Relationship of smoking cessation period with the incidence of complications in lung cancer surgery.

OBJECTIVES: The incidence of postoperative complications is relatively high in smokers. Although 4-week smoking cessation before surgery is generally recommended, it has not been sufficiently studied in lung cancer surgery. This study investigated whether smoking cessation for a short period of time significantly reduced complications after lung cancer surgery. METHODS: This was a retrospective, observational study that investigated the relationship between the smoking cessation period and the incidence of complications in lung cancer surgery. Patients who underwent curative-intent surgery for lung cancer at our institution between January 2014 and December 2017 were included. The smokers were classified into the following 4 categories of smoking cessation period before surgery: current (<4 weeks), recent (4 weeks to 12 months), distant (12 months to 5 years) and ex-smokers (>5 years). RESULTS: A total of 911 patients were included in this study. The incidence of pulmonary complications was 5 times higher in the smoker group than in the never smoker group (12.9% vs 2.5%, P < 0.001). On multivariable analysis in both models, the odds ratio for complications was significantly higher in distant smokers than in recent smokers and never smokers. Across all models, low lung function significantly predicted the development of postoperative complications. CONCLUSIONS: The evidence-based smoking cessation duration that reduces the incidence of complications after thoracic surgery remains unclear. The incidence of postoperative complications was more strongly affected by low pulmonary function than by the duration of preoperative smoking cessation. For patients with marginal indications for surgery, postponing surgery to accommodate a smoking cessation period seemed unnecessary.

Pleural Invasion Depth of Disseminated Nodules in Patients with Stage IVa or Recurrent Thymoma: Assessment, Curative Impact, and Surgical Outcomes.

BACKGROUND: Thymoma patients with pleural dissemination are difficult to manage, and their treatment strategy remains undefined. This study aimed to investigate the clinicopathologic features of these patients, focusing on the association between the depth of pleural invasion and prognosis. METHODS: Between 2003 and 2019, the study identified 120 disseminated lesions in 20 thymoma patients. Seven patients had de novo stage IVa thymoma and 13 were recurrent cases. Extrapleural pneumonectomy was performed for 8 patients and debulking surgery for 12 patients. Invasion depth of pleural tumors was classified into two groups: when the disseminated tumors invaded the pleura beneath the elastic layer, the tumor was diagnosed as Da, and when the disseminated tumors invaded the pleura beyond the elastic layer, the tumor was diagnosed as Db. RESULTS: Of 120 nodules, 31 (26%), found in eight patients with recurrent malignancies, were classified as Db. The pathologic status of the surgical margin (PSM) was positive in eight patients, seven of whom had Db nodules. The 5-year overall survival (OS) rate was 100% in the Da group and 75% in the Db group (P = 0.02). The 5-year progression-free survival (PFS) rate was 66.7% in the Da group and 25% in the Db group (P = 0.02). Cox univariate analysis showed that PFS was significantly influenced by the depth of invasion (P = 0.04) and PSM (P = 0.03). CONCLUSION: Depth of pleural invasion may influence survival outcomes for thymoma patients with pleural dissemination. The patients in this study with Da-disseminated nodules had an increased probability of a longer OS and PFS and tended to achieve negative PSM compared with the patients with Db.

Removal of hematoma due to massive hemoptysis after transbronchial biopsy: a case report.

BACKGROUND: Massive hemoptysis is a life-threatening complication after transbronchial biopsy (TBB). Reports on massive hemoptysis occurring several days after TBB are scarce. CASE PRESENTATION: A 62-year-old man presented with massive hemoptysis and was admitted to hospital as an emergency on the eighth day after TBB. On the 12th day after TBB, computed tomography showed complete atelectasis of the right middle and lower lobes. The patient underwent emergent right upper lobectomy. The right upper lobe bronchus was separated with a scalpel, the hematoma was pulled out with forceps, and the bronchus subsequently sutured shut. The patient was discharged from the hospital uneventfully. CONCLUSIONS: We experienced a case of massive hemoptysis on the eighth day after TBB, which required emergency surgery due to persistent bleeding into the airway and airway obstruction during follow-up. Postoperative pneumonia and atelectasis could be prevented by manual removal of the residual hematoma.

