Non-stapling thoracoscopic surgery for spontaneous pneumothorax in young patients.

OBJECTIVES: Spontaneous pneumothorax in young patients has a high recurrence rate, even after surgical treatment, and bulla neogenesis around stapled lesions has been reported as a cause of postoperative recurrence. We investigate the clinical safety and long-term outcome of non-stapling thoracoscopic surgery for spontaneous pneumothorax in young patients. METHODS: Twenty-seven non-stapling thoracoscopic surgeries for pneumothorax in 24 patients younger than 25 years were retrospectively reviewed. The non-stapling surgical techniques used to treat bullae included thoracoscopic suture plication, soft-coagulation, covering, and ligation. Long-term follow-up was conducted by telephone or by a mailed questionnaire. RESULTS: In 22 (81.5%) operations, suture plication, soft-coagulation, and covering procedures were used in combination. The median number of bullae treated in one operation was 2 (range, 0-6). The median operative time was 97 min, and the median postoperative drainage and postoperative hospital stay periods were 1 and 3 days, respectively. No complications of grade 2 or higher were observed. Patients were followed for at least 30 (median, 37) months. The postoperative recurrence rate was 3.7%, with one case of recurrence due to bulla neogenesis at a distant site. CONCLUSION: Non-stapling thoracoscopic surgery with covering procedure for pneumothorax in young patients might reduce postoperative recurrence.

Characteristic differences in the abundance of tumor-infiltrating lymphocytes and intratumoral developing T cells in thymoma, with special reference to PD-1 expression.

PURPOSE: Though programmed cell death-1 (PD-1) inhibitors mainly target tumor-infiltrating lymphocytes (TILs) expressing PD-1, developing T cells in thymus also express PD-1 in their process of maturation. To predict the therapeutic effect of PD-1 inhibitors for thymoma, it is necessary to clarify the proportions of TILs and intratumoral developing T cells. METHODS: The expressions of CD4, CD8, and PD-1 on T cells were analyzed by flow cytometry in 31 thymomas. The amount of T cell receptor excision circles (TRECs), which can be detected in newly formed naïve T cells in the thymus, was evaluated using sorted lymphocytes from thymomas by quantitative PCR. The expressions of granzyme B (GZMB) and lymphocyte activation gene-3 (LAG-3) in PD-1 + CD8 T cells were analyzed by image cytometry using multiplex immunohistochemistry. RESULTS: The PD-1 + rate in both CD4 and CD8 T cells was significantly higher in type AB/B1/B2 than in type A/B3 thymomas. The amounts of TRECs in CD4 and CD8 T cells were significantly higher in type AB/B1/B2 than in type A/B3 thymomas and comparable to normal thymus. PD-1 expression at each stage of T cell development of type AB/B1/B2 thymomas was comparable to that of normal thymus. Both the percentages and cell densities of PD-1 + CD8 T cells expressing GZMB or LAG-3, which are known to contain tumor-reactive T cells, were significantly lower in type AB/B1/B2 thymomas. CONCLUSION: Most PD-1 + T cells in type AB/B1/B2 thymomas are intratumoral developing T cells and are not TILs.

[Robot-assisted Segmentectomy for Lung Cancer].

The role of segmentectomy for lung cancer is expected to increase owing to the results of Japan Clinical Oncology Group (JCOG) 0802. Moreover, the major advantage of robot-assisted thoracic surgery (RATS) is that it allows high precision of dissection. The surgical approach comprised the placement of four robotic ports on the lower intercostal space with an assistant hole. While performing robotic surgery without haptic sensation, it is considered safe to dissect the bronchus first followed by the interlobar and intersegmental plane dissection at the end. In our institution, 52 lung cancer segmentectomies were performed between April 2020 and April 2022, out of which 8 (15.4%)were robot-assisted. The median operating time and console time for RATS were 233 and 182 minutes, respectively, showing a trend towards significantly longer operating time as compared to thoracoscopic segmentectomy( 184 vs. 233 minutes, p=0.007). There were no significant differences in the time to drain removal, the incidence of complications, or pain scores at discharge. Although robotic surgery provides the surgeon with better view and greater precision, it does not decrease the operation time and pain. However, robot-assisted surgery is expected to deliver greater benefits to the patient with technological advances in devices and surgical techniques.

Thymic Hyperplasia With Lymphoepithelial Sialadenitis-Like Features Arising in a Patient With Immunoglobulin G4-Related Disorders: A Case Report.

