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Biomedical subjects

Y Sohara

Publications and source records attributed to Y Sohara.

At least 37 records · Page 2Linked to original sources
PubMed1999

Guideline of surgical management based on diffusion of descending necrotizing mediastinitis.

BACKGROUND: Descending necrotizing mediastinitis resulting from oropharyngeal abscess, is a serious, life-threatening infection. Exisiting strategies for surgical management, such as transcervical mediastinal drainage or aggressive thoracotomic drainage, remain controversial. METHODS: Four patients, (three males and one female) were treated for descending necrotizing mediastinitis resulting from oropharyngeal infection. Two had peritonsillar abscesses, while the others experienced dental abscess and submaxillaritis. Descending necrotizing mediastinitis received its classification according to the degree of diffusion of infection diagnosed by computed tomography. Mediastinitis in two cases, (Localized descending necrotizing mediastinitis-Type I), was localized to the upper mediastinal space above the carina. In the others, infection extended to the lower anterior mediastinum (Diffuse descending necrotizing mediastinitis-Type IIA), and to both anterior and posterior lower mediastinum (Diffuse descending necrotizing mediastinitis-Type IIB). The spread of infection to the pleural cavity occurred in three cases. RESULTS: The surgical outcome concerning each of the patients was successful. Radical cervicotomy (unilateral in three patients, bilateral in the other) in conjunction with mechanical ventilation with continuous postoperative positive airway pressure, was performed in all cases. Tracheostomy was established in three patients and pharyngostomy in two. The two descending necrotizing mediastinitis-Type I cases were successfully managed with transcervical mediastinal drainage. The descending necrotizing mediastinitis-Type IIA case received treatment through transcervicotomy and anterior mediastinal drainage through a subxiphoidal incision. The patient with descending necrotizing mediastinitis-Type IIB required posterior mediastinal drainage through a right standard thoracotomy followed by left minimal thoracotomy. CONCLUSIONS: The mediastinal infection, the extent of which has been accurately determined by computed tomograms, necessitates radical cervicotomy followed by pleuromediastinal drainage. Situations where infection has spread to posterior medisatinum, particularly when it reaches in the level of the carina (descending necrotizing mediastinitis-type I), may not always require aggressive mediastinal drainage. In comparison, diffuse descending necrotizing mediastinitis-Type IIB demands complete mediastinal drainage with debridement via thoracotomy. Subxiphoidal mediastinal drainage without sternotomy may provide adequate drainage in diffuse descending necrotizing mediastinitis-Type IIA.

Abscess↗
PubMed1999

Late pleuropulmonary aspergillosis after the treatment of pneumothorax: report of three cases.

A bullectomy for spontaneous pneumothorax is often combined with pleurodesis to prevent recurrence. A recurrent or progressive residual bullous lung beneath adhesive pleura neovascularized from the chest wall may be affected by aspergillosis. Of the 12 patients with pulmonary aspergillosis secondary to bullous lung disease treated surgically at our hospital since 1974, 3 underwent a bullectomy with pleurodesis for spontaneous pneumothorax. The presenting symptoms in all cases were hemosputum. Aspergillus lesions affected the patients in the right upper lobe, the left apical segment, and both apical segments at 16, 9, and 13 years, respectively, after a bullectomy. Angiograms demonstrated hypervascularization in the intercostal and internal thoracic arteries, as well as in the bronchial branches. Catheter embolization for airway bleeding was not effective in 1 patient. Four operations, including an emergency procedure for massive intrapulmonary bleeding, were performed. These included a right upper lobectomy followed by a left upper segmentectomy at second-look operation in 1 patient who required bilateral chest wall resections. All patients survived the operations. Intraoperative bleeding ranged between 700 and 3 500 ml (1 543 ml on average), and bleeding foci were mainly from the chest wall, with hypervascularization stemming from the ipsilateral chest wall. Postoperative complications included pleural space hemorrhaging and a bronchopleural fistula, both of which required additional chest wall resections. Patients with bullous lung disease late after a bullectomy with pleurodesis may thus be associated with complex pleuropulmonary aspergillosis, which requires surgical therapy concomitant with a chest wall resection.