Diagnostic utility of metabolic parameters on FDG PET/CT for lymph node metastasis in patients with cN2 non-small cell lung cancer.

BACKGROUND: The aim of this study was to assess the diagnostic utility of metabolic parameters on fluorine-18-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET)/computed tomography (CT) for predicting lymph node (LN) metastasis in patients with cN2 non-small cell lung cancer (NSCLC). METHODS: We retrospectively reviewed patients who underwent surgery for cN2 NSCLC between 2007 and 2020. Those who had clinically diagnosed positive hilar and mediastinal LNs by routine CT and PET/CT imaging were investigated. To measure the metabolic parameters of LNs, the data according to maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and LN-to-primary tumor ratio of SUVmax (LPR) were examined. The diagnosis of each retrieved LN was confirmed based on histopathological examination of surgical tissue specimens. Receiver operating characteristics (ROC) curves with area under the curve (AUC) calculations and multivariate analysis by logistic regression were performed. RESULTS: Forty-five patients with 84 clinically diagnosed positive hilar or mediastinal LNs were enrolled in the present study. Of the 84 LNs, 63 LNs were pathologically proven as positive (75%). The SUVmax, MTV, TLG, and LPR of LN metastasis were significantly higher than those of benign nodes. In the ROC analysis, the AUC value of LPR [AUC, 0.776; 95% confidence interval (CI), 0.640-0.913] was higher than that of LN SUVmax (AUC, 0.753; 95% CI, 0.626-0.880) or LN TLG3.5 (AUC, 0.746; 95% CI, 0.607-0.885). Using the optimal LPR cutoff value of 0.47, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 84.1, 66.7, 88.3, 58.3, and 79.8%, respectively. Multivariate analysis by logistic regression showed that LPR was an independent predictor for LN metastasis (odds ratio, 6.45; 95% CI, 1.785-23.301; P = 0.004). In the subgroup analysis of adenocarcinoma patients (n = 18; 32 LNs), TLG3.5 was a better predictor (AUC, 0.816; 95% CI, 0.639-0.985) than LPR (AUC, 0.792; 95% CI, 0.599-0.986) or LN SUVmax (AUC, 0.792; 95% CI, 0.625-0.959). CONCLUSIONS: Our findings suggest that LPR on FDG-PET is a useful predictor for LN metastasis in patients with cN2 NSCLC. TLG can be a good predictor for LN metastasis in patients with adenocarcinoma.

Miniaturization of Respiratory Measurement System in Artificial Ventilator for Small Animal Experiments to Reduce Dead Space and Its Application to Lung Elasticity Evaluation.

A respiratory measurement system composed of pressure and airflow sensors was introduced to precisely control the respiratory condition during animal experiments. The flow sensor was a hot-wire thermal airflow meter with a directional detection and airflow temperature change compensation function based on MEMS technology, and the pressure sensor was a commercially available one also produced by MEMS. The artificial dead space in the system was minimized to the value of 0.11 mL by integrating the two sensors on the same plate (26.0 mm × 15.0 mm). A balloon made of a silicone resin with a hardness of A30 was utilized as the simulated lung system and applied to the elasticity evaluation of the respiratory system in a living rat. The inside of the respiratory system was normally pressurized without damage, and we confirmed that the developed system was able to evaluate the elasticity of the lung tissue in the rat by using the pressure value obtained at the quasi-static conditions in the case of the ventilation in the animal experiments.

＜Editors' Choice＞ Learning curve of robotic lobectomy for lung malignancies by certified thoracic surgeons.

