Biomedical subjects

Y Umebayashi

Publications and source records attributed to Y Umebayashi.

At least 37 records · Page 2Linked to original sources

PubMed1996

[An evaluation of aortic root reconstruction using Carrel patch method with coronary anastomosis].

During the past 4 years, from January 1991 to December 1994, we experienced 12 cases of aortic root reconstruction utilizing Carrel patch method. The cases included annulo-aortic ectasia (AAE), root aneurysm with aortic regurgitation (AR), and aortic dissection with AR. The aortic valve and aortic root were resected, the coronary ostia were dissected free, mobilized, and then implanted to the composite graft. Coronary anastmosis was performed by mattress suture and reinforced by Tefron felt strips. It was necessary in one case to undergo coronary artery bypass grafting for myocardial ischemia due to coronary ostial stenosis. Operative procedure could be performed in 4 cases without blood transfusion. Post operative death was seen in only 1 case at 25 postoperative day, who underwent on emergency operation for cardiac tamponade due to aortic dissection. Pseudoaneurysm formations of coronary ostia or hospital death was not observed in any other cases during follow up period (average 25 months). Late tamponade was shown in one case as a complication, and the majority of cases had uneventful postoperative course. The operative procedure is considered feasible in any anatomic variation of the aortic root disease, even if dislocation of coronary ostia is minimal, and can be expect for prevention of pseudoaneurysm formation, and long term survival.

Adult↗

PubMed1996

[Cerebral complication during open heart surgery in relation to cerebral arterial stenosis documented by angiography].

To determine the cause of a cerebral lesion after open heart surgery, a cranial 4-vessel-study was performed prior to an elective operation in 89 patients, who were over 70 years of age and/or had a previous history of cerebro-vascular diseases (CVD). Patients with arterial stenosis over 75% to complete obstruction were categorized as the significant stenosis group and the others as the normal findings group. Of the 89 cases, 19 (21.1%) showed significant stenosis, among which six patients were found to have complete occlusion of the internal carotid artery. Seven patients (7.9%) developed postoperative neurological complications, with four patients having single or plural significant stenosis. Angiograms of three of those four patients revealed complete obstruction of their internal carotid arteries. The stenotic group showed a tendency toward neurological complications in comparison with the non-stenotic group although the incidence was not significant (p = 0.054). However analysis of the group with complete occlusion of the internal carotid artery indicated significant increased risk for cerebral complication (p < 0.013). Besides the 89 patients studied, an additional 479 patients who had not undergone preoperative angiography were subjected to this study whether the patient's age, previous history of CVD and extracorporeal circulation (ECC) time or aortic cross-clamp time were of the risk factors for postoperative cerebral complications or not. There was significant correlation between age (p = 0.044) and/or the previous history of CVD (p < 0.001) and neurological complications. Although there was no correlation between either the duration of ECC or aortic cross-clamp time and neurological problems within the whole study population, when only the patients over 70 years old and/or having history of CVD were studied, an increased tendency towards neurological complications was seen when the ECC time was longer than 120 minutes (p = 0.045).

Aged↗

PubMed1995

Prognostic significance in malignant melanoma of nuclear DNA content measured by a microfluorimetric method.

The nuclear DNA content of 47 primary malignant melanomas was measured by 4',6-diamidino-2-phenylindole-DNA (DAPI-DNA) microfluorimetry, and the DNA index, a quantitative measure of nuclear DNA content, was calculated. The DNA index and other clinical and pathological variables were examined and compared with patient survival using univariate and multivariate analyses. The Kaplan-Meier life table method revealed that the DNA index and metastases to regional lymph nodes significantly correlated with patient survival. A Cox proportional hazards multivariate analysis demonstrated that the DNA index, which was not significantly correlated with other variables, was the most reliable and independent factor for predicting patient survival.

Adult↗

PubMed1995

Hereditary multiple glomus tumors involving the glans penis. A case report and review of the literature.