Thymic hyperplasia with lymphoepithelial sialadenitis-like features is characterized by thymic hyperplasia with lymphocytic infiltrates in the thymic epithelium. The lesion differs from other forms of thymic hyperplasia, including true and follicular thymic hyperplasia, in that it presents at an advanced age and has been reported to be unassociated with autoimmune diseases. We report a case of thymic hyperplasia with lymphoepithelial sialadenitis-like features in a 55-year-old male patient with a history of an immunoglobulin G4 (IgG4)-related disorder. Histologically, the resected mediastinal mass showed features consistent with those of thymic hyperplasia with lymphoepithelial sialadenitis-like features. In addition, the IgG4/IgG ratio was elevated in the polyclonal plasmacytoid infiltration. Thymic hyperplasia with lymphoepithelial sialadenitis-like features has not been reported to be associated with IgG4-related disorders; however, as shown in our report, it is crucial to include it in the differential diagnosis of a mediastinal mass in a patient with IgG4-related disorders.

Surgical intervention for non-small-cell lung cancer with minimal malignant pleural effusion.

PURPOSE: We assessed the clinical significance of minimal malignant pleural effusion (MPE) using liquid-based cytology (LBC) and immunocytochemistry and reviewed the postoperative outcomes of patients with non-small-cell lung cancer (NSCLC). METHODS: We reviewed 240 patients with cM0 NSCLC who underwent lobectomy. Carcinoembryonic antigen (CEA) immunocytochemistry was performed with LBC to aid in the diagnosis of minimal MPE. We assessed the efficacy of this diagnostic method, relevant clinical factors, and postoperative outcomes. RESULTS: LBC showed positive results in two patients and suspicious results in 21. Of the 21 patients, immunocytochemistry showed minimal MPE in 10 (47.6%); therefore, a total of 12 patients (5%) showed minimal MPE. Minimal MPE is associated with an older age, increased consolidation tumor ratio, and adenocarcinoma histology. The 12 patients with minimal MPE had a 3-year overall survival rate of 90%. Postoperative recurrence was observed in seven patients (58.3%), four of whom were treated with epidermal growth factor receptor-tyrosine kinase inhibitors or immune checkpoint inhibitors, while three are still undergoing treatment, with a survival of 2.2, 2.5 and 5.5 years. CONCLUSIONS: CEA immunocytochemistry offers high sensitivity for the diagnosis of minimal MPE. Surgical intervention may be considered for select patients with NSCLC showing minimal MPE.

Spread through air spaces is a powerful prognostic predictor in patients with completely resected pathological stage I lung adenocarcinoma.

PURPOSE: To evaluate the frequency of spread through air spaces (STAS) in patients with early-stage primary lung cancer and to elucidate the association between STAS and various clinicopathological factors. METHODS: We retrospectively reviewed data from a total of 265 consecutive patients who underwent lobectomy and mediastinal lymph node dissection (172 patients) or sublobar resection (93 patients) for completely resected pathological stage I lung adenocarcinoma. We evaluated clinical variables, including the preoperative serum carcinoembryonic antigen (CEA) level, tumour size, consolidation tumour ratio (CTR), maximum standardized uptake value (SUVmax) on FDG-PET, histological results, presence of STAS and vascular and lymphatic invasion. RESULTS: The median follow-up time after surgery was 49 months. Eighty-seven patients (32.8 %) had STAS. The overall survival rates of patients in the STAS-positive and STAS-negative groups were 92.7 % and 97.1 % at 3 years, respectively (p = 0.1255), and the recurrence-free survival rates were 82.1 % and 95.9 % at 3 years, respectively (p = 0.0001). STAS was found in 73 patients (42.4 %) in the lobectomy group, which was a significantly higher proportion than the 14 patients (15.1 %) in the sublobar resection group. The STAS-positive group had significantly larger areas of invasion, higher CTRs, preoperative CEA and SUVmax levels, and more lymphatic and vascular invasion. STAS also correlated significantly with large consolidation sizes, larger invasive size, higher CTRs and the presence of a micropapillary pattern. Cox regression analysis after adjustment for important prognostic factors revealed that the presence of STAS was an independent predictor associated with postoperative recurrence, most of which was observed locoregionally. CONCLUSIONS: STAS was an independent factor associated with postoperative recurrence after lung resection for stage I lung adenocarcinoma. Among stage IA patients, the postoperative outcomes of STAS-positive patients were worse than those of STAS-negative patients and were similar to those of stage IB patients.

Prognostic Impact of Using Combined Plasma Fibrinogen Level and Neutrophil-to-Lymphocyte Ratio in Resectable Non-small Cell Lung Cancer.