Video-assisted thoracic surgery (VATS) has become widespread in the last 20 years, followed by robot-assisted thoracic surgery (RATS). Few studies compared the learning curve between RATS lobectomy and conventional VATS. This study included 79 RATS lobectomy cases performed in our hospital from November 2015 to October 2019. To estimate the required number for learning, the cumulative sum method, which is to plot a value obtained by sequentially accumulating a difference from a mean value was applied. As a result, the median total operative time and the median console time for all cases were 167 minutes and 138 minutes, respectively. Firstly, for our team, 28 cases were estimated to be required for learning curve for RATS lobectomy. For individual, each surgeon might be learned in only 5 to 6 cases. By contrast, the number of cases for learning VATS lobectomy which was underwent by a 'single' surgeon from 2009 was estimated to be 35 cases. The time to dock from start operation (median 14 minutes) reached plateau in 18 cases, but the time after rollout was median of 18 minutes and there was no significant change from the beginning. In conclusion, RATS lobectomy might be a technique that could be learned in a small number of cases compared to VATS. The results of this study might be helpful for certified surgeons who tried to get started with RATS and for establishing a learning program.

Preoperative paraspinous muscle sarcopenia and physical performance as prognostic indicators in non-small-cell lung cancer.

BACKGROUND: Despite the associations of both preoperative sarcopenia and physical performance with post-operative mortality in non-small-cell lung cancer (NSCLC), there have been no comprehensive studies of the impact of physical status on prognosis. This study was performed to investigate the prognostic significance of preoperative sarcopenia and physical performance in NSCLC. METHODS: This retrospective cohort study was performed in NSCLS patients undergoing curative lung resection at a university hospital between January 2014 and December 2017. The patients were divided into four groups according to the skeletal muscle index [sarcopenia (lowest sex-specific tertile) and non-sarcopenia] and 6 min walking distance (6MWD) [short distance (<400 m) and long distance (≥400 m)]. Sarcopenia was assessed by preoperative cross-sectional areas of right and left paraspinous muscles at the level of the 12th thoracic vertebra from computed tomography images, and physical performance was determined by preoperative 6MWD. The primary and secondary endpoints were post-operative overall survival (OS) and disease-free survival (DFS). RESULTS: The 587 patients [mean age: 68.5 ± 8.8 years, 399 men (68%)] included in the study were divided into the non-sarcopenia/long-distance group (58%), sarcopenia/long-distance group (26%), non-sarcopenia/short-distance group (9%), and sarcopenia/short-distance group (7%). A total of 109 (18.6%) deaths and 209 (35.6%) combined endpoints were observed over a mean follow-up of 3.1 ± 1.3 years. After adjusting for other covariates, the sarcopenia/short-distance group showed significant associations with shorter OS (hazard ratio, 3.38; 95% confidence interval, 1.79-6.37; P < 0.001) and DFS (hazard ratio, 2.11; 95% confidence, 1.27-3.51; P = 0.004) compared with the non-sarcopenia/long-distance group on multivariate analyses. Although not significant, adding skeletal muscle index and 6MWD to the pre-existing risk model increased the area under the curve on time-dependent receiver operating characteristic curve analysis for OS and DFS, except within 2 years of surgery. CONCLUSIONS: The presence of both preoperative paraspinous muscle sarcopenia and short distance in 6MWD had an adverse effect on post-operative prognosis in patients with NSCLC, suggesting that preoperative assessment of thoracic sarcopenia and physical performance may be useful for risk stratification of surgical candidates with potential for targeted interventions.

Left brachiocephalic vein aneurysm: a case report.

BACKGROUND: Aneurysm of the left brachiocephalic vein is a very rare clinical disease and only 40 cases have been reported so far. CASE PRESENTATION: The patient was a 61-year-old woman with no related medical history. She underwent CT to investigate the cause of a cough and a mass was noted in the anterior mediastinum. Dynamic computed tomography with contrast medium injected into the left basilic vein demonstrated the venous aneurysm with blood flow to the left brachiocephalic vein. The patient had no symptoms, but because of the risk of pulmonary infarction and aneurysm rupture, the aneurysm was surgically resected. A median sternotomy was a reasonable approach because of the fragility of the venous aneurysm wall with little working space in the anterior mediastinum. CONCLUSIONS: We diagnosed an aneurysm of the left brachiocephalic vein on preoperative imaging and excised it through a median sternotomy. The venous wall was thin and fragile in some areas and so this approach was appropriate in view of the possibility of intraoperative injury.