BACKGROUND: Multiple glomus tumors are extremely rare and seldom demonstrate malignant change. OBJECTIVE: To describe an exceptionally rare case of familial multiple glomus tumors involving the glans penis. METHODS: Multiple glomus tumors in a father and son were studied by light and electron microscopy. RESULTS: The clinical presentation of the two patients was similar, and atypical glomus cells were identified in both son and father. The histology of the tumor cells suggested that they were malignant, yet the clinical course has been benign. CONCLUSION: Despite their malignant histologic appearance, the behavior of familial glomus tumors is benign. A conservative approach to treatment appears warranted. The diagnosis and management of these lesions should be based on clinical behavior rather than histopathology.

Adult↗

PubMed1995

Proton radiotherapy for malignant melanoma of the skin.

BACKGROUND: Malignant melanoma, a tumor with reduced radiosensitivity, has been suggested to be overcome by a high-dose fractionation radiotherapy. The proton beam presents physical characteristics that enable such high-dose irradiation. OBJECTIVE: Our aim is to answer whether or not the proton beam can provide useful treatment for cutaneous melanoma. METHODS: Five primary melanomas (4 acral lentiginous and 1 superficial spreading type) and 3 metastatic lymph nodes of 3 different patients were irradiated using the proton beam with a total dose of around 100 Gy fractionated into single doses of approximately 10 Gy. RESULTS: All the macular lesions and a tumor lesion of primary melanoma disappeared completely, and other tumor lesions regressed by 80-90%. The 3 metastatic lymph nodes also regressed by 50-90%. No severe radiation-related complication occurred. CONCLUSION: Proton radiotherapy may prove to be a useful therapeutic modality for the management of cutaneous malignant melanoma.

Aged↗

PubMed1994

Proton radiotherapy of skin carcinomas.

At the Proton Medical Research Center, University of Tsukuba, we performed a pilot study of proton-beam radiotherapy in 12 patients with the following types of carcinoma: Bowen's disease (4), oral verrucous carcinoma (5), and squamous cell carcinoma (3). They received total doses of 51-99.2 Gy in fractions of 2-12.5 Gy. All of the tumours responded well to the treatment. All four lesions of Bowen's disease, three of the five oral verrucous carcinomas, and the three squamous cell carcinomas completely regressed following irradiation. Two squamous cell carcinomas recurred during the follow-up period. One recurrent squamous cell carcinoma was successfully treated by a salvage surgical operation, and in the other case the patient refused further therapy. In two verrucous carcinomas there was 90% regression of tumour volume. No severe radiation-related complication occurred. As proton radiotherapy produces good local tumour control without significant morbidity to the surrounding normal tissues, it may prove to be a useful therapeutic modality for the treatment of skin carcinomas.

Aged↗

PubMed1994

[Multi-organ ischemia due to traumatic lesion of the descending thoracic aorta--a case-report].

This is a case of severe ischemic and reperfusion multi-organ failure due to descending thoracic aortic rupture. A 25 year-old man received a hard blow on his chest in a traffic accident. Chest X-ray, CT scans and aortogram elucidated descending thoracic aortic rupture. Emergency operation was performed 18 hours after the injury. The aortic rupture, 4/5 of the aortic circumference with intact adventitia was seen. The descending aorta 22 distal to the left subclavian artery was repaired under cardio-pulmonary bypass with selective cerebral perfusion. Ischemia due to aortic occlusion with thrombus and reperfusion injury after reconstruction of the aorta connected with rhabdmyolysis and severe multi-organ failure. Intestinal necrosis required laparotomy on the 9th and 15th post operative day. The patient died on 15th postoperative day of multi-organ failure.

Accidents, Traffic↗

PubMed1993

Epithelioid cell melanomas have greater DNA ploidy abnormalities than spindle cell melanomas: cytological evidence for a higher malignant potential of the former.

