Motohiro Yamashita

Experimental study of tracheal allotransplantation with cryopreserved grafts

OBJECTIVE Tracheal reconstruction is necessary in patients with extensive tracheal stenosis caused by neoplasm, trauma, and congenital disease. We investigated the possibility of tracheal allotransplantation with cryopreserved grafts in a canine model. METHODS A seven-ring section of thoracic trachea was removed in 19 adult mongrel dogs. In group A (n = 4), a five-ring tracheal autograft was implanted. In group B (n = 6), a five-ring allograft was implanted without immunosuppression. In group C (n = 9), a five-ring cryopreserved tracheal allograft was implanted without immunosuppression. Omentopexy wrapping around the grafts and both anastomotic sites was used in all animals. RESULTS All grafts survived without any evidence of atrophy or stenosis in group A. All animals in group B died of severe airway obstruction within 1 month, and postmortem examination of these grafts showed epithelial defect and necrotic tracheal cartilage in the scar tissue. In group C, no animals died of asphyxia caused by severe stenosis of the grafts. The graft epithelium was no longer present 20 days after transplantation, and the graft was covered with regenerated epithelium within about 60 days after the operation. CONCLUSION These findings show that cryopreserved tracheal allografts can be transplanted by means of omentopexy without immunosuppression and that cryopreservation may reduce tracheal allogenicity.

Cardiac and pulmonary replacement Inhaled nitric oxide improves lung allograft function after prolonged storage

Morbidity caused by early allograft dysfunction, manifested by a progressive increase in pulmonary vascular resistance and a decrease in oxygenation, remains a serious problem in lung transplantation. Inhalation of nitric oxide, an essential homeostatic molecule, has been shown to have beneficial effects on a variety of acute lung injuries. The purpose of the present study was to investigate the effect of inhaled nitric oxide on posttransplant function of canine left lung allografts. Fourteen dogs underwent left lung allotransplantation. Donors received systemic heparin and prostaglandin E1 followed by pulmonary artery flush with modified Euro-Collins solution. Donor left lungs were stored for 18 hours at 1 degree C and subsequently implanted. Immediately after reperfusion, the contralateral right main pulmonary artery and bronchus were ligated. The chest was closed and recipients turned to the supine position for the 6-hour assessment period. Hemodynamic and arterial and venous blood gas analyses were made at 15-minute intervals at an inspired oxygen fraction of 1.0 and 5 cm of water positive end-expiratory pressure. Animals were killed at the end of the assessment. Allograft myeloperoxidase activity assays and wet/dry weight ratios were done. In group I (n = 5), nitric oxide gas was administered continuously at concentrations of 60 to 70 ppm before reperfusion and throughout the 6-hour assessment period. In group II (n = 5), nitric oxide administration was initiated at the same concentration after reperfusion injury had developed. Group III animals (n = 4) received no nitric oxide. Significant improvement in gas exchange was apparent in group I. At the end of the 6-hour assessment period, mean arterial oxygen tension was 253.8 +/- 44.7 mm Hg and 114.9 +/- 25.5 mm Hg in groups I and III, respectively (p < 0.05). Group II animals had no improvement in oxygenation with nitric oxide. Systemic hemodynamics were unaffected by nitric oxide. However, an immediate decrease in pulmonary vascular resistance was noted. Group I myeloperoxidase activity was significantly lower than that in control group III (0.24 +/- 0.06 versus 0.36 +/- 0.04 units, respectively; p < 0.05).

Evaluation of lesions corresponding to ground-glass opacities that were resected after computed tomography follow-up examination

BACKGROUND Ground-glass opacity (GGO), which is closely related with bronchioloalveolar carcinoma (BAC), is being detected more frequently. BAC is considered to be a relatively less aggressive tumor, and immediate resection at the time of detection might not be necessary. Therefore, when GGO is detected, a CT follow-up examination is often performed. If growth is detected during the follow-up CT examination, resection is usually considered. However, the possible treatment delay caused by the scheduling of a CT follow-up examination is an issue that must be clarified. Since the cancer might progress during the follow-up period, such follow-up periods might have a negative influence on the patients prognosis. This study attempted to clarify whether CT follow-up causes treatment delay. METHODS A total of 113 lung cancer patients with pure or mixed GGO findings who underwent a resection after a CT follow-up examination between 1999 and 2005 were retrospectively examined. The CT findings at the initial detection, the changes in the CT findings during the CT follow-up period, the histology, the pathological stage and the outcomes after resection were reviewed and evaluated. RESULTS The CT finding at the time of the initial detection showed pure GGO in 63 patients and mixed GGO in 50 patients. Histology revealed that adenocarcinoma was found in all 113 patients; squamous cell carcinoma was not found in any of the patients. One-hundred twelve patients were diagnosed as having Stage IA, and a singe patient with visceral pleura invasion was diagnosed as having Stage IB. Complete resections were performed in all the patients. The median postoperative follow-up period was 45.0 months. No recurrences or deaths were observed during the study period. CONCLUSIONS No treatment delays or negative influences on patient outcome resulted from the CT follow-up period. A future prospective study should be conducted to establish the optimal CT follow-up program.

