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Biomedical subjects

T Yagihara

Publications and source records attributed to T Yagihara.

At least 91 records · Page 5Linked to original sources
PubMed1995

Coronary arterial anatomy in double-outlet right ventricle with subpulmonary VSD.

We have examined 38 hearts with a double-outlet right ventricle with a subpulmonary ventricular septal defect. We divided the hearts into three groups according to the angle between the planes formed between the outlet septum and the remainder of the muscular ventricular septum; namely, at approximately right angles (15 hearts), parallel (11 hearts), and at an acute angle (12 hearts). The coronary arterial pattern corresponding to that seen in the normal heart was present in 11 hearts (73%) of the "right angle" group, in only one heart (8%) of the "acute angle" group, and in none of the "parallel" group. In contrast, the most common pattern in the setting of complete transposition was observed in none, 8%, and 91% of each group, respectively. Other diverse patterns were recognized in the hearts in the acute angle group, and the incidence of abnormal branching was significantly higher in this than in the other groups (p < 0.01). Knowledge of these anatomic variations in the course of the coronary arteries, some of which would cause problems at either definitive repair or reoperation, are essential for those seeking to achieve optimal surgical repair.

Coronary Vessel Anomalies↗
PubMed1995

Intrapulmonary reconstruction of pulmonary arteries using a heterologous pericardial roll.

Pulmonary artery reconstruction using a handmade heterologous pericardial roll was achieved in 5 patients with severe hypoplasia of the intrapericardial pulmonary arteries and in 9 patients with critical hilar pulmonary stenosis occurring subsequent to previous construction of a systemic-pulmonary shunt. The pericardial roll was 12 to 16 mm in diameter and was anastomosed to the pulmonary arteries through divided interlobar fissures. At the opposite end, it was fixed anteriorly to the chest wall and connected to a prosthetic tube so as to obtain a blood supply from the systemic circulation. The flow through the roll measured intraoperatively was 95 +/- 23 mL.kg-1.min-1. Postoperative catheterization showed that the mean pressure in the roll was 31 +/- 18 mm Hg. Eleven patients have subsequently undergone anatomic repair using an external conduit after 8 +/- 4 months. There were no operative deaths, but 1 patient died of esophageal bleeding after the definitive intracardiac repair. We conclude that this technique is a feasible surgical option as a part of staged operations leading to biventricular repair.

Adolescent↗
PubMed1995

What factors affect ventricular performance after a Fontan-type operation?

Postoperative conditions after a Fontan-type operation, particularly as they affect results in the early term, are thought to depend on factors such as the state of pulmonary circulation and ventricular function. In this study, we attempted to determine the factors that influence ventricular characteristics in the middle term after Fontan-type procedures. Catheterization was performed at a mean of 15 months after operation in 57 patients with univentricular atrioventricular connection who underwent the operation between 1.0 and 22.6 years of age. End-diastolic volume, end-systolic volume, ejection fraction, and end-diastolic pressure of the systemic ventricle were analyzed together with an estimation of the systemic flow index. These parameters were influenced significantly by the presence of atrioventricular valve insufficiency. The morphologically left ventricle showed a better ejection fraction than did the morphologically right ventricle, whereas the systemic flow index was greater in patients undergoing total cavopulmonary connection than in those receiving an atriopulmonary connection. Young age was significantly associated with a better postoperative contractility, whereas the potential for impaired ventricular compliance was suggested in several patients undergoing operation after 4 years of age. On the basis of our results, we conclude that total cavopulmonary connection performed at a young age should be the surgical procedure of choice and that atrioventricular insufficiency must be treated properly at, and even after, the initial definitive repair.

Adolescent↗
PubMed1995

The surgical anatomy of coronary venous return in hearts with isomeric atrial appendages.

Although absence of the coronary sinus is widely recognized in hearts with isomerism of the right atrial appendages, little attention has been paid to the fashion of the venous return from the heart itself. In this study, the arrangement of coronary venous return was investigated in 99 specimens with isomeric right and 49 with isomeric left appendages. In the normal heart, the coronary veins consist of a circumflex component within the atrioventricular groove and longitudinal components on the ventricular mass. The circumflex venous system was seen in 44 hearts with isomerism of left appendages (90%), but 23 of these hearts lacked the anatomic features of the coronary sinus. Circumflex veins were entirely lacking in the other 10% of hearts with isomeric left appendages and in all those with isomeric right appendages. In these hearts, longitudinal veins drained independently into the atria in three patterns. The first was a direct connection, with the venous orifice opening between the trabeculations of the atrial wall immediately having crossed the atrioventricular groove. The second was a crooked return, with the vein running an intramural course along the atrioventricular groove. The third was a distant connection, reaching superiorly to the smooth-walled atrial component after running an intramural course. Intramural courses were seen in 19% of the longitudinal veins, such veins being found in 62% of all hearts with no circumflex venous system. These findings, which to the best of our knowledge have never previously been recognized in detail, almost certainly have potential surgical significance.

