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Biomedical subjects

Y Imoto

Publications and source records attributed to Y Imoto.

At least 37 records · Page 2Linked to original sources
PubMed1996

Postoperative cardiac rhythms with superior-septal approach and lateral approach to the mitral valve.

BACKGROUND: The superior-septal approach provides an excellent view of the mitral valve and therefore has received considerable interest. However, the safety of this approach is controversial because it requires division of the sinus node artery in most cases. METHODS: Postoperative cardiac rhythms were analyzed in 152 consecutive patients who underwent mitral valve procedures between January 1992 and February 1995 with a conventional right lateral left atriotomy (group 1, n = 69) or the superior-septal approach (group 2, n = 83). Follow-up ranged from 2 to 38 months, and the mean follow-up was 16.1 months in group 1 and 13.8 months in group 2. RESULTS: The mortality rate was similar in the two groups (1.4% in group 1 and 1.2% in group 2), and the causes of death were not related to the left atriotomy. At discharge, 96% of the patients in group 1 who were in sinus rhythm preoperatively and 78% of those in group 2 remained in sinus rhythm. At the last follow-up, 88% of these patients in group 1 and 83% in group 2 remained in sinus rhythm. Among the patients in atrial fibrillation or junctional rhythm before operation, 12% in group 1 and 11% in group 2 had regained sinus rhythm at the last follow-up. There were no significant differences in these values. CONCLUSIONS: Although the incidence of dysrhythmias was higher with the superior-septal approach in the early postoperative period, this approach provides an excellent operative view of the mitral valve and similar results in terms of late postoperative cardiac rhythms as the right lateral left atriotomy.

Arrhythmias, Cardiac↗
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

[Questionnaire of cryopreserved allograft valves in Kyushu and Yamaguchi area].

Japanese Society of Cryopreserved Thoracic Tissue Implantation was recently set up. Cryopreserved allograft valves are about to pervade in Japan. To clarify the interest, demands and supply of cryopreserved allograft valve in the area of Kyushu and Yamaguchi, we performed questionnaire investigation regarding this issue. Collection rate of this questionnaire was 87.5% (35/40 hospitals). Ninety-seven percent of the hospitals answered that they were interested in cryopreserved allograft. Ninety-four percent of the hospitals answered that they did not ethically hesitate to use cryopreserved allograft. Ninety-one percent of the hospitals hoped to perform cardiac surgery using allograft aortic valve if allograft is available. With respect to securing donors of allograft, two-third of the hospitals did not decide whether they could be involved in obtaining donors of allograft. As the number of the cadaver kidney donors is about 20 per year in the area of Kyushu and Yamaguchi, shortage of donors of allograft valve is anticipated.

Attitude to Health↗
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

[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↗
PubMed1992

New technique in the transfer of an anomalously originated left coronary artery to the aorta.

A 21-month-old girl with an anomalous origin of the left coronary artery underwent a transfer of the left coronary artery to the aorta using a new technique of coronary prolongation. Because the anomalous left coronary artery arising from the left anterior aspect of the pulmonary trunk was too short to reach the aorta, a simple transfer of the left coronary artery to the aorta was deemed impossible. Therefore, a transfer was performed with the help of a coronary prolongation technique using the cuff of the pulmonary trunk and an aortic flap. The new route of the left coronary artery was established anterior to the pulmonary trunk. Postoperative angiography showed a patent left coronary artery without any narrowing or kinking, as well as an improved contractility of the left ventricle. Postoperative cardiac scintigraphy showed a decreased ischemic area. This technique is thus considered applicable when the orifice of the anomalous left coronary artery is too distant from the aorta for a direct anastomosis.

Aorta↗
PubMed1992

[Rigidity abolished by intravenous dantrolene in a patient with Parkinson's disease under spinal anesthesia].

Spinal anesthesia was given to a patient with right femur fracture and Parkinson's disease (PD). Although sufficient analgesia was obtained up to L1 level after spinal anesthesia, the muscular rigidity remained. Furthermore, tremor of the upper extremities continued. After administering dantrolene sodium (DT) intravenously, these untoward features were abolished. These findings suggest that DT abolishes rigidity and tremor in PD, and is useful for the management of anesthesia for a patient with PD.

Aged↗
PubMed1992

[Methicillin-resistant Staphylococcus aureus endocarditis following patch closure of ventricular septal defect].

Mediastinitis due to methicillin-resistant Staphylococcus aureus was found on the ninth postoperative day after patch closure of ventricular septal defect (VSD) in a six-month-old girl. Intravenous administration of vancomycin and debridement of the wound followed by irrigation with povidone iodine and vancomycin led to wound disinfection, but blood cultures continued positive. On the 22nd postoperative day, an echocardiographic examination revealed vegetations in the right ventricle. An emergency open heart operation was undergone. The largest vegetation was 1 x 2 cm in size, originating from the intracardiac patch used for closure of the VSD. The pulmonary and tricuspid valves were also involved. After removal of the infected tissues, including the two cusps of the pulmonary valve and a part of the tricuspid valve, the ventricular septal defect was closed again with a woven Dacron patch. The defect in the tricuspid valve was repaired. Postoperative examinations revealed severe pulmonary regurgitation and mild tricuspid regurgitation, but the cardiac function was good and neither vegetation nor leakage around the patch was recognized.

