Biomedical subjects

T Yagihara

Publications and source records attributed to T Yagihara.

At least 37 records · Page 2Linked to original sources

PubMed2001

Repair of double outlet right ventricle with doubly-committed ventricular septal defect.

OBJECTIVE: To investigate our surgical results of intraventricular rerouting in patients having double outlet right ventricle with doubly-committed ventricular septal defect. METHODS: We undertook repair in 8 patients with this particular feature. Of these, 2 patients had pulmonary stenosis, and another had interruption of the aortic arch. The subarterial defect was unequivocally related to both the aortic and the-pulmonary orifices in all, albeit slightly deviated towards the aortic orifice in one, and towards the pulmonary orifice in another. Intraventricular rerouting was carried out via incisions to the right atrium and the pulmonary trunk. To ensure reconstruction of an unobstructed pulmonary pathway, a limited right ventriculotomy was made in 5. RESULTS: All patients survived the procedure, and are currently doing well, with follow-up of 25 to 194 months, with a mean of 117+/-68 months. Catheterization carried out 16+/-6 months after repair demonstrated excellent ventricular parameters. Mean pulmonary arterial pressure was 16+/-7 mmHg, being higher than 20 mmHg in 2 patients. No significant obstruction was found between the right ventricle and the pulmonary arteries. A pressure gradient across the left ventricular outflow tract became significant in one patient in whom a small outlet septum was present, and a heart-shaped baffle had been used for intraventricular rerouting. Reoperation was eventually needed in this patient for treatment of the obstruction, which proved to be progressive. CONCLUSION: Precise recognition of the morphologic features is of paramount importance when choosing the optimal options for biventricular repair in patients with double outlet right ventricle and doubly-committed interventricular communication.

Adult↗

PubMed2001

Approach to the neoaortic valve for replacement after the arterial switch procedure in patients with complete transposition.

We report our experience of aortic valvar replacement subsequent to the arterial switch procedure, incorporating the Lecompte maneuver, in patients with complete transposition. The anterior wall of the neoaorta was incised in continuity with the posterior wall of the pulmonary trunk. The aortic root was reconstructed with or without augmentation using a patch after the operative procedures to the aortic valve. With this approach, the neoaortic root could readily be exposed without extensive dissection, and valvar replacement was safely achieved. These patients experienced no postoperative complications.

Aortic Valve↗

PubMed2001

Effect of synchronized intermittent mandatory ventilation on respiratory workload in infants after cardiac surgery.

BACKGROUND: Synchronized intermittent mandatory ventilation (SIMV) is commonly used in infants and adults. However, few investigations have examined how SIMV reduces respiratory workload in infants. The authors evaluated how infants' changing respiratory patterns when reducing SIMV rate increased respiratory load. The authors also investigated whether SIMV reduces infant respiratory workload in proportion to the rate of mandatory breaths and which rate of SIMV provides respiratory workloads similar to those after tracheal extubation. METHODS: When 11 post-cardiac surgery infants aged 2-11 months were to be weaned with SIMV, the authors randomly applied five levels of mandatory breathing: 0, 5, 10, 15, and 20 breaths/min. All patients underwent ventilation with SIMV mode: pressure control ventilation, 16 cm H2O; inspiratory time, 0.8 s; triggering sensitivity, 0.6 l/min; and positive endexpiratory pressure, 3 cm H2O. After establishing steady-state conditions at each SIMV rate, arterial blood gases were analyzed, and esophageal pressure, airway pressure, and airflow were measured. Inspiratory work of breathing, pressure-time products, and the negative deflection of esophageal pressure were calculated separately for assisted breaths, for spontaneous breaths, and for total breaths per minute. Measurements were repeated after extubation. RESULTS: As the SIMV rate decreased, although minute ventilation and arterial carbon dioxide tension were maintained at constant values, spontaneous breathing rate and tidal volume increased. Work of breathing, pressure-time products, and negative deflection of esophageal pressure increased as the SIMV rate decreased. Work of breathing and pressure-time products after extubation were intermediate between those at a SIMV rate of 5 breaths/min and those at 0 breaths/min. CONCLUSION: When the load to breathing was increased progressively by decreasing the SIMV rate in post-cardiac surgery infants, tidal volume and spontaneous respiratory rate both increased. In addition, work of breathing and pressure-time products were increased depending on the SIMV rate.

