Biomedical subjects

M Otaki

Publications and source records attributed to M Otaki.

At least 55 records · Page 3Linked to original sources

PubMed1993

Permanent cardiac pacing after cardiac operations.

From January 1980 through December 1990, implantation of a permanent pacemaker was performed in 34 patients following open heart surgery. The patients were divided into two groups according to the clinical indications for implantation of permanent pacemakers. Group 1 (9 patients) had surgical atrioventricular block, and Group 2 (25 patients) had sick sinus syndrome. Tricuspid valve surgery was involved in 67% of Group 1 and 64% of Group 2. Adams-Stokes syncopal attack was the prime indication for permanent pacing in 100% of Group 1 and in 72% of Group 2. There were 2 operative deaths in Group 1, and no deaths in Group 2 (22% in Group 1 vs. 0% in Group 2, p < 0.005). Causes of the deaths were not related to the pacemaker implantation but to congestive heart failure following surgery. Among 32 survivors, there were 2 late deaths in Group 1, and 4 deaths in Group 2 (25% in Group 1 vs. 16% in Group 2, p < 0.05). The overall actuarial survival rate at 10 years was 82.1 +/- 2.8%. However, the actuarial survival rate of patients in Group 1 is 70.2 +/- 4.1%, which is statistically less than 85.4 +/- 2.2% in Group 2 (p < 0.01). As judged by these results, patients in Group 1 should be followed on a regular out-patient basis even if they are asymptomatic and there is no evidence of pacemaker failure.

Adult↗

PubMed1993

Reoperations on prosthetic heart valves: an analysis of outcome.

To evaluate risks and complications of reoperations on prosthetic heart valves, we reviewed data on 70 patients who underwent reoperations because of prosthetic valve malfunction. Overall hospital mortality was 13% (9/70 patients). The common cause of death was low cardiac output syndrome following surgery (4 patients). Respiratory failure and mediastinal infection accounted for 2 deaths each, and neurological complication for 1 death. However, hospital mortality was different according to the risk factors; reoperations for prosthetic valve endocarditis (18%, p < 0.05), advanced New York Heart Association (NYHA) class (50%, p < 0.001), and emergency operation (33%, p < 0.005) were the significant risk factors. In contrast, advanced age, female sex, type of prosthesis, valve position, and diagnosis (leak, structural deterioration, or valve thrombosis) did not appear to be significant risk factors. There were 7 late deaths (4 valve-related, 2 cardiac, and 1 noncardiac). Inasmuch as emergency operation, advanced NYHA class, and prosthetic valve endocarditis affected hospital mortality, these factors contributed to late death. Actuarial survival rate and freedom from valve-related mortality at 10 years were 75.8 +/- 2.8% and 87.2 +/- 2.3%, respectively. There were 8 valve-related complications, and freedom from valve-related complications at 10 years was 73.5 +/- 3.5%. As judged by these data, hospital mortality and late survival can be improved if hemodynamic conditions leading to myocardial damage can be prevented.

Adult↗

PubMed1993

Left ventricular rupture following mitral valve replacement.

During a 10-year period, we have encountered 6 patients (mean age, 61.2 years) with left ventricular rupture following mitral valve replacement, with an overall incidence of 1.8 percent. Four patients had early rupture, one had delayed rupture, and one had late rupture with a false aneurysm formation. Among four patients with early rupture, there were two patients with external repair by using a large ventricular patch and two patients with internal and the external repair by removing the prosthetic valve and patching both the inside and outside of the ventricle. In a patient with delayed rupture, bleeding from an epicardial hematoma was recognized along the atrioventricular groove in the intensive care unit. It was possible to control bleeding by packing the gauze, hemostatic cellulose [Surgical], and fibrin glue. Late rupture was recognized as a false aneurysm; however, there were no clinical symptoms. All patients survived the surgery, but two patients with early rupture subsequently died. One of these died of renal failure and the other died of multiple organ failure. The sites of rupture in all patients were in accordance with type 1 rupture (Treasure's classification); however, an autopsy review demonstrated the initial laceration in one case was recognized in the membranous septum 5 mm below the mitral ring and extended to the posterior atrioventricular groove. These findings suggest that the injury in the anterior mitral annulus could lead to type 1 rupture, although in the posterior mitral annulus more commonly. Since 1987, we have preserved the posterior leaflet with attached chordae when the mitral valve was fragile and myxomatous. As a result, no instances of left ventricular rupture were encountered.

