Biomedical subjects

T Isomura

Publications and source records attributed to T Isomura.

At least 37 records · Page 2Linked to original sources

PubMed2000

[Surgery for idiopathic cardiomyopathy].

Among the patients with idiopathic cardiomyopathy, those with dilated cardiomyopathy were surgically treated. Initial 18 patients were treated with partial left ventriculectomy(PLV) and thereafter PLV in 26 patients, septal exclusion technique (EVCPP) in 5 patients, or solo-valvular surgery in 12 patients were applied according to the findings of the intraoperative cardiac echogram. The postoperative morbidity and mortality decreased after the selection of the operative procedures. Conclusively, left ventriculoplasty with PLV or EVCPP is a hope for the patients with dilated cardiomyopathy.

Adolescent↗

PubMed2000

[Combined valve and coronary artery bypass surgery].

Between January 1997 and November 1999, 31 patients underwent combined valve and coronary artery bypass grafting (CABG) surgery in our institute. There was no hospital death and clinical symptom improved in all patients after surgery. Mean follow-up was 16.3 months. The actuarial survival rate was 96.8% at 1 year. There were 4 late deaths (CHF in 3, arrhythmia in 1). Tepid blood cardioplegia was effective for those operations. Operation of CABG combined with valve surgery or LV surgery could be safely performed. We therefore considered that complete correction of the lesion with not only CABG but also combined valve surgery or LV surgery was the procedures of choice in patients with complicated lesions.

Aged↗

PubMed2000

[Coronary artery bypass grafting without cardiopulmonary bypass in 200 patients].

OBJECTIVES: To evaluate the efficacy of off pump coronary artery bypass grafting (CABG), results in the initial consecutive 200 patients were reviewed. METHODS: Between October 1996 and December 1999, 200 patients underwent CABG without cardiopulmonary bypass. There were 146 men and 54 women aged from 27 to 89 years (mean 68 years). Single, double, triple and left main disease were noted in 94, 55, 33 and 18 patients, respectively, with a mean ejection fraction of 51%. Preoperative complications were previous stroke in 34 patients, chronic renal failure in 22 patients, previous CABG in 18 patients, and aortoiliac aneurysm or occlusive disease in 14 patients. Fifty-five patients (28%) were 75 years or older. Surgical approach was made through a midsternal incision including lower half small sternotomy in 105 patients, left anterior small thoracotomy in 92 and small epigastric incision (gastroepiploic-right coronary anastomosis) in 3. Mean number of distal anastomoses was 1.3 (range 1-4). Anastomosis was performed in 189 left anterior descending, 13 diagonal, 27 circumflex and 41 right coronary arteries. The conduits were 174 internal thoracic, 10 internal thoracic-inferior epigastric composite, 22 right gastroepiploic and 5 radial arteries, and 50 saphenous vein grafts. Four patients underwent combined off pump CABG and transmyocardial laser revascularization, and 36 patients underwent hybrid (off pump CABG and angioplasty) revascularization. RESULTS: Four patients (2.0%) died in the hospital due to intestinal necrosis in 2 patients, postoperative aortic dissection in one, and multiorgan failure with stroke in one. No serious ventricular tachyarrhythmia or use of intraaortic balloon pump occurred. Perioperative myocardial infarction was noted in one patient. Stroke occurred in 4 patients (2.0%) but 3 patients recovered in a short period. Three-year survival and cardiac event free rate were 90.3% and 81.1% by the Kaplan-Meier method. Postoperative angiographic study showed excellent patent graft in 92% of grafts (192/209), stenosed (> or = 50%) graft in 5% (10/209) and occlusion in 3% (7/209). CONCLUSIONS: Off pump CABG can be performed safely and effectively in both high risk and low risk patients with coronary artery disease. Refinement of surgical technique and equipment will make this procedure more useful.

Adult↗

PubMed1999

Isolated effect of partial left ventriculectomy for dilated cardiomyopathy: a case report.

