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Biomedical subjects

T Iwa

Publications and source records attributed to T Iwa.

At least 109 records · Page 6Linked to original sources
PubMed1989

Surgical management of tachyarrhythmias.

In this study of surgical procedures for various tachyarrhythmias, Wolff-Parkinson-White syndrome comprised most of the cases. An endocardial approach was used to ablate accessory pathways. Additional use of cryocoagulation after surgical incision of the atrium, previously routinely performed, is at present only done occasionally for septal accessory pathways. Ventricular tachycardia (VT) was the next most frequent condition. The surgical procedures for ischemic and nonischemic VTs are completely different, although both are based on the principle of complete electrophysiologic mapping. For ischemic VT, surgery consists of resection of the left ventricular aneurysm and excision or cryocoagulation of the endocardium, or both. For nonischemic VT, either excision of the entire thickness of the myocardium (2.0 X 2.5 cm on average) at the earliest excitation site of the right ventricle and cryocoagulation of the area of delayed potential or only incision and cyrocoagulation of the left ventricle were performed to avoid reduction of the left ventricular cavity. Ectopic atrial tachycardia was cured by excision of the earliest excitation site without use of a heart-lung machine, when the focus was located in the atrial free wall. Other successful treatments were of reentrant atrial tachycardia by cryocoagulation, atrial flutter by cryocoagulation of impulse pathways at the coronary sinus and around the atrioventricular node, and a new surgery for atrial fibrillation and flutter, which retained sinus rhythm. Johnson's procedure was used for surgical ablation of atrioventricular nodal reentrant tachycardia.

Adolescent↗
PubMed1989

The histological effects of cryocoagulation on the myocardium and coronary arteries.

The effects of epicardial and endocardial cryolesions were histologically studied in 29 dogs. To produce epicardial lesions, hypothermic exposure was applied at -60 degrees C for 3 minutes, over or adjacent to the left anterior descending coronary artery. To produce endocardial lesions, exposure was applied at -60 degrees C for 2 minutes, using the inflow occlusion technique over the ventricular septum. The dogs were killed 30 minutes to 6 months later. The cryolesions were sharply demarcated from the surrounding tissues and showed similar healing processes. The lesions showed no tendency to form aneurysms or rupture, although moderate intimal thickening of the coronary artery subjacent to the probe was observed. Our results indicate that cryocoagulation may greatly contribute to the surgical treatment of cardiac arrhythmias.

Animals↗
PubMed1989

Cardiac phaeochromocytoma of the interatrial septum.

A patient with a phaeochromocytoma arising from the interatrial septum is reported. A 131I-metaiodobenzylguanidine scan and magnetic resonance imaging were useful for tumour localization. Complete removal of the tumour in the right atrium was performed on cardiopulmonary bypass. The right atrial wall and the interatrial septum were reconstructed with two patches. This is the first successful operation for an intracardiac phaeochromocytoma arising from the interatrial septum.

Heart Neoplasms↗
PubMed1989

Intraarterial digital subtraction angiography for evaluation of internal mammary artery graft in coronary bypass surgery.

Digital subtraction angiography (DSA) was performed to evaluate graft patency in 60 patients who had undergone coronary artery bypass grafting with the internal mammary artery (IMA). Sixty IMA grafts with 62 distal anastomoses, and 84 saphenous vein grafts with 85 distal anastomoses were evaluated by intraarterial DSA with an image frequency of 4 frames/sec. A No. 4 Fr. angiography catheter was introduced percutaneously into the left brachial artery and contrast medium was injected both into the subclavian artery for opacification of the IMA grafts and into the ascending aorta for opacification of aortocoronary saphenous vein grafts. Bypass grafts were defined as patent when grafts were opacified through their entire course, including anastomotic sites. Fifty-nine IMA grafts with 61 distal anastomoses (98%) and 76 saphenous vein grafts with 77 distal anastomoses (91%) were patent. The overall patency rate for total grafts was 94%. In 4 patients, DSA showed a "string sign" in the IMA graft which was patent but narrowed at its distal segment. In 5 patients, large first intercostal branches were opacified. Intraarterial DSA with the retrograde brachial approach is not difficult, and is an excellent low risk method of evaluating the patency of IMA and saphenous vein grafts. DSA provided information about functional patency as well as anatomical patency of the IMA graft.