Aged↗

PubMed1993

Six years' experience with the Omnicarbon valve prosthesis.

Between January 1985 and March 1990, isolated Omnicarbon valve replacement operations were performed on 90 patients aged 25-72 years. There were 53 aortic valve replacements (AVR) and 37 mitral valve replacements (MVR). The cumulative follow-up was 320 patient-years, with a mean(s.d.) follow-up of 3.7(1.4) years. There were three operative and hospital deaths (3.3%) resulting from retrograde aortic dissection during cardiopulmonary bypass, postoperative renal failure and postoperative mediastinitis. Seven patients died during the late postoperative period, four from valve-related causes. Two of these patients died from prosthetic valve endocarditis, and the others died from thromboembolism and valve thrombosis. The mean(s.d.) actuarial survival rate at 6 years was 86.2(4.3)% (98.8(0.8)% for AVR, 82.1(4.8)% for MVR). The mean(s.d.) actuarial survival rate of freedom from all valve-related mortality at 6 years was 93.5(2.6)% (100% for AVR, 88.1(2.9)% for MVR). There were two thromboembolic events (one mesenteric artery thrombosis and one valve thrombosis). The standardized incidence of thromboembolism was 0.63% per patient-year. Prosthetic valve endocarditis occurred in three patients (0.94% per patient-year). One patient (0.31% per patient-year) was found to have a paravalvular leak resulting from aortitis syndrome. The mean(s.d.) actuarial rate of freedom from all valve-related complications at 6 years was 89.2(2.0)% (98.6(1.0)% for AVR, 86.4(2.2)% for MVR). There were no instances of anticoagulant-related haemorrhage, valve-related haemolysis, or structural failure. Results of a follow-up period of 6 years indicated that good clinical results and a low incidence of valve-related complications can be demonstrated with the Omnicarbon valve.

Adult↗

PubMed1993

A new procedure for aortic valve repair.

A new technique is presented for aortic valve repair. This procedure involves shaving the surface of rheumatic aortic valves using a high-speed electric rasp. It is safer and more expeditious to shave the concave shaped aortic cusp at the base, and then shave the body of the cusp along the flexion stress line. In a patient treated using this procedure, aortic valve regurgitation decreased and the aortic valve gradient almost disappeared.

Aortic Valve↗

PubMed1993

[Three-dimensional CT images of the lung--preliminary study using inflated lung specimens].

Three-dimensional CT images of six inflated lung specimens (4 lung cancer, 1 bronchiectasis, 1 hamartoma) were reconstructed from contiguous serial sections to study some probable problems in the clinical application of the technique. Optimal thickness and space of sections were evaluated, and contiguous 1.5-mm serial sections were found to provide a clear 3-D image with high fidelity. It was difficult to set a proper threshold to create clear images because a wide CT window is inconsistent with low noise. The images of tubular and linear structures such as from bronchi and vessels demonstrated higher resolution when reconstructed from scanning in the more perpendicular cross-sectional direction to their axis. Although 3-D images obtained here were not as clear as expected, technological advances such as helical CT or MRI may provide 3-D images with sufficient resolution to be applied clinically.

Aged↗

PubMed1993

[Surgical treatment of cardiac cachexia with mitral valve disease: the effect of preoperative IVH and left atrial plication on postoperative respiratory condition].

Twenty-four patients with cardiac cachexia associated with mitral valve disease were evaluated from the point of postoperative respiratory management. Our previous study suggested that preoperative intravenous hyperalimentation (IVH) had just a effect on postoperative respiratory management, but another study suggested that left atrial plication (LAP) for giant left atrium might improve the postoperative respiratory function. Therefore, four groups could be identified: (1) IVH group (17 patients), (2) No-IVH group (7 patients), (3) LAP group (6 patients), (4) No-LAP group (18 patients). The hospital mortality was 18% in IVH group and was not related to the postoperative respiratory distress. On the contrary, the mortality in No-IVH group was 57%, related to the postoperative respiratory distress. The mortality of LAP group was 67%, and was related to the respiratory distress except one patient. In No-LAP group which had undertaken preoperative IVH, the mortality was 17%. As a result, preoperative IVH therapy may consider to be a favorite procedure in order to get the good postoperative respiratory condition, but LAP itself would be suspicious for this purpose.

Adult↗

PubMed1993

[Autotransplantation as optimal technique for recurrent malignant myxoma of left ventricle].