Local Control of Metastatic Lung Tumors Treated with SBRT of 48 Gy in Four Fractions: In Comparison with Primary Lung Cancer

OBJECTIVE The optimal dose of stereotactic body radiotherapy (SBRT) for metastatic lung tumors has not been clarified. Local control rates of metastatic lung tumors treated with SBRT of 48 Gy in four fractions, which is one of the common dose schedules for Stage I primary lung cancer in Japan, were examined. METHODS Between 2006 and 2008, 12 metastatic lung tumors (colorectal cancer, 7; others, 5) in 10 patients and 56 lesions of Stage I primary lung cancer (T1, 43; T2, 13) in 52 patients were treated with SBRT of 48 Gy in four fractions at the isocenter. RESULTS Two-year overall survival rates were 86% for patients with metastatic lung tumors and 96% for patients with Stage I primary lung cancer (P = 0.4773). One- and 2-year local control rates were 48% and 25% for metastatic lung tumors, and 91% and 88% for Stage I primary lung cancer, respectively (P < 0.0001). CONCLUSIONS The local control rates after SBRT of 48 Gy in four fractions were significantly worse in metastatic lung tumors compared with Stage I primary lung cancer. In SBRT, metastatic lung tumors should be clearly differentiated from primary lung cancer and should be given higher doses.

Comparison in prognosis after VATS lobectomy and open lobectomy for stage I lung cancer: retrospective analysis focused on a histological subgroup.

BackgroundVideo-assisted thoracoscopic surgery (VATS) has become an attractive surgical procedure, but several issues remain to be resolved. Prognosis after VATS lobectomy is important to evaluate the adequacy of VATS lobectomy as a cancer operation. Interestingly, several investigators, including us, have reported that prognosis after VATS lobectomy was superior to that after open lobectomy in early non-small-cell lung cancer (NSCLC). One of the possible reasons is the low invasiveness of VATS lobectomy. But we considered that patient bias might have some influence favoring VATS lobectomy. To evaluate our hypothesis, we reviewed medical records of stage I NSCLC patients undergoing operation between 1993 and 2002. We compared and evaluated the relationship between patient characteristics and prognosis after VATS and open lobectomy. We focused particularly on histological type, classifying it into four subgroups; (1) bronchioloalveolar carcinoma (BAC), (2) mixed BAC + papillary adenocarcinoma (BAC + Pap), (3) other adenocarcinoma (Other adeno), (4) squamous cell carcinoma + others (Sq +others).ResultsA total of 165 patients underwent VATS lobectomy, and 123 patients underwent open lobectomy. The 5-year survival rate of the VATS lobectomy group was 94.5% and that of the open lobectomy group was 81.5%. Univariate Cox regression of survival revealed that male, CEA > 5, Other adeno, Sq + others, open lobectomy, and tumor size > 3 cm were significant negative prognostic variables. Multivariate Cox regression of survival revealed that histological subtype and tumor size were independent prognostic factors, but surgical procedure was not an independent prognostic factor.CommentsPrognosis after VATS lobectomy was superior to that after open lobectomy, but patient bias influenced the prognosis in favor of VATS lobectomy, and the surgical procedure itself was not a prognostic factor.

Living-donor lobar lung transplantation for primary ciliary dyskinesia.

A ventilator-dependent patient with primary ciliary dyskinesia underwent successful living-donor lobar lung transplantation. The case was a 24-year-old woman who had developed recurrent lower respiratory infection and became ventilator-dependent due to severe bronchiectasis. Transmission electron microscopy of the resected bronchus demonstrated inner dynein arm deficiency.

Bilateral Lung Volume Reduction Surgery via Median Sternotomy for Severe Pulmonary Emphysema

BACKGROUND Lung volume reduction surgery either via sternotomy or by thoracoscopy has been demonstrated to be effective for selected emphysema patients in North America and Europe. The present study summarizes short-term results of bilateral lung volume reduction performed via median sternotomy for the first consecutive 39 patients with severe diffuse emphysema in Okayama, Japan, from July 1995 to February 1997. METHODS There were 35 men and 4 women, and the age range was 54 to 74 years with a mean age of 65 years. All were former heavy smokers and none of them had alpha1-antitrypsin deficiency. Only 9 patients (23%) showed a bilateral upper lobe pattern of emphysema. The operation was done through a median sternotomy, and the most emphysematous portions were excised bilaterally with a linear stapling device fitted with strips of bovine pericardium to prevent air leakage. RESULTS No operative death was encountered. The first 33 patients completed 3-month follow-up assessment, and their mean forced expiratory volume in 1 second had improved by 41% from 735 mL to 1,037 mL. Other parameters of pulmonary function tests, arterial blood gas analysis, 6-minute walking distance, and dyspnea scale also had improved significantly. These improvements lasted for at least a year. CONCLUSIONS Bilateral lung volume reduction surgery via median sternotomy is a safe and effective procedure for selected severe emphysema patients. Although the pattern of emphysema might be different between countries, the results in Japanese patients were similar to those previously reported in North American and European patients.