Coronary Vessel Anomalies↗
PubMed1995

Left ventricular structures in atrioventricular septal defect associated with isomerism of atrial appendages compared with similar features with usual atrial arrangement.

In patients with isomeric atrial appendages, regurgitation of atrioventricular valves is recognized clinically as one of the risk factors that militate against successful achievement of definitive repairs. To determine whether this reflected anatomic features, we investigated 91 specimens with atrioventricular septal defect that had a common atrioventricular valve and biventricular atrioventricular connections. Of these specimens, 35 had isomeric right appendages, 23 showed isomeric left appendages, and 33 had usual atrial arrangement. We measured either the size or location of the supporting papillary muscles and the circumference of the mural leaflet within the morphologically systemic ventricle, as well as the length of outlet, inlet, and so-called scooped dimensions of the muscular ventricular septum. Presence of a solitary papillary muscle, or deviation of the attachments of the papillary muscles, was more frequent in hearts with isomeric right appendages. Values for the diameter and lengths of the papillary muscles were significantly smaller in hearts with isomeric right appendages compared with those with usual atrial arrangement (p < 0.001), as were the distances between the papillary muscles (p < 0.002) and the circumference of the mural leaflet (p < 0.001). The proportional length of ventricular outlet was longer in the setting of isomeric right appendages than in the other groups (p < 0.001), whereas the extent of septal scooping showed no differences among these three groups. We conclude that these structural features could be factors in the known insufficiency of the common atrioventricular valve and the ventricular dysfunction in patients with isomeric right appendages.

Heart Atria↗
PubMed1995

Biventricular repair in cardiac isomerism. Report of seventeen cases.

Ninety-three patients with cardiac isomerism were treated surgically from July 1985 to June 1991. Among them, three patients with right and 14 with left isomerism underwent biventricular repair. Ages ranged from 4 months to 41 years (mean 4.8 years). Anatomic repair was accomplished in 15 patients and functional repair with the right ventricle used as the systemic ventricle in two patients. Methods of atrial septation to separate pulmonary venous flow from systemic venous flow included atrial partition with a straight patch in seven patients, intraatrial rerouting with a tailored baffle in five, and a Mustard-type atrial switch in five. One hospital death (5.8%) and two late deaths (12%) occurred. Two patients required reoperation (12%), one reconstruction of a stenotic systemic venous connection and one mitral valve replacement because of incompetence. Surgically induced complete atrioventricular block was not observed in any of the patients. Optimal atrial septation offers the possibility of biventricular repair for patients with acceptable intraventricular structure.

Abnormalities, Multiple↗
PubMed1995

The earliest site of atrial activation in patients with isomeric appendages.

BACKGROUND: The sinus node is known to be duplicated in hearts with bilateral right appendages, but its site is uncertain when both appendages are of morphologically left pattern. OBJECTIVE: To determine the earliest site of activation of the atria, and to assess this site of activation relative to the anticipated location of the sinus node in patients with isomeric atrial appendages. STUDY DESIGN: Electrophysiological recordings by epicardial mapping during operations through a median sternotomy. PATIENTS: Since 1987, 44 consecutive patients with isomeric right appendages and 23 with isomeric left appendages. RESULTS: In 77% of the patients with isomeric right appendages, the site of earliest activation was superiorly located at the junction of one or other atrium and a superior caval vein; in other words, in the anticipated site of a sinus node. In contrast, an inferior site of earliest activation at the junction of an atrium with an hepatic vein was most common in patients with isomeric left appendages (56%). The site of earliest activation was not related to the veno-atrial junctions in six patients with isomeric right appendages (14%), nor in five with isomeric left appendages (22%). Moreover, in six patients with isomeric right appendages (13%), and three with isomeric left appendages (13%), additional sites of earliest activation were observed when the dominant site was suppressed. The locations of the earliest activation observed by epicardial mapping did not always accord with those expected from the preoperative electrophysiological examination, nor did they always match the anticipated site of the sinus node as documented by previous histological investigations. CONCLUSIONS: Epicardial mapping showed marked variation in functional arrangement of the earliest atrial activation. This information could be of future use when planning surgical procedures.