Application of autotransplantation for left ventricular recurrent malignant tumor which was considered to be originating from the posterior leaflet of mitral valve was presented. A patient was 29 year-old-female and underwent the resection of tumor. The tumor was resected en bloc with the mitral valve, and its histology was myxoma. But she was required reoperation two times because of the recurrence of the tumor unfortunately. The tumor was ultimately diagnosed as the myxofibrosarcoma with chondroid differentiation. At the time of the third surgery, the heart transplantation was thought to be only treatment for radicality. While sounding American counterparts on the possibility of the heart transplantation, her condition took a sudden turn for the worse. An autotransplantation technique was applied for the resection of the tumor emergently. As a result, it was impossible to completely resect the tumor because of severe invasion to the left ventricle, and the patient died suddenly on the 75th day after the operation due to fetal arrhythmia. Through this case, heart transplantation should be considered for such a case, but autotransplantation technique allowed to be a life-prolonging in this case. We believe that this technique which will be obtained the excellent operative field could be used for repair of complex cardiac anomalies and rupture of left ventricle and so on.

Adult↗

PubMed1992

Competitive flow from a fully patent coronary artery does not limit acute mammary graft flow.

The shriveled, stenotic mammary graft sometimes observed after internal mammary artery (IMA) to coronary artery bypass grafting has been attributed to competitive flow from the insufficiently stenosed native coronary vessel. To study further the effects of native coronary artery competing flow on IMA graft flow, 10 dogs (mean weight, 23.5 +/- 3.69 kg) underwent coronary artery bypass grafting using the pedicled left IMA anastomosed to a normal, fully patent proximal circumflex (CFX) coronary artery. The procedure was performed through a left thoracotomy, off pump, using a brief local occlusion to perform the anastomosis. Native in situ IMA flow, CFX flow distal to the anastomosis, and IMA graft flow were measured using calibrated electromagnetic flow probes. When the CFX proximal to the anastomosis was occluded transiently, IMA flow increased to supply 100% of the previously measured distal CFX flow (60.2 +/- 7.9 mL/min). When both the IMA graft and CFX proximal to the anastomosis were patent, total distal perfusion was maintained (58.9 +/- 7.8 mL/min) and relative IMA graft flow (26.5 +/- 3.3 mL/min) was proportional to the relative diameter of the IMA graft to the native coronary artery (r = 0.96). The mean flow in the IMA in situ on the chest wall before its division was 23.8 +/- 8.1 mL/min. These results suggest that, at least acutely in a canine model, IMA graft flow is maintained above in situ levels even when grafted to a completely patent coronary artery and that acute competitive flow probably does not cause mammary artery shriveling.

Animals↗

PubMed1992

Percutaneous transradial approach for coronary angiography.

A percutaneous radial artery approach for coronary angiography was performed in 40 patients using a 5-F catheter. The patients, in whom the femoral artery approach was difficult or contraindicated because of advanced arteriosclerosis, were selected on the basis of easily palpable radial and ulnar arteries and a normal Allen test. In 1 patient the catheter could not be advanced to the brachial artery, and subsequently this patient underwent the brachial approach. In all 39 patients, selective left coronary angiography was accomplished using a left Judkins catheter, and the right coronary artery and the saphenous vein graft were entered successfully using a right Judkins or Amplatz catheter. All patients had excellent quality of images of coronaries and vein grafts. In 5 patients (13%), the pulse remained acutely diminished, but there were no evidences or complaints of pain. Bleeding at the puncture site occurred in 1 patient (3%), and 5 patients (13%) had subcutaneous bleeding around the puncture site. Pseudoaneurysm, nerve injury and arteriovenous fistula were not detected at the time of discharge.

Adult↗

PubMed1992

[Percutaneous transluminal coronary angioplasty in patients with previous coronary artery bypass grafting].

Percutaneous transluminal coronary angioplasty (PTCA) has been used to treat patients with previous coronary artery bypass grafting (CABG). Seven patients with previous CABG underwent coronary artery or vein graft angioplasty following a recurrence of symptoms. Fifteen lesions were attempted in 7 patients. The primary angiographic success rate was 100%. The primary angiographic success rate was defined as reduction of a stenosis by at least 20% of the vessel diameter, leaving a stenosis of less than 60%. There were no complications following PTCA such as death or myocardial infarction. No patients were referred for urgent surgery. Three patients have undergone another PTCA after 3 months and remain well. All patients at follow-up continue to have improved symptoms. Our experience suggests that the patients with recurrence of coronary artery or bypass stenosis following CABG may be suitable for PTCA.

