Biomedical subjects

H Misumi

Publications and source records attributed to H Misumi.

At least 37 records · Page 2Linked to original sources

PubMed1994

[Reoperations of extracardiac valved conduit for congenital cardiac defects].

Fifteen of 223 patients who have had extracardiac conduit repair at the Heart Institute of Japan from January, 1970, to April, 1991, have required conduits replacement because of conduit obstruction or infection. The main causes of obstruction were degeneration of the prosthetic valve and proliferative pseudo-intima in the conduit. The interval between initial conduit repair and conduit replacement was 2.2 to 18.3 years (mean 10.5 +/- 4.4). The average pressure gradient through the conduit decreased from 74.7 +/- 42.0 mmHg preoperatively to 12.3 +/- 7.1 mmHg postoperatively (p < 0.05). There was no early and late death. We concluded that xeno-pericardial roll conduits were superior to others and that conduit replacement procedure following the extracardiac conduit repair was safe and effective.

Adolescent↗

PubMed1994

[Reoperation after surgical repair of atrioventricular canal defect].

Among 114 survivors who underwent total repair of atrioventricular canal defect between 1981 and 1993, 19 patients underwent reoperation for the occurrence and progression of mitral valve insufficiency (18 patients), thrombosed prosthetic valve (1 patient), and subaortic stenosis (4 patients) on one or two occasions after operation. There were 7 males and 12 females with ages at reoperation ranging from 3 months to 13.8 years (mean, 3.8 years), and was no operative but one late death. At reoperation, reparative procedures involving the readjustment of previously repaired mitral cleft and annuloplasty were successfully achieved in 6 patients who had no additional abnormalities of subvalvar apparatus. Twelve patients, who were associated with additional valvar and subvalvar lesions, needed a prosthetic valve replacement. We emphasized that surgical technique based on precise knowledge of each individual mitral and submitral anatomy is indispensable to achieve good surgical results. When the anatomy involves submitral abnormalities, careful postoperative follow-up should be recommended to take measures of the progression of mitral valve regurgitation.

Adolescent↗

PubMed1993

Seasonal development of Leptotrombidium pallidum (Acari: Trombiculidae) observed by experimental rearing in the natural environment.

Engorged larvae of Leptotrombidium pallidum Nagayo, Miyagawa, Mitamura & Tamiya, the vector mite of scrub typhus in Japan, were reared by feeding them with fresh eggs of the collembolan Sinella curviseta Brook while confined in small plastic containers under natural conditions in a copse. The larvae were collected from wild rodents (Apodemus speciosus) in autumn 1985 and spring 1986. Adults were kept alive for 2 yr or longer. The larvae obtained in autumn became dormant in the cold winter season, and growth recommenced in the spring. Thus, the development of mites collected in April became synchronized with that of larvae obtained in the autumn. Most larvae developed into protonymphs in May, deutonymphs in June, tritonymphs in July, and adults in August. The females laid eggs in two consecutive summers. Some larvae collected in autumn were kept in a refrigerator until the following summer. They developed into deutonymphs, tritonymphs, or adults and then became dormant in the winter. Development restarted the next spring and all became adult by summer, when the females laid eggs. Under experimental conditions, all larvae are hatched in the autumn, unlike the natural situation in which two peaks of larval occurrence on wild rodents are observed in autumn and spring.

Animals↗

PubMed1993

[Pre and postoperative left ventricular volume and function in infants and children with total anomalous pulmonary venous return].

From January, 1989, to December, 1991, 36 consecutive patients with total anomalous pulmonary venous return (TAPVR) underwent intracardiac repair (ICR) in our institute. We studied the relationship between the size of atrial septal defect (ASD), age and preoperative left ventricular end-diastolic diameter (LVEDD) in 28 patients with regression analysis. There was no statistical relationship between the size of ASD, age and LVEDD. We measured LVEDD, RV to LV pressure ratio (RVP/LVP) and LV fractional shortening (LVFS) using two dimensional echocardiography in 15 patients, prior to and following ICR. LVEDD increased from 1.16 +/- 0.40 cm to 1.62 +/- 0.28 cm immediately following ICR, and then increased to 1.79 +/- 0.34 cm one month following ICR again. LVFS decreased from 38% to 35% immediately following ICR but still remained within normal range (normal range 28-45%). RVP/LVP decreased from 1.0 to 0.69 immediately following ICR, and to 0.39 one month following ICR. We concluded that the decrease of preoperative LV end-diastolic volume in TAPVR was not due to the decrease of LV preload but to anterior deviation of the ventricular septum caused by high RV pressure. There was significant increase of LV volume immediately following ICR, but LVFS maintained in normal range. This study suggested that small LV volume in patients with TAPVR did not influence the surgical results.

