遠藤 俊輔

Background. The benefit of thymectomy in myasthenia gravis management is recognized but the perioperative course can fluctuate. The goal of this study was to assess the feasibility and clinical benefit of dose-escalated steroid therapy with thymectomy for nonthymornatous myasthenia gravis. Methods. We reviewed the records of 69 myasthenia gravis patients who were followed up after undergoing transsternal thymectomy with extended anterior mediastinal dissection in our hospital between 1976-2000. Forty-eight patients in the programmed treatment group who had dose-escalated and de-escalated steroid therapy during the perioperative period comprised 17 patients with ocular myasthenia gravis and 31 patients with generalized myasthenia gravis. Clinical benefits and clinical remission, which was diagnosed when the patients were symptom-free without medications for at least 1 year, were compared with those of 21 patients in the occasional treatment group who received medications occasionally over the perioperative period. Results. Postoperative respiratory failure and myasthenic crisis did not occur in the programmed treatment group but did occur in 6 patients in the occasional treatment group. Remission rates in the programmed treatment group (mean follow-up, 6.4 years) were 30% at 3 years, 38% at 5 years, and 46% at 10 years; rates in the occasional treatment group (mean follow-up, 9.6 years) were 25% at 3 years, 25% at 5 years, and 45% at 10 years. Conclusions. Programmed steroid therapy in patients with nonthymomatous myasthenia gravis is feasible and it provides clinical benefit when fluctuating symptoms occur during the perioperative period.

Background. The benefit of thymectomy in myasthenia gravis management is recognized but the perioperative course can fluctuate. The goal of this study was to assess the feasibility and clinical benefit of dose-escalated steroid therapy with thymectomy for nonthymornatous myasthenia gravis. Methods. We reviewed the records of 69 myasthenia gravis patients who were followed up after undergoing transsternal thymectomy with extended anterior mediastinal dissection in our hospital between 1976-2000. Forty-eight patients in the programmed treatment group who had dose-escalated and de-escalated steroid therapy during the perioperative period comprised 17 patients with ocular myasthenia gravis and 31 patients with generalized myasthenia gravis. Clinical benefits and clinical remission, which was diagnosed when the patients were symptom-free without medications for at least 1 year, were compared with those of 21 patients in the occasional treatment group who received medications occasionally over the perioperative period. Results. Postoperative respiratory failure and myasthenic crisis did not occur in the programmed treatment group but did occur in 6 patients in the occasional treatment group. Remission rates in the programmed treatment group (mean follow-up, 6.4 years) were 30% at 3 years, 38% at 5 years, and 46% at 10 years; rates in the occasional treatment group (mean follow-up, 9.6 years) were 25% at 3 years, 25% at 5 years, and 45% at 10 years. Conclusions. Programmed steroid therapy in patients with nonthymomatous myasthenia gravis is feasible and it provides clinical benefit when fluctuating symptoms occur during the perioperative period.

Objective: Massive hemoptysis is a life-threatening condition. Surgery is effective but we are sometimes reluctant to operate on patients with this condition. We reviewed our experience with patients who underwent emergency surgery for massive hemoptysis to verify the indications for non-emergency surgical intervention. Methods: We reviewed chest computed tomography (CT) and angiographic and pathological findings and the postoperative course of 25 patients who underwent emergency pulmonary resection in our department between 1979 and 2001 due to life-threatening hemoptysis. Results: CT revealed a persistent cavity within the radiological opacity before massive hemoptysis in 12 patients (48%). Of the 21 patients who underwent angiography, nine showed focal bleeding in one bronchial branch and the others showed bleeding in multiple branches. Of these nine patients, seven did not undergo embolotherapy mainly due to minor vascularity. In the remaining patients, embolotherapy was not indicated in six due to multiple bleeding feeders and recurrence after embolotherapy was seen in six. Pathological findings showed that eight of the 12 patients with multiple systemic shunts had a fungal infection. Operative morbidity and hospital mortality were 32 and 4%, respectively. There was no recurrence in patients who underwent surgical treatment. Conclusions: Early pulmonary resection is indicated in patients with hemoptysis of multiple branches from the cavity and chest wall, such as in fungal infections. When a bronchial branch is the only bleeding focus, superselective embolotherapy should be considered prior to surgery even if the localized focus of the bronchial branch shows minor vascularity on the angiography. (C) 2003 Elsevier Science B.V. All rights reserved.

Background. To clarify the effects of partial liquid ventilation, we visualized and morphologically analyzed real-time alveolar recruitment. in a model of acute lung injury. Methods. Male Wistar rats were divided into 3 groups: a group that underwent hydrochloric acid aspiration and mechanical gas ventilation (ALI group, n = 15), a group that underwent acid aspiration and partial liquid ventilation beginning 90 minutes after acid aspiration (PLV group, n = 15), and a group that underwent mechanical ventilation without acid aspiration (control group, n = 5). The number of ventilated alveoli and the diameter of the largest ventilated alveolus in each of 10 high-power fields observed on fluorescence micrographs with a tracer of labeled albumin were determined and averaged from 90 to 210 minutes after acid aspiration. Results. The number of alveoli in the PLV group significantly increased in comparison to that in the ALI group. The diameter of the largest alveolus in the PLV group decreased from 103.7 +/- 16.3 mum to 76.3 +/- 6.5 mug in until the end of the experiment. This diameter was equivalent to that in the control group. Conclusions. The excellent alveolar recruitment suggests that liquid ventilation ameliorates ventilator-associated lung injury.