Air Pressure↗

PubMed2001

Incidence of spontaneous closure of outlet ventricular septal defect.

The present study examined the Doppler echocardiograms of 742 patients with an outlet ventricular septal defect (VSD) who were seen at the National Cardiovascular Center from 1987 to 1999. Of these, 450 patients were followed for longer than 1 year; 161 of these 450 were younger than 12 months when first examined. During follow-up, Doppler echocardiographic examination was repeated at least once a year. The medical charts of these patients were reviewed. Doppler echocardiographic findings were analysed in patients whose defect closed spontaneously:spontaneous closure at the age of 1-25 years was identified in 17 (3.8%) of 450 patients who were followed for longer than 1 year, and 7 (4.3%) of the 161 patients who were younger than 12 months at the first examination. All closed VSDs were originally smaller than 4mm. Although 5 cases of 17 developed trivial deformity of the right coronary cusp, suggesting a prolapse, this did not progress. Of these 5, trivial aortic regurgitation (AR) was detected in one patient, while another patient in the group of 17 developed trivial AR without any deformity of the right coronary cusp. Aortic regurgitation was not progressive in either patient. An outlet VSD closes spontaneously in a small percentage of patients without developing progressive AR.

Adolescent↗

PubMed2001

Imbalance of cusp width and aortic regurgitation associated with aortic cusp prolapse in ventricular septal defect.

The Doppler echocardiograms of the aortic valve and associated aortic regurgitation (AR) were reviewed in 72 patients with a ventricular septal defect (VSD). Group I comprised 13 patients without any deformity of the aortic cusp for > or = 10 years, group 2 included 35 patients who did not develop AR for > or = 10 years after right coronary cusp prolapse (RCCP) was first detected, group 3 comprised 11 patients with RCCP and AR in whom the AR remained subclinical for > or = 10 years, and group 4 was 13 patients who underwent surgical treatment because of moderate to severe AR. The cusp imbalance index [width of right (R) or non- (N) coronary cusp/width of left coronary cusp (L)] was compared among the 4 groups. R/L or N/L was larger in group 4 than in groups 1-3; R/L exceeded 1.30 in all the patients in group 4, whereas it was less than 1.30 in all the atients in groups 1-3. Two patients in group 4 with non-coronary cusp prolapse had an N/L greater than 1.50. No other patients in any group had an N/L larger than 1.20. An imbalance of cusp width may predict possible progressive deterioration of AR.

Adolescent↗

PubMed2001

Balloon aortic valvuloplasty in children: a multicenter study in Japan.

A questionnaire was used to survey the experience of 8 Japanese institutions with percutaneous transluminal aortic valvuloplasty (PTAV) in children. Among 99 procedures reported in 88 patients, sufficient data for analysis was obtained from 76 procedures in 72 patients. In those 76 procedures the pressure gradient decreased significantly from 68+/-25 (20-140) to 33+/-22 (0-100) mmHg (p<0.01), whereas aortic regurgitation (AR) increased at least one grade in 26 cases (34%). None of the parameters analyzed in this study were predictors of an increase in AR. The reduction in pressure gradient was judged as good in 44 of the 76 procedures (58%). A larger ring diameter, larger balloon diameter and larger ratio balloon diameter/the normal predicted diameter of the aortic valve ring significantly contributed to an effective reduction of pressure gradient. Follow up data (mean interval, 4 years) was available for 26 of 39 clinically effective procedures. AR progressed at least 1 grade in 11 (42%), and the pressure gradient re-developed to more than 50mmHg in 2 cases (8%). In Japan, PTAV has been accepted as a useful procedure for valvular aortic stenosis in children, but progressive AR or re-development of the pressure gradient is not uncommon even after clinically effective PTAV.

