Biomedical subjects

K Sawatari

Publications and source records attributed to K Sawatari.

At least 55 records · Page 3Linked to original sources

PubMed1991

[Hemodynamic changes and ventricular function before and after Fontan procedure for univentricular heart].

Ventricular function and hemodynamic parameters before and after Fontan operation were studied in patients with univentricular heart (UVH) of left ventricular (LV) type (9 cases, ages: 6-66, mean 13 years) and right ventricular (RV) type (13 cases, ages: 6-17, mean 9 years) without atrioventricular valve regurgitation. The preoperative ejection fraction (EF) was poor and only 44% of LV type and 23% of RV type met the Choussat's criterion (EF greater than or equal to 60%). There were 2 hospital deaths each in LV type and in RV type, but their causes could not be attributed to preoperative parameters of ventricular function. In survivors, the EF reduced from 62.9 +/- 7.0% before Fontan procedure to 43.4 +/- 12.6% after the procedure in LV type (p less than .05) and from 54.5 +/- 7.0% to 47.0 +/- 9.0% in RV type (p less than .01), although the ventricular end-diastolic pressure (EDP) also reduced from 12.7 +/- 2.7 mmHg before to 6.6 +/- 1.9 mmHg after the operation in LV type (p less than .05) and 10.4 +/- 2.6 mmHg to 5.5 +/- 2.4 mmHg in RV type (p less than .05). the ventricular end-diastolic volume (EDV) also reduced from 185 +/- 35% to 126 +/- 58% of expected normal volume in LV type (p less than .05) and 173 +/- 28% to 99 +/- 18% of expected normal volume in RV type (p less than .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1990

Development of an inhalation system of high melting point metal fumes and its use for exposure of rats to chromium and nickel fumes.

An experimental inhalation system was developed for fumes generated from powders of high melting point metals such as chromium, nickel, manganese and iron. The system consisted of a plasma flame metal sprayer as a fume generator, a granular bed type fume collector, a fluidized bed aerosol generator, an exposure and a control chamber of a horizontal-flow type and inhalant monitoring and controlling units. Performance of the chambers was ensured by a distribution test using flyash as a test aerosol. Using this system, rats were exposed to chromium fumes for one week or to nickel fumes for two months. The exposure concentrations of the chromium and nickel fumes were 1.85 +/- 0.55 mg/m3 and 0.51 +/- 0.15 mg/m3 (mean +/- SD), near the target levels of 2 mg/m3 and 0.5 mg/m3, respectively. The mass median aerodynamic diameter and the geometric standard deviation of the chromium fumes were 2.1 microns and 2.00, respectively. Those of the nickel fumes were 3.7 microns and 1.74, respectively. Species analysis of these fume particles revealed that 26.4% of the total chromium was hexavalent and the residue was trivalent and that 1-3% of the total nickel was nickel(III) and the residue was nickel(II). Inhaled-metal concentrations in the lungs showed steady increases with the exposure periods and were within the normal range of variation. On the basis of these results, it is concluded that this system is useful for long-term inhalation experiments using high melting point metal fumes.

Administration, Inhalation↗

PubMed1990

[Pulmonary artery banding for double inlet left ventricle].