Echocardiography↗

PubMed1993

[A case report of pulmonary valve blood cyst].

A six-year-old boy with pulmonary stenosis was hospitalized in order to examine the cause of pulmonary stenosis. The right-ventriculography showed a large shadow defect in the right ventricular outflow tract. But the echocardiography showed the cystic tumor, which was covered with thin wall and had echo-free space in it, in the right ventricular outflow tract. We made a diagnosis of pulmonary blood cyst. After cardiopulmonary bypass was established, the main pulmonary artery was incised longitudinally. There were two blood cysts at the left pulmonary cusp which were 1.5 x 1.5 cm and 0.7 x 0.5 cm in size. The cysts were resected and the pulmonary cusp was plicated. Histologically, the wall of the cysts was consisted thick valvular tissues. No pulmonary valve pressure gradient was detected with the echocardiography following the operation.

Child↗

PubMed1993

[Surgical treatment of double orifice mitral valve in atrioventricular septal defect].

Ten patients with double orifice mitral valve and atrioventricular septal defect (AVSD) were examined. There were four cases with incomplete type, three with intermediate type and three with complete type AVSD. All patients with incomplete type AVSD were doing well after the mitral cleft repair, Leaving the accessory orifice untouched. Various valve repair procedures and prosthetic valve replacement were performed in the patients with intermediate and complete types of AVSD with left-sided atrioventricular valve regurgitation. There were three operative deaths, which included one patient with the intermediate type and two with the complete type. All of them were one-month old babies and were operated on emergency. Their general operative findings were hypoplasia of the common atrioventricular valve leaflets, abnormal attachment of the chorda tendineae and papillary muscle dysplasia. These findings increased the difficulty of the valve plasty to control mitral regurgitation.

Child↗

PubMed1992

[Two-stage Jatene procedure after Mustard or Senning operation].

We have successfully performed a two-stage Jatene procedure in four patients who showed severe anatomical right ventricular dysfunction after atrial switch (Mustard or Senning) operation for transposition of the great arteries. All four patients developed an adequate left ventricular pressure for the arterial switch operation by one or two-stage pulmonary artery banding. Left ventricular posterior wall thickness increased sufficiently enough after the banding although left ventricular ejection fraction showed significant decrease. After Jatene procedure left ventricular ejection fraction recovered, and RV end-diastolic volume which had been prominently enlarged preoperatively was dramatically normalized. Cardiac index increased from 3.6 +/- 1.6 l/min/m2 preoperatively to 5.3 +/- 6.1 l/min/m2 postoperatively with the decrease in left atrial pressure. Postoperative electrophysiological study revealed the recovery of sinus node function and atrial conduction by means of the take-down of atrial switch operation previously performed. We conclude that the Jatene procedure should be an ideal alternative in patients with right ventricular dysfunction after atrial switch operation. The left ventricle could be prepared by an effective pulmonary artery banding in most instances.

Cardiac Surgical Procedures↗

PubMed1992

[Left ventricular approach for muscular ventricular septal defects in infant].

Two infants less than 4 months of age underwent repair of apical muscular VSD with left ventriculotomy. First case was 3 months old boy who had already undergone enlargement of the hypoplastic aortic arch with subclavian flap aortoplasty and pulmonary artery banding because of the associated aortic coarctation. Second case was 4 months old Down syndrome girl who associated with ASD and PDA. Both infants were diagnosed the apical muscular VSD with echocardiography and left ventriculography. We performed short longitudinal left ventriculotomy which was parallel to the left anterior descending coronary artery between the diagonal branch and left circumflex artery. VSD was closed with Gore-Tex patch using 6-0 prolene buttress stitches. Post operative echocardiography showed good LV contractile function (Ejection Fraction = 71%, 80%), and no residual interventricular shunt. Left ventriculotomy for the apical VSD closure allowed good exposure and did not reduce the LV function even in infants. Therefore, we concluded that left ventriculotomy was an useful procedure for the apical muscular VSD in infants.

Cardiac Surgical Procedures↗

PubMed1992

[Surgical treatment of total anomalous pulmonary venous connection Darling type Ib using pedicled right atrial flap].

A one-month-old baby with total anomalous pulmonary venous connection (TAPVC) type Ib underwent a total correction with a pedicled right atrial (RA) flap, which was made by incising the RA wall in a quadrangular configuration. The common pulmonary vein (PV) was cut back into the left atrium (LA). Then the RA flap was sutured along the limbus of PV recess and atrial septal defect (ASD) to create a new pulmonary venous channel. The defect in the RA wall was directly closed without any prosthetic patch. Absorbable sutures (# 6-0 PDS) were used throughout. Postoperative course was uneventful and echocardiogram showed widely opened PV channel draining into the LA. We think that this procedure could be applied in various types of total and partial anomalous pulmonary venous connection, avoiding pulmonary venous obstruction on the assumption that the RA flap should grow.

