Biomedical subjects

S Minohara

Publications and source records attributed to S Minohara.

35 records · Page 2Linked to original sources

PubMed1994

[Reoperation for mitral valve disease].

From 1978 to March 1994, 95 patients underwent repeated open heart surgery for mitral valve diseases. There were 48 men and 47 women. The mean age was 50 and the mean interval between initial and second operation was 8 years. The initial operations were OMC in 39, MAP in 13, OMC+MAP in 11, MVR in 30 and AVR in 2 patients. The hospital death occurred in 31 cases (32.6%). In recent cases, however the hospital death were reduced to 4 (14.8%). This was attributed to the change in myocardial protection from previous intermittent antegrade crystalloid to recent continuous combined antegrade and retrograde cardioplegia.

Adolescent↗

PubMed1993

[Risk factors and therapeutic methods for sternal wound infection following cardiac surgery].

In a study of 1040 patients undergoing cardiac surgery at The Osaka Medical College Hospital from 1984 through 1991, we analyzed the correlation between a variety of preoperative and operative parameters and the risk of postoperative sternal wound infection, as well as the efficacy of various therapeutic method for this condition. Sternal infection or mediastinitis developed after cardiac surgery in 31 patients (3.0%). As the risk factors for wound infections, age, diabetes mellitus, reexploration, duration of cardiopulmonary bypass and use of bilateral internal thoracic artery grafting were listed. Application of pectoral muscle flaps significantly led to shorten a duration between diagnosis of infection and hospital discharge, and increased survival rate, than the other treating methods such as debridement or irrigation. We conclude that bilateral internal thoracic artery grafts should not be used in the cases with diabetes, and closure with pectoral muscle flaps is effective for sternal infection and mediastinitis.

Coronary Artery Bypass↗

PubMed1993

Dosimetry and measured differential W values of air for heavy ions.

Heavy-ion irradiation systems were designed and constructed at two cyclotron facilities in Japan for use in various fields of radiation physics and radiation biology. A 135 MeV/u carbon beam as well as 12 MeV/u carbon and helium-3 beams were first used in experiments. We have established a systematic method for heavy-ion dosimetry at both high and low incident energies involving measurements of fluences. We also obtained differential W values (w) of air for those beams by comparing the results of fluence measurement dosimetry with ionization chamber dosimetry. The differential W values of air were found to be 36.2 +/- 1.0, 34.5 +/- 1.0, and 33.7 +/- 0.9 eV for 6.7 MeV/u carbon ions, 10.3 MeV/u 3He ions, and 129.4 MeV/u carbon ions, respectively. The w value for high-energy heavy ions approaches the W value for high-energy electron or photon beams. In ionization chamber dosimetry for a heavy-ion beam, we found a track-size effect. A difference in the track sizes of heavy ions in the gas and solid phases affected the output current of the ion chamber in the case of high-energy heavy ions.

Carbon↗

PubMed1993

[The effect of Ryanodine for the myocardial protection in the working heart model of rabbit].

The purpose of this paper is to evaluate the effects of Ryanodine for myocardial protection. Twenty-four rabbits were studied using the working heart model divided four groups. The first is control group with no Ryanodine, the second is 10(-9) M, the third is 10(-8) M and the last one is 10(-7) M Ryanodine with GIK cardioplegic solution respectively. The hemodynamics was studied and the elemental concentrations (Ca, Mg, K, Na, Cl) of myocardial cell was measured using X-ray microanalysis. The results showed that intracellular Ca accumulation was dose-dependently suppressed with Ryanodine during reperfusion and also Ryanodine was significantly effective to maintain the hemodynamics during same one.

Animals↗

PubMed1992

[A case report of aorto-pulmonary window associated with atrial septal defect].

The patient was a one-year-old boy, who underwent surgery with a diagnosis of atrial septal defect (ASD). During operation, aorto-pulmonary window (A-P window) which had not been detected by the preoperative examinations, was found. Therefore, the A-P window was divided prior to closing ASD. The patient is in good condition six months after the operation. The causes of the inaccurate preoperative diagnosis were discussed.