Thirteen patients with double-inlet left ventricle who had undergone pulmonary artery banding (PAB) were reviewed. At the time of PAB, the age ranged from 2 months to 3 years. Pulmonary-systemic arterial pressure ratio and pulmonary arterial mean pressure were reduced from 0.95 +/- 0.12 to 0.4 +/- 0.18, and from 57.3 +/- 11.6 mmHg to 29.9 +/- 12.7 mmHg after PAB. Pulmonary resistance showed no statistically significant change after PAB. (from 7.6 +/- 5.2 unit to 4.8 +/- 3.9 unit) Ventricular end-diastolic volume decreased from 379.9% +/- 140.0% to 275.7% +/- 118.0% after PAB. The smallest one was 170% who successfully underwent septation procedure. Ejection fraction significantly decreased from 64.5 +/- 6.1% to 56.3 +/- 7.9%. (p less than 0.005) Ventricular end-diastolic pressure showed no significant change after PAB. (from 9.2 +/- 2.8 mmHg to 9.9 +/- 2.0 mmHg) After PAB subaortic stenosis occurred in three cases and pressure gradient were 10, 20, and 85 mmHg, respectively. Seven cases, including three cases with subaortic stenosis, underwent septation procedure and all survived. Before septation, ventricular end-diastolic volume calculated as % of normal left ventricular volume ranged from 173% to 570% and pulmonary resistance ranged from 1.6 unit to 11 unit. These data suggested that the patients with double-inlet left ventricle had efficient ventricular volume and cardiac function for septation even after PAB.

Child, Preschool↗

PubMed1990

[Konno procedure for congenital aortic valve stenosis with pulmonary valve stenosis].

Although aortic and pulmonary valve stenosis are among the most common congenital heart defects, the combination of both aortic and pulmonary valve stenosis in the same patient appears to be very uncommon. Accurate diagnosis of combined valvular stenosis is imperative prior to surgical correction, otherwise surgery of one of the lesions may result in an insufficient hemodynamic improvement. A seven-year-old girl with congenital aortic and pulmonary valve stenosis associated with hypoplastic aortic annulus underwent Konno's operation, pulmonary valvotomy and resection of anomalous muscle of the right ventricular outflow tract simultaneously. The operation was successfully performed and postoperative course was uneventful.

Aortic Valve Stenosis↗

PubMed1990

Septation and Fontan repair of univentricular atrioventricular connection.

From April 1986 to September 1988, 12 patients with double- or common-inlet left ventricle and left anterior rudimentary right ventricle underwent septation while 17 patients with double- or common-inlet left or right ventricle underwent the Fontan operation. In the septation group, three patients who had pressure gradients ranging from 10 to 85 mm Hg between the left ventricle and the aorta underwent enlargement of the outlet foramen, and all survived. One of the 12 patients had a common atrioventricular valve that was repaired by separating the atrioventricular valve by the procedure used for atrioventricular septal defect. One had complete heart block before septation and the other one had it after separation. One 17-year-old woman, who had the smallest left ventricle (168% of normal), died in the hospital (mortality, 8.3%). In the Fontan group, one patient who died in the hospital (5.9%) had high pulmonary resistance of 4.4 U/m2, and one late death (5.9%) occurred in a patient who had complete heart block and a high mean pulmonary arterial pressure of 20 mm Hg. Because of suprasystemic pressure in the pulmonary ventricle, two patients had immediate takedown of the septation repair and substitution of the Fontan repair. Although right atrial pressure was almost equal in both groups after operation, the cardiac index was significantly higher in the septation group than in the Fontan repair group (p less than 0.01). These data suggest that patients who are candidates for either septation or Fontan repair might fare better with septation.

Adolescent↗

PubMed1990

[Semicircular annuloplasty in regurgitation of the systemic atrioventricular valve].

Semicircular annuloplasty was applied to 16 patients with congenital heart diseases with systemic atrioventricular valve regurgitation (congenital MR 4, ECD 4, Fontan 7, BWG 1). This annuloplasty was performed additionally after the conventional valvulocommissuroplasty. Regurgitation disappeared or was reduced in most of the cases and typical improvement was recognized in the congenital MR group. This procedure was able to be performed rapidly and was applicable to the various heart diseases with systemic atrioventricular valve regurgitation.

Adolescent↗

PubMed1990

[Surgical problems in d-TGA with VSD and PS associated with insertion of tricuspid valve chordae to the infundibular septum--the Rastelli operation by translocation of the infundibular septum].