The cellular DNA ploidy of 30 cases of malignant melanoma was measured by 4',6-diamidino-2-phenylindole-DNA (DAPI-DNA) microfluorometry. DNA histograms and DNA index values were compared among melanomas of different cell morphology. Epithelioid cell melanomas often showed greater DNA aneuploidy than spindle cell melanomas in terms of histographic pattern. DNA index values of the former (mean +/- standard error, 1.84 +/- 0.31) were significantly higher than those of the latter (1.55 +/- 0.24; P < 0.05). The DNA index values of mixed-type melanomas were intermediate. These results indicate that the epithelioid cell melanomas have greater DNA ploidy abnormalities which are usually correlated with a greater malignant potential in pigmentary neoplasms. Thus our results confirm clinical evidence that melanoma patients with the epithelioid type of cells have a poorer prognosis than those with the spindle type of cells.

Adult↗

PubMed1993

Porokeratosis large skin lesions are susceptible to skin cancer development: histological and cytological explanation for the susceptibility.

Porokeratosis (PK), an autosomal dominant inherited skin disorder, is known to develop malignant skin tumors on its skin lesions. Our recent literature survey has revealed that large PK skin lesions are frequently a precursor of malignant changes. In the study, large and small PK skin lesions were investigated in terms of histological features of the epidermis and of the cellular DNA content of epidermal cells. Large PK lesions frequently showed hypertrophic epidermis with many mitotic cells, while small lesions usually presented atrophic epidermis without such mitotic cells. Abnormal cells, like those containing hyperchromatic, large, and/or irregularly shaped nuclei, were present in the epidermis of both large and small lesions with a preponderance in the former over the latter. DNA polyploidy was seen more frequently in large PK lesions than in small ones. DNA index values were significantly higher in large lesions than in small ones. The histological features and DNA ploidy abnormalities probably reflect the higher proliferation and the greater potential for malignant changes of large PK skin lesions. Our study helps to explain the clinical evidence that large PK skin lesions are frequently a precursor of malignant skin tumors.

Adult↗

PubMed1993

Successful differentiation of Spitz naevus from malignant melanoma by microfluorometric analysis of cellular DNA content.

Two cases of presumed Spitz naevus, whose diagnosis on clinical and histological grounds was uncertain, were examined for cellular DNA content using the technique of DAPI-DNA microfluorometry. They were compared with 20 cases, respectively, of clinically and histologically confirmed, Spitz naevus, malignant melanoma and acquired pigmented naevus. The two Spitz naevi showed a diploid pattern in a distribution histogram of cellular DNA content. The pattern was similar to that of confirmed Spitz naevi and of acquired pigmented naevi but different from the aneuploid pattern of malignant melanomas. DNA index values of the two cases were within the range of confirmed Spitz naevi and different from those of malignant melanomas. The DAPI-DNA microfluorometric method thus provided confirmatory evidence for the diagnosis of Spitz naevus. The method appears to reflect sensitively the biological behaviour of tumour cells, and is a useful aid to the diagnosis of uncertain Spitz naevi.

Adult↗

PubMed1993

[Surgery for ventricular septal defect with aortic regurgitation].

Twenty-two patients (mean age of 12.9 years) with ventricular septal defect (VSD) associated with aortic regurgitation (AR) were treated surgically. Sixteen patients had subpulmonic VSD and six had infracristal VSD. Fourteen patients with subpulmonic VSD underwent VSD closure alone. VSD was closed by pulling up the inferior rim to the pulmonary valve thus support the prolapse aortic cusp. AR improved in two and has remained stable in eleven for 0.5 to 12.7 years (mean 4.4 years). Aortic valve replacement (AVR) was necessary in an adult patient later. Plication of the aortic valve was effective in a young patient but ineffective in an adult patient. In infracristal VSD, AVR was necessary in two adult patients. In a young patient, AR improved by plication. Direct VSD closure ceased progression of AR in three patients. The long-term follow-up shows that VSD closure with our technique has been sufficient to arrest progression of AR in subpulmonic VSD. Early closure of VSD should be emphasized to prevent aortic valve prolapse and regurgitation.