A 38-year-old man underwent the Batista operation to treat end-stage dilated cardiomyopathy. There was no associated mitral regurgitation, so only partial left ventriculectomy was performed. The patient recovered successfully. His New York Heart Association (NYHA) class improved from IV to I, ejection fraction increased from 8% to 37% and left ventricular diastolic dimension decreased from 89 to 68 mm. Cardiac output and stroke volume increased from 3.8 to 6.7 l/min and from 52 to 85 ml/min, respectively. This case shows the isolated positive effect of partial left ventriculectomy without mitral valve reconstruction.

Adult↗

PubMed1998

Minimally diluted tepid blood cardioplegia.

BACKGROUND: To evaluate the effects of minimally diluted tepid blood cardioplegia, a prospective, randomized study was undertaken. METHODS: Thirty-seven patients undergoing isolated primary coronary artery bypass grafting were randomized to receive standard 4:1 diluted tepid blood cardioplegia (4:1 group, n = 18) or minimally diluted tepid blood cardioplegia (Mini group, n = 19). Cardioplegic solution was delivered in an intermittent antegrade fashion in both groups. Myocardial oxygen and lactate metabolism, release of the MB isoenzyme of creatine kinase and thiobarbituric acid reactive substances, and cardiac function were measured during and after the operation. RESULTS: Myocardial oxygen consumption was significantly greater and lactate release was significantly lower in the Mini group than in the 4:1 group during cardioplegia. Minimally diluted blood cardioplegia resulted in more prompt resumption of lactate extraction, lower levels of release of the myocardial-specific isoenzyme of creatine kinase and thiobarbituric acid reactive substances during reperfusion, and better postoperative left ventricular function compared with the standard 4:1 cardioplegia. CONCLUSIONS: Minimally diluted tepid blood cardioplegia may provide superior myocardial protection than the standard 4:1 dilution technique by optimizing the aerobic environment through an increase in oxygen supply during intermittent cardioplegia.

Adult↗

PubMed1998

Interobserver agreement in sonographic diagnosis of breast tumors.

OBJECTIVE: To evaluate interobserver agreement in the interpretation of breast ultrasonography. METHODS: 55 breast masses (30 benign, 24 malignant) were interpreted by seven radiologists using a CRT viewing station. US criteria for differentiating between benign and malignant lesions included shape, border, boundary echoes, internal echoes, posterior echoes, and bilateral shadows. Each criterion and the observers' final impression was scored using the 5-point rating scales. For analyzing interobserver agreement, the kappa (kappa) values were employed. RESULTS: The kappa values of shape and posterior echoes were significantly higher than those of the other four criteria (P<0.05). Agreement was intermediate in border and internal echoes, and was low in boundary echoes and bilateral shadows. Agreement in the senior group (four observers) was relatively higher than that in the junior group (three observers) for all criteria but for internal echoes. Easily-diagnosed cases showed significantly higher kappa values compared with more ambiguous cases (P<0.05). CONCLUSION: Interobserver agreement in shape and posterior echoes was significantly higher than those of the other four criteria. Agreement was significantly dependent on case difficulty.

Breast Diseases↗

PubMed1998

Use of the Harmonic Scalpel for harvesting arterial conduits in coronary artery bypass.

A simple and effective technique is described here for harvesting the gastroepiploic artery (GEA) and radial artery (RA) using the Harmonic Scalpel. The mean time of harvesting GEA was 9 min and that of RA was 17 min. There were no injuries or spasms of those grafts and the postoperative angiograms performed in 28 patients. This shows 100% patency of the conduits. The GEA and RA are safely harvested by using the Harmonic Scalpel and the use of arterial conduits in coronary artery bypass grafting (CABG) seems to be easily achieved.

Aged↗

PubMed1998

Disaccharide analysis of heparin and heparan sulfate using deaminative cleavage with nitrous acid and subsequent labeling with paranitrophenyl hydrazine.