Twelve (37.5%) out of 32 patients who underwent surgical repair of complete transposition of the great arteries (d-TGA) with ventricular septal defect (VSD) and pulmonary stenosis (PS) from 1978 to 1987 had insertion of tricuspid valve (TV) chordae to the infundibular septum, i.e. superior margin of the VSD, which precluded the ordinary Rastelli type operation. Of these 12 patients early 5 patients (ages: 2-11 mean 7 years) underwent atrial switch operations with VSD closure and pulmonary valvotomy with or without fibromyotomy, and recent 6 patients (age: 4-8, mean 6 years) underwent the Rastelli operation (3 cases) or REV (3) by translocating the infundibular septum with TV chordae to the right ventricular side of the internal conduit. None died in hospital in the former group and 1 in the latter. Pulmonary/systemic ventricular peak pressure ration (Ppv/sv) was 0.75 +/- 0.22 (mean +/- standard deviation) in the atrial switch group v. 0.49 +/- 0.08 in the Rastelli/REV group 1 month postoperatively. The higher Ppv/rv in the atrial switch group was attributed to the pressure gradient across the pulmonary outflow tract, which was 37.8 +/- 16.6 mmHg in the atrial switch v. 16.7 +/- 4.2 mmHg in the Rastelli/REV (p less than 0.05). No pressure gradient was demonstrated between left ventricle (LV) and aorta in the both groups. Pulmonary wedge pressure was higher in the atrial switch group (13.8 +/- 1.9 mmHg) than in the Rastelli/REV (10.0 +/- 2.7 mmHg) (p less than 0.05). Systemic atrioventricular (AV) valve regurgitation was noted in 2 of the atrial switch group but none in the Rastelli/REV.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗

PubMed1989

[New selection criterion for Fontan procedure: pulmonary artery clamping test and pulmonary vascular resistance in increased pulmonary blood flow].

A new selection criterion for Fontan procedure, pulmonary artery clamping test (PACT) was developed and employed in 13 candidates for Fontan procedure. PACT was aimed to evaluate the response of pulmonary vascular bed to increased pulmonary blood flow and calculate the pulmonary vascular resistance in the increased pulmonary blood flow as a selection criterion for Fontan procedure, preoperatively. After a median sternotomy incision, an electromagnetic flow meter was employed for measuring the pulmonary blood flow (Qp) on the pulmonary trunk. By clamping the left pulmonary artery and the right pulmonary artery, right pulmonary vascular resistance and the left pulmonary resistance in the pulmonary blood flow of Qp were calculated respectively. By means of electrical analogue, right and left lungs were simulated as resistors in parallel. And the equivalent pulmonary vascular resistance Rpc was calculated as the predicted pulmonary vascular resistance in the increased pulmonary blood flow of two times Qp. Fontan procedure was performed in 9 cases with a Rpc of less than 3 unit.m2 with a successful result and no death. Postoperative cardiac index ranged from 2.6 to 3.7 L/min.m2 with a mean of 2.8 L/min.m2. Postoperative pulmonary vascular resistance ranged from 1.6 to 3.2 unit.m2. Postoperative cardiac index was correlated with postoperative pulmonary vascular resistance. And postoperative pulmonary vascular resistance was well correlated with equivalent pulmonary vascular resistance but was not correlated with preoperative pulmonary vascular resistance measured by Fick's method at the preoperative catheterization. In Fontan procedure, the pulmonary blood flow frequently increases to a certain degree postoperatively. And pulmonary vascular resistance is not a static resistance, but a dynamic resistance. Hence, in discussing a pulmonary vascular resistance as a selection criterion for Fontan procedure, the pulmonary blood flow in which the pulmonary vascular resistance stand should be taken into account. Equivalent pulmonary vascular resistance Qpc is a theoretical selection criterion for Fontan procedure and well reflects the postoperative pulmonary vascular resistance. Fontan procedure can be successfully performed with a Rpc of less than 3 unit.m2.