Adult↗
PubMed1999

Helical computed tomographic minimum-intensity projection of a slit in an airway obstruction.

We treated a 54-year-old man with an anastomotic obstruction after a right upper sleeve lobectomy. By using minimum intensity projection images that were generated from helical computed tomographic data sets that indicated a twisted slit enhanced with air a few millimeters in length, through anastomosis to the distal bronchus, we successfully treated the obstruction by bronchoscopic balloon dilatation.

Airway Obstruction↗
PubMed1999

[Multiple intrapulmonary rheumatoid nodules].

A 66-year-old woman who had been treated at a nearby hospital since 1977 for rheumatoid arthritis complained of cough. Chest X-ray films disclosed multiple nodular shadows with cavitation in the fields of both lungs. The patient was admitted to our hospital and a thoracoscopic lung biopsy was performed. Histologically, the nodule consisted of necrotizing granuloma, indicating a necrobiotic nodule. Rheumatoid nodule was diagnosed because the patient exhibited rheumatoid arthritis. The chest X-ray shadow disappeared without medication. Rheumatoid nodules without coniosis are uncommon, but should be considered in the differential diagnosis of lung nodular lesions in patients with rheumatoid arthritis.

Aged↗
PubMed1998

Subcarinal neurogenic tumor: report of a case.

We present herein the rare case of a 63-year-old man in whom a subcarinal tumor, demonstrated by enhanced chest computed tomograms (CT), was subsequently confirmed to be a neurilemmoma by histological examination following tumor resection through a diagnostic thoracoscopy. Magnetic resonance imaging (MRI) and transesophageal ultrasonogram findings excluded the possibility of malignant lymphoadenopathy. As the patient was also found to have an elevated level of the squamous cell carcinoma (SCC) tumor marker which did not resolve postoperatively, close follow-up will be required.

Humans↗
PubMed1998

Pulmonary histoplasmosis in a Japanese male: report of a case.

A case of pulmonary histoplasmosis, which is rare in Japan, is reported herein. A 43-year-old man who had worked in Mexico for 2 years and had come back to Japan 3 months earlier, presented at our hospital because of an abnormal shadow on his chest roentogenogram with no symptoms. His chest roentogenogram as well as chest computed tomograms revealed a 2-cm-diameter nodule in the anterior basal segment of his right lung and an enlargement of the subcarinal lymph node. Although these pictures seemed to indicate an advanced lung cancer, no malignant cells were found based on the brushing cytology findings after bronchoscopy. An exploratory thoracoscopic tumor resection and biopsy of the enlarged lymph node led to a histological diagnosis of an abscess due to histoplasma. The hospital course was uneventful. Postoperatively, amphotericin B was administered for 1 year. This is the eighth case of pulmonary histoplasmosis reported in Japan. A pulmonary nodule together with mediastinal lymphoadenopathy seems to be characteristic in these patients. Histoplasmosis should therefore be considered in the differential diagnosis, since overseas travel has now become common-place for the Japanese.

Adult↗
PubMed1997

Successful surgical treatment of a complete traumatic tracheal disruption.

We report a case of a survivor who suffered a complete traumatic disruption of the cervical trachea associated with multiple organ injuries. She underwent an emergent operation including end-to-end anastomosis of the disrupted trachea with pedicled omental coverage to prevent dehiscence and mediastinitis. The postoperative course was uneventful, with hospital discharge on day 36. She returned to her previous lifestyle.

Anastomosis, Surgical↗
PubMed1997

Computed tomography analysis of the anterior mediastinal fat after left upper lobectomy.

RATIONALE AND OBJECTIVES: The authors evaluate changes in the anterior mediastinal fat (AMF) after left upper lobectomy. METHODS: In 36 carcinoma patients undergoing left upper lobectomy, the area and volume of AMF were measured using computed tomography before and after surgery, and their relations to postoperative mediastinal deviation were examined. RESULTS: The postoperative AMF distribution was changed distinctly, showing marked increase from the aortic arch to the main pulmonary arterial level, with converse decrease at upper and lower slices, but no significant postoperative change was noted in total AMF volume. There was a close correlation between changes in AMF area and mediastinal deviation after lobectomy. In two patients, a pseudotumor composed of AMF was depicted on frontal radiograph postoperatively, pseudotumor was thought to appear when the postoperative mediastinal deviation was marked but unaccompanied by marginal fluid or fibrosis. CONCLUSIONS: The AMF distribution is distinctly changed postoperatively, the displaced AMF redistribution is considered to be the main cause of seemingly increased fat or pseudotumor.

