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Biomedical subjects

S Yamaki

Publications and source records attributed to S Yamaki.

At least 91 records · Page 5Linked to original sources
PubMed1982

Histologic findings of ductus arteriosus and pulmonary vascular disease in interrupted aortic arch.

There are still a number of unsolved problems concerning the total correction of interruption of the aortic arch. Here we report a histopathological investigation of the patent ductus arterious and pulmonary vascular disease using autopsy material of a patient with Celoria type B interruption of the aortic arch who died postoperatively. The so-called ductus arteriosus between the pulmonary arterial trunk and the descending aorta was lacking in elastic fibers and smooth muscle cells at the media showing discontinuous, transverse fibrous tissue. The vessel walls were weak and normal development was apparently impossible. Consequently, it was concluded that in the reconstruction of the aortic arch in such cases with PDDT, it is advisable not to use the patent ductus arteriosus. In this case, hypertrophy of the media of small pulmonary arteries was marked, but pulmonary vascular intimal lesions were mild. With regard to the pathogenesis, it is thought that there was sufficient thickening of the media of the pulmonary arterial system in response to the pulmonary hypertension present from birth, and it prevented the progression of the intimal lesions by accommodating to the intraarterial pressure.

Aorta↗
PubMed1982

Significance of lung biopsy in determining surgical indication in cases of congenital cardiac anomalies with pulmonary hypertension.

Correlation between the grade of pulmonary arterial change and pulmonary arterial pressure was studied in 60 patients with congenital cardiac anomalies associated with pulmonary hypertension. Of the 60, 45 specimens of pulmonary arteries were obtained by autopsy and 15 by biopsy. Pulmonary arterial pressure was correlated with the products of the medial thickness and intimal lesions of small pulmonary arteries both in the autopsy and in the biopsy specimens. Also, medial thickness and intimal lesions were independently correlated to the pulmonary arterial pressure. However, the regression equation was not identical among the kinds of diseases, although significant correlation was found between the degree of intimal lesions and pulmonary arterial pressure. Medial hypertrophy was reversible after corrective surgery, but intimal lesions were irreversible except for cellular proliferation. Therefore, to determine the indication for corrective surgery, it should be emphasized that intimal change of the small pulmonary arteries should be carefully evaluated. Since the degree of intimal lesions is not accurately diagnosed from hemodynamic parameters alone, diagnosis of intimal lesions by lung biopsy is indispensable to determine the possibility of corrective surgery in the congenital heart disease with severe pulmonary hypertension.

Biopsy↗
PubMed1981

Plexogenic pulmonary arteriopathy: significance of medial thickness with respect to advanced pulmonary vascular lesions.

Plexogenic pulmonary arteriopathy runs a more progressive course in transposition of the great arteries with pulmonary hypertension (TGA) and in primary pulmonary hypertension (PPH) than, for instance, in isolated ventricular septal defect (VSD). Fibrinoid necrosis and plexiform lesions occur more often and at a younger age in TGA and PPH than in VSD. A morphometric study in 18 patients with VSD, 14 patients with TGA, 38 patients with PPH, and 21 controls showed that the media of muscular pulmonary arteries is significantly thicker in VSD than in TGA or PPH, with the sole exception of very young children with PPH. This difference in medial thickness is apparent at any level of pulmonary arterial pressure. Conversely, the more advanced pulmonary vascular lesions were particularly prominent in TGA and PPH. It is likely that medial hypertrophy, at least to a certain extent, protects the pulmonary arteries from the development of more ominous vascular alterations.

Adolescent↗
PubMed1980

Quantitative analysis of the thickness of arterial walls in complete transposition of the great arteries.

Histometrical analyses were performed to estimate the medial thickness of the pulmonary and renal arteries in 35 autopsy cases of complete transposition of the great arteries (TGA). Twenty-one autopsy cases of ventricular septal defect (VSD) and 33 autopsy cases of normal cardiovascular systems were also examined for comparative analysis. The medial thickness of renal arteries was not influenced by age and remained unchanged throughout life. However, there were significant differences in medial thickness among TGA, VSD and normal cases. Normal and VSD cases showed higher value of medial thickness than TGA cases. The results suggest retarded development of the arterial walls in TGA. A positive correlation was observed between medial thickness and blood pressure in both the pulmonary and renal arterial systems in TGA and VSD. One of the most important findings in the comparative analysis of TGA and VSD was that the media of TGA was more remarkably attenuated than that of VSD at the same blood pressure level in both the pulmonary and renal arterial systems. The results suggest an underdevelopment of arterial media in pulmonary and systemic circulation in TGA and a possible supression of medial hypertrophy in TGA by some unknown factors.

Adolescent↗
PubMed1980

Medial thickness of intrarenal arteries in congenital heart disease.