Compositional analyses of heparin (Hep) and heparan sulfate (HS) have been undertaken with disaccharide units obtained by either enzymatic digestion with heparitinases or hydrazinolysis/deamination reaction of polysaccharides. Unsaturated disaccharide units generated by the enzymatic method are detectable on HPLC with a uv detector recording absorbance at 230 nm. On the other hand, disaccharide units generated by the chemical method possess a component of 2,5-anhydromannose (AnMan) bearing aldehyde groups in addition to intact iduronic acid (IdoA) or glucuronic acid (GlcA). The aldehyde groups of the disaccharide units are usually reduced with sodium borotritide, and detected by radiochromatography. Both of them, however, involve inevitable experimental problems, such as the use of costly enzymes and radioisotopes. In the present study, we have established a novel composition analysis system for Hep and HS essentially based on the chemical method. After hydrazinolysis/deamination treatment of Hep and HS, the aldehyde groups of AnMan in the disaccharide units generated were coupled with paranitrophenyl (PNP-) hydrazine instead of reduction with sodium borotritide, AnMan-CH=N-NH-PNP (AnMan-PNP) being formed. Then, the PNP-labeled disaccharides were pre-treated on a SepPak C-18 cartridge column, and subsequently separated and detected on ion-pairing reversed-phase HPLC with a detector recording absorbance at 390 nm. With the present system, the order of elution was GlcA-AnMan-PNP (GM), IdoA-AnMan-PNP (IM), IdoA(2S)-AnMan-PNP (ISM), IdoA-AnMan(6S)-PNP (IMS), and IdoA(2S)-AnMan(6S)-PNP (ISMS). As an application, the disaccharide compositions of heparin from bovine intestine and heparan sulfate from bovine kidney were analyzed by the present method, and the results were comparable to those obtained by a well-established enzymatic method. The present compositional analysis was demonstrated to be reliable and economical.

Acetylation↗

PubMed1998

[Early result of volume reduction left ventriculoplasty (Batista operation) for dilated cardiomyopathy].

The Batista operation is intended to improve cardiac function by reducing the diameter of the left ventricle by excising of a sizable amount of the left ventricular free wall. Candidates for this operation are patients awaiting cardiac transplantation due to end-stage dilated cardiomyopathy and those unsuitable for transplantation because of age, physical or economical reasons. We performed this operation in 10 patients between December 1996 and October 1997. The baseline indication is left ventricular diastolic dimension > or = 70 mm and New York Heart Association (NYHA) class III or IV. There were eight men and two women aged from 16 to 60 years (mean 46 years). All had non-ischemic cardiomyopathy including seven idiopathic and one each of hypertrophic, arrhythmogenic right ventricular and valvular (sarcoidosis) cardiomyopathy. Eight patients were in NYHA class IV and six needed inotropic drip therapy prior to the operation. Nine patients had significant mitral regurgitation and six had tricuspid insufficiency concomitantly. Eight patients underwent mitral valve replacement and one was treated with mitral valve plasty. Six patients also had tricuspid plasty combined with partial left ventriculectomy. Eight patients survived. Mean value of left ventricular end-diastolic diameter was reduced from 77.8 mm to 59.8 mm, left ventricular end-diastolic volume index was reduced from 189.3 to 99.2 ml/m2, ejection fraction was increased from 19.0% to 33.8% and NYHA class improved from 3.8 to 1.8. Six months later, left ventricular dilatation was not noticed in four patients examined. The Batista operation offers real hope for patients with end-stage dilated cardiomyopathy, but we still have much to learn.

Adolescent↗

PubMed1998

[Dor operation for end-stage ischemic cardiomyopathy].