Adolescent↗

PubMed1989

[A case of mitral valve replacement with autologous pulmonic valve in congenital mitral stenosis].

A one-year-old infant with congenital mitral stenosis and pulmonary hypertension underwent by mitral valve replacement with his pulmonic valve autograft and pulmonary tract reconstruction with heterogeneous pericardial conduit. His postoperative hemodynamics data showed that left atrial pressure decreased and pulmonary hypertension continued. Echocardiography showed that the implanted autograft functioned properly. On the seventh postoperative day, he died of pulmonary hypertension. In case with congenital mitral stenosis with the small mitral annulus and the small left ventricular cavity, it is difficult to perform mitral valve replacement by commercially available mechanical or tissue valves. Because these valves are not suitable for the small mitral annulus. The mitral valve replacement with pulmonic valve autograft is recommended in such a case with the congenital mitral stenosis.

Female↗

PubMed1989

[The results of surgical treatment of total anomalous pulmonary venous return in neonates].

By the time, the results of surgical treatment for total anomalous pulmonary venous return have been unsatisfactory. From 1981, we changed a surgical procedure fro Gersony-Malm procedure to the posterior approach method, and a surgical technique from the deep hypothermia and the circulatory arrest to the moderate hypothermia and the pump perfusion. Consequently, the results of surgical treatment was improved. From 1981 to 1987, 18 neonates with total anomalous pulmonary venous return underwent corrective operations in our institute. This diagnosis was decided by echocardiography without cardiac catheterization, because the preoperative status of these neonates were poor. Under the cardiopulmonary bypass, we performed the posterior approach method for type I and III, the cut-back method and Van Praagh procedure for II and IV without aortic clamping. According to the posterior approach method, the atrial septal defect was closed through the left atrial incision and the left atrium was anastomosed to the common pulmonary trunk during ventricular fibrillation. The incision was limited within the common pulmonary trunk or the vertical vein and was not extended into the pulmonary veins. According to cut-back method and Van Praagh procedure, the coronary sinus was closed internally so as to avoid the postoperative conduction disturbance. There were four hospital deaths (22.2%). The causes of deaths were pulmonary hypertension in two, low cardiac output in one, and intracranial bleeding in one. From the results of our institution, we concluded that the primary factors determining the outcome were the condition of the patients prior to repair and the severity of pulmonary hypertension.

Cardiopulmonary Bypass↗

PubMed1989

[Jatene procedure for the intermediate type between original Taussig-Bing malformation and posterior transposition of the great arteries: a case report].

A successful Jatene procedure (Lecompte modification) in a 8-month old boy with the intermediate type between the original Taussig-Bing and the posterior transposition of the great arteries (p-TGA) is described. The aorta was located posterior to the right of the pulmonary artery (PA) which overrode the interventricular septum. There was no fibrous continuity between aortic and atrioventricular valves. In the original Taussig-Bing, intraventricular rerouting is applicable because of malaligned infundibular septum. However, in our case which was similar to p-TGA, the infundibular septum extending anteriorly as far down as the anterior papillary muscle, was almost aligned to the interventricular septum, so that intraventricular rerouting is not applicable but arterial switch operation is preferable. Hence, the primary interventricular foramen was enlarged by the wedge resection and the secondary interventricular foramen was closed using pericardial patch through PA. The continuity of PA was reestablished anterior to the new aorta. The left half of distal orifice of PA was suture-closed to shift the site of anastomosis rightwards to avoid kinking and compression on the coronary arteries. Postoperative catheterization demonstrated no pressure gradient between left ventricle and aorta.

Aorta↗

PubMed1989

[New technique for enlargement of the pulmonary outflow tract in corrected transposition of the great arteries [SLL]--a report of 2 cases].