The medial thickness of intrarenal arteries was assessed morphometrically at autopsy in 15 patients with acyanotic heart disease, 30 patients with cyanotic heart disease, and in 33 normal individuals of the same age range. The arterial media was not influenced by age but was thinner in patients with cyanotic heart disease than in acyanotic patients and normal persons. This difference was apparent at any blood pressure level, though the medial thickness showed a positive correlation with the height of the systolic blood pressure. There was also a significant negative correlation between the medial thickness of the intrarenal arteries and the hemoglobin value in the patients with congenital heart disease. The thin media may result from atrophy or dilation. Possibly both factors contributed through combination of arterial relaxation, dampening of systolic pressure peaks, and increase of blood volume.

Adolescent↗
PubMed1980

Indication for total correction of complete transposition of the great arteries with pulmonary hypertension.

Pulmonary vascular disease (PVD) was histologically evaluated and its severity was expressed as an index of PVD in 14 autopsied and eight biopsied cases of complete transposition of the great arteries (TGA) in patients more than 6 months of age. The index varied from 1.0 to 2.3 in six patients who had survived complete surgical repair and ranged from 2.3 to 3.3 in five patients who had died of PVD postoperatively. Consequently, an index of 2.2 could be regarded as an upper limit of PVD for complete surgical repair. The index was significantly correlated to some hemodynamic factors. From the regression equation, the value 2.2 of histologic index could be translated into the clinical factors concerning hemodynamics. We consider that patients with pulmonary vascular resistance of less than 10.6 units . m2, and pulmonary arterial mean pressure less than 51 mm Hg, are suitable candidates for complete surgical repair in TGA, if more than 6 months of age. Thus histologic assessment of PVD in a lung biopsy as an indication for total correction of TGA with pulmonary hypertension appears to be useful in patients who are in borderline hemodynamic condition or in whom the hemodynamics could not be evaluated although pulmonary hypertension was suspected.

Autopsy↗
PubMed1980

Severity of PVD.

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Child, Preschool↗
PubMed1979

Quantitative analysis of postoperative changes in the pulmonary vasculature of patients with complete transposition of the great arteries and pulmonary hypertension.

Postoperative changes in the medial thickness of the small pulmonary arteries and the degree of pulmonary vascular disease were estimated histometrically and histopathologically in three cases of late death after total correction of complete transposition of the great arteries with large ventricular septal defect and pulmonary hypertension. In the postoperative course of two of the three cases extreme medial hypertrophy of the small pulmonary arteries as well as severe pulmonary vascular disease were found. In the third case, the thickening of the media was mild and pulmonary vascular disease had not progressed owing to a residual ventricular septal defect. Examination of three additional cases of late death and 15 autopsy cases of complete transposition of the great arteries revealed that hypertrophy of pulmonary arterial media after radical surgery for complete transposition of the great arteries is a common phenomenon. In cases of complete transposition of the great arteries with severe pulmonary hypertension, the deveopment of marked hypertrophy of the media accompanied by pulmonary vascular disease after total correction is usually seen and seems to be the most likely cause of death in the postoperative period.

Autopsy↗
PubMed1979

Quantitative evaluation of hypertensive pulmonary arterial change.

A new method to quantitatively evaluate pulmonary arterial change in pulmonary hypertension is presented in this paper. Hypertensive pulmonary arterial changes are classified into four grades according to severity and a score from 1 to 4 is given to each arterial change according to the grading. An index of pulmonary vascular disease is then defined as a relative mean value of all scores. It is concluded that this index accurately expresses the grade of pulmonary arterial change in the whole pulmonary arterial system in any given case and makes possible a detailed statistical analysis of large numbers of cases.

Adult↗
PubMed1979

Recent experiences with the Mustard procedure for the complete transposition of the great arteries by means of "bypass hypothermia".

This paper presents our recent results of the Mustard procedure (intra-artrial baffle operation) for the complete transposition of the great arteries performed in 24 infants and children during the past 6 years at the Tohoku University Hospital. All intracardiac repairs were performed using "bypass hypothermia" (surface-induced deep hypothermia, circulatory arrest, and limited cardiopulmonary bypass). The hospital mortality rate was 8% in patients with simple transposition without pulmonary hypertension (Group I, one death in 12 patients), 50% in patients with ventricular septal defect (VSD) and pulmonary hypertension (Group II, 3 deaths in 6 patients), and 20% in patients with VSD and pulmonary stenosis (Group III, one death in 5 patients). Various types of longstanding dysrhythmia were found in 6 out of 18 long-term survivors, and subsequent pace-maker implantation was necessary in one infant. Postoperative pulmonary venous obstruction occurred in 3 infants, and surgical relief of the obstruction was successfully undertaken in 2 of them. Prevention of postoperative dysrhythmia, pulmonary venous obstruction, and possible brain damage are also discussed.

Cardiopulmonary Bypass↗