Adolescent↗

PubMed2001

Life-threatening pulmonary edema following unilateral stent implantation for bilateral branch pulmonary stenosis: recovery after contralateral stent implantation.

A 13-year-old girl, who was suffering complications with bilateral pulmonary artery stenosis after intracardiac repair for tetralogy of Fallot, suffered life-threatening left pulmonary bleeding and edema following inadvertent unilateral stent implantation for a left pulmonary stenosis. Pulmonary edema and subsequent hypoxia persisted despite intensive medical treatment; however, contralateral stent deployment resolved her symptoms quickly.

Adolescent↗

PubMed2001

[Developing the best and the brightest in academic surgery for next generation].

Major advances have been achieved in surgery during the past century and further dynamic changes are expected along with progress in immunology, tissue and mechanical engineering, etc. in the 21st century. However, fewer medical students will choose the surgical field as their specialty, primarily due to the long training period, and inadequate income as compared to the heavy workload. To recruit the best and the brightest students in surgery, early exposure to the positive aspects of the surgical field is desirable. The training system should be further refined, and a sufficient number of positions with appropriate remuneration must be mode available.

Education, Medical, Graduate↗

PubMed2001

[Reconstruction of the right ventricular outflow tract in patients undergoing the Ross procedure].

Since 1992, 46 patients have undergone the Ross procedure. Of these, a pulmonary homograft was used for reconstruction of the RVOT in 16, and a tailored heterologous or autologous pericardial roll tube in 9. In the remaining 21, the autologous tissues were used as a posterior wall of the channel, placing another patch (bearing a monocusp in 14) anteriorly. All the patients survived the procedure. Reoperation has been needed thus far in one for infection of the prosthetic patch placed at the right ventricular outflow tract, and catheter intervention in 2 for mild obstruction across the channel. On the basis of postoperative catheterization, presence or absence of a valvar structure across the right ventricular outflow tract did not affect ejection fraction of the right ventricle and right atrial pressure. In contrast, right ventricular end diastolic volume was smaller, as well as diastolic pulmonary arterial pressure was higher, when a competent trifoliate valve was provided at the right ventricular outflow tract. An incision to the ventricular septum for subaortic stenosis, coronary arterial obstruction preoperatively present, and age at operation younger than 2 years old, were unfavourable factors affecting right ventricular performance. We conclude that, in the majority of our patients, right ventricular performance was unlikely impaired even without a competent pulmonary valve. Use of a homograft, however, could be preferred in a selected group of patients with deleterious circumstances on the postoperative circulation.

Adolescent↗

PubMed2001

[Tricuspid atresia and univentricular heart].

Recent modification of the Fontan operation was followed by remarkable improvement of surgical results in patients with tricuspid atresia and univentricular heart. Application of TCPC-type procedures contributed to this progress and new developments will yield better long-term postoperative results. Surgical strategies with the Fontan operation should include various preparatory procedures, such as systemic-pulmonary shunt, pulmonary arterial banding, plasty or reconstruction of pulmonary arteries, bidirectional Glenn anastomosis, creation of additional aortopulmonary anastomosis, and coil embolization of aortopulmonary collateral arteries.

Fontan Procedure↗

PubMed2000

Evolution of aortic regurgitation following simple patch closure of doubly committed subarterial ventricular septal defect.