Electrocardiography↗
PubMed1995

Regurgitation through the morphologically pulmonary valve after additional aortopulmonary anastomosis.

Although additional aortopulmonary anastomosis established by creating double outlet from the systemic ventricle and anastomosing the pulmonary trunk to the ascending aorta can undoubtedly provide an unobstructed outlet for the systemic ventricle, postoperative regurgitation of the morphologically pulmonary valve, if it occurs, may spoil the efficacy. To determine whether the pulmonary valve can be regurgitant, 11 patients undergoing this surgical option, six accompanying a Fontan-type operation and five associated with biventricular repair, were reviewed. Postoperative regurgitation was observed echocardiographically in five patients. One patient with severe pathologic changes of the valve showed progressive regurgitation, necessitating valve replacement two months after the aortopulmonary anastomosis. The other four patients, including one with slight thickening of the pulmonary leaflets, had previously undergone banding of the pulmonary trunk. Slight regurgitation in these cases appeared between one month and two years after the procedure, but then neither progressed nor regressed. Pathologic changes of the pulmonary valve, and previous banding, therefore, can be recognized as risk factors for postoperative regurgitation. The morphologically pulmonary valve, nonetheless, proved to be feasible for this surgical option unless it possessed severe organic changes.

Anastomosis, Surgical↗
PubMed1994

Prevention of lung injury during open heart operations for congenital heart defects.

To elucidate free radical-induced lung injury associated with open heart operations for congenital heart defects, we studied 23 such patients. Maximum plasma chemiluminescence level (a marker of peroxylipids) in patients with pulmonary hypertension (n = 8) was higher than in patients with cyanotic disease (n = 8) (1,115.4 +/- 189.9 versus 728.8 +/- 48.3 counts; p < 0.05). There was a significant correlation between the maximum chemiluminescence level and preoperative pulmonary to systemic arterial pressure ratio (r = 0.929; p < 0.05). To investigate the effect of allogeneic leukocytes, we compared pulmonary hypertensive patients without allogeneic leukocyte transfusion during operation (n = 7) with the group with pulmonary hypertension. Both maximum chemiluminescence level during bypass (712.4 +/- 24.9 versus 1,115.4 +/- 189.9 counts; p < 0.05) and percent decrease in pulmonary arterial pressure after bypass (44.7% +/- 6.2% versus 28.2% +/- 4.5%; p < 0.05) were significantly improved, suggesting that depletion of leukocytes decreased the lung injury induced by free radical reaction.

Adolescent↗
PubMed1994

[Successful aortic root replacement with pulmonary autograft in two infants].

Two infants with congenital aortic valve stenosis underwent successful aortic root replacement with pulmonary autograft. One of the patients was 9 months and weighted 4.2 kg, and the other was 10 weeks weighing 4.6 kg. The former had undergone balloon valvotomy with a resultant severe aortic regurgitation. Operative method was basically similar to that taught by Ross. In terms of the right ventricular outflow reconstruction, however, left atrial appendage was utilized as the posterior wall while equine pericardial monocusp patch formed the anterior wall in the former patient. In the latter, morphology of the left atrial appendage was not suitable for the same kind of reconstruction, and nonvalved equine pericardial tube was used. Both of the patients eventually gained satisfactory circulatory condition. Advantages of aortic root replacement with pulmonary autograft are good competence without residual stenosis, avoidance of anticoagulation, and the high potential of future growth. So this operation is especially indicated for neonates and infants with left ventricular outflow obstruction.

Aorta↗
PubMed1994

Double switch operation in cardiac anomalies with atrioventricular and ventriculoarterial discordance.

Since June 1987, 10 of 19 consecutive patients with atrioventricular and ventriculoarterial discordance (average age 4 +/- 2 years) had undergone a double switch operation with the morphologically left ventricle used as a systemic ventricle. There were two combinations of procedures. Atrial switch combined with arterial switch was used in two patients who had a normal pulmonary valve. Atrial switch combined with ventriculoarterial switch by Rastelli's procedure was used in eight patients with pulmonary stenosis or atresia and a large ventricular septal defect. One early death and two late deaths have occurred in a postoperative follow-up period of up to 4 years. Subsequent problems were mainly related to the results of atrial switch procedures in patients who had a small atrium because of low pulmonary flow, especially in patients with apicocaval juxtaposition. Our experience suggested that the double switch operation would open a new era of definitive surgical treatment in half of the patients with atrioventricular and ventriculoarterial discordance.

