Biomedical subjects

R Tominaga

Publications and source records attributed to R Tominaga.

At least 91 records · Page 5Linked to original sources

PubMed1991

[Informed consent in cardiac surgery].

Recently, it has been recognized in Japan that informed consent is indispensable to make decisions for medical treatment, although it had been already confirmed in western countries for several decades of years. However, there may be some differences in the content of informed consent between Japan and western countries. We discussed the problems of informed consent in Japan concerning the choice of prosthetic valve, mechanical prosthesis or bioprosthesis, in patients to be undergone valve replacement. We conclude that informed consent should be the humane relationship between therapists and a patient.

Bioprosthesis↗

PubMed1990

Vascular stenting in normal and atherosclerotic rabbits. Studies of the intravascular endoprosthesis of titanium-nickel-alloy.

Percutaneous transluminal balloon angioplasty would be more effective if the rate of recurrent stenosis were reduced. To evaluate the prevention of restenosis after percutaneous transluminal angioplasty, intravascular endoprosthetic stents of titanium-nickel-alloy were implanted transluminally in seven normal and 21 atherosclerotic rabbits. In normal rabbits, a 3.5-mm diameter stent was implanted in the aorta and a 2.5-mm diameter stent in the right iliac artery, which were followed with serial angiograms from 6 weeks (n = 7) to 8 months (n = 4). There was a mean stenosis of 13.1% in the 2.5-mm and 13.6% in the 3.5-mm stent. There was no significant narrowing compared with the adjacent control segments of artery; histopathology showed a thin, fibrous neointima with smooth muscle cells. Each atherosclerotic rabbit was balloon dilated at two separate stenotic sites; each site was 2.0 cm in length. The aortic site (with 28.8 +/- 13.8% mean stenosis [+/- SD]) was dilated with a 3.5-mm balloon, and the iliac site (with 36.5 +/- 14.2% stenosis) was dilated with a 2.5-mm balloon. In each site, an intravascular stent of corresponding diameter and 7-mm length was implanted in one half of the dilated segment, assigned randomly, and the other half served as the angioplasty control. Angiographically observed restenosis rates and the corresponding histopathology were similar in the atherosclerotic segments that had angioplasty alone versus the atherosclerotic segments that had angioplasty plus stenting. The mean neointimal thickness in the aortas and iliac arteries, respectively, measured 247 +/- 181 microns (+/- SD) and 218 +/- 77 microns after 6 weeks (n = 8) versus 321 +/- 168 and 308 +/- 189 microns after 20 weeks (n = 5, p = NS). At 20 weeks follow-up, there was 29.1 +/- 29.8% (median, 16.4%) stenosis in the aortic stent versus 38.9 +/- 24.1% (median, 34.0%) stenosis in the percutaneous transluminal angioplasty control segment of aorta (n = 5, p = NS) and 81.4 +/- 25.5% stenosis in the iliac artery stent versus 89.3 +/- 15.3% stenosis in the PTA control segment of the right iliac artery (n = 5, p = NS). Comparing stenotic arterial segments treated with angioplasty alone with angioplasty plus intravascular stenting in the atherosclerotic rabbits showed that there was no significant difference in either the histopathologic changes or the restenosis rates.

Alloys↗

PubMed1990

[Effects of He-Ne laser irradiation on fibroblasts derived from scar tissue of rat palatal mucosa].

This study was carried out to clarify the mechanism of stimulating effects of low power He-Ne laser irradiation on wound healing process of rat palatal mucosa. Experimental wounds were made in 8-week-old male SD rats by surgically excising mucoperiosteum in hard palate. Fibroblasts were cultured from the scar tissue one month after the excision. Cells were investigated ultrascopically and the effects of He-Ne laser irradiation were examined by measuring DNA and collagen synthesis. Thermal change of the medium was also monitored. Cultured cells from the palatal wounds exhibited features of myofibroblasts. They exhibited well-developed bundles of microfilaments in the cytoplasm and had nuclei with foldings. Single irradiation of He-Ne laser at 28J/cm2 stimulated uptake of [3H] Thymidine into myofibroblasts and the stimulating effect decreased time dependently. There was no significant change in collagen synthesis. No thermal change was detected during irradiation. Ultrascopically, dilatation of rER was observed immediately after irradiation at 28J/cm2. But there was no modification in other cytoplasmic structures. The author concludes that He-Ne laser irradiation stimulates DNA synthesis of myofibroblasts without any degenerative changes in the organelle.

Animals↗

PubMed1990

[Surgical treatment of constrictive pericarditis].

Since 1957, 30 patients with constrictive pericarditis have been treated surgically in Kyushu University Hospital. The surgical approaches were the left anterolateral thoracotomy in 17 patients (group I); the median sternotomy without cardiopulmonary bypass (CPB) in 6 patients (group II); and the median sternotomy with CPB in 7 patients (group III). The hospital mortality was 3.3 percent. The mean postoperative follow-up period was 11.7 years (longest 30 years). The actuarial survival rate at 5 years postoperatively was 88% in total cases (100% in group I, 82% in group II and 52% in group III), 88% at 10 years, 75% at 15 years and 67% at 20 years. Several patients in group III, who underwent complete pericardiectomy using CPB showed severe congestive heart failure and arrhythmia postoperatively. The comparative study between an poor result group (patients who died within 10 years post-operatively) and a good result group (patients who survived more than 10 years postoperatively revealed that preoperative hepatomegaly, atrial fibrillation and the interval between the onset of symptoms and the pericardiectomy influenced the survival rate significantly. These results suggested that pericardiectomy using CPB was a safe method for removing the calcified pericardium in the patient with severe constrictive pericarditis. However, a careful long term follow-up was necessary for the patient with severe myocardial damage even though the complete pericardiectomy was performed.