We reviewed the Doppler echocardiographic findings of the aortic valve and associated aortic regurgitation (AR) in 55 patients who underwent patch closure of doubly committed subarterial ventricular septal defect (VSD). The maximal diameter of the VSD measured > or = 5 mm, whereas the postoperative follow-up interval was > or = 5 years. Twenty-three patients underwent closure before they developed aortic cusp prolapse or AR (group A). In 15 patients the VSD was closed when aortic cusp prolapse was recognized, but AR was absent (group B). Aortic cusp prolapse with AR was detected before closure in a further 15 patients (group C). Of 8 patients with no AR before closure, AR was detected during follow-up in 6 group A and in 2 group B patients. In group C, AR resolved after surgery in 4 patients, whereas AR grade improved in a further 8 patients and remained unchanged in 3. Although residual AR was more frequent in patients with aortic cusp prolapse and AR before closure, it was silent and asymptomatic.

Adolescent↗

PubMed2000

Ventilatory response to exercise in patients with major aortopulmonary collateral arteries after definitive surgery.

Patients with pulmonary atresia and major aortopulmonary collateral arteries (MAPCAs) may be at risk for both ventilatory impairment and abnormal pulmonary circulation after definitive surgery. We measured the ventilatory response to exercise in 16 patients with MAPCAs after definitive surgery (group A) and compared the results with those in 16 patients with tetralogy of Fallot with pulmonary atresia and without MAPCAs after definitive operation (group B), with 24 patients with tetralogy of Fallot after one-stage repair without previous palliation (group C), and with 48 healthy subjects (group D). Pulmonary function and treadmill exercise tests were performed. Arterial blood gases were also analyzed and the dead space to tidal volume ratio calculated. In group A, the vital capacity, diffusion capacity, and peak oxygen uptake were lowest (p <0.001), whereas the ventilatory equivalent for carbon dioxide was highest and its value at peak exercise correlated with age at time of surgery (r = 0.73, p <0.002). The arterial oxygen tension decreased progressively in group A and its value at peak exercise inversely correlated with the mean pulmonary artery pressure in all patients (r = -0.75, p <0.001). The arterial carbon dioxide tension decreased significantly at peak exercise in controls but showed no change in group A. The dead space to tidal volume ratio decreased during exercise in patients without MAPCAs and in controls but increased in group A, and the dead space to tidal volume ratio at peak exercise was inversely correlated with vital capacity in all patients (r = -0.77, p <0.001). Diffusion capacity independently predicted arterial carbon dioxide tension and dead space ventilation during exercise. Marked restrictive ventilatory impairment with low diffusion capacity along with a pulmonary obstructive change contributed to the abnormal pulmonary gas exchange during exercise in group A. Earlier repair of MAPCAs may prevent the progression of the impaired ventilatory response to exercise in these patients.

Adolescent↗

PubMed2000

A staged Fontan approach in patients initially unsuitable for the primary Fontan procedure.

OBJECTIVE: To determine the efficacy of the Glenn procedure in terms of establishing the Fontan procedure. METHODS: Surgical results were investigated in 248 patients undergoing either the total or partial right heart bypass. Of these, the conventional and the bidirectional Glenn procedures were employed in 27 and 58 patients, respectively. RESULTS: Conversion to the Fontan circulation was attempted in 32 of 58 patients initially considered unsuitable for the Fontan circulation and undergoing the bidirectional Glenn procedure, with 2 operative deaths. Of the 27 undergoing the conventional Glenn procedure, 13 have undergone conversion with 2 deaths. Actuarial survival rate after the staged Fontan approach did not statistically differ from that after the primary Fontan procedure. Catheterization in 130 patients with the established Fontan circulation showed no significant differences in ejection fraction, end diastolic volume, and end diastolic pressure of the systemic ventricle, as well as in Cardiac Index, between the group of patients treated with the primary Fontan procedure and the group treated with the staged Fontan procedure. When achieving the bidirectional Glenn procedure, the size of the additional channel from the ventricles to the pulmonary arteries was correlated with the postoperative change in pulmonary arterial size, but such additional forward flow produced insufficient ventricular offloading in 9 of 16 patients with significant atrioventricular valvar regurgitation. CONCLUSION: The staged Fontan strategy has an advantage in patients with complicated circumstances. Whether the primary or the staged Fontan procedure was used, however, did not affect the Fontan circulation itself when once the Fontan circulation was established. The additional forward flow in the bidirectional Glenn physiology, if employed, should be appropriately adjusted, considering both the advantages and the disadvantages of the option.

