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Biomedical subjects

C Oyama

Publications and source records attributed to C Oyama.

At least 19 recordsLinked to original sources
PubMed1995

Usefulness of femoro(ilio)-axillar bypass surgery for the treatment of subclavian steal syndrome caused by aortitis syndrome.

In two patients with subclavian steal syndrome associated with aortitis syndrome, retrograde bypass grafting from the femoral or common iliac artery to the axillary artery resulted in the disappearance of symptoms. One patient, a 37-year-old female, was treated with a bypass from the left femoral artery to the left axillary artery with a 10-mm ring-supported double velour knitted Dacron graft. The other patient, a 54-year-old female, with the complication of moderate aortic regurgitation, was treated with a bypass from the left common iliac artery to the left axillary artery with an 8-mm EPTFE graft. These bypass grafts were angiographically confirmed to be patent after the operation. When changes in graft flow in different body positions (supine, sitting, and standing) were examined, using a transcutaneous Doppler flow meter, 5 years after the operation, resting graft flow to the upper extremities showed no consistent changes among the three different positions and was maintained in a stable condition, regardless of the patients' positions. Furthermore, graft flow increased while the left arm exercised. This finding, together with the clinical efficacy, indicates that this mode of retrograde bypass grafting may be effective in some selected patients with this complicated syndrome.

Adult↗
PubMed1992

[Angioscopic prediction of late vascular patency after transluminal balloon angioplasty for arteriosclerotic obstructions of the artery of the lower extremities].

Arterial occlusion or stenosis of the lower extremity due to arteriosclerosis obliterans (ASO) was treated by transluminal balloon angioplasty (TBA). Angioscopic observation of the vascular lumen, performed immediately after TBA, provided five major findings: (1) abrasion of the intima, (2) irregularity of the lumen due to poor expansion, (3) laceration of the wall, (4) mural thrombus and (5) calcification. The degree of each of these abnormalities was scored with a 3-grade scale (0, 1 and 2), and scores for the 5 abnormalities were totaled in each patient. Analysis of the relationship between scores and postoperative vascular patency demonstrated that patients without vascular patency in the early (within 6 months) or late period (6 months or more) after the operation had higher total scores as compared to those in whom the vessel remained patient in the corresponding postoperative periods (p less than 0.01, p less than 0.05). Among others, patients with a total score over 5 showed markedly lower patency rates in the early period (10%) as well as late period (0%) after the operation (p less than 0.01). These results indicate the usefulness of post-TBA angioscopic observation of vascular lumen in predicting the long-term patency of the vessels operated on.

Aged↗
PubMed1990

[Prostate specific monoclonal antibody gained by glycolipid immunization].

Extraction of glycolipid component from hypertrophic and cancerous prostatic tissue were performed using chloroform-methanol solution and isopropanol-hexan-solution. The extract was separated into the "upper phase" and "lower phase" by Folchs fractionation technic. Each fraction was conjugated with acid treated salmonella minesota and than it was injected subcutaneously, intra-peritoneally and finally intravenously to BALB/c mice. Spleen cells from immunized mice were fused with P3X63, and antibody APG1 was obtained. APG1 shows a preferential reactivity towards prostatic tissue by the immunohistochemical analysis. Furthermore, the immunohistochemical analysis using enzyme and acid treated tissue and TLC immunostaining indicate that this monoclonal antibody specifically recognizes the sialylglycochain expressed in the prostatic tissue.

Adenocarcinoma↗
PubMed1989

[A right common iliac aneurysm perforating into the inferior vena cava with resultant congestive heart failure].

A 69 year-old male with a right common iliac aneurysm perforating into the inferior vena cava was admitted with severe cardiomegaly and dyspnea. He had been suffering from recurrent congestive heart failure for the last 8 years prior to surgery. At operation, the fistula of 15mm diameter was closed with interrupted sutures of 3-0 nylon with pledgets within the aneurysm by controlling bleeding from the fistula by digital compression. The right common iliac aneurysm was resected and replaced with a double velour knitted dacron graft of 10mm diameter. The postoperative course was uneventful. The CTR was reduced to 57% from 70%, and the cardiac index was normalized from 6.10 to 3.39 l/min/m2. This complication is rare with only 4 previous reports in Japan. Hemodynamic improvements were dramatic after surgery in spite of poor response to medical treatments. This complication should be surgically managed as soon as the diagnosis is confirmed.

Aged↗
PubMed1988

Relations of preoperative hemodynamics and coronary blood flow to improved left ventricular function after valve replacement for aortic regurgitation.