Adolescent↗

PubMed1989

[Clinical assessment of anticoagulation therapy during left ventricular assist with artificial heart: induction with protease inhibitor].

Left ventricular assist device was attached to five patients suffered from severe low cardiac output after open heart surgery. In two patients, anticoagulation therapy with heparin started just after the operation. Repeated operations for hemostasis were required because of massive bleeding in these two patients. Anticoagulation therapy was not performed in another one, and thrombus formation in the device was recognized in this patient. In the other two patients, anticoagulation therapy was started with large dose of protease inhibitor (gabexate mesilate or nafamstat mesilate). Heparin infusion was combined with protease inhibitor during the period of weaning from the device. Thrombosis and massive bleeding were not recognized in these two patients, and they were able to wean from the device successfully.

Aged↗

PubMed1989

[Clinical assessment of prosthetic valve replacement of the right-sided cardiac valves: mechanical or bioprosthesis?].

Clinical results with mechanical and bioprosthetic valve replacements for tricuspid and/or pulmonary positions were reviewed. Between February 1975 and December 1985, 34 bioprostheses (B) (22 Hancock, 9 Ionescu-Shiley and 3 Carpentier-Edwards pericardial) and 18 mechanical prostheses (M) (St. Jude Medical) were implanted in our institute excluding hospital death. Group with B included 29 tricuspid valve replacements and 5 pulmonary valve replacements. Group with M included 9 tricuspid valve replacements, 7 pulmonary valve replacements and 1 both valve replacements. The cumulative follow-up period was 207.2 patient-years (p-t) in group B and 55.0 p-y in group M. The incidence of valve failure was 0.48 +/- 0.48% per p-y in group B and 7.27 +/- 3.64% per p-y in group M (p less than 0.001). The incidence of valve-related events was 1.93 +/- 0.97% per p-y in group B and 9.09 +/- 4.07% per p-y in group M (p less than 0.001). At 3 years, the percent free of valve failure was 100 +/- 0% in group B and 76.8 +/- 10.2% in group M (p less than 0.05). Fourteen bioprosthetic valves (B') and 10 mechanical valves (M') were implanted at the right-sided cardiac valve position alone. The cumulative follow-up period was 94.2 p-y in group B' and 32.3 p-y in group M'. The incidence of valve-related events was 1.06 +/- 1.06% per p-y in group B' and 12.4 +/- 6.19% per p-y in group M' (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1989

[Effects of open-heart surgery on renal function].

Effects of open-heart surgery on renal function were studied in 38 patients who had uneventful postoperative course with no sign of acute renal failure. Of these, 19 underwent aorto-coronary bypass grafting (Group 1) and 19 underwent valve replacement (Group 2). During cardiopulmonary bypass (CPB), renal plasma flow (RPF) and glomerular filtration rate (GFR) significantly decreased in both groups as compared to the preoperative values. The decreased GFR remained significantly low on the day of operation in both groups and returned to the preoperative level on the 1st postoperative day (POD) in group 1 and on the 3rd POD in group 2. On the other hand, plasma antidiuretic hormone (ADH) level markedly increased during CPB and remained significantly higher than the preoperative level through the 1st POD. Despite the decreased GFR and increased ADH, however, urinary flow markedly increased during CPB in both groups and remained at significantly higher level than the preoperative values through the 3rd POD in group 1 and through the 5th POD in group 2. Fractional excretion of sodium significantly increased during CPB in both groups and remained high through the 1st POD in group 1 and through the 3rd POD in group 2. These data demonstrate that the renal function of urine concentration is disturbed in the early phase following open-heart surgery even in the patients who have uneventful postoperative course.

Adult↗

PubMed1989

[Surgical aspect of active infective endocarditis].

Twenty patients with active infective endocarditis, 11 with native valve endocarditis (NVE) and 9 with prosthetic valve endocarditis (PVE), were treated surgically from 1975 through April 1987 at Kyushu University Hospital. The operative indications were congestive heart failure mainly due to massive aortic regurgitation in 18, periannular abscess in 6, major embolism in 5 and severe hemolysis in 3 patients. In the group of NVE, single aortic valve replacement was performed in 4 patients and multiple valve replacement in the remainder. One patient died early postoperatively from LOS. Two patients with recurrent infective endocarditis, which occurred within 60 days after previous prosthetic valve replacement, were operated subsequently as early PVE. All other patients became NYHA class I postoperatively except for one patient who died from thrombosed valve. In the group PVE, re-AVR was done in 3, re-MVR in five, double valve replacement in two and re-fixation of the prosthesis to the aortic annulus in one patient. Two patients with early PVE died from recurrent endocarditis late postoperatively. One of 7 patients with late PVE, who had suffered from myocardial and cerebral infarction before reoperation, died from multiple organ failure. There were 3 patients with perivalvular leakage due to late active PVE, whose preoperative signs of inflammation were negative or minimum. As recurrent perivalvular leakage due to persistent infective endocarditis might frequently occur in such cases, complete resection and debridement of infected foci should be emphasized.

Adolescent↗

PubMed1988

Intraoperative pulmonary embolization by the tip of a Polystan venous return catheter.

In a 10-year-old girl being treated for ventricular septal defect, the tip of a Polystan venous return catheter broke away when the catheter was being removed at the time of bypass disconnection. Following fluoroscopic identification of the tip in the left peripheral pulmonary artery, it was removed via arteriotomy.

Catheterization, Central Venous↗

PubMed1988