Adipose Tissue↗
PubMed1997

[CT analysis of the anterior mediastinal fat: before and after lobectomy].

CT analysis was performed to evaluate change in the anterior mediastinal fat (AMF) after lobectomy and differences in AMF in the lobectomized region. In 67 carcinoma patients who underwent lobectomy, the area and volume of AMF were measured on CT before and after surgery. Mediastinal deviation after lobectomy was also correlated to the altered fat tissue. The postoperative AMF distribution was distinctly changed in the left upper lobectomy (LUL) group, showing a marked increase from the infra-aortic arch to the carina level, with converse decreases in upper and lower slices. No significant post-operative change was noted in total AMF volume. There was a close correlation between changes in AMF area and mediastinal deviation after lobectomy, and postoperative mediastinal deviation was also greater the in the LUL group than in any other group. In conclusion, postoperative change in the AMF area was distinctly different in the LUL group. Redistribution of displaced AMF is considered to be the main cause of seemingly increased fat tissue.

Adipose Tissue↗
PubMed1997

[Cardiac tamponade caused by diffuse pericardial mesothelioma].

A 75-year-old woman was admitted to our hospital because of dyspnea and fever. A chest roentgenogram obtained on admission showed cardiomegaly. An echocardiogram, a computed tomogram, and a magnetic resonance computed tomogram revealed a pericardial tumor and a large pericardial effusion. A tumor biopsy was done under echocardiographic guidance, and sarcomatous mesothelioma was diagnosed on the basis of histological and immunohistological studies of biopsy specimens. Pericardial fenestration followed by tumor resection gave relief from cardiac tamponade. The postoperative course was good, and the patient was discharged from the hospital on the 19th postoperative day. Four months later the pericardial mesothelioma recurred and the patient died of constrictive pericarditis. Palliative resection was useful in this case because it allowed the patient to resume activities of daily living by relieving the cardiac tamponade.

Aged↗
PubMed1996

Flow patterns in dog aortic arch under a steady flow condition simulating mid-systole.

To elucidate the possible connection between blood flow and localized pathogenesis and the development of atherosclerosis in humans, we studied the flow patterns and the distribution of fluid axial velocity and wall shear stress in the aortic arch in detail. This was done by means of flow visualization and high-speed cinemicrographic techniques, using transparent aortic trees prepared from the dog. Under a steady flow condition at inflow Reynolds numbers of 700-1600, which simulated physiologic conditions at early- to mid-systole, slow, spiral secondary, and recirculation flows formed along the left anterior wall of the aortic arch and at the entrance of each side branch adjacent to the vessel wall opposite the flow divider, respectively. The flow in the aortic arch consisted of three major components, namely, an undisturbed parallel flow located close to the common median plane of the arched aorta and its side branches, a clockwise rotational flow formed along the left ventral wall, and the main flow to the side branches, located along the right dorsal wall of the ascending aorta. Thus, looking down the aorta from its origin, the flow in the aortic arch appeared as a single helical flow revolving in a clockwise direction. Regions of low wall shear stress were located along the leading edge of each side branch opposite the flow divider where slow recirculation flows formed, and along the left ventral wall where slow spiral secondary flows formed. If we assume that the flow patterns in the human aortic arch well resemble those observed in the dog, then it is likely that atherosclerotic lesions develop preferentially at these sites of low wall shear stress in the same manner as in human coronary and cerebral arteries.

Animals↗
PubMed1996

[Chest wall reconstruction, relation between reconstruction method and infection].