Short-term inhaled nitric oxide in canine lung transplantation from non-heart-beating donor.

BACKGROUND Use of lungs harvested from non-heart-beating donors (NHBDs) would increase the pulmonary donor pool; however, this strategy would have higher risk of early postoperative graft dysfunction due to unavoidable warm ischemic time. We evaluated the effects of short-term inhaled nitric oxide (NO) during reperfusion in canine left single-lung allotransplantation from a non-heart-beating donor. METHODS The donor dogs were sacrificed without heparinization and left at room temperature for 3 hours. Then, recipient dogs received a left single-lung allotransplantation. After implantation, the right bronchus and pulmonary artery were ligated. In group 1 (n = 6), NO gas was administered continuously at a concentration of 40 parts per million throughout a 6-hour assessment period. In group 2 (n = 6), NO gas was administered for the initial 1 hour during reperfusion. In group 3 (n = 6), nitrogen gas was administered for control. RESULTS Groups treated with NO exhibited lower pulmonary vascular resistance, as well as improved survival and oxygenation. There was no significant difference in these parameters between group 1 and group 2. Myeloperoxidase activity was significantly lower in NO-treated groups. CONCLUSIONS Inhaled NO during reperfusion is beneficial in lung transplantation from non-heart beating donors. The beneficial effect is obtained mainly during the first hour of reperfusion.

Prospective Analysis of Oncogenic Driver Mutations and Environmental Factors: Japan Molecular Epidemiology for Lung Cancer Study

PURPOSE Oncogenic driver mutations are critical for lung cancer development and serve as therapeutic targets. However, their associations with environmental factors are not fully understood. We aimed to elucidate the relationship between tumor developmental biology and exposure to environmental factors. PATIENTS AND METHODS This was a prospective, multicenter, molecular epidemiology study. Eligible patients were those with newly diagnosed stages I to IIIB non-small-cell lung cancer (NSCLC) who underwent surgery. The tumors were examined for somatic mutations in 72 cancer-associated genes by targeted deep sequencing, estrogen receptor β (ERβ) expression using immunohistochemical staining, and infection with any of 37 types of human papillomavirus (HPV) using a polymerase chain reaction-based microarray system. Detailed information on patient demographics and environmental factors was obtained from a comprehensive questionnaire. RESULTS From July 2012 to December 2013, 957 patients were enrolled, and molecular analyses were performed on 876 samples (from 441 ever- and 435 never-smokers). Oncogenic driver mutations in P53 and KRAS increased proportionally with smoking status, whereas mutations in EGFR and SMAD4 decreased. KRAS mutations in smokers and SMAD4 mutations were observed more frequently in proportion to body mass index. TP53 and NFE2L2 mutations were observed more frequently in advanced NSCLC stages. As for never-smokers, no environmental factors were significantly associated with mutational changes. EGFR mutations and TP53 mutations were observed more frequently in women and in men, respectively. Mutations in these two genes were also potentially associated with ERβ expression. Only three patients (0.3%) were HPV positive. CONCLUSION The mutational spectrum is associated with smoking, body mass index, and other environmental factors, as well as with ERβ expression. Little association was observed between HPV and NSCLC.

Long-term outcome and prognostic factors of surgically treated thymic carcinoma: results of 306 cases from a Japanese Nationwide Database Study

OBJECTIVES Thymic carcinoma is a rare thymic malignancy. The purpose of this study was to evaluate the prognostic impact of clinicopathological variables and perioperative therapy for surgically treated thymic carcinoma using a nationwide database. METHODS Of 2835 patients with surgically treated thymic epithelial tumours collected from 32 Japanese institutions, a total of 306 patients with thymic carcinomas, excluding neuroendocrine tumours, were enrolled in this retrospective study. Multivariable Cox regression analyses were performed for overall (OS) and recurrence-free survival (RFS) after R0 resection. RESULTS Of 306 patients, 228 (75%) patients presented with Masaoka stage III-IV. Squamous cell carcinoma was the most common histological type (n = 216, 71%). R0 resection was performed in 181 (61%) patients, R1 in 46 (16%), R2 sub-total (≥80% tumour resection) in 43 (14%) and R2 non-resection in 27 (9%). The 5-year OS rate was 61%. Prognostic factors for OS were Masaoka stage and resection status. R0 resection was associated with most improved OS; however, both R1 and R2 sub-total resection resulted in superior OS compared with R2 non-resection [hazard ratio (95% confidence interval) for R0, R1 and R2 sub-total, 0.27 (0.15-0.48), 0.40 (0.22-0.74) and 0.38 (0.20-0.72), respectively]. Histological type and perioperative therapy did not affect OS, whereas tumour size and postoperative radiotherapy were associated with improved RFS after R0 resection. CONCLUSIONS R0 resection is essential for prolonged OS for surgically treated thymic carcinoma, but maximal debulking surgery might be beneficial and worth evaluating for advanced disease deemed difficult for R0 resection. The benefit of postoperative radiotherapy after R0 resection should also be evaluated prospectively.