Search PubMed⌕ Search

Biomedical subjects

H Kado

Publications and source records attributed to H Kado.

At least 55 records · Page 3Linked to original sources
PubMed1997

Degeneration of the ipsilateral substantia nigra after striatal infarction: evaluation with MR imaging.

PURPOSE: To evaluate the degeneration of the ipsilateral substantia nigra after striatal infarction by using magnetic resonance (MR) imaging. MATERIALS AND METHODS: Twenty-five adult patients with embolic cerebral infarction of the middle cerebral artery distribution underwent MR imaging 0-4, 5-9, 12-15, and 27-29 days after the stroke. Sixteen of them also underwent follow-up MR imaging 2-12 months after the stroke. RESULTS: Ten patients had an infarct in the striatum with or without a cortical infarct (striatal infarction group); the other 15 patients had an infarct in the cerebral cortex of the middle cerebral artery distribution without a striatal infarct (cortical infarction group). In all 10 patients with striatal infarction, a hyperintense spot appeared in the ipsilateral substantia nigra on T2-weighted fast spin-echo images 7-12 days after the onset. This area became less intense and smaller 3 months later. In the cortical infarction group, no hyperintense spot in the ipsilateral substantia nigra was observed at any time. CONCLUSION: Degeneration of the substantia nigra ipsilateral to the striatal infarction was clearly demonstrated at MR imaging. This finding should not be mistaken for further cerebral infarction.

Aged↗
PubMed1996

Influence of head model in biomagnetic source localization.

We evaluated the influence of the head model on biomagnetic source localization by utilizing a computer simulation. We localized the source of a magnetic field that was calculated using a realistic head model, and then evaluated the localization errors. It was seen that the sphere model adequately localized the dipole in cases near the sensor, but not in cases where the dipole was deeply situated.

Brain↗
PubMed1996

Selective cerebral perfusion technique during aortic arch repair in neonates.

We describe selective cerebral perfusion techniques for repair of the aortic arch in neonates. These techniques may help protect the brain from ischemic injury caused by a cessation of cerebral perfusion for aortic arch reconstruction in patients with hypoplastic left heart syndrome or interrupted aortic arch.

Aorta, Thoracic↗
PubMed1996

Subaortic stenosis caused by anomalous papillary muscle of the mitral valve.

We report on a rare case of subaortic stenosis caused by an anomalous posteromedial papillary muscle inserting directly into the anterior mitral leaflet, which had muscular extension to the subaortic region. Resection of the muscular extension alone was ineffective. A second operation including entire resection of the anomalous papillary muscle and mitral valve replacement resulted in successful relief of the obstruction. Microscopic findings of the resected tissue were compatible with those of hypertrophic cardiomyopathy.

Aortic Valve Stenosis↗
PubMed1996

Successful management of junctional tachycardia by hypothermia after a Fontan operation.

We report herein the findings of a 2-year-old boy in whom junctional tachycardia developed 2 days after he underwent a modified Fontan operation and thereafter was successfully treated by hypothermia without paralyzing and artificially ventilating the patient. Chlorpromazine was useful in achieving moderate hypothermia by surface cooling without producing any unfavorable effects associated with topical cooling.

Child, Preschool↗
PubMed1996

[Staged repair for bilateral ductus arteriosus with pulmonary atresia and non-confluent pulmonary artery--a case report].

Staged operation was successfully performed in an infant with bilateral ductus arteriosus, and absence pulmonary artery. The first stage operation was performed at 2 months old of age. The left pulmonary artery was reconstructed using an equine pericardial roll sized 10 mm in diameter, and a 5 mm Dacron graft was anastomosed between the left subclavian artery and the roll as an aortopulmonary shunt. In the second stage, the same procedure was done on the right side at eight months of age. In the last stage, the patient underwent Rastelli procedure at 2 years old of age. The central pulmonary artery was created with a ring forced EPTFE graft above the ascending aorta, and a Carpentier-Edwards valved conduit (14 mm) was anastomosed between the right ventricle and the EPTFE graft. Post operative course was uneventful. We consider that the staged procedure including the pulmonary artery reconstruction and the aortopulmonary shunt on both sides is recommended in the case of absent central pulmonary artery in infant.

Blood Vessel Prosthesis↗
PubMed1995

[Postoperative pulmonary stenosis after arterial switch operation, comparison in three methods of pulmonary reconstruction: modified Pacifico, autologous pericardial patch, and equine pericardial patch].