New technique for enlargement of the pulmonary outflow tract was performed in two patients with corrected transposition of the great arteries [SLL] associated with atrial septal defect, ventricular septal defect, pulmonary stenosis and mitral regurgitation. The middle of the anterior leaflet of the mitral valve was incised to the valve annulus towards the mid-point of the mitral-pulmonary fibrous continuity. In this approach, anterior node and anterior atrioventricular conduction bundle were securely protected from the surgical incision. The pulmonary annulus was divided posterolaterally and the incision was further extended into the pulmonary trunk to the bifurcation. The pulmonary trunk was enlarged with a fusiform patch of the xenogenous pericardium bearing monocusp. In case 1, St. Jude Medical valve #31 was implanted in the mitral position. In case 2, mitral valvular annuloplasty with Carpentier ring #36 which was deformed to admit enlarged portion of the pulmonary trunk. The VSD was closed through the right atrium, placing the suture on the left side of the septum. However, complete A-V block ensured temporarily due to retraction at the operation in case 1. No conduction disturbance ensured in case 2. This technique can provide some advantage in avoidance of injuries to the anterior node and the anterior atrioventricular conduction bundle. Application of this technique to the corrected transposition of the great arteries without mitral regurgitation is to be further evaluated.

Adolescent↗

PubMed1989

Staged operation for pulmonary atresia and ventricular septal defect with major aortopulmonary collateral arteries. New technique for complete unifocalization.

A new staged operation for total correction of pulmonary atresia and ventricular septal defect with major aortopulmonary collateral arteries has been developed. In first-stage repair (complete unifocalization), intrapulmonary arteries were unified at the hilum with equine pericardial conduits (intrapulmonary bridges). In case of absent or severely hypoplastic central pulmonary arteries, new central pulmonary arteries were created. Finally, the unifocalization was completed by modified Blalock-Taussig shunts with the ligation of collateral arteries. In second-stage repair, right ventricular-pulmonary arterial continuity was established with a trileaflet pericardial conduit and closure of the ventricular septal defect. From January 1982 through July 1988, 34 patients, whose ages ranged from 1 month to 24 years (mean 6.6 years), underwent first-stage repair with two resultant late deaths (mortality rate 5.9%). Second-stage repair has been completed in 16 patients. There were two early deaths (mortality rate 12%) from bacterial infection. Postoperative right ventricular/left ventricular systolic pressure ratios ranged from 0.36 to 1.0 (mean 0.72). In four patients in whom the ratio was 1.0, the ventricular septal defect had been closed with a perforated patch. By complete unifocalization with the intrapulmonary bridge technique and the creation of new central pulmonary arteries, the majority of patients with major aortopulmonary collateral arteries can have successful repair.

Aorta↗

PubMed1989

[Modified Fontan procedure on 106 cases: indication and surgical results].

Since 1974, we have performed modified Fontan procedure on 106 patients, ranging in ages from 1 to 32 years, consisting of 44 cases of tricuspid atresia (TA), 21 with univentricular heart (UVH) of right ventricular type, 18 with UVH of left ventricular type, for which ventricular partition was unfeasible, and 23 with various complex anomalies. Hospital mortality rates for TA and other complex anomalies were 11.4 and 11.3%, respectively. Surgical results have markedly improved recently. Since 1986, 50 cases underwent Fontan procedure with 3 hospital deaths (6.0%). Late death occurred in 4 cases in a mean follow-up period of 49 months. Regarding the indication for operation, majority of patients had 2 to 3 parameters which were out of 10 criteria for Fontan procedure. Regurgitation of atrioventricular valve was repaired by annuloplasty in 19 patients underwent Fontan procedure and 17 survived. Abnormal systemic venous connection was seen in 11 cases and all survived. Association of total anomalous pulmonary venous connection is still a difficult problem and 2 of 5 cases died. Fontan procedure was performed in 8 patients following palliative right ventricular outflow reconstruction for poor development of pulmonary artery and 7 survived. Cumulative mortality rate for the entire series was relatively well at 15.1%.

Adolescent↗

PubMed1988