Heart Atria↗

PubMed1991

[Successful complete repair of interrupted aortic arch and associated with DiGeorge syndrome in neonate].

We report a rare case of interrupted aortic arch and a right aortic arch associated with DiGeorge syndrome, in neonate. Through a median sternotomy bypass was established placing an arterial perfusion cannula both in the ascending aorta, and in the main pulmonary artery. The right and left pulmonary arteries were temporarily occluded, while this pulmonary cannula perfused the lower part of the body. The arch reconstruction was performed during profound hypothermic total circulatory arrest. The right descending aorta had an adequate length and direct anastomosis was carried out without any tension. The VSD was repaired through a right atrial approach. The patient had hypocalcemia and thymic abnormalities which was consistent with the DiGeorge syndrome. He was treated with calcium gluconate and alfacalcidol, but no serious infection due to immunodeficiency was seen after operation. Post operative catheterization revealed no pressure gradient at the site anastomosis of the aortic arch and satisfactory results.

Aorta, Thoracic↗

PubMed1991

[Clinical results of free (aorta-coronary) internal thoracic artery grafting].

In the two year period from 1989 to 1990, 22 patients (18 men, 4 women; age range from 40 to 59 years) underwent coronary artery bypass grafting (CABG) using in situ and free internal thoracic arteries (ITAs). 23 of total 38 ITA grafts were free grafts in the aorta-coronary position, mainly to provide sufficient graft length. All of 34 ITA grafts were patent in 20 patients with coronary arteriography about one month after operation. There were no early and late death, and all patients were free from angina after a 9.4 month mean follow-up. Perioperative complications included reoperation for the bleeding in one case and the elevation of left diaphragm in one case, but there was no other major complication such as perioperative myocardial infarction, cerebral infarction or mediastinitis. These results indicated that the free ITA could be applied as well as the in situ ITA in multiple CABG of the Japanese with good patency rate and low operative risk.

Adult↗

PubMed1990

Results of newborn screening for galactose metabolic disorders.

A screening strategy has been used which uses the Paigen and Beutler methods for the determination of galactose and galactose-1-phosphate. A blood spot test for epimerase has also been developed. In the last 10 years, 265,019 samples from newborns have been tested by these methods. Among the 154 screening positives, we have detected seven cases of epimerase-deficient galactosaemia (Type III), seven cases of Duarte/galactosaemia heterozygotes, 48 cases of other various types of heterozygotes, four cases of persistent hypergalactosaemia, three cases of hepatitis and one case of congenital atresia of the bile duct. These results indicate that our screening system has effectively detected the infants with galactose metabolic disorders.

Carbohydrate Metabolism, Inborn Errors↗

PubMed1990

[Shortest route for in situ left thoracic artery to left anterior descending coronary artery].

For coronary artery bypass grafting, the internal thoracic artery (ITA) graft carries a greater long-term patency and a decreased need for reoperation when compared with the saphenous vein graft. However, the number and length of ITAs limit their use. In an effort to extend the use of the ITA and to improve patency, we evaluated the shorter course from the left ITA (LITA) origin to the left anterior descending coronary artery (LAD). We compared the distance using the conventional route over the lung (20 patients) with that using the newly-devised route medial to the lung and through the pericardial incision (20 patients). The distance using the route medial to the lung and through the pericardial incision was 12.6 +/- 1.4 cm (mean +/- SD), which was shorter compared with 15.1 +/- 1.1 cm of the route over the lung (p less than 0.01). And also the route medial to the lung and through the pericardial incision could avoid the danger of strectching or kinking by the inflated left lung. From these results, we concluded that the use of the route medial to the lung and through the pericardial incision was better method of extending the use of the in situ LITA to LAD.

Coronary Artery Bypass↗

PubMed1989

Stability of RNA chain elongation complexes formed with RNA polymerase and denatured DNA templates.