Differential impacts of postoperative complications on patients' survival in completely resected non-small-cell lung cancer.

OBJECTIVE: The aim of this study was to investigate the effects of inflammatory respiratory complications on long-term survival in patients with resected non-small cell lung cancer. We defined inflammatory respiratory complications to include the following six conditions: pneumonia, empyema, bronchial fistula, respiratory dysfunction, acute interstitial pneumonia, and atelectasis. METHODS: Part of the National Clinical Database was linked to our prospective database from 2014 to 2017. Linkage was achieved for 866 patients. The Kaplan-Meier method was used to evaluate the overall, relapse-free, and cancer-related survival. The Cox proportional hazard model was used to analyze the impact of each complication. RESULTS: Of the 736 patients included in the study, 149 had complications. The 5-year overall and cancer-specific survival rates were significantly lower in patients with inflammatory respiratory complications. The Cox proportional hazard model showed that the inflammatory respiratory complications had a significant impact on overall survival (hazard ratio 2.48, 95% confidence interval 1.41-4.38) but not air leak (hazard ratio 1.38, 95% confidence interval 0.70-2.70). CONCLUSIONS: Our study shows the differential impact of each complication on the survival of patients with non-small cell lung cancer. The presence of inflammatory respiratory complications was the only predictor of poor overall survival.

Prognostic factors of stage I thymic epithelial tumors.

OBJECTIVE: According to the tumor-node-metastasis classification for thymic malignancies, the proportion of patients diagnosed with stage I is expected to increase significantly. However, whether those patients have homogenous clinicopathological features and survival has not been fully evaluated. METHODS: We reviewed 153 consecutive patients with stage I thymic epithelial tumors (133 thymomas, 15 thymic carcinomas, and 5 neuroendocrine tumors) who underwent complete resection at our institution between 2001 and 2016 and evaluated the prognostic significance of their clinicopathological factors. RESULTS: The stage I patients accounted for 78% of all thymic epithelial tumors. The 5-year overall survival and recurrence-free survival rates of the 153 patients were 94% and 80%, respectively. The patients with the histology of thymic carcinoma or neuroendocrine tumor and with a tumor larger than 5.0 cm showed significantly worse recurrence-free survival in multivariate analysis (p = 0.027 and 0.038, respectively). Only the tumor size was revealed as a significant prognostic factor for recurrence-free survival when limited in the 133 cases of thymoma (p = 0.048). CONCLUSIONS: Patients with large tumors showed significantly worse recurrence-free survival than those with small tumors both in stage I thymic epithelial tumors and thymomas.

Current trends in thoracic surgery.

Thoracic surgery has evolved drastically in recent years. Although thoracic surgeons mainly deal with tumorous lesion in the lungs, mediastinum, and pleura, they also perform lung transplantation surgery in patients with end-stage lung disease. Herein, we introduce various major current topics in thoracic surgery. Minimally invasive surgical procedures include robot-assisted thoracic surgery and uniportal video-assisted thoracic surgery. Novel techniques for sublobar resection include virtual-assisted lung mapping, image-guided video-assisted thoracic surgery, and segmentectomy using indocyanine green. Three-dimensional (3D) computed tomography (CT) simulation consists of surgeon-friendly 3D-CT image analysis systems and new-generation, dynamic 3D-CT imaging systems. Updates in cadaveric lung transplantation include use of marginal donors, including donation after circulatory death, and ex vivo lung perfusion for such donors. Topics in living donor lobar lung transplantation include size matching, donor issues, and new surgical techniques. During routine clinical practice, thoracic surgeons encounter various pivotal topics related to thoracic surgery, which are described in this report.