To prevent postoperative pulmonary stenosis in arterial switch operation for transposition of the great arteries, pulmonary reconstruction without patch augmentation (modified Pacifico method: Pa-group) and reconstruction using W-shaped fresh autologous pericardium (AW-group) were introduced instead of the former method using equine pericardium (XW-group). Postoperative pulmonary stenosis (RV-PA pressure gradient greater than 30 mmHg) was not seen among the 17 cases in the Pa-group (0%), and was seen in 2/14 (14.3%) in the AW-group and in 4/14 (29%) in the XW-group. Progressive increase in pressure gradient was seen in the XW-group in the midterm cardiac catheterization (p < 0.01), but such tendency was not observed in the Pa-group and the AW-group. Sectional area at the pulmonary valve ring, at the anastomotic site in the main pulmonary artery, and at the pulmonary branches just distal to the bifurcation, standardized by the body surface area, increased in the Pa-group and the AW-group, but were unchanged or slightly decreased in the XW-group in the midterm cardiac angiography. We believe that postoperative pulmonary stenosis can be best avoided if modified Pacifico method is used. The cases in which postoperative pulmonary stenosis or coronary artery compression is anticipated such as those with side-by-side aortopulmonary relationship or after pulmonary artery banding, should be operated upon using fresh autologous pericardial patch.

Humans↗
PubMed1995

[Surgical results of valvuloplasty for common atrioventricular valve regurgitation in single ventricle].

From 1988 through 1994, 18 patients who had common atrioventricular valve regurgitation associated with single ventricle underwent valvuloplasty. All patients had isomerism heart (right isomerism: 16, left isomerism: 2). The preoperative degree of regurgitation was 3.3 +/- 0.4 (Sellers). Valvuloplasty was performed by two different procedures. Semi-circular annuloplasty was used in nine patients. Dividing the common atrioventricular valve orifice into two parts (bivalvation) with or without annuloplasty was used in nine. The concomitant procedures varied: three patients underwent systemic pulmonary shunt, two underwent repair of total anomalous pulmonary venous drainage, one underwent pulmonary arterial banding, five underwent bidirectional Glenn, shunt, and four underwent Fontan operation. One early death and three late deaths have occurred. The early postoperative degree of regurgitation was reduced to 1.3 +/- 1.0. In nine patients, however, the degree of regurgitation increased late postoperatively. Seven patients were reoperated on because of regurgitation: three patients had valve replacement and four had reannuloplasty. Increased incidence of deterioration of regurgitation in late period was seen in patients under 2 years old and those receiving a concomitant Blalock shunt. Lower event-free rate after 2 years was seen in patients with double inlet right or indeterminate ventricle and those underwent the annuloplasty alone. We conclude that the dividing common atrioventricular valve orifice into two parts with annuloplasty could effectively reduce the regurgitation in most patients with isomerism heart, and the concomitant ventricular unloading operation seems to offer promise for improving long-term results.

Adolescent↗
PubMed1995

[Valve replacement in an infant with congenital mitral stenosis--report of a case which showed hemodynamics similar to that of hypoplastic left heart syndrome in neonatal period].

In the neonatal period, the patient showed severely hypoplastic left ventricle, severe mitral stenosis, patent foramen ovale and patent ductus arteriosus with right-to-left shunting, which resulted in the hemodynamics similar to that of hypoplastic left heart syndrome. However, progressive left ventricular growth was recognized after spontaneous closure of the foramen ovale, and the cardiac catheterization at the age of 6 months revealed almost normal left ventricular volume and systolic forward flow from the left ventricle to the descending aorta. The operation was performed at the age of 7 months under cardiopulmonary bypass with moderate hypothermia and cardiac arrest. The mitral leaflets were thickened and dysplastic, two short papillary muscles were hypertrophic and very closely related, and the chordae were extremely short and fused each other making the interchordal space obstructed. Because the mitral annular diameter (13 mm) was too small for conventional valve replacement, the prosthetic valve (CarboMedics #16) was sewn to the left atrial wall 5 to 10 mm above the mitral annulus. The ductus arteriosus was ligated. The postoperative cardiac catheterization showed residual pulmonary hypertension, but pulmonary vascular response to oxygen-inhalation was recognized. We consider that there were two important hemodynamic factors which led to successful biventricular repair in this case. First, early spontaneous closure of the foramen ovale accerelated the left ventricular growth and prevented right ventricular failure resulting from increased pulmonary blood flow. Second, considerable part of the systemic output was supplied through a large ductus arteriosus, and thus over-systemic pulmonary hypertension was avoided.