We have operated 52 cases of chest wall resection in these 20 years. Twenty five cases in it were reconstructed by unabsorbable artificial materials such as Marlex mesh, Gore-Tex sheet and some others (Group 1). Eleven cases were covered with the net knitted by absorbable threads or muscle flaps (Group 2). Resting 16 cases have not received any definitive renovations (Group 3). Group 1 has suffered from such severe postoperative complications as acute empyema (8%) and chronic empyema (8%). Few cases in Group 2 has had infectious complication and ventilatory disturbance. Rate of postoperative vital capacity in Group 3 was the lowest value among three groups, though they had the smallest chest wall defects. We obtained following conclusions from this study. Every chest wall defect should be repaired by some way even if the defect were small. Chest wall defect in compromised host should be repaired by absorbable artificial material and muscle flap. Unabsorbable artificial materials are now indispensable for the reconstruction of large chest wall defect, however we must fully take care of postoperative infections in cases of its use.

Biocompatible Materials↗
PubMed1996

[Diagnosis and treatment of pulmonary nodules by video-assisted thoracoscopic surgery--surgeons' view].

We reviewed 48 cases of pulmonary nodules in which video-assisted thoracoscopic surgery was done at Jichi Medical School Hospital from 1992 through 1995. The pulmonary nodules comprised 14 malignant tumors (9 lung cancers and 5 pulmonary metastases), 10 benign tumors (7 hamartomas, 2 localized mesotheliomas and 1 tumorlet), 19 granulomas (8 inactive infectious tumors, 7 active infectious tumors, and 4 granulomas as sequelae of other diseases), 4 intrapulmonary lymph nodes, and 1 pulmonary cyst. Conventional operations for lung cancer were done in 7 cases, and 6 were found to be ST-I. Tumor resection by video-assisted thoracoscopic surgery allowed diagnosis of rare diseases and treatment of benign lung tumors and of lung metastases. We conclude this procedure is very useful for diagnosis and treatment of indeterminate pulmonary nodules.

Adult↗
PubMed1995

[A case of primary pulmonary cryptococcosis associated with pneumothorax].

We report a case of primary pulmonary cryptococcosis. A 20-year-old woman was admitted to the hospital complaining of coughing, fever, and dyspnea on exertion. She had no underling disease or immunological abnormality. Chest X-ray film revealed bilateral diffuse infiltrative shadows, which were first believed to have been caused by a community-acquired pneumonia. Pulmonary cryptococcosis was diagnosed from the results of a transbronchial lung biopsy. After 2.5 years of anti-mycotic chemotherapy with amphotericin B and flucytosine, pneumothorax occurred in the left lung. Thoracotomy and open lung biopsy were done. Histological findings of the open lung biopsy specimens showed numerous broken cryptococcal organisms within alveolar macrophages. Diffuse fibrosis accompanied by multiple bullae may have punctured bullae or blebs and thus led to pneumothorax.

Adult↗
PubMed1994

The effectiveness of transesophageal ultrasonography in preoperatively diagnosing an esophageal cyst in a 75-year-old woman: report of a case.

We present herein the unusual case of a 75-year-old woman in whom an esophageal cyst was preoperatively identified with the aid of transesophageal ultrasonography. She underwent successful extirpation and has remained well since her discharge from hospital. The transesophageal ultrasonogram was shown to be a powerful diagnostic tool for the identification of a mediastinal mass located adjacent to the esophagus.

Aged↗
PubMed1994

[A case of lung cancer with cryptococcal infection in resected lymph nodes].

A 68-year-old female was admitted because of an abnormal shadow on chest X-ray film. Chest CT showed a nodular shadow in right S3a. Right upper lobectomy with mediastinal lymph node resection was performed under a diagnosis of lung cancer made by TBLB. Pathological examination of the resected lung revealed well differentiated adenocarcinoma. In addition, examination of the resected lymph nodes showed granulomas, some of which contained numerous cryptococci and showed central caseous necrosis, and others showed non-caseating epithelioid cell granulomas suggesting sarcoid reaction. No cryptococcal infection was found in the resected lung. Mediastinal lymph node involvement of cryptococcus in this case was considered to be the lymph node component of the primary pulmonary complex of cryptococcosis. Such a primary complex was demonstrated in 1% of the cases of cryptococcosis in previous reports.

Adenocarcinoma↗