Involvement of heme oxygenase-1 in suppression of T cell activation by quercetin.

AIM: Acute rejection is still a major problem in transplantation and one of the most important causes of late graft loss. Cyclosporine and tacrolimus are widely used for suppression of T cell function to avoid graft rejection, but long-term use of these compounds is associated with serious toxicities. Quercetin, a flavonoid found in fruits and vegetables, has been demonstrated to exhibit cytoprotective effects through the induction of heme oxygenase (HO) -1, an enzyme involved in heme catabolism. We hypothesized that quercetin induces HO-1 in T cells and suppresses T cell function via HO-1. In the present study, we showed that quercetin suppressed the A23187-mediated expression of interleukin (IL) -2 in T cells. METHODS: Mouse splenocytes, enriched T cells, and EL4 cells, a mouse T cell line, were treated with quercetin, and then stimulated with A23187, a calcium ionophore, concanavalin A, or anti-CD3ε and anti-CD28 antibodies. Cell proliferation, expression of IL-2, calcium mobilization, apoptosis, cell cycle, and phosphorylation of extracellular signal-regulated kinase (ERK) were investigated. RESULTS: Quercetin induced HO-1, and this induction of HO-1 was implicated in the suppression of IL-2 production. Furthermore, the induction of HO-1 by quercetin suppressed the influx of calcium ions, a known trigger of IL-2 production. Additionally, quercetin suppressed T cell proliferation through promotion of cell cycle arrest via HO-1 induction, but quercetin did not induce apoptosis. To investigate the role of the signal transduction pathway in quercetin's effect on cell proliferation, we evaluated the phosphorylation of ERK in T cells. Quercetin suppressed the A23187-mediated stimulation of ERK, an effect that was mediated through HO-1. These results suggested that HO-1 is involved in the suppressive effects of quercetin on T cell activation and proliferation. CONCLUSION: Our findings indicate that the quercetin may be a promising candidate for inducing HO-1 in T cells, thereby facilitating immunosuppressive effects.

The Role of 18F-fluorodeoxyglucose Positron Emission Tomography-Computed Tomography for Predicting Pathologic Response After Induction Therapy for Thymic Epithelial Tumors.

BACKGROUND: We investigated the role of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) in predicting the effect of induction therapy in patients with thymic epithelial tumors. METHODS: Fourteen patients with thymic epithelial tumors who underwent PET-CT before and after induction therapy were retrospectively analyzed. The relationship between the change in the maximum standardized uptake value (SUVmax) in PET-CT, the response evaluation criteria in solid tumors and the pathologic response (Ef0, no necrosis of tumor cells; Ef1, some necrosis of tumor cells with more than one-third of viable tumor cells; Ef2, less than one-third of tumor cells were viable; and Ef3, no tumor cells were viable) was analyzed. RESULTS: The study cohort consisted of 5 males and 9 females. Nine of the patients had thymoma, and 5 had thymic carcinoma. The induction therapy included chemotherapy in 9 cases, chemoradiation therapy in 4 cases and radiation therapy in 1 case. Among the 8 patients with a pathologic response of Ef0/1, 5 were clinically evaluated as having stable disease (SD), while 3 were found to have had a partial response (PR). The SUVmax was elevated in 2 cases, unchanged in 1 and decreased in 5. On the other hand, 3 of the 6 patients with a pathologic response of Ef2, 3 were classified as having SD, while the other 3 had a PR. The SUVmax decreased in all of the patients. CONCLUSIONS: In comparison with CT, PET-CT seems to be useful for predicting the pathologic response to induction therapy in patients with thymic epithelial tumors.

Nontuberculous mycobacterial disease concomitant with a pulmonary artery occlusion caused by Takayasu's arteritis.