Adolescent↗

PubMed1993

[Gastrointestinal complication after open cardiac operation].

Seven cases of abdominal complications necessitated laparotomies within 30 days after open heart surgery are presented. They consist of five cases of mesenteric infarction, one acalculous cholecystitis and one hemorrhagic ulcer of the rectum. The incidence is 0.9 percent at our institute. They also had a very complex course after their cardiac surgery such as cardiogenic shock, respiratory failure and renal failure prior to the development of their acute surgical abdomen. It is proposed that the cause of acute abdomen is attributed basically to the low cardiac output state. Surgery must be performed without delay because unnecessary passage of time is accompanied by unacceptable mortality rate.

Abdomen, Acute↗

PubMed1993

[Surgical treatment of primary cardiac tumors].

Thirty-four cases of primary cardiac tumors, consisted of 11 men and 23 women, aged between 26 and 80 years have been operated on in our institution. A total of 30 myxomas and four malignant tumors were resected. The clinical presentations included congestive heart failure in 25 patients, tachyarrhythmia in 6, chest pain in 4, and embolism in 10. All 30 myxoma lesions were completely resected, although none of the malignant tumors could be resected completely because of invasion of the tumor to the surrounding tissues. Four patients with malignant tumors died of tumor recurrence within 9 months after operation. Histological diagnosis was rhabdomyosarcoma in two patients, round cell sarcoma in one and malignant fibrous histiocytoma in one. All patients with myxoma survived operation. Follow-up was completed in 28 patients (range 1 month to 15 years, mean 5.5 years): Twenty-four were in New York Heart Association Class I, and the remaining two in Class II. Actuarial survival rate was 89% at 15 years after operation. No recurrent myxoma have been identified clinically or by echocardiography. For malignant primary tumors, more effective adjuvant therapy with aggressive resection will be inevitable to improve long-term prognosis.

Adult↗

PubMed1993

[Surgical repair of total anomalous pulmonary venous drainage--four adult cases of successful operation].

We have experienced four adult cases of total anomalous pulmonary venous drainage (TAPVD). They were three females and one male, age between 18-51 with a mean of 33.8. In Darling's classification, they constituted of three cases of type Ia and one type IV. Cardiac catheterization revealed 1.71-5.93 with a mean of 3.92 in Qp/Qs and 0.34-0.49 with a mean of 0.38 in Pp/Ps. The pulmonary to systemic resistance ratio (Rp/Rs) was then calculated as 0.02-0.15 with a mean of 0.09. All cases showed short route type of drainage vein in pulmonary arteriography. None of them had stenosis or obstruction in the drainage veins. The operation was composed of anastomosis between the left atrium and the common pulmonary vein, closure of the atrial septal defect (ASD), and ligation of the drainage vein. Gersony-Malm's method was adopted in two cases and the posterior approach in two cases in anastomoses between the left atrium and the common pulmonary vein. Intraatrial approach combined with posterior approach was tried in a case with small left atrium. The mean size of ASD was 43 mm (35-55 mm) in diameter. Patch closure was performed in three cases. Important factors in survival for adult TAPVD are large ASD and short route type drainage vein without stenosis. All of four cases had good results. The operation method is variable and an easier approach must be adopted.

Adolescent↗

PubMed1993

[Simultaneous cesarean section and mitral valve replacement for infective endocarditis during pregnancy--a case report].