Endoventricular circular patch plasty (Dor operation) was used to treat end-stage dilated ischemic cardiomyopathy in 13 patients from January to December, 1997. There were 10 men and three women aged from 57 to 78 years (mean 63 years). Single, double, triple and left main trunk coronary disease was present in one, two, eight and two patients, respectively. Mean ejection fraction was 22% (6-30%) and signs of congestive heart failure were clear in all patients [New York Heart Association (NYHA) class III in eight patients and class IV in five patients]. Angina pectoris was present in five patients. Six patients had associated significant mitral regurgitation. Coronary artery bypass grafting (mean 3.2 grafts) was used in 11 patients and mitral valve reconstruction was performed in 6 patients (4: replacement and 2: repair) combined with akinetic area exclusion by the Dor technique. All patients were successfully weaned from cardiopulmonary bypass without mechanical support and no perioperative death occurred. Three patients died in hospital at 1-2 postoperative months due to pneumonia, stroke and heart failure, respectively. Two patients died during the late period due to stroke and sudden death. Among the eight survivors, six patients were in NYHA class I-II and two patients in class III. Ejection fraction increased from 22% to 36%, end-diastolic and systolic volume indices decreased from 168 +/- 58 to 123 +/- 39 ml/m2 and from 131 +/- 60 to 81 +/- 33 ml/m2, respectively. Pulmonary capillary wedge pressure decreased from 19 +/- 10 to 14 +/- 5 mmHg. The Dor procedure is an effective surgical alternative for patients with end-stage ischemic cardiomyopathy who are considered to be candidates for cardiac transplantation.

Aged↗

PubMed1998

[Minimally invasive direct coronary artery bypass for ischemic heart disease associated with preoperative severe complications].

Our experiences of minimally invasive direct coronary artery bypass (MIDCAB) were reported with review of literatures. Patient #1 was a 69 years-old man with left main lesion associated with cerebral infarction and impaired renal function. Preoperative CT examination showed calcified ascending aorta. There was no significant lesions in the large right coronary artery and the circumflex was small. The patient underwent MIDCAB via minithoracotomy on the fourth intercostal space with left internal thoracic artery (ITA) to left anterior descending artery (LAD). The patient was weaned from ventilator 3 hours after the operation and his postoperative course was uneventful. Patient #2 was a 80 years-old man with acute myocardial infarction requiring intraaortic balloon pumping (IABP) due to significant stenosis in the right coronary artery and left main lesion associated with chronic hemodialysis due to renal failure. The right coronary artery was dilated by balloon angioplasty at the time of emergency coronary angiogram. However, the emergent operation was required because of the left main lesion. The circumflex was relatively small and because of severe complication, MIDCAB was selected to improve his condition. He underwent MIDCAB via minithoracotomy. The heart was enlarged because of congestive heart failure and left inferior epigastric artery was used to extend the length of the left ITA. The composite graft of ITA and IEA was anastomosed to the LAD under beating heart. The IABP was removed 8 hours after the operation and his postoperative course was uneventful. The MIDCAB for coronary artery bypass was first reported by Benetti et al in 1995 and the procedure seemed to be very effective for preventing postoperative complications in selected patients as seen in ours.

Aged↗

PubMed1998

Bilateral thoracotomy for coronary artery bypass grafting in a patient with unfavorable median sternotomy.

In this report, we describe a patient who underwent coronary artery bypass grafting (CABG) through bilateral thoracotomy and distal median sternotomy, because he had received terminal tracheotomy as a treatment to prevent aspiration pneumonia due to Wallenberg's syndrome. On the first day after the terminal tracheotomy, he suddenly complained of severe anterior chest pain. Emergency coronary angiogram revealed complete occlusion of the proximal right coronary artery (RCA), severe stenosis of the left anterior descending artery (LAD) and the large first diagonal branch. Catheter intervention for RCA was attempted but it was unsuccessful, and therefore he was required to have urgent operation. The patient had received total laryngectomy and terminal tracheotomy two weeks before urgent CABG, and the large hole of the tracheotomy was just placed above the incisura juglaris of the sternum. So high risks of sternal infection and severe mediastinitis after ordinary median sternotomy were considered and we applied the bilateral thoracotomy approach. To our knowledge, this is very rare but effective approach to vascularize both right and left coronary artery and to use both left internal thoracic artery (LITA) and gastroepiploic artery (GEA) graft. It seemed that this approach is safe and effective for cardiac surgery in such situations that median sternotomy is not favorable as in the described patient or in patients having reoperation.