Cardiopulmonary Bypass↗
PubMed1994

[Extended aortic arch anastomosis for coarctation of the aorta and interruption of the aortic arch in early infancy].

We performed extended aortic arch anastomosis, which was so called EAA procedure, for Coarctation of the Aorta (CoA) with hypoplastic aortic arch (HAA) and interruption of the aortic arch (IAA) in 17 infants under three months of age. The proximal anastomosis site was extended into ascending aorta in order that we could make non-obstructive pathway of systemic flow. During anastomosis, we employed mild systemic hypothermia and topical cooling of head and lumber lesion. Satisfactory anastomoses were performed without any neurological and renal complications except one case. Postoperative Doppler echographic evaluation revealed that the mean peak flow velocities at anastomotic site were under 2.0 m/sec at 1 and 2 years after surgery. We concluded that EAA procedure was useful for CoA with HAA and IAA in early infancy.

Anastomosis, Surgical↗
PubMed1994

[Reoperation for transposition of the great arteries: mid-term results and reoperation after arterial switch operation].

The arterial switch operation for transposition of the great arteries is now widely accepted as the therapeutic method of choice. As of December 1993, a total of 162 patients underwent the arterial switch. There were 100 patients with transposition and intact ventricular septum, 48 with a ventricular septal defect, 14 with ventricular septal defect and arch anomalies (coarctation: 11, interruption: 3). Early and late mortality were 3.7% (6 patients) and 4.5% (7 patients), respectively. Postoperative pulmonary stenosis (> 30 mmHg) was noted in 33 patients (22%), aortic regurgitation (> mild) in 20 (13%), supravalvular aortic stenosis (> 20 mmHg) in 5 (3%) and mitral regurgitation (> mild) in 5 (3%). Reoperation was performed in 27 patients with no mortality. Mean interval between the switch and the reoperation was 30 months. Twenty-three patients with pulmonary stenosis underwent patch plasty of pulmonary artery. Two children with severe aortic regurgitation underwent aortic valve replacement. Two patients who had undergone one-staged repair for interruption complex were reoperated due to supravalvular aortic stenosis and pulmonary stenosis. Actuarial survival and freedom from reoperation at 9 years were 90% and 69%, respectively.

Aortic Valve Stenosis↗
PubMed1993

Revised technique of cardiopulmonary bypass in one-stage repair of interrupted aortic arch complex.

Twenty infants with interrupted aortic arch associated with various intracardiac anomalies underwent primary complete repair using pulsatile high-flow cardiopulmonary bypass with a short period of circulatory arrest. Age at repair ranged from 11 to 126 days (mean age, 43 days). Weight ranged from 2.2 to 5.5 kg (mean weight, 3.4 kg). Associated cardiac lesions included ventricular septal defect (14 patients), truncus arteriosus (3), transposition of the great arteries (2), and aortopulmonary window (1 patient). Left ventricular outflow tract obstruction was relieved in 2 patients. The aortic arch was reconstructed with a polytetrafluoroethylene graft in 7 patients and by direct anastomosis in the most recent 11 patients. An arterial cannulation method has been devised to facilitate direct anastomosis between the ascending aorta and the descending aorta, to lessen circulatory arrest time, and to prevent dangerous laceration and postoperative narrowing of the thin, small ascending aorta at the cannulation site. Two patients died, a surgical mortality rate of 10%. There has been one late death, which was due to severe truncal valve insufficiency. The other patients are doing well with a mean follow-up of 3 years 6 months. Restenosis of the direct anastomosis has not been noted in any patient. However, subaortic stenosis with pressure gradients of 30 to 40 mm Hg developed in 3 patients. In conclusion, one-stage repair including direct anastomosis for the aortic arch reconstruction and repair of all coexisting intracardiac defects is thought to be the treatment of choice.

Anastomosis, Surgical↗
PubMed1993

Trans-ventricular septal defect approach for resection of accessory mitral valve tissue.

Accessory mitral valve tissue is a rare cause of left ventricular outflow tract obstruction, which can be difficult to recognize. Surgical resection by the conventional transaortic approach with or without left atriotomy is extremely difficult in infants with a small aorta. When a ventricular septal defect is present, it may be the best way to approach the accessory mitral valve tissue, because the ventricular septal defect is located just in front of it. Five infants underwent resection of accessory mitral valve tissue together with repair of other intracardiac malformations. In 3 infants, resection of accessory mitral valve tissue was easily performed through the ventricular septal defect, which required enlargement in 2 patients.

Female↗