Background. To clarify the effects of partial liquid ventilation, we visualized and morphologically analyzed real-time alveolar recruitment. in a model of acute lung injury. Methods. Male Wistar rats were divided into 3 groups: a group that underwent hydrochloric acid aspiration and mechanical gas ventilation (ALI group, n = 15), a group that underwent acid aspiration and partial liquid ventilation beginning 90 minutes after acid aspiration (PLV group, n = 15), and a group that underwent mechanical ventilation without acid aspiration (control group, n = 5). The number of ventilated alveoli and the diameter of the largest ventilated alveolus in each of 10 high-power fields observed on fluorescence micrographs with a tracer of labeled albumin were determined and averaged from 90 to 210 minutes after acid aspiration. Results. The number of alveoli in the PLV group significantly increased in comparison to that in the ALI group. The diameter of the largest alveolus in the PLV group decreased from 103.7 +/- 16.3 mum to 76.3 +/- 6.5 mug in until the end of the experiment. This diameter was equivalent to that in the control group. Conclusions. The excellent alveolar recruitment suggests that liquid ventilation ameliorates ventilator-associated lung injury.

We report on a 67-year-old woman with a rare Scopulariopsis fungus ball in the right middle lung lobe. Pathologic examinations after right middle lobectomy showed that the lesion contained a moniliaceous mold fungus that was cultured and identified as Scopulariopsis. The patient's postsurgery course was uneventful. © 2002 by The Society of Thoracic Surgeons.

We report on a 67-year-old woman with a rare Scopulariopsis fungus ball in the right middle lung lobe. Pathologic examinations after right middle lobectomy showed that the lesion contained a moniliaceous mold fungus that was cultured and identified as Scopulariopsis. The patient's postsurgery course was uneventful. © 2002 by The Society of Thoracic Surgeons.

Background. Diagnosis and treatment of pulmonary actinomycosis is difficult without surgical intervention. Methods. Thirteen patients (10 men, 3 women; mean age, 62 years) underwent pulmonary resection and were given a pathologic diagnosis of pulmonary actinomycosis at our institution between 1976 and 2001. To clarify when pulmonary actinomycosis should be suspected in patients and the role of surgical intervention, we reviewed preoperative clinical characteristics, computed tomography findings, surgical indication, operative procedure, postoperative clinical course, and outcome. Results. Ten patients (77%) had poor oral hygiene. Twelve patients (92%) were symptomatic, and 10 patients (77%) had hemoptysis. The mean interval between radiographic identification of the abnormality and surgical intervention was 8 months (interquartile range, 3.25 to 8 months). Computed tomography findings in all cases included radiologic opacity with air bronchogram or a low attenuation area. Lung cancer was diagnosed initially because of computed tomography findings of spiculation or pleural indentation, and operation was required in 8 patients (62%). The others were diagnosed with chronic pneumonia, and surgical intervention became necessary because of recurrent hemoptysis or prolonged illness. Six patients underwent lobectomy; the others underwent partial resection or segmentectomy. Neither complication nor recurrence has occurred. Conclusions. When patients, particularly those with poor oral hygiene, show radiologic opacity with an air bronchogram or low attenuation area on the computed tomography scan, pulmonary actinomycosis should be considered and penicillin should be administered as diagnostic therapy. Surgical intervention may be necessary when frequent hemoptysis has no resolution or lung neoplasm cannot be ruled out. (C) 2002 by The Society of Thoracic Surgeons.

Background. Diagnosis and treatment of pulmonary actinomycosis is difficult without surgical intervention. Methods. Thirteen patients (10 men, 3 women; mean age, 62 years) underwent pulmonary resection and were given a pathologic diagnosis of pulmonary actinomycosis at our institution between 1976 and 2001. To clarify when pulmonary actinomycosis should be suspected in patients and the role of surgical intervention, we reviewed preoperative clinical characteristics, computed tomography findings, surgical indication, operative procedure, postoperative clinical course, and outcome. Results. Ten patients (77%) had poor oral hygiene. Twelve patients (92%) were symptomatic, and 10 patients (77%) had hemoptysis. The mean interval between radiographic identification of the abnormality and surgical intervention was 8 months (interquartile range, 3.25 to 8 months). Computed tomography findings in all cases included radiologic opacity with air bronchogram or a low attenuation area. Lung cancer was diagnosed initially because of computed tomography findings of spiculation or pleural indentation, and operation was required in 8 patients (62%). The others were diagnosed with chronic pneumonia, and surgical intervention became necessary because of recurrent hemoptysis or prolonged illness. Six patients underwent lobectomy; the others underwent partial resection or segmentectomy. Neither complication nor recurrence has occurred. Conclusions. When patients, particularly those with poor oral hygiene, show radiologic opacity with an air bronchogram or low attenuation area on the computed tomography scan, pulmonary actinomycosis should be considered and penicillin should be administered as diagnostic therapy. Surgical intervention may be necessary when frequent hemoptysis has no resolution or lung neoplasm cannot be ruled out. (C) 2002 by The Society of Thoracic Surgeons.

Symptomatic accessory cardiac bronchus is rare. A 52-year-old woman with an accessory bronchus, who had had frequent episodes of hemosputum for 6 years, suffered from empyema complicated by a right lower lung abscess infected with Pseudomomas aeruginosa. Resection of the anomalous cardiac bronchus after open drainage of the pleural cavity was successful. (C) 2000 by The Society of Thoracic Surgeons.

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. (Ann Thorac Surg 1999;67:847-9) (C) 1999 by The Society of Thoracic Surgeons.

To elucidate the possible connection between blood flow and localized pathogenesis and tile 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 highspeed cinemicrographic techniques, using transparent aortic tries 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 wail opposite the flow divider, respectively. The flow in the aortic arch consisted of three major components, namely, an undisturbed parallel now located close to the common median plane of the arched aorta and its side branches, a clockwise rotational now 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.