Aortopulmonary Septal Defect↗

PubMed1992

[Coronary artery bypass utilizing vein grafts: why didn't we use an arterial graft?].

Internal thoracic artery (ITA) grafts for coronary artery bypass grafting (CABG) are superior to SVG in the long-term patency and survival. In spite of our effort to utilize ITA whenever possible, we still have some cases which have to receive only vein grafts. Among the consecutive 201 patients undergoing CABG in the past three years, 32 patients (16%) received only vein grafts. We compared these patients (SVG group) with those who received ITA grafts (ITA group). The SVG group consisted of all emergency cases and many cases with single and double vessel disease. In the SVG group, perioperative use of IABP was more frequent and operative mortality was higher, although the number of grafts was fewer (2.66 vs 3.61) and aortic cross clamping time was shorter in this group. Main reasons for selecting only vein grafts were emergency surgery, inadvertent injury of ITA, inadequate ITA free flow etc. Technical refinement in the preparation of ITA is important to make possible wider application of arterial grafts for CABG.

Aged↗

PubMed1992

[The results and problems of reoperation for coronary artery disease].

In six hundred and six consecutive patients undergoing coronary artery bypass grafting (CABG) within the past 17 years (May 1974 to March 1991), repeated CABG were performed on 10 patients (1.65%). The main reasons for repeated CABG were graft failure (GF) in 8, progression of native disease (NP) in 5 and incomplete revascularization (IR) in 3 patients. The incidence of GF was high either within a half year or around 5 years after CABG. Although all patients survived from reoperation, four patients continued to have mild angina pectoris. When the recurrence of angina is noted after CABG, coronary arteriography and if necessary PTCA should be done as soon as possible. If a second surgery is inevitable, maximum utilization of arterial graft and accomplishment of complete revascularization are emphasized.

Aged↗

PubMed1991

[The effects of dopamine on the renin-angiotensin-aldosterone system after extracorporeal circulation].

Thirty-one patients underwent elective coronary bypass grafting were studied about the effects of dopamine (DOP) on the renin-angiotensin-aldosterone system (RAAS) for 24 hours after extracorporeal circulation (ECC). All of them had no evident of renal dysfunction nor other complication preoperatively. Patients were divided according to the administration of DOP 5-10 micrograms/kg/min (group D, n = 16) and control group without any catecholamine including DOP (group N, n = 15). Criteria for DOP administration were systolic blood pressure less than 100 mmHg and central venous pressure greater than 15 cmH2O. Hemodynamically no significant difference was observed between the two groups. The RAAS was activated by ECC in both groups. Plasma renin activity (PRA) and plasma angiotensin II-levels (AII) returned to normal range at 6 hours after ECC in group D which is significantly less than group N where PRA and AII remained elevated at 24 hours after ECC. Plasma aldosterone levels (ALD) did not show any significant difference between the two groups. AII changed proportionately to PRA, whereas ALD did not correlate with PRA or AII in the both groups. These results suggested that in early postoperative period angiotensin II didn't cause peripheral vasoconstriction in group D, and administration of DOP in doses of 5-10 micrograms/kg/min resulting in a low level of AII is safe and useful in view of data that a high AII promotes multifocal myocardial necrosis and renal tubular degeneration.

Adult↗

PubMed1991

[Utility and limitation of sequential saphenous vein graft for complete revascularization in coronary artery surgery].