Adult↗
PubMed1989

[Comparative study of tegafur (p.o.) and mitomycin C (MMC) plus tegafur in cases of unresectable gastric cancer].

Sixteen cases of gastric cancer with liver metastases (H2 less than) as group A, fifteen with distant peritoneal metastases (P2 less than) as group B, twenty-five with distant lymph nodes metastases (N3 less than) as group C, twenty-eight with two prognostic factors as group D, and seven with three factors as group E were treated. A1, B1, C1, D1 and E1 groups were treated with mitomycin C (MMC) (4 mg) + tegafur (FT) (400 mg) (i.v.-weekly) and A2, B2, and C2 group with FT (600 mg) (p.o.-daily). Partial response in the evaluable cases was found in 7 cases and a total response rate was 11.7%. The 50% survival interval was as follows; 8.5 months (M) in A1 group, 10.0 M in A2, 7.2 M in B1, 2.3 M in B2, 10.4 M in C1, 14.2 M in C2, 5.2 M-7.2 M in D1, and 3.1 M in E1. In the cases with H2 less than or N3 less than, FT (p.o.) and with P2 less than, MMC + FT (i.v.) were effective respectively. Chemotherapeutic effect was better in A1 and A2 group from the aspects of prognostic factors and in the cases of poorly differentiated adenocarcinoma from histological types than in B1 and B2 group and well or moderately differentiated adenocarcinoma.

Adenocarcinoma↗
PubMed1989

[A hepatocellular carcinoma revealed by paraplegia caused by a vertebral metastasis].

Described is a 57-year-old male with a complaint of a gait disturbance. On admission to hospital, he was suffering from almost complete paraplegia. Roentgenograms of the spine showed extensive destruction in the body of the second thoracic vertebra. Magnetic resonance computed tomography revealed a vertebral tumor that was compressing the vertebral cord. Thus, a laminectomy of the 1st to 3rd thoracic vertebra was performed to relieve the compression. Histological examination of the tumor showed it to be a metastatic vertebral tumor from a hepatocellular carcinoma (HCC). Subsequently, by abdominal computed tomography and an examination of the AFP serum level the existence of the HCC was confirmed. This is a very rare case of an HCC that was revealed by paraplegia caused by bone metastasis.

Carcinoma, Hepatocellular↗
PubMed1989

[Revascularization with the branched graft in middle aortic syndrome].

A case of middle aortic syndrome which was thought to be the thoracoabdominal type of Takayasu's disease was successfully treated with the branched graft bypass. Patient was a 23 year-old woman with hypertension and abdominal pain. The preoperative angiography revealed aortic stenosis from the celiac axis to the left renal artery. The operative procedures were as follows; patient was positioned in supine with her left shoulder and arm raised. Eighth intercostal thoracotomy and midline laparotomy was performed with the thoracoabdominal incision. The branched graft was made previously with woven Dacron (phi 18 mm) and three EPTFEs (phi 8mm). The woven Dacron of the graft was used for the bypass from the descending thoracic aorta to the infrarenal abdominal aorta, and the branched EPTFEs of the graft were used for the bypasses to the common hepatic artery, the superior mesenteric artery and the right renal artery in this order. The bypasses were placed along the anatomical courses in the retroperitoneal space. Postoperatively, the blood pressure dropped and the abdominal pain disappeared. The plasma renin activity decreased and the renal function improved. Two months after operation the bypasses were patent by the angiography and now six months after operation she has returned to her social life healthily. The approach to the aorta and its abdominal branches by thoracotomy and laparotomy and bypass with the three branched graft was useful for middle aortic syndrome.

Adult↗
PubMed1989

[Immunotherapy for lung cancer by streptococcal preparation OK-432].