Aorta↗
PubMed1994

[Inhaled nitric oxide after Fontan type operation].

The indication of Fontan type operation has been extending, but some cases on the boundary of the indication resulted in low cardiac output syndrome (LOS) postoperatively. Recently the inhalation of nitric oxide (NO) has been revealed to produce selective pulmonary vasodilatation, and it has come to be applied in the clinical setting. We experienced a case of 6-year-old boy with complex cardiac anomaly in whom the inhalation of nitric oxide was remarkably effective for the LOS caused by increased pulmonary vascular resistance after Fontan type operation. In the case various conventional treatments failed to improve his LOS during the weaning from a respirator on the second postoperative day. After the initiation of the inhalation of nitric oxide at a concentration of 6ppm, a rapid decreasing of pulmonary artery pressure concomitant with an improvement of hemodynamics were obtained. We concluded that the inhalation of nitric oxide is an effective strategy for the increased pulmonary resistance after Fontan type operation.

Administration, Inhalation↗
PubMed1993

Radionuclide assessment of left ventricular performance on exercise after external conduit operation.

Only limited information is available concerning left ventricular (LV) response to exercise after an external conduit operation for cyanotic congenital heart disease. Sixteen patients who had undergone external conduit repair (EC group) were studied with multi-gated cardiac pool imaging using a supine bicycle ergometer on 20 occasions. Six patients with a history of Kawasaki disease without coronary artery stenosis served as controls (control group). Myocardial imaging and cardiac catheterization were also performed in the EC group. There was no significant difference in left ventricular ejection fraction (LVEF) at rest between the groups. However, on exercise, LVEF of the EC group was significantly lower than that of the control group. Nine patients in the EC group showed a perfusion defect (PD) on 12 occasions. LVEF on exercise of the patients with PD was significantly lower than that of the patients without PD. Furthermore, only the patients with PD showed a LVEF decrease of 5% or more in response to exercise. In the EC group, a significant inverse relationship was demonstrated between right ventricular systolic pressure (RVP) and LVEF response to exercise. However, two out of four patients who underwent external conduit replacement improved their LVEF response to exercise with successful reduction of RVP. These findings indicate that an impaired left ventricular response to exercise was common in patients after external conduit operations. Myocardial damage and right ventricular outflow tract obstruction could be the causes of this left ventricular dysfunction.

Adolescent↗
PubMed1993

Right-to-left interatrial shunt in rats with progressive pulmonary hypertension.

A right-to-left interatrial shunt may prolong survival in patients with pulmonary hypertension presumably because of decompression of the right side of the heart. To test this hypothesis, 74 rats with monocrotaline-induced pulmonary hypertension were followed up weekly with cardiopulmonary exercise testing with a metabolic treadmill system for exercise tolerance, heart rate, oxygen uptake, carbon dioxide production, and survival until subsequent or induced death 8 weeks after monocrotaline treatment. In rats with an interatrial shunt, oxygen uptake and carbon dioxide production were higher and survival was better (n = 22, 27%) than those in rats without a shunt (n = 52, 0%; p < 0.05). For the prospective assessment of the effects of a reversed shunt, 24 other rats underwent a left superior vena cava-to-left atrial appendage anastomosis as a functional interatrial shunt (atrial septal defect group) 4 weeks after monocrotaline treatment when severe pulmonary hypertension had developed and were compared with an additional 25 rats receiving a sham operation. Both groups had exercise capacity depressed to the resting levels by 2 weeks after operation. Although transcutaneous oxygen levels decreased in response to exercise in the atrial septal defect group, uptake and carbon dioxide production stayed higher than those in the sham operation group with significantly better survival 4 weeks after operation (atrial septal defect 30% versus sham operation, 0%; p < 0.05), at which time a reversed shunt was determined with systemic embolization of intravenously infused microspheres. A right-to-left interatrial shunt, anatomic or functional, preserved basal metabolism and prolonged survival in rats with progressive pulmonary hypertension.

Animals↗