Acute Disease↗
PubMed1991

Amino acids and peptides. XIII. Synthetic studies on N-terminal tripeptide amide analogs of fibrin alpha-chain.

N-Terminal tripeptide analogs of fibrin alpha-chain were synthesized and their inhibitory effect on fibrinogen/thrombin clotting was examined. A new water-soluble active ester, 3-pyridinium ester, was used for the synthesis. Among the synthetic peptides, H-Gly-Pro-Arg-hexamethyleneimine exhibited the highest inhibitory effect on fibrinogen-thrombin clotting.

Amino Acid Sequence↗
PubMed1990

[Quality evaluation of oriental medicines. I. Quantitative analysis of marker substances in the ethical extract preparation of Hangekouboku-to].

For the purpose of evaluating a Kampo preparation, Hangekouboku-to, the contents of 6-gingerol (Gi), guanosine (Gu) and rosmarinic acid (R) in twelve kinds of ethical extract preparations were compared with the self-made decoctions. Little difference was found in the availability of the three compounds among three decoction methods. A great difference was found in the R content in the ethical extract preparations while no significant difference was found in the Gi and Gu contents, showing that they were not lost in the manufacturing process. These results suggested that Perilla Herb of quite different quality was used as raw materials.

Catechols↗
PubMed1990

Effects of orally administered human epidermal growth factor on natural and delayed healing of acetic acid-induced gastric ulcers in rats.

We examined the effects of orally administered human epidermal growth factor (hEGF) on healing of acetic acid-induced gastric ulcers in rats. hEGF, given twice daily at 30 and 100 micrograms/kg for 2 weeks or at 100 micrograms/kg for 4 weeks to rats with ulcers, had no effect on natural healing or the gastric secretion, delayed one caused by indomethacin. Oral hEGF had no effect on basal histamine-stimulated gastric secretion, and stomach weight. These results indicate that oral hEGF has no biological activity on the pathophysiology of the stomach.

Acetates↗
PubMed1990

[Surgical treatment of total anomalous pulmonary venous connection under three months of age].

Nine infants under 3 months of age with total anomalous pulmonary venous connection underwent total correction between June, 1986 and September, 1988. The age at operation ranged from 4 days to 59 days, averaging 19 days, and the body weight ranged from 1,814 g to 4,105 g, with a mean of 3,050 g. The types of TAPVC were Darling Ia in 4, Ib in 1 and III in 4. All the patients were operated by the posterior approach under cardiopulmonary bypass with high flow (130-200 ml/kg/min) and mild hypothermia using modified GIK-cardioplegia, topical cooling and aortic cross clamping. Although the incision in the common pulmonary vein trunk was never extended into the pulmonary veins or vertical vein, the length of the mouth was at least 10 mm. In the postoperative management, care was taken to avoid overhydration and rapid volume infusion. Blood pressure was kept just enough to maintain urine output. Heart rate was kept over 170/min for early postoperative days with the use of isoproterenol or atrial pacing. There was no operative or late death. Postoperative course was uneventful in all cases except one with low output syndrome in which mechanical ventilation for 8 days was required. Postoperative catheterization and angiography revealed normal intracardiac pressure values and no pulmonary venous obstruction in all cases. Follow-up period ranged from 10 to 37 months, and there has been no patient with the signs of PVO.

Age Factors↗
PubMed1989

New positive inotropic agent OPC-8212 modulates single Ca2+ channels in ventricular myocytes of guinea pig.

The effects of a new positive inotropic drug, OPC-8212 (a quinolinone derivative, 3,4-dihydro-6-[4-(3,4-dimethoxybenzoyl)-1 -piperazinyl]-2(1H)-quinolinone), on whole-cell and single-channel calcium currents of guinea pig ventricular myocytes were studied by the patch-clamp method. OPC-8212 increased whole-cell calcium currents in a concentration-dependent manner. The concentration-response curve was fitted by a single binding site model that has an ED50 of 2.7 microM. At the single-channel level, OPC-8212 increased calcium currents mainly by increasing the probability of channel opening on depolarization; the open times were slightly increased, but single-channel conductance did not change. The actions of OPC-8212 on single calcium channel currents were compared with those of forskolin, isoproterenol, and caffeine, agents that cause positive inotropic effects associated with an increase in cytoplasmic cyclic AMP level, and with those of the dihydropyridine calcium channel agonist (-)Bay K 8644, an agent that has a positive inotropic effect but does not act through cyclic AMP. OPC-8212 increased calcium currents in a manner that resembled the actions of forskolin, isoproterenol, and caffeine rather than the actions of (-)Bay K 8644. We suggest that activation of calcium currents by OPC-8212 is mediated by an elevation of intracellular cyclic AMP. Since OPC-8212 produces bradycardia and antitachycardiac effects in animals and humans, unlike agents that increase cyclic AMP, additional effects on other currents are likely.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