In this study of the limits of reversibility of left ventricular function after aortic valve replacement for aortic regurgitation, measurements were made of pre- and postoperative coronary blood flow and left ventricular volumes. Eighteen patients who had undergone aortic valve replacement for pure aortic regurgitation using the Björk-Shiley valve or the Bicerval valve were restudied an average of 8 +/- 3 months after surgery. Postoperative left ventricular end-systolic and end-diastolic volumes returned to near normal values. The slight left ventricular wall thickening apparent before surgery remained unchanged after surgery and, consequently, left ventricular mass, though somewhat reduced, remained abnormally high. Ejection fraction, which was low preoperatively, returned to normal postoperatively. Total coronary sinus blood flow decreased after surgery, but coronary sinus blood flow per 100 g of left ventricular mass increased. This recovery of coronary flow per unit mass was believed to cause the improvement in left ventricular function. A significant correlation was found between postoperative systolic function and preoperative left ventricular end-systolic and end-diastolic volumes, wall thickness and, especially, left ventricular mass, the latter indicating that, if preoperative left ventricular mass is less than 350 g/m2, postoperative improvement of systolic function is attainable. Another significant correlation was indicated by measurements of coronary sinus blood flow per 100 g of left ventricular mass. If this is greater than 35 ml/min before surgery, a postoperative improvement in systolic function to within the normal range may be expected.

Adult↗
PubMed1987

Results of internal mammary artery-coronary artery bypass surgery and the characteristics of internal mammary artery grafts.

Coronary artery bypass grafting utilizing the internal mammary artery (IMA) was performed in 108 patients with an operative mortality (less than 1 month) of 0% and a hospital mortality of 1.9%. The IMA was used most often in the left anterior descending artery system in combination with saphenous vein grafts (SVG) to the right and left circumflex artery systems. Although the IMA flow was smaller than the SVG flow when measured intraoperatively by an electromagnetic flow meter, postoperative clinical, electrocardiographic, isotopic, angiographic and coronary sinus flow-metric studies all demonstrated that the IMA can respond well to myocardial blood flow demand both at rest and during exercise, resulting in excellent clinical improvements with no detectable signs of flow deficiency. In addition, no signs of ischemia were detected in any of the 15 patients with stenosis in the left main trunk treated with an IMA graft. The IMA graft appears to have a great adaptive capacity to meet increased myocardial demand. Postoperative angiography performed at an average of 3 months after surgery in 60 unselected patients demonstrated an IMA patency rate of 98% in comparison with 88% patency in SVGs to the left anterior descending artery (p less than 0.05). Not only the patency rate, but also the graft wall characteristics were much better in IMA grafts than in SVGs. Some SVGs showed marked wall irregularity as early as 3 months after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Changes in myocardial oxygen consumption and coronary sinus blood flow before and after resection of left ventricular aneurysm after myocardial infarction.

The patients in this study consisted of eight men who underwent resection of left ventricular aneurysm. Right and left heart catheterization at rest and measurement of coronary sinus blood flow by continuous thermodilution were performed preoperatively and an average of 6 months after the operation. Coronary sinus blood flow decreased significantly from 161 to 118 ml/min and myocardial oxygen consumption decreased significantly from 17.2 to 10.5 ml/min postoperatively. Cardiac index increased postoperatively. Ejection fraction increased from 0.31 to 0.49 and mean velocity of circumferential fiber shortening significantly increased from 0.53 to 1.0 circ/sec postoperatively. Left ventricular end-diastolic volume decreased significantly from 166 to 120 ml/m2 postoperatively. The mean systolic circumferential tension significantly decreased postoperatively. We believe that the decrease in wall tension postoperatively brought about the reduction in myocardial oxygen consumption. Thus the high wall tension and myocardial oxygen demand, present preoperatively, were improved postoperatively, with a resultant lowering of oxygen consumption and equivalent or better left ventricular function.

Adult↗
PubMed1986

Coronary sinus blood flow and myocardial oxygen consumption after valve replacement for aortic insufficiency.

Seven cases are reviewed in which the aortic valve was replaced with a Björk-Shiley tilting disk valve to treat aortic insufficiency. Comparative studies were made to determine coronary sinus blood flow (CSF) and myocardial oxygen consumption (MVO2) by using a continuous thermodilution method both before and after the operation. Additionally, indexes of left ventricular function were obtained by catheterization of the right and left heart and by left ventriculography. Postoperative total CSF decreased significantly compared with the preoperative value (p less than 0.02). However, in all cases, the postoperative CSF per 100 g of left ventricle (LV) increased compared with the preoperative measurement (p less than 0.001). The CSF per beat per 100 g LV also increased postoperatively (p less than 0.001). Total MVO2 decreased postoperatively (p less than 0.02). However, the MVO2 per unit mass tended to increase postoperatively; these increases were not significant. Postoperatively the left ventricular mass and left ventricular wall stress decreased considerably. The left ventricular ejection fraction (EF) and the mean velocity of circumferential fiber shortening (mVCF) remained at normal levels, whereas the left ventricular function improved markedly. In short, the total CSF decreased, along with LVM and left ventricular wall stress. However, because CSF per unit mass increased and EF and mVCF remained at normal values, it is assumed that the increase in CSF is associated with improvement in postoperative contractility.

Adult↗