Coronary Angiography↗

PubMed1998

Two-year experience of the Batista operation for non-ischemic cardiomyopathy.

The Batista operation was performed in 30 patients (25 men and 5 women, mean age 47 years) to treat cardiac failure due to non-ischemic cardiomyopathy, mostly idiopathic dilated cardiomyopathy, from December 1996 to June 1998. Preoperative New York Heart Association (NYHA) class was IV in 21 patients including 17 receiving inotropic support, and class III in 9 patients. Seven patients required emergency surgery because of on-going shock and 23 patients were operated electively. Combined cardiac procedures were; mitral valve reconstruction in 26 patients (19 replacements, 7 repairs), tricuspid annuloplasty in 15, aortic valve replacement in 3 and one each of maze and coronary artery bypass grafting. All patients successfully weaned from cardiopulmonary bypass. Intraaortic balloon pump was used in 6 patients but no left ventricular assist device was used. Two of 23 patients (8.7%) who underwent elective operation died during hospitalization and 3 patients (13.0%) died in the late period. Six of 7 patients (85.7%) with emergency operation died in the hospital and only one survived. Sixteen of 19 survivors returned to NYHA class I-II, and 3 were in class III. Mean ejection fraction increased from 18 +/- 6% to 31 +/- 5%. Diastolic dimension decreased from 79 +/- 8 to 60 +/- 8 mm. End-diastolic and systolic volume indices decreased from 203 +/- 43 to 103 +/- 25 ml/m2 and from 164 +/- 39 to 70 +/- 25 ml/m2, respectively, at the second postoperative week. Six patients had ventriculography at one year after the operation, and no redilation was noted. Increased thickness of left ventricular wall was observed postoperatively. The Batista operation can be performed with relatively low risk and clinical improvement was obvious in elective operation, wheras risk is very high in emergency cases. Therefore, proper guidelines for patient selection and choice of procedure are critically important to achieve a successful outcome in the Batista operation.

Adolescent↗

PubMed1997

Development of computer assisted orthosis design and manufacturing system for malformed ears.

Most cases of malformed ears in neonates can be treated by mounting a suitably shaped orthosis. Our objective was to develop a computer-assisted orthosis design and manufacturing system for the treatment of malformed ears. Also, we aimed to manufacture a first experimental orthosis made of nitinol shape-memory alloy wire. First, the target posttherapeutic auricular shape is input from computed tomography scans, and characteristic points and contours are extracted. The shape of the orthosis is then created by tracing the necessary contours automatically. Finally, the orthosis shape data are projected onto one or more approximate planes and autoconverted into numerical control (NC) data for plate groove processing. The nitinol shape-memory alloy wires are inserted in the groove and the shape is memorized by heat treatment. The shape of the manufactured orthosis can be memorized from the generated NC data within 1.0 mm of error. Stahl's ear in a 9-month-old baby was treated 7 months ago by mounting the orthosis manufactured by the system. The developed system allows the design and manufacture of orthoses made of nitinol shape-memory alloy wire for the treatment of malformed ears.

Alloys↗

PubMed1997

Coronary artery revascularization concomitant with vascular surgery.

Patients with vascular disease and coronary disease are usually treated initially by coronary artery bypass grafting (CABG), and vascular surgery is generally performed later. In this study we assessed the feasibility of combined CABG and vascular surgery in a single operation. Between 1988 and 1995, 16 patients received combined operations for vascular and cardiac lesions and the clinical results were assessed. There were no operative or hospital deaths. The mean time for operation was 421 min and the duration of the stay in the intensive care unit (ICU) was a mean of 3.6 days. In one patient with an ischemic left leg, the left internal thoracic artery (ITA) had become a collateral source of the ischemic leg, and the need for preoperative angiography of the ITA in such patients was indicated. The combined operation clearly takes longer than either vascular surgery or CABG alone, but the length of the postoperative intensive care unit stay was essentially the same as that after a single operation and the patient was still managed safely after the combined operation. In patient requiring both operations, the combined procedure therefore appears to be safe and to have a good clinical outcome.