Child, Preschool↗

PubMed2000

Result of surgical treatments in patients with coronary-arterial obstructive disease after Kawasaki disease.

OBJECTIVE: To determine the efficacy of coronary artery bypass grafting (CABG) in young patients with coronary-arterial obstructive disease subsequent to Kawasaki disease. METHODS: CABG was employed in 100 patients. Age at operation ranged from 1 to 23 years at a mean of 10+/-5 years. The number of bypass grafts placed was 1-5/patient (a mean of 1.7+/-0.8). The left internal-thoracic artery (ITA) was used as a graft in 99 patients; the right internal thoracic artery in 39, the gastroepiploic artery in nine and the saphenous vein in 21. RESULTS: All patients survived the procedures. In the follow-up of 6.7+/-4.5 years, two patients died, one because of a traffic accident and the other due to sudden death. Considerable myocardial ischemia recurred postoperatively in 15, because of either obstruction of the bypass grafts or progression of other coronary-arterial obstructions. Of these, symptoms spontaneously regressed without interventional procedures in four, reoperation was indicated in four and catheter intervention was efficiently carried out in the remaining seven. Another two patients had episodes of critical ventricular arrhythmia; one of them with severe left ventricular dysfunction subsequently underwent cardiac transplantation. The patency rates of the arterial grafts were 94, 82 and 78% at 1, 5 and 10 years, respectively, and this was higher than that of the venous grafts (82, 63 and 36%, respectively). Strenuous exercise is currently prohibited in 15 patients, while the remaining 83 patients are doing well with no obvious restriction in their daily lives. CONCLUSION: Collaborating with catheter interventions, CABG using the arterial grafts can provide attractive results in patients with obstructive coronary arteries associated with Kawasaki disease.

Adolescent↗

PubMed2000

Total cavopulmonary connection in children with body weight less than 10 kg.

OBJECTIVE: To evaluate the results after total cavopulmonary connection (TCPC) in small children, our clinical experience was retrospectively reviewed. METHODS: Of 164 patients undergoing TCPC, the body weight at operation was less than 10 kg (8.8+/-1.1 kg) in 54, including 21 with visceral heterotaxy. The superior caval vein (SVC) was anastomosed to the pulmonary arteries in a bidirectional fashion. To construct a channel draining the inferior caval vein (IVC), an extended polytetrafluoroethylene (ePTFE) tube was placed intraatrially (in 15 patients) or outside the heart (in 13), its diameter being 14 mm in two patients, 16 mm in 12, and 18 mm or greater in 14. A heterologous pericardial baffle was used for intraatrial rerouting in 12 patients. A pedicled autologous pericardial roll was tailored as an extracardiac conduit in 11 patients, and the pulmonary trunk was directly anastomosed to IVC orifice in three. RESULTS: Seven patients, including five with right isomerism, died in the intermediate term because of infection of the ePTFE tube in two, respiratory problems in three, atrioventricular valvar regurgitation in one, and pulmonary venous obstruction in one. Postoperative catheterization showed; SVC pressure, 11+/-2 mmHg without a pressure gradient between SVC and IVC; systemic ventricular end diastolic pressure, 5+/-2 mmHg; end diastolic volume, 122+/-54% of the anticipated normal value; ejection fraction, 0. 56+/-0.11; and cardiac index, 2.9+/-0.7 l/min per m(2). With the follow-up of 1-116 (35+/-31) months, the IVC channel has not become obstructive in all, except for one, in whom a pedicled pericardial roll was severely obstructed because of its tortuous extracardiac course crossing in front of the vertebrae. Postoperative growth was generally stable, although body weights and heights were smaller in the majority of patients when compared with the anticipated standards for Japanese children. CONCLUSION: TCPC can be justifiably established in small children. The use of autologous tissues seemed preferable for constructing the IVC channel unless anatomic orientation was unsuitable.