To evaluate the clinical efficacy of OK-432 immunotherapy, patients admitted between 1975 and 1982 were randomized into two groups: An immunochemotherapy (IM-C) group and a chemotherapy (control) group. For each group, a fixed chemotherapy was administered using a combination of three drugs. The survival rates of cases with non-small cell carcinoma were evaluated at the end of 1987. One hundred and fifty-seven cases in the IM-C group and 148 in the control group were eligible for evaluation of long-term survival rates. Statistically significant improvement of the survival rates in the IM-G group were noted in the following items: All cases, resected cases, non-resected cases, resected stage I + II cases, resected stage III cases, completely resected cases, incompletely resected cases, and cases with epidermoid carcinoma. However, in comparison of adenocarcinoma there was no significant difference between the two groups. SU-polysaccharide skin test and natural killer activity were the best immunological parameters during the OK-432 therapy. To intensify the effects of immunotherapy, a possibility of regional immunotherapy was studied following some experimental works. Regional infusion of LAK cells (induced by incubation of patient's lymphocytes with rIL-2) through bronchial artery after regional infusion of OK-432 and chemotherapeutics showed favorable effect for advanced lung cancer. Future prospect of these regional adoptive immunotherapy was discussed.

Biological Products↗
PubMed1989

[Pulmonary embolectomy for a patient of chronic pulmonary embolism].

Chronic pulmonary embolism is resistant to medicinal treatment. This is a report of the successful operation for chronic pulmonary embolism. A 29-year-old man suffered from dyspnea attack twice half a year in spite of intensive anticoagulant therapy. Cardiac catheterization showed pulmonary hypertension of 72/25 mmHg, mean 42 mmHg. Pulmonary angiogram demonstrated emboli in the right pulmonary artery and pulmonary perfusion scintigram revealed large perfusion defect in the right lung. The patient underwent pulmonary embolectomy after the total cardiopulmonary bypass. After surgery, blood gas showed an increased PaO2 from 65 to 77 mmHg. Pulmonary artery pressure decreased to 39/12 mmHg, mean 23 mmHg. Pulmonary arteriogram showed increased pulmonary vascular beds and pulmonary scintigram showed an increased perfusion in the right lung. The patient has been free from symptom and a half year after surgery.

Adult↗
PubMed1989

[Mitral regurgitation due to anomalous attachment of chordae tendineae to the left atrial wall].

A 47-year-old female admitted to our hospital with exertional dyspnea and cerebral thromboembolism. There was no history of rheumatic fever. The chest roentgenogram showed marked cardiomegaly with pulmonary congestion. Ultrasound cardiogram showed mitral valve incompetence and abnormal echo shadow in the left atrium. Left ventriculogram revealed grade 3 mitral regurgitation. At operation, a 5-cm anomalous chordae tendineae was attached to the left atrial wall through the mitral orifice. The mitral valve showed thickening of the leaflets and fusion of the posterior commissure. The mitral valve was replaced with a mechanical prosthesis. The patient has been doing well after her surgery.

Chordae Tendineae↗
PubMed1989

[Second surgical intervention for contralateral recurrence or second primary lung cancer].

Resection of contralateral lung cancer (6 cases of pulmonary metastasis from the first lung cancer and one case of second primary lung cancer) were evaluated retrospectively in terms of postoperative complication, pulmonary function and survival rate. Out of 691 cases with resected non small cell lung cancer, 7 cases (1.0%) had contralateral lung cancer which were resected as the second operation. Six cases were squamous cell carcinoma and one case was adenocarcinoma. The interval between the first and the second operation was 12 months to 10 years (average 46 months). The post-operative stage of first lung cancer were stage I in 5 cases and stage IIIB in 2 cases, but no case had lymphadenopathy at the first operation. Operative procedures for contralateral lung were as follows; one case of lobectomy----lobectomy, one case of lobectomy----segmentectomy, two cases of lobectomy----partial resection, two cases of pneumonectomy----partial resection. For a metachronous lung cancer, right upper sleeve lobectomy was done as the first operation followed by left lower sleeve lobectomy as the second cancer five years later. Contralateral lung resection impaired pulmonary function, but all cases well tolerated the second operation. The five-years survival rate after second operation was 40.0%.

Aged↗
PubMed1989

[A successful one stage treatment in angina pectoris and intermittent claudication of both legs].