Aged↗

PubMed1992

[A case report of Candida prosthetic endocarditis: an autopsy review].

Most of the increasing numbers of cases of Candida endocarditis have developed after cardiac surgery. We report a case of Candida parapsilosis endocarditis after mitral valve replacement in a patient with no predisposing factors. In this report we mainly examined the pathological findings in this patient with postmortem examination. A woman, age 55, underwent valve replacement with a Björk-Shiley prosthesis for mitral stenosis. The spike fever occurred on the 22nd postoperative day and Candida parapsilosis was cultured from the blood. On the 76th day, a conscious disturbance with the right side hemiplegia was experienced. A CT scan revealed massive hemorrhagic infarction. Despite the intensive care the patient died of cerebral damage. Pathologic findings showed that the vegetation in the major orifice of the Björk-Shiley valve was composed of both necrotic debris and tissue, with Candida organisms being scattered throughout the interstices. Additionally there were also multiple myocardial abscesses with necrotic tissue.

Candidiasis↗

PubMed1992

[Operative results with total composite replacement of the aortic valve and ascending aorta].

From December 1980 to December 1990, ten patients, 9 male and 1 female, ranging in age from 21 to 68 years, were operated on for aortic valve insufficiency associated with an aneurysm of the ascending aorta. The surgical treatment in all cases consisted of total replacement of the ascending aorta with Bentall's procedure (n = 4), or Cabrol's procedure (n = 6). In 5 patients an uncomplicated annulo-aortic ectasia existed. Three of them had annulo-aortic ectasia with an aortic dissection. One had aortitis syndrome, and one had syphilitic aortitis. The operative mortality for the entire group was 0% (0 death). Hospital survivors revealed satisfactory clinical improvement in NYHA class (mean value: 3.2 to 1.0). Late complications developed in 2 of the 10 patients. They had a picture of pseudoaneurysm formation at the anastomoses between the graft and the right coronary 46 months and 15 months, respectively, after the initial operation. Despite the reoperation, one died of hepatic failure 30 days after the operation, and the other died of postoperative bleeding at the anastomosis sites. We, furthermore, considered the difference in aortic cross clamp time and cardiopulmonary bypass time between Bentall's procedure and Cabrol's procedure. Aortic cross clamp time and cardiopulmonary bypass time were significantly shorter in Cabrol's procedure than in Bentall's procedure, if a probability value less than 0.20 was considered to be of statistical significance. We were able to conclude that the treatment of aortic valve regurgitation associated with an aneurysm of the ascending aorta by insertion of a composite graft is a reliable method with low operative mortality and excellent long term results, especially in Cabrol's procedure.

Adult↗

PubMed1992

[Pseudoaneurysm of the left ventricle following mitral valve replacement].

This report describes a false aneurysm of atrioventricular groove in the patients who underwent the reoperation of the mitral valve replacement (MVR). Patient 1 underwent reMVR with a SJM prosthesis because of the malfunction of the previous prosthetic valve. A large hematoma was observed in the posterior atrioventricular groove with bleeding at weaning from cardiopulmonary bypass. Ventricular rupture was repaired under the cardioplegic arrest successfully from the epicardial surface with a woven Dacron felt. The postoperative left ventriculogram revealed the false ventricular aneurysm along the atrioventricular groove. Patient 2 underwent reMVR with Carpentier-Edwards prosthesis because of the malfunction of the previous Carpentier-Edwards prosthesis. Cardiopulmonary bypass was discontinued uneventfully, and there were no clinical symptoms suspicious of the formation of the false left ventricular aneurysm. The left ventriculogram at the discharge showed the false left ventricular aneurysm along the atrioventricular groove. Although both patients are in good condition without significant complications, we should involve in the postoperative care of the patients on a regular outpatient basis.

Aged↗

PubMed1992

[Comparative study of anticoagulant management after coronary artery bypass surgery--warfarin versus dipyridamole].