Blood Vessel Prosthesis Implantation↗

PubMed2000

Right-to-left shunt through the cardiac veins after the Fontan procedure.

We found right-to-left shunts through the cardiac veins postoperatively in 2 patients who had undergone the Fontan procedure. In one of the patients, channels were present through the cardiac veins independent of the coronary sinus. In the other patient, an atretic orifice for the coronary sinus, coupled with a persistent left-sided superior caval vein, complicated the postoperative course.

Blood Gas Analysis↗

PubMed2000

Cardiac transplantation under new legislation for organ transplantation in Japan: report of two cases.

During the past 2 years since new legislation for organ transplantation from brain-dead donors came into effect in Japan, 3 cardiac transplants have been carried out, 2 of which were performed at the National Cardiovascular Center (NCVC). The recipient cases were 46- and 25-year-old male patients who suffered from end-stage dilated cardiomyopathy and had been listed for cardiac transplantation in the Japan Organ Transplantation Network as status I candidates. The first patient was supported by the use of a paracorporeal air-driven left ventricular assist device of the NCVC type, and had a moderate degree of renal and hepatic dysfunction at the time of transplantation. Donor hearts were transported from distant hospitals (Tokyo and Miyagi prefecture) and the transportation time was 1 h 33 min and 2h 4 min, respectively. The operation was performed by the standard technique (Lower-Shumway) in the first patient and by the bicaval anastomosis technique in the second patient. Reperfusion of the transplanted heart was performed retrogradely through the coronary sinus utilizing leukocyte-depleted blood with a gradual increase in temperature. Total ischemic time was 3 h 34 min and 3 h 35 min, respectively. Weaning from the cardiopulmonary bypass was easy and uneventful in each patient. Immunosuppressive therapy was conducted with OKT-3 induction in the first patient because of the coexisting renal dysfunction and with a triple immunosuppressive regimen for both patients. Routine endomyocardial biopsy showed acute rejection of less than grade Ib, and the patients were discharged on the 65th and 46th postoperative day, respectively. At present, both patients are in the NYHA class I state and are ready to return to work. The uneventful recovery seen in these patients shows the advances made in transplant medicine, including the progress and improvement of immunosuppressive therapy, surgical techniques, myocardial protection, and detection and treatment of infection. Further efforts are required to fully establish the cardiac transplantation program in Japan.

Adult↗

PubMed2000

[An experience with the Ross operation utilizing cryopreserved pulmonary homografts procured by and stored in our homograft valve bank].

Eight patients, 4 males and 4 females ranging in age from 10 to 54 years (mean 27 +/- 13 years) underwent the Ross operation using a cryopreserved pulmonary homograft harvested by and cryopreserved in our institutional "Tissue Bank". Seven patients had a congenital bicuspid aortic valve and 3 patients had had healed infective endocarditis of the aortic valve. Four young female patients wanted to have a baby after operation. The Ross procedure was carried out utilizing aortic root replacement techniques in all patients. All patients survived and are currently in NYHA class 1, but 2 cardiac events occurred in 2 patients during the mean follow-up term of 29 +/- 19 months. The one was the anastomic stenosis between the homograft and distal pulmonary artery treated by balloon dilatation and the other was ventricular tachycardia eventually managed by the insertion of an ICD. Pulmonary autograft valve regurgitation is present in 3 patients, but it is not progressive up to the present time. Pulmonary homograft valves function well in all patients. The Ross operation for adolescents and young adults should become more popular along with more easy availability of homograft valves based upon the establishment of the "Homograft Valve Bank" system in Japan.

Adolescent↗