BACKGROUND: Both plasma fibrinogen level and neutrophil-to-lymphocyte ratio (NLR) are associated with malignant potential in different cancer types. The current study evaluated the use of combined plasma fibrinogen level and NLR (F-NLR) as a prognostic predictor in patients with non-small cell lung cancer (NSCLC). METHODS: Data collected from 279 patients with resectable NSCLC were retrospectively reviewed. Patients were divided into three groups based on the F-NLR score: score 2, high fibrinogen level (≥350 mg/dL) and high NLR (≥2.5); score 1, either high fibrinogen level or high NLR; and score 0, neither abnormal. Overall survival (OS) and relapse-free survival (RFS) were evaluated using the Kaplan-Meier method and log-rank test. Cox proportional hazard model was used to assess prognostic factors. RESULTS: Numbers of patients with F-NLR score of 0, 1, and 2 were 122 (43.7%), 105 (37.6%), and 52 (18.6%), respectively. The F-NLR was found to be significantly associated with age, male sex, heavy smoking history, high pT status and pathological stage, and nonadenocarcinoma. Moreover, the OS and RFS significantly differed according to the F-NLR score (P < 0.001, P = 0.003). A multivariate analysis revealed that a high F-NLR score (≥1) was an independent poor prognostic factor for OS (P = 0.027). In subgroup analyses, an adverse prognostic impact of the F-NLR score on OS was identified regardless of nodal involvement or pathological stage. CONCLUSIONS: The F-NLR score, which is based on histological inflammation and coagulability, could be a potential prognostic indicator in patients with resectable NSCLC.

Clinical significance of postoperative pulmonary complications in elderly patients with lung cancer.

OBJECTIVES: An increasing number of elderly patients with impaired immunity, malnutrition and comorbidities are considered surgical candidates. This study aimed to clarify the predictive factors and prognostic impact of postoperative pulmonary complications in elderly patients with lung cancer. METHODS: This retrospective study included 188 patients (≥75 years) who underwent complete anatomical lung resection for non-small cell lung cancer between 2005 and 2019. Postoperative pulmonary complications graded ≥II in the Clavien-Dindo classification, occurring within 30-day post-surgery were evaluated. Multivariate logistic regression analyses and Cox proportional hazard models were used to analyse predictors and prognostic impact of complications. RESULTS: Video-assisted thoracoscopic surgery was performed in 154 patients (81.9%). The 90-day mortality rate was 0.5%. Postoperative pulmonary complications including air leak, pneumonia, sputum retention, atelectasis, bronchopleural fistula and empyema occurred in 29 patients (15.4%). A lower prognostic nutritional index (<45) and longer operative time were independent predictive factors of pulmonary complications, with 33.3% of patients experiencing both factors. Following a median follow-up of 48 months, the 5-year overall and relapse-free survival rates were significantly worse in patients with pulmonary complications than in those without them (54.4% vs 81.5% and 41.2% vs 74.9%). Pulmonary complications were significantly associated with worse overall and relapse-free survival [hazard ratio (95% confidence interval): 1.97 (1.01-3.66), P = 0.047 and 2.35 (1.28-4.12), P = 0.007, respectively] along with pathologic stage and carcinoembryonic antigen levels. CONCLUSIONS: Postoperative pulmonary complications are associated with a lower prognostic nutritional index and prolonged operative time; the complications are independent adverse prognostic factors in elderly patients.

Robotic subxiphoid-optical thymectomy.

Robot-assisted thymectomy through a subxiphoid scopic approach can provide a good surgical view, similar to that of median sternotomy. We originally used the subxiphoid port only for the robotic scope to avoid instrument collision with the assistant device. This approach, robotic subxiphoid-optical thymectomy, is advantageous for the safe and accurate dissection of the bilateral phrenic nerves and the left brachiocephalic vein, which are especially needed in extended thymectomy for patients with myasthenia gravis.

Endoscopic Surgery Using Ultrasonic Energy Device for Tracheal Metastatic Tumor.

We describe a rare case of tracheal metastasis from endometrial carcinoma obstructing the central airway. A 57-year-old woman who underwent previous surgery for endometrial serous adenocarcinoma presented with severe tracheal stenosis caused by a stalked tracheal tumor. Urgent debulking surgery was performed under rigid bronchoscopy. The tumor stem was dissected using ultrasonically activated device blades. Rigid bronchoscopy combined with an ultrasonically activated device is an effective option for relieving tracheal stenosis and resecting the intratracheal tumor.

Volume-Based Consolidation-to-Tumor Ratio Is a Useful Predictor for Postoperative Upstaging in Stage I and II Lung Adenocarcinomas.