We herein describe a surgical case of pulmonary involvement in Takayasu's arteritis with pulmonary infections of nontuberculous mycobacteria. A 24-year-old female was admitted to our hospital because of a recurrent fever, and contrast-enhanced computed tomography of the chest revealed the occlusion of the right pulmonary artery and cavitary lesions in the right lower lobe of the lung. A further examination of the neck revealed the occlusion of aortic branches, and the patient was diagnosed with Takayasu's arteritis. The cavitary lesions were diagnosed as nontuberculous mycobacteria disease according to the sputum culture result of Mycobacterium intracellulare. After antibiotic treatment for 6 months, the right pneumonectomy was performed with a good result. We should be aware of Takayasu's arteritis as a disease which can lead to the development of unexplained respiratory symptoms due to pulmonary artery involvement in young adults.

[A STUDY OF SURGICAL TREATMENT FOR PATIENTS WITH MYCOBACTERIUM ABSCESSUS PULMONARY DISEASE AND A COMPARATIVE EXAMINATION OF MYCOBACTERIUM AVIUM COMPLEX DISEASE].

OBJECTIVE: This is a retrospective study on six surgical cases of Mycobacterium abscessus pulmonary disease, including a comparison with M. avium complex (MAC) disease. SUBJECTS AND METHODS: We performed surgery for six cases of M. abscessus pulmonary disease between July 2012 and June 2014. In all the cases, video-assisted thoracic surgery alone was performed. Age, sex, bacillus identification method, disease type, preoperative anti-glycopeptidolipid core immunoglobulin A antibody value, preoperative chemotherapy, preoperative chemotherapy period, adaptation of the operation, surgical method, result of the bacillus culture of an organization that was extracted at operation, postoperative hospitalization period, surgical complications, and postoperative relapse were examined for the six cases of M. abscessus pulmonary disease. In addition, the cases were compared with 36 cases of MAC disease for which operation was performed during the same period. RESULT: None of the patients had major surgical complications or in-hospital death. Although three patients survived for more than 1 postoperative year and completed chemotherapy, relapses are not accepted in all cases at present. In the comparison with MAC disease, the mean preoperative chemotherapy period for M. abscessus pulmonary disease was 5.5 months, which was 18.9 months shorter than that for MAC disease, with a statistically significant difference. CONCLUSION AND CONSIDERATION: Surgery for M. abscessus pulmonary disease may be considered a safe and effective therapeutic procedure. Moreover, some physicians believe that surgical treatment is required at an earlier stage of M. abscessus pulmonary disease compared with MAC disease.

[A study of relapse/recurrence cases after surgical treatment for patients with pulmonary nontuberculous mycobacteriosis].

PURPOSE: This is a retrospective study on relapse/recurrence of surgical cases of pulmonary nontuberculous mycobacteriosis (NTM). Surgical treatment was performed at one hospital and by one surgeon. METHOD: Fifty patients had undergone surgical treatment from August 2004 to July 2011 in hospital. From this group, 37 patients were selected after one year, and of these, 9 patients had a relapse/recurrence (group A) and the others (28 patients without relapse/recurrence, group B). Data was recorded about their age, gender, pre-operative image score, cavernous lesions, residual lesions after operation, drugs of pre-operative chemotherapy, the duration of pre-operative chemotherapy, the duration of any follow-up after operation, type of mycobacteria, the results of bacterial cultivation of surgical specimens, type of mycobacterium and operative procedure. RESULT: Three factors, the result of bacterial cultivation of surgical specimens, duration of chemotherapy before operation and existence of residual lesions, showed a significant difference statistically. No case with major surgical complication and hospital death was recognized. CONCLUSION: The visible foci should be removed as thoroughly as possible. Pre-operative chemotherapy should not be continued unnecessarily, and surgical treatment should be chosen at an early stage. The results of bacterial cultures of surgical specimens could be very useful for predicting the possibility of relapse/recurrence after operation. Surgical treatments of our patients were carried out safely. However, as the patients have a risk of relapse/recurrence, they require careful monitoring and post-operative chemotherapy over along period.