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Biomedical subjects

H Kado

Publications and source records attributed to H Kado.

At least 91 records · Page 5Linked to original sources

Arterial switch operation for transposition of the great arteries, with special reference to left ventricular function.

Between June 1984 and September 1987, 48 patients underwent Lecompte's modification of the arterial switch operation for transposition of the great arteries, including transposition with intact ventricular septum with preparatory pulmonary artery banding (n = 18), with patent ductus arteriosus (n = 11), with dynamic left ventricular outflow tract obstruction (n = 4), and transposition with ventricular septal defect (n = 15). Ages ranged from 12 days to 36 months (mean 8 months) and weights ranged from 2.7 to 12.8 kg (mean 5.7 kg). Two deaths occurred, yielding an operative mortality rate of 4.2%. Preparatory pulmonary artery banding resulted in an increase to 65 +/- 5 mm Hg in the left ventricular afterload. Linear regression of the optimum circumference of the band (Y, millimeters) against left ventricular end-diastolic volume (X, milliliters) yielded the following formula: Y = 0.23X + 19.7 (r = 0.885, p less than 0.001). Influence of left ventricular mass on cardiac function after anatomic correction was evaluated. The total amount of dopamine used after repair in patients in whom the left ventricular mass was less than 60% of normal was significantly larger than that in patients with a left ventricular mass greater than or equal to 60% of normal (p less than 0.002). The left ventricular end-diastolic volume in patients with a left ventricular mass less than 60% of normal increased significantly 2 months after operation (p less than 0.05), whereas it decreased in patients with a left ventricular mass greater than 60% of normal (p less than 0.01). We believe it is safe to perform this procedure in patients in whom the left ventricular mass is larger than 60% of normal. Most newborn infants with simple transposition can undergo correction between 10 and 20 days of life if the ductus arteriosus is kept patent with prostaglandin E1 and the left ventricle is thereby loaded. Preparatory pulmonary artery banding, when necessary, will be satisfactory if the left ventricular pressure is greater than 65 mm Hg and/or the left ventricular/right ventricular pressure ratio is greater than 0.8.

Aorta↗

[Anatomic correction of transposition of the great arteries].

The present status of the surgical treatment of transposition of the great arteries was described by showing the analysis of our results of an arterial switch operation in addition to the review of the literatures. The arterial switch operation recently has become the operation of first choice because of its low surgical mortality (author 4.5%) and low incidence of postoperative complication. One-stage anatomic correction has been performed with low mortality less than 10% in centers dealing high volumes of neonatal surgery (author: 7%). One-stage correction is preferable and it can be accomplished with the cooperative treatment plan of surgeon and pediatrician, starting immediately after birth.

Humans↗

Primary repair of interrupted aortic arch and severe aortic stenosis in neonates.

Two infants, aged 36 days old (Case 1) and 18 days old (Case 2) with interrupted aortic arch types B and A, respectively, and with severe aortic stenosis, were successfully operated on by use of pulsatile cardiopulmonary bypass. The great arteries were normally related in Case 1 and were transposed in Case 2. Repair involved the following procedure: ligation of the patent ductus arteriosus, restoration of aortic continuity with an 8 mm polytetrafluoroethylene graft, placement of an internal patch to tunnel all left ventricular blood from the left ventricle through the ventricular septal defect into the pulmonary artery in Case 1 and patch closure of the ventricular septal defect in Case 2, transection of the main pulmonary artery, anastomosis between the proximal pulmonary artery and the ascending aorta, and interposition of a valved conduit between the right ventricle and the distal pulmonary artery. The operative field could be approached easily through a median sternotomy. Postoperative cardiac catheterization revealed satisfactory anatomical and hemodynamic results in both cases.

Aorta↗

Autoregulation of pituitary growth hormone messenger ribonucleic acid levels in rats bearing transplantable mammosomatotrophic pituitary tumors.

Female Wistar-Furth rats were implanted sc with GH3 rat pituitary tumor cells. Tumors were palpable by 4 weeks, and animals were killed periodically from 5-9 weeks. Tumor-bearing rats (n = 10) were heavier than their respective controls, reaching a weight of 372 +/- 3 by 9 weeks vs. 195 +/- 5 g in controls (mean +/- SE). Circulating serum GH levels increased in tumor-bearing animals from 218 +/- 50 to 9067 +/- 962 ng/ml. Serum insulin-like growth factor I (IGF-I) levels were elevated 3-fold in tumor-bearing rats. After death, pituitary glands were excised, and their total RNA was extracted. GH mRNA was assayed by dot hybridization of immobilized pituitary RNA with [32P]cDNA for rat GH. The hybridization signal was quantified by densitometry of autoradiographs. Pituitary rat GH mRNA levels were suppressed 50% in tumor-bearing animals after 5 weeks. By the end of the 9-week period, pituitary GH mRNA levels were undetectable in tumor-bearing animals. The results show that GH tumor-bearing animals exhibit high levels of circulating GH and IGF-I and suppressed endogenous pituitary GH mRNA levels. This may be caused by autoregulation of pituitary GH gene expression either at the level of the hypothalamus or by a direct effect of GH on the pituitary. Alternatively, the elevated levels of IGF-I may be responsible for the suppression of pituitary GH gene expression .

Actins↗

Kay's mitral valve repair for mitral regurgitation due to ruptured chordae tendineae--clinical and hemodynamic observations.

Kay's mitral valve repair was performed in six consecutive patients with symptomatic mitral regurgitation due to ruptured chordae tendineae of the posterior leaflet. All patients including one with mild residual murmur showed a marked decrease in the heart size and significant clinical improvement. Postoperative hemodynamic studies, performed in four patients, showed restoration of normal or near-normal dynamics. The medium-term follow-up, 15 to 30 months after the operation, revealed continuing asymptomatic states in all. The function of the repaired valves was significantly better than that of the Hancock mitral bioprostheses. The advantages of this procedure compared with mitral valve replacement for the same condition were stressed.

Aged↗

A case of idiopathic hypertrophic obstructive cardiomyopathy causing severe right ventricular outflow tract obstruction in infancy.

An infant with idiopathic hypertrophic obstructive cardiomyopathy, presenting as severe right ventricular outflow obstruction, is described. The nonspecific clinical features and an unexpected angiocardiographic appearance made determining the correct diagnosis difficult. This infant was mistakenly diagnosed as having severe pulmonary stenosis. Attempted surgical correction was unsuccessful and at necropsy this diagnosis was confirmed. It is suggested that cross-sectional echocardiography may be diagnostic for infants with idiopathic hypertrophic obstructive cardiomyopathy.

Cardiac Catheterization↗