Search PubMed⌕ Search

Biomedical subjects

S Miki

Publications and source records attributed to S Miki.

At least 199 records · Page 11Linked to original sources
PubMed1988

Early and late results of reconstructive operation for congenital mitral regurgitation in pediatric age group.

Sixty-six children aged between 8 months and 15 years (average age 5.5 +/- 3.8 years) underwent mitral reconstructive operations for congenital mitral regurgitation between June 1969 and February 1987. The pathologic findings of the mitral valves were annular dilatation in 37 patients, cleft of the leaflet in eight, hypoplasia of the leaflet in 44, perforation of the leaflet in one, chordal elongation in 22, chordal absence in 16, and chordal shortening in seven. The methods of repair consisted of asymmetric annuloplasty (Kay-Reed method) in 61 patients, De Vega-type annuloplasty in one, plication of redundant leaflet in 15, and closure of cleft or perforation in nine. The single operative death (1.5%) was due to heart block. Follow-up data were available over 373.8 patient-years (average 5.7 years). The four late deaths (6.0%) were due to heart failure in two patients, pneumonia in one, and hepatitis in one. The actuarial survival rate was 93.1% +/- 3.1% at 7 years and 88.4% +/- 5.1% after 17 years. Valvuloplasty failed in 19 of the long-term survivors. One of these patients underwent mitral valve replacement 11 years after initial operation. The rate of freedom from reoperation was 86% +/- 10% after 17 years. The rate of freedom from valvuloplasty failure was 80% +/- 6.7% after 5 years, 67% +/- 7.2% after 10 years, and 44% +/- 11.9% after 15 years.

Adolescent↗
PubMed1987

Usefulness of electromagnetic flowmetry in intraoperative evaluation of aortic regurgitation associated with ventricular septal defect.

In 38 patients with aortic regurgitation (AR) associated with ventricular septal defect (VSD), indications for aortic valvuloplasty (AVP) or aortic valve replacement (AVR) were investigated by assessing AR ratio, which was measured by electromagnetic flowmetry of the ascending aorta during the operation. Residual AR was evaluated by auscultation postoperatively. Patients were assigned to group A if they underwent VSD closure alone and to group B if they underwent AVP in addition to VSD closure; patients who had no postoperative AR were assigned to group I and those with persistence of AR to group II. Thus, the patients were separated into 4 subgroups; A-I (9 patients), A-II (5 patients), B-I (20 patients) and B-II (4 patients). In subgroup A-I, mean AR ratio decreased from 9% to 7% postoperatively, in A-II from 19% to 16% (p less than 0.1), in B-I from 36% to 9% (p less than 0.01) and in B-II from 44% to 20% (p less than 0.05). An AR ratio of more than 25% should be regarded as an absolute indication for AVP or AVR. If the AR ratio is between 20 and 25%, the indication of AVP is determined by inspection of the aortic valve. A good correlation was found between AR ratio and the AR rate determined by the aortic angiographic findings (Sellers classification): grade I AR corresponded to an AR ratio of 5 to 15%, grade II to 20 to 35%, grade III to 25 to 50% and grade IV to 45% or higher (r = 0.87, p less than 0.01).

Aortic Valve↗
PubMed1987

Optimal flow of aorta-pulmonary artery shunt in patients with cyanotic heart disease.

An aorta-pulmonary artery shunt with an expanded polytetrafluoroethylene (Gore-Tex) tube graft (3 to 6 mm in diameter) was done in 33 cyanotic patients with complex congenital heart disease. The patients ranged from 14 days to 22 years old. In 28, the shunt flow (QB) was measured, and the optimal QB and graft size were determined. Nine patients had severe heart failure because of an excessively large shunt. Seven of these patients died, 5 early and 2 late after operation. The QBS in these 9 patients were extremely high; the QB index and the ratio of shunt flow to systemic flow (QB/QS) were 3.86 +/- 0.91 L/min/m2 (mean +/- standard deviation) and 52.4 +/- 9.7%, respectively. The QB index and the QB/QS of patients without severe cardiac failure were 1.49 +/- 0.92 L/min/m2 and 27.2 +/- 11.4%, respectively. In conclusion, the QB index, the QB/QS, or both should be maintained in the range of 1.6 to 2.4 L/min/m2 and 30 to 40%, respectively. In infants, however, it is advisable to control the flow at less than the range just given. Analysis of graft size in relation to body weight (BW, in kilograms) and body surface area (BSA, in square meters) showed that the optimal diameter (D, in millimeters) could be calculated by the following formulas: D = 1.88 In(BW) + 1.8 (r = .86) D = 0.87 In(BSA) + 5.3 (r = .73).

Aorta, Thoracic↗
PubMed1987

A giant aneurysm of the non-coronary sinus of Valsalva.

A 54-year-old woman complained of shortness of breath. She was diagnosed to have an aneurysm of the non-coronary sinus and underwent a radical operation. The aneurysm had a diameter of 10 cm. Superior vena cava, right atrium, and right ventricle were severely compressed and deformed. The non-coronary sinus and ascending aorta were reconstructed with a 24 mm Dacron graft using the graft inclusion technique. The ostiums of both coronary arteries were skirted. The postoperative course was uneventful.

Angiocardiography↗
PubMed1987

[Screening test for calcium antagonist in natural products. The active principles of Uncariae ramulus et uncus].

We have previously reported on the Ca2+-blocking activity and active constituents of natural products. In the course of screening, Uncariae ramulus et uncus, a chinese herbal medicine, was found to possess such activity. In this paper, we attempted to characterize its active constituent which plays an important role in Ca2+-blocking activity. Its active principles were identified to be oxyindole-type alkaloids, rhynchophylline, corynoxeine, isorhynchophylline and isocorynoxeine, that showed inhibitory effects, similar to that of verapamil, on contractile response to high concentration of potassium ion (rats), CaCl2 (rats), norepinephrine in normal and Ca2+-free medium (rats and rabbits) and 45Ca2+-uptake (rats) in thoracic aorta with an activity two orders of magnitude less than the activity of verapamil.

Alkaloids↗
PubMed1986

Reoperation after aortic valvuloplasty for aortic regurgitation associated with ventricular septal defect.

Five patients underwent reoperations because residual or recurrent aortic regurgitation occurred after aortic valvuloplasty for aortic regurgitation associated with ventricular septal defect. The mean age at reoperation was 22 years old, and the mean time interval between initial and second operation was 6 years, 10 months. The pathological findings of the aortic valves showed tears and perforation of repaired leaflets in four patients and a giant pseudoaneurysm of the Valsalva sinus in one. Aortic valvuloplasties were performed again in three patients, and aortic valves were replaced with prosthetic valves in two. Slight to moderate regurgitant murmurs are still audible in patients who underwent these valvuloplasties. Ventricular septal defects should be closed before aortic regurgitation develops. If it has developed, however, valvuloplasty should be considered as a first choice in young patients. For adult patients, aortic valve replacement is recommended.

Adolescent↗