Aged↗

PubMed1997

Effects of minimal-dose aprotinin on coronary artery bypass grafting.

OBJECTIVE: To evaluate the effects of minimal-dose aprotinin in patients undergoing coronary artery bypass grafting, we conducted a prospective randomized study. METHODS: A total of 167 patients were randomized to receive no aprotinin treatment (control, n = 57), minimal-dose aprotinin (1.0 x 10(6) KIU; n = 55), or low-dose aprotinin (2.7 +/- 0.5 x 10(6) KIU; n = 55). Blood loss and transfusion requirements, parameters of clotting and fibrinolysis, renal function, and early graft patency rates were assessed. RESULTS: Postoperative blood loss and transfusion requirements were significantly (p = 0.01) lower in both the minimal-dose and low-dose groups than in the control group. The increase in D-dimer level after cardiopulmonary bypass was significantly (p < 0.05) less marked in the low-dose group than in the control group. The alpha 2-plasmin inhibitor and plasminogen activator inhibitor-1 levels were significantly (p < 0.05) greater in the minimal-dose and low-dose groups than in the control group after bypass, suggesting the prevention of fibrinolysis by both aprotinin doses. No statistically significant differences in postoperative renal function and early vein graft patency rates were noted (control group, 93.8%; minimal-dose group, 95.5%; low-dose group, 92.3%; p = 0.25). CONCLUSIONS: Aprotinin was not associated with a significant increase in the prevalence of renal dysfunction or early vein graft occlusion. Minimal-dose aprotinin inhibited enhanced fibrinolytic activity and reduced blood loss and transfusion requirements after bypass equivalently to low-dose aprotinin. The dose of 1 x 10(6) KIU added to the pump prime may be acceptably effective in reducing blood loss in patients undergoing primary coronary operations.

Aprotinin↗

PubMed1997

Coronary artery revascularization in an adult with coronary aneurysms probably secondary to childhood Kawasaki disease.

Kawasaki disease is an acute febrile illness affecting mainly infants and children. The fatal complication of Kawasaki disease is coronary involvement pertaining to coronary artery aneurysms. Surgical experience of adults that had childhood Kawasaki disease with coronary lesion has been rarely reported. We experienced coronary artery bypass grafting in a 44 year old man with no risk factors for atherosclerosis but with coronary lesions possibly secondary to Kawasaki disease. Coronary artery sequelae of Kawasaki disease may become part of a cause of coronary disease in young adults and we should recognize this condition in such patients with coronary disease but no coronary risk factors.

Adult↗

PubMed1997

Hemodynamic performance of the St. Jude Medical Hemodynamic Plus valve.

The hemodynamic performance of the St. Jude Medical Hemodynamic Plus valve (HP) for a small aortic annulus was compared to that of the standard St. Jude Medical valve (SJM). Doppler echocardiographic parameters were evaluated in patients undergoing aortic valve replacement with either a 19 mm HP (HP19, n = 7), a 21 mm HP (HP21, n = 8), a 19 mm SJM (SJM19, n = 16), or a 21 mm SJM (SJM21, n = 34). The peak and mean pressure gradients and peak flow velocity were significantly (p < 0.05) lower in both patients with the HP21 and those with the HP19 than patients with the SJM21 and those with the SJM19, respectively. The echocardiographic parameters of the patients with the HP19 corresponded closely to those of patients with the SJM21. The left ventricular mass index regressed markedly in patients with the HP19 during the late postoperative period. The results suggested that the hemodynamic performances of certain sizes of the HP were superior to those of the same size SJMs and were considered to be equivalent to those of the next size larger SJM.

Adolescent↗