Multiple bypass grafting in complete myocardial revascularization requires frequently the use of sequential saphenous vein grafts as well as arterial grafts. To expect the favorable good clinical results of revascularization, therefore, refined surgical technique for saphenous vein grafting and proper selection of suitable coronary arteries for bypass are important. Between January 1989 and April 1990, 91 patients underwent CABG utilizing internal thoracic arteries (ITA) in 79% and SVG in 99% of the patients with an average of 3.3 anastomoses per patients. Postoperative angiography was performed 4 or 8 weeks after surgery. Early patency rates were 92% (204/221) in overall anastomotic sites, 96% (52/54) in ITA and 91% (152/167) in SVG respectively. There was no difference in patency rates between individual (90%) and sequential (92%) grafts. In sequential grafting, however, patency rate of side-to-side anastomosis was higher than that of end-to-side anastomosis. Patency rates of the grafts were also evaluated in terms of the sizes of coronary arteries and intraoperative graft flows. These studies lead to the following conclusions: In individual grafting, the acceptable patency rate can be expected when the graft flow exceeds 30 ml/min even if the internal diameter of coronary artery is less than 1.5 mm. In sequential grafting, on the other hand, a diameter more than 1.5 mm is desirable for the coronary artery at the site of end-to-side anastomosis.

Adult↗

PubMed1990

Easy dissection of hard and thickened pericardium on constrictive pericarditis.

The keys to successful pericardiectomy for constrictive pericarditis are early operation and as complete a pericardiectomy as possible. With the high-speed burr it is easy and safe to dissect the calcified pericardium and define the epicardium even in a small operative field such as the inferior or posterior portion of the heart. This method has the important ability to perform very complete pericardiectomy.

Adult↗

PubMed1990

[Results of sequential aorto-coronary bypass grafting using saphenous vein graft].

Seventy patients underwent sequential coronary artery bypass grafting with saphenous vein during 28 months period. Seventy eight sequential grafts comprising 165 distal anastomoses were performed. Early death was 2.9%. Postoperative angiographic evaluation within 6 months showed 86% patency of the 65 sequential grafts and 89% patency of the 136 distal anastomoses. The patency of anastomosis to left anterior descending artery (LAD), diagonal branch (Dx), obtuse marginal branch (OM), posterior lateral branch (PL), and posterior descending branch (PD) was 87% (13/15), 92% (36/39), 91% (40/44), 81% (26/32) and 100% (6/6), respectively. The patency of Dx-LAD, Dx-OM and OM-PL was 86% (12/14), 94% (15/16) and 76% (13/17), respectively. There was no significant difference in the patency rate according to the site of anastomosis and the inner diameter of the coronary artery. The patency of side to side anastomoses was 92% (65/71) which was not significantly different from that of the end to side anastomoses; 86% (56/65). These results showed sequential aorto-coronary vein grafting means to be effective for the complete coronary artery revascularization .

Aged↗

PubMed1989

[Successful repair of post-operative rupture of the left ventricular wall after mitral valve replacement].

Rupture of the left ventricular wall after mitral valve replacement (MVR) is a rare but lethal complication, particularly in delayed type. We have encountered five cases of this complication, and the last case who was suffered 6 hours after MVR was successfully repaired. This case is a 56-year-old woman with MS. She underwent MVR with a Duromedics 25 M. She was transferred to the ICU and the postoperative course was uneventful until 6 hours after the operation, then bleeding from chest drainage tubes increased suddenly. She was promptly brought to the operating room, and the cardiopulmonary bypass was restarted. A tear and hematoma at the posterior wall of the left ventricle (Type II perforation) were found. The rupture was closed with three interrupture mattress sutures with a teflon felt strip. Bleeding was decreased, but oppression with sponge was applied to small but continuous bleeding. At present, she is in a good condition without occurrence of pseudoaneurysm of the left ventricle. We investigated our own five cases and sixty cases reported in Japan, and etiology, surgical repair and prevention of this complication were discussed.

Adult↗

PubMed1989

[Multiple cerebral infarction following coronary artery bypass grafting for the patient with calcified aorta--a case report].

The cardiac surgeon occasionally may encounter a diseased or rigidly calcified aorta in the patient requiring myocardial revascularization. In this paper, a 72-year-old woman who suffered from neurological injury following coronary artery bypass grafting due to embolization of atheromatous debris from the calcified ascending aorta was described. A review of the literature was also performed to emphasize the importance of the recognition, and management of the calcified and diseased ascending aorta.

Aged↗

PubMed1988