal defect and a well-developed subaortic conus; it was trivial (asymptomatic) in the other patient. Transaortic ventricular septal defect closure, suturing a patch on the anatomic left ventricular side in patients with atrioventricular discordance and double-outlet right ventricle or similar anomalies, might help to avoid postoperative complete heart block if the aorta is large and the subaortic conus is not well developed.

Aorta↗
PubMed1984

[Reconstructive valve surgery in congenital heart disease].

As part of various defects in congenital heart disease, valvular lesions are frequently encountered and remain as one of the difficult subjects. Recent advances in the management of valvular lesions and late results of repair and replacement were reported. In congenital aortic stenosis, most of patients have obtained satisfactory results with valvotomy, but some required reoperation with valve replacement even during childhood. In supracristed VSD associated with aortic regurgitation, late recurrence of regurgitation was found in some, but 70% of the patients showed free of diastolic murmur after 10 years. In tetralogy of Fallot, definitive repair of pulmonary valve was performed in last 5 years with composite patch with patient's own pericardium to reduce postoperative pulmonary regurgitation. Recently, pericardium is treated with glutaraldehyde on the operating table to prevent late shrinkage. As external conduit, homograft aorta, which had been utilized previously, showed good late results comparable to xenograft in terms of free from reoperation. Xenograft has been frequently utilized without significant late obstruction so far. In atrioventricular canal, endocardial cushion prosthesis technique has been utilized satisfactory with recent modification of the wings made by glutaraldehyde treated patient's own pericardium as well as in tetralogy.

Follow-Up Studies↗
PubMed1984

Total cavopulmonary shunt operation in complex cardiac anomalies. A new operation.

Four patients with presently uncorrectable cyanotic cardiac anomalies underwent a new operation, "total cavopulmonary shunt operation" or "total right heart bypass operation." These anomalies included single ventricle, single atrium, common atrioventricular valve with or without regurgitation, pulmonary stenosis, and most important, absent inferior vena cava with azygos or hemiazygos continuation. All patients had had previous systemic-pulmonary shunts. The new operation consisted of end-to-side anastomosis between the superior vena cava with azygos or hemiazygos continuation and the confluent pulmonary artery, division or ligation of the pulmonary artery trunk, and replacement of the common atrioventricular valve when regurgitation was present. Thus total venous return, except for hepatocardiac venous and coronary sinus flow, drains directly into the pulmonary artery, bypassing the right atrium and ventricle. Three patients survived the operation, and two of the three patients are now alive 4 years, 8 months and 2 years, 6 months after the operation. The two long-term survivors are in significantly improved condition, both clinically and hemodynamically. We believe that this new operation is promising in the treatment of the otherwise uncorrectable complex cardiac anomalies associated with azygos or hemiazygos continuation of the inferior vena cava. A longer follow-up is certainly mandatory before final conclusions can be reached.

Adult↗
PubMed1983

Operative results in patients with pseudotruncus arteriosus.

Total repair was carried out in 18 patients with pseudotruncus arteriosus. Age at the time of operation ranged from 1 to 25 years and averaged 9 years. Operative methods were transannular patch reconstruction for the relief of pulmonary atresia in 4 patients (no deaths) and reconstruction with a valved external conduit from the right ventricle to the pulmonary arteries in 14 patients (5 deaths). The overall operative mortality was 28%. An average cross-sectional area of the right and left pulmonary arteries (PA area) was calculated using angiograms and compared with the cross-sectional area of the normal right pulmonary artery (N-rPA area) in all patients. The PA area ranged from 0.06 to 2.60 cm2 and averaged 1.02 cm2; the PA area/N-rPA area ratio ranged from 0.03 to 1.05, with an average of 0.54. Three patients who died of hypoplastic right and left pulmonary arteries had a PA area/N-rPA area ratio less than 0.20. These patients had a right-to-left ventricular peak systolic pressure ratio (pRV/LV) greater than 1.0 after total repair. Fifteen patients had a PA area/N-rPA area ratio greater than 0.20, and 13 survived corrective procedures. One patient died of lung edema, which was due to failure to ligate the large bronchial collateral artery properly, and the other died of pulmonary vascular obstructive disease. Our results show that a PA area/N-rPA area ratio greater than 0.20 is a necessity in performing total repair of pseudotruncus arteriosus.

Adolescent↗