A random transcription system was used to analyze RNA chain-elongation complexes with RNA polymerases I and II from mouse ascites sarcoma cells. The molecular size of synthesized RNA was analyzed to characterize the elongation reaction by RNA polymerases. The RNA chain-elongation complex after initiation of RNA synthesis on denatured DNA by RNA polymerase II was not decomposed with heparin which dissociated the DNA-RNA polymerase complex, whereas the elongation complex on denatured DNA by RNA polymerase I was more susceptible to decomposition with heparin. RNA transcribed by RNA polymerase I on denatured DNA 30 min after the start of the reaction contained large RNA around 28S and small RNA. The small RNA could be formed by reinitiation and early termination of elongation. RNA transcribed by RNA polymerase II on denatured DNA was only large RNA around 28S. The elongation reaction by RNA polymerases I and II on denatured DNA was not inhibited by rifamycin AF/013, an inhibitor of initiation. These results suggest that RNA polymerase II could synthesize large transcripts without reinitiation and early termination of elongation and that RNA polymerase II formed more a stable elongation complex on denatured DNA than RNA polymerase I.

DNA↗

PubMed1989

[St. Jude Medical valve replacement: clinical experience with 1,039 patients].

St. Jude Medical valve replacement was performed in 1,039 patients; 320 had aortic (AVR), 543 mitral (MVR), and 176 had double valve replacement (DVR). There were 44(4.2%) early deaths. Follow-up extended in 995 patients from 10 to 130 months, with a cumulative period of 2,730 patients-years. The overall survival rates of AVR, MVR, and DVR patients at 10 years were 60.5%, 89.6%, 90.3% respectively. The linearized incidences of valve thrombosis, thromboembolism, anticoagulation-related hemorrhage, prosthetic valve endocarditis, and significant hemolysis were as follows: 0.11%/pt-yr, 1.33%/pt-yr, 0.04%/pt-yr, 0.18%/pt-yr, and 0.11%/pt-yr, respectively. There were no structural failure after 10 years follow-up. Reoperation (explant and re-replacement or suture repair) was required in 10 patients. Seven of them had periprosthetic leakage, 2 had valve thrombosis, and one underwent reoperation because of a technical error. Actuarially over 98% of patients were free of valve-related mortality at 10 years. St. Jude Medical valve is an excellent alternative for use in the surgical treatment of valvular heart disease.

Adolescent↗

PubMed1989

[A case of successful surgical treatment of straddling tricuspid valve associated with dextrocardia and VSD].

A case of straddling tricuspid valve associated with dextrocardia and VSD was presented. Closure of ventricular septal defect and tricuspid valve replacement were performed on this patient. Since the straddling septal leaflet of the tricuspid valve shared a posterior papillary muscle in the left ventricle with the posterior mitral leaflet, division of this papillary muscle was thought to induce papillary muscle dysfunction of both leaflet. Hence, the chordae of straddling tricuspid leaflet was detached from the shared papillary muscle and the ventricular septal defect was closed by a large pericardial patch. Because of peculiar anatomy of the conduction system in this situation, the junctional area of the inlet septum and tricuspid annulus was avoided from stitching in VSD closure. Suture through the tricuspid septal leaflet and pericardial patch for VSD were used for tricuspid valve replacement as well. The patient showed uneventful postoperative course without any conduction disturbance including the right bundle branch block.

Adult↗

PubMed1989

[Malfunction of the Björk-Shiley valve prosthesis due to disc defacement--report of two cases of successful reoperation].

Derlin-disc model Björk-Shiley valve prosthesis was reoperated due to the disc defacement. One had admitted cerebral embolism which was suggested due to the prosthetic valve malfunction of aortic position and the other had congestive heart failure due to the malfunction of mitral position. These patients had implanted Derlin-disc model Björk-Shiley valve prosthesis in the aortic and mitral position 10 and 11 years ago. One's cineangiocardiography showed mild aortic regurgitation and the other showed mitral regurgitation due to the malfunction of the prosthesis. The episode of cerebral embolism in one patient was suggested due to the malfunction of aortic prosthetic valve, and congestive heart failure in the other patient was due to the malfunction of mitral prosthetic valve. These prostheses which removed at the reoperation were observed with strat shape indentation and distinct of the disc which resulted the malfunction of the prostheses. In patient who replaced with Derlin-disc model Björk-Shiley valve prosthesis should be carefully followed up.

Aortic Valve↗

PubMed1988

Necrotizing myelopathy associated with hepatocellular carcinoma.

A 43-year-old Japanese male with hepatocellular carcinoma suddenly developed paraplegia. The spinal cord signs first progressed rapidly but then gradually subsided. The patient died of hepatic failure ten months later. The autopsy disclosed cavitation and softening of the spinal cord from the level of C6 to T10, a characteristic of necrotizing myelopathy. Neither local nor apparent systemic causes to explain the spinal cord lesion were disclosed at the autopsy. This seems to be the first documented rare paraneoplastic syndrome, associated with hepatocellular carcinoma.

Adult↗