A prospective randomized study was performed in 137 coronary artery bypass surgery cases to determine if the administration of antiplatelet drugs would improve the patency of coronary artery bypass grafts. The warfarin group received warfarin and thrombotest was controlled to 20% or so. The dipyridamole group received both 300 mg of dipyridamole and 250 mg of aspirin orally each day. These two groups were compared for study in grafts patency. Results were analyzed by chi-square. In the warfarin group, 66 patients had three ITA-LAD grafts and 115 saphenous vein grafts (including 4 sequential grafts). In the dipyridamole group, 71 patients underwent 38 ITA grafts and 167 saphenous vein grafts (including 56 sequential grafts). Eighty-eight of the 107 grafts (82%) were patent in the warfarin group, and 190 of 205 grafts (95%) were patent in the dipyridamole group (p less than 0.01). Of the two ITA grafts in the warfarin group, no graft was occluded, a patency of 100%. In the dipyridamole group, 35 of 38 ITA grafts (92%) were patent. In the warfarin group, 86 of 105 saphenous vein grafts (82%) were patent. In the dipyridamole group, 155 of 167 saphenous vein grafts (95%) were patent (p less than 0.01). In the study of grafted coronary vessel, the patency of left anterior descending coronary artery, diagonal branch and right coronary artery was not significant between two groups. In the dipyridamole group, the patency of left circumflex coronary artery was 93%, and that of the warfarin group was 50% (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

[A case of "postoperative erythroderma" following coronary artery bypass grafting operation].

So-called "Postoperative Erythroderma" was experienced in a 68 year-old man who received CABG for unstable angina. After a seemingly uneventful recovery, he revealed high grade fever on 13th post operative day (POD), rashes over the whole body on 15th POD and pancytopenia on 20th POD. He died of sepsis, multiple organ failure and DIC on 21st POD. Blood transfusion (concentrated red cell: 3 units) was done on operation. In this case, the rate of premature and atypical lymphocytes increased, and the ratio of OKT4 (helper)/OKT8 (suppressor) decreased. These findings of the examination suggested that there was a possibility of cell-mediated immunological depression. We considered this to be acute GVHD after blood transfusion.

Aged↗

PubMed1991

[A case report of a thrombosed mitral prosthesis diagnosed by 111In-oxine platelets scintigraphy].

The purpose of this report was to evaluate the efficacy of 111In-oxine labeled platelets scintigraphy for detection of thrombus in the prosthetic valve. A 50-year-old man underwent re-mitral valve replacement with a Björk-Shiley prosthesis because of malfunction of the xenograft in a previous operation. Almost one year later, this patient suffered from peripheral embolism and sight disturbance. There was no evidence of a thrombosed valve although it was suspected. Cineradiography showed the valve almost fully open, and there were no abnormal sounds when the valve closed. 111In-oxine labeled platelets scintigraphy was performed for the detection of thrombus in the mitral position. Hot areas of high quality in the scintigram were demonstrated in the mitral position. As a result, Björk-Shiley prosthesis was replaced with a Duromedics prosthesis. A small thrombus (10mm) surrounded by fresh tiny thrombi was found in a minor orifice of the Björk-Shiley prosthesis.

Heart Valve Prosthesis↗

PubMed1991

[Active bronchial tuberculosis--a clinical study on 36 cases].

A total of 36 patients (16 male and 20 female) with tracheobronchial tuberculosis were admitted during the last nine years and were evaluated for their clinical features. The chief complaint in three quarters of the patients was intractable cough, in particular, in those with tracheal tuberculosis. One of three patients who suffered from wheezing was prescribed steroid, being diagnosed as having bronchial asthma instead of tuberculosis. Plain chest X-rays of two patients revealed no abnormality. Pleural effusion was observed in three patients, and miliary tuberculosis in two patients. Bronchial biopsy was carried out in 23 patients, however, in only 11 patients a histopathological diagnosis of tracheobronchial tuberculosis could be made. In contrast, in all 36 patients smear and/or culture for tubercle bacilli were positive. Therefore, bronchial biopsy was considered not to be essential in making a definite diagnosis of bronchial tuberculosis, although it did not exacerbate the lesion to lead to endobronchial stenosis. Only seven out of 36 patients were in the habit of smoking but three of the four had already broken the habit at least one year before being diagnosed as having the disease. The remaining four patients were still smoking but less than 10 cigarettes a day, with one exceptional patient who was smoking 30 cigarettes on average a day. It has been well known that there is a sexual difference in the incidence of bronchial tuberculosis, namely among females with relatively low population of smokers, the incidence is high. Another probable reason for the higher female incidence is assumed to be due to the structural susceptibility of the bronchus with smaller diameter lumen.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