Infective endocarditis (IE) during pregnancy is uncommon. A 31-week-pregnant, 21-year-old woman suffered from severe mitral regurgitation caused by IE. She fell into heart failure and threatened abortion. Following to cesarean section, an emergent mitral valve replacement with a bioprosthetic valve was successfully performed. Her postoperative recovery was uneventful and she was discharged home 30 days after the operation. Her baby, however, died of intracranial hemorrhage caused by hypoxia 171 days after delivery. A strategy of simultaneous open heart surgery and cesarean section is recommended when emergent open heart surgery is inevitable for the treatment of cardiac diseases in cases with 24 and/or more weeks' gestation.

Adult↗

PubMed1992

[Open-heart surgery without donor-blood transfusion--a clinical study].

Since October 1987, 80 patients underwent open-heart surgery without donor-blood transfusion. 50 (Group I) out of these 80 cases were selected to be paired with 50 patients (Group II) who underwent open-heart surgery with homologous blood transfusion in the same period. Twelve cases (Group III) underwent open-heart surgery without homologous blood transfusion but were transfused after surgery. To decrease the homologous blood requirements, ultra-filtration system as well as conservation and autotransfusion of autologous blood was employed. Peripheral blood count, blood chemistry for liver and renal function were analyzed and compared among these three groups. Although hematocrit of Group I was lower than that of Group II until the third postoperative day, there was no difference after the seventh postoperative day. The platelet count was more in Group I than in Group II or III on the first and the seventh postoperative day. The level of lactate dehydrogenase was higher in Group II than in Group I. Total bilirubin was more elevated in Group II than in Group I on the first and the fourteenth postoperative day. Direct bilirubin was also higher in Group II than in Group I till fourteenth postoperative day. Five cases in Group II fulfilled the criteria of the serum hepatitis. Blood urea nitrogen and creatinine were less in Group I than in Group II. The duration of the intra-tracheal intubation was shorter in Group I than in Group II or III. There was no difference in postoperative dosage or duration of catecholamines among three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

[Functional pulmonary atresia: a case report].

A male neonate, two days of age, was admitted with cyanosis and tachypnea. Chest roentgenograms showed massive cardiomegaly and decreased pulmonary vasculatures. Echocardiographic and the right ventriculographic findings were interpreted as showing primary pulmonary atresia with secondary tricuspid incompetence. At a Brock operation, however, there was no resistance in passing the instrument through the pulmonary valve. The baby died twelve hours after surgery. Postmortem examination showed that the tricuspid regurgitation was a cause of the functional pulmonary atresia (FPA). It is important to distinguish FPA from pure pulmonary atresia because conservative therapy is the first choice for the FPA.

Diagnosis, Differential↗

PubMed1991

[Sudden onset of systemic hypoxia associated with both tricuspid regurgitation and persistent foramen ovale: a case report].

A 33-year-old female who had undergone closure of VSD 20 years before, was hospitalized for sudden onset of dyspnea without history of febrile or traumatic disorder. On admission, she had cyanotic lips and nailbeds but no clubbed finger. Chest x-ray film showed neither lung congestion nor cardiomegaly. Arterial blood gas analysis revealed deep hypoxia (PaO2 = 49.6 mmHg). Echocardiogram clarified massive tricuspid regurgitation (TR) due to chordal rupture of anterior leaflet, small VSD jet stream through the membranous aneurysm and a great deal of R-L shunt on the atrial level through a persistent foramen ovale. Cardiac catheterization data confirmed 35% of R-L shunt. At operation, a torn chordal tendon of anterior leaflet and an adhered septal leaflet to aneurysm of membranous portion of ventricular septum were seen. There were two pledgets, used at the first surgery, at the base of the aneurysm and a couple of tiny holes (VSDs) above and below the pledgets were recognized. Following resection of anterior and posterior leaflet, plication of septal leaflet and closure of VSD, a Xenograft valve (Carpentier-Edwards 29-M) was implanted. Then persistent foramen ovale, 20 x 20 mm in large, was closed directly. Her postoperative course was excellent with disappearance of cyanosis, normalized oxygen saturation in arterial blood and improved activity without dyspnea.

Adult↗