A successful surgical case of concomitant aorto-coronary bypass grafting and aorto-right iliac, left femoral bypass grafting was presented. A sixty-two years old male admitted to our institution with complaints of angina pectoris and intermittent claudication of both legs who had a history of acute inferior myocardial infarction for which emergency percutaneous coronary balloon dilatation was carried out prior to this admission. In this admission, he was found out to have diabetes mellitus moreover and he hoped to have one staged operation for two different type of the disease. After general anesthesia, at first, aorto-right coronary bypass grafting with saphenous vein graft was carried out under cardio-pulmonary bypass, then aorto-right iliac, left femoral bypass grafting with a dacron bifurcated graft was made only with one time of systemic heparinization. His postoperative course was uneventful and discharged in good condition. We conclude that simultaneous aorto-coronary bypass and revascularization of both legs can be done with minimal risk.

Angina Pectoris↗
PubMed1989

[Left ventricular performance before and after left ventriculotomy and removal of a left ventricular aneurysm].

The effects of left ventriculotomy on left ventricular performance were studied in seven patients with ventricular tachyarrhythmia (VT) and nine patients with left ventricular aneurysm (LVA). Hemodynamic and left ventriculographic findings were evaluated before and after operations. In VT the non-contracting areas, measured at end-diastole, as mean 10.8 +/- 7.1% of the left ventricular internal surface area. There was no significant fall in left ventricular ejection fractions (EF), cardiac indexes (CI) and left ventricular end-diastolic volume indexes (LVEDVI) after left ventriculotomy. In LVA, the non-contracting areas decreased from 31.0 +/- 7.4% to 13.7 +/- 13.5% (p less than 0.01) in association with a reflex decrease in LVEDVI from 117 +/- 31.8 ml/m2 to 90.4 +/- 24.7 ml/m2 (p less than 0.05). EF increased from 40.8 +/- 7.00% to 54.6 +/- 10.7% (p less than 0.01). There was no significant change in CI and left ventricular stroke volume index after left ventricular aneurysmectomy. The observations indicate that left ventriculotomy of limited size is an acceptable and a safety approach to the ventricular tachyarrhythmias and another cardiac operations.

Adolescent↗
PubMed1989

[A case report of a giant cell carcinoma of the thyroid].

Discussed is a case of a giant cell carcinoma that presented a high value of serum thyroglobulin. Histopathologically, this tumor had been diagnosed as being an anaplastic carcinoma that had transformed from a differentiated carcinoma, with calcification that was thought to have occurred from a preceding adenoma. To study the possibility of a malignant transformation, an immunohistochemical study of a specimen confirmed the production of thyroglobulin and vimentin, though the specimen stained negatively for keratin.

Aged↗
PubMed1989

[Surgical management of infective endocarditis].

We reviewed fourty-six patients who had undergone surgery for infective endocarditis in the past fifteen years and identified risk factors affecting the outcome. Twenty-nine patients had infection of the native valve only, 11 had infective endocarditis associated with congenital heart disease, and 6 had prosthetic valve endocarditis. Overall hospital mortality was 6.5%. Prosthetic valve endocarditis carried a higher mortality (33%) than native valve endocarditis (3.4% or congenital heart disease with infective endocarditis (0%). For the patients with active endocarditis, the early mortality rate was higher (13%) than with inactive endocarditis (3.2%). Staphylococcal infections were more likely to cause severe valve destruction and residual infection than streptococcal infection. Our results indicated that surgical management of infective endocarditis should be done after the completion of adequate antibiotic therapy. Early diagnosis should reduce the mortality, prevent fatal complications, and lead to qualitative improvement of infective endocarditis.

Adolescent↗
PubMed1989

[Surgical treatment of ventricular tachycardia caused by abnormal muscle band].

A 57-year-old male was introduced to our hospital for his drug resistant non-ischemic ventricular tachycardia causing faintness attack. Preoperative electrophysiological studies led to a diagnosis of ventricular tachycardia originating from the right ventricular outflow tract. After ventriculotomy, an abnormal muscle band was noticed in the right ventricular outflow tract, which seemed to be a focus of tachycardia by endocardial mapping. Myocardial excision with the abnormal muscle band was performed. In addition to, cryoablation was performed surrounding this area. After the operation, the ventricular tachycardia disappeared completely. No antiarrhythmic drug have been required at 18 months postoperative months.

Cryosurgery↗