BACKGROUND: We investigated the postoperative upstaging of stage I and II lung adenocarcinoma patients to identify useful predictors for accurate staging. METHODS: We retrospectively reviewed data from 80 consecutive patients undergoing lobectomy and mediastinal lymph node dissection for clinical stage I and II lung adenocarcinomas. We evaluated clinical variables, including the preoperative serum carcinoembryonic antigen (CEA), tumor diameter, consolidation-to-tumor ratio (CTR), maximum standardized uptake value (SUVmax) on FDG- PET, expression of epithelial growth factor receptor mutations, and pathological invasion to the pleura (pl), lymph duct (ly), and vein (v). RESULTS: Eleven patients (13.8%) showed postoperative upstaging. Three cases had pN1 migrating from cN0, four cases had pN2 from cN0, and four cases showed malignant pleural effusion. The CEA level and CTR were significantly higher in the upstaging group. The tumors in the upstaging group showed more frequent pathological invasion to the visceral pleura and vein. In patients with 3 cm or smaller consolidation, two-dimensional (2D)-CTR and volume-based CTR were independent predictors of upstaging. CONCLUSIONS: Volume-based CTR could be a useful predictor for accurate clinical staging in stage I and II adenocarcinoma patients in addition to consolidation size, serum CEA level, and 2D-CTR. Both volume-based and 2D-CTRs might be especially useful in T1 diseases.

Prognostic significance of spread through air spaces in pulmonary metastases from colorectal cancer.

OBJECTIVES: Surgical resection for pulmonary metastases from colorectal cancer could provide long-term survival in selected patients, and it is commonly performed in practice. However, surgical margin relapse sometimes occurs and is a problematic issue to resolve. Spread through air spaces (STAS) is one of the invasion forms in primary lung cancer and is associated with local recurrence and a poor prognosis. The aim of this study was to evaluate the prognostic significance of STAS for pulmonary metastases from colorectal cancer and to assess the predictability of STAS with preoperative clinical information. METHODS: A total of 96 pulmonary metastatic lesions from colorectal cancer in 37 patients who underwent metastasectomy at our institution from January 2008 to December 2013 were retrospectively analyzed. RESULTS: STAS was identified in 41.6 % of the 96 lesions. Surgical margin relapse was found in 8 lesions (8.3 %) from 7 patients (18.9 %). The distance of STAS was identified as an independent risk factor for surgical margin relapse on multivariable analysis (p =  0.033). The patients with STAS showed significantly worse overall survival than those without (5-year overall survival rate: 30.3 % vs. 76.9 %; p =  0.002). On multivariable analysis, patients with STAS had a significantly higher risk of death than those without (p =  0.019). An elevated pre-metastasectomy serum carcinoembryonic antigen level was independently correlated with STAS on multivariable analysis (p =  0.049). CONCLUSION: STAS was related to a poor prognosis and surgical margin relapse in pulmonary metastases from colorectal cancer.

One-stage closure of large bronchopleural fistula with pedicled latissimus dorsi muscle flap after preemptive antibiotics: A case report.

INTRODUCTION: Bronchopleural fistula (BPF) after lung cancer surgery is a life-threatening complication and often needs two-stage closure after fenestration. Although one-stage closure of BPF is challenging, it would provide shorter treatment time and lower patient physical burden than two-stage closure. However, there have been few reports of one-stage closure of a large BPF. PRESENTATION OF CASE: A 53-year-old man underwent robotic right lower lobectomy with systematic lymph node dissection. Postoperative bronchoscopy revealed an ischemic change in the bronchial stump, which progressed to a large BPF. However, under the preemptive antibiotic treatment without chest drainage, local infection was controlled within a limited pleural space. We successfully performed one-stage closure of a 3-cm sized BPF with pedicled latissimus dorsi (PLD) muscle flap. DISCUSSION: Early diagnosis of ischemic bronchitis and appropriate preceding antibiotic treatment could minimize the local infection around the fistula. To our knowledge, our case represented the largest BPF that was successfully treated by one-stage procedure using preemptive antibiotics and the PLD muscle flap. CONCLUSION: One-stage closure using the PLD muscle flap may be a treatment option even for a 3-cm sized BPF, wherein infection is controlled and the relevant pleural cavity is limited.

Programmed death-ligand 1 expression profiling in thymic epithelial cell tumors: Clinicopathological features and quantitative digital image analyses.

OBJECTIVES: Whether the extent of expression of programmed death-ligand 1 (PD-L1) is clinically significant remains uncertain, although immuno-oncological features have been studied in thymic epithelial cell tumors (TETs). We investigated the histological features of PD-L1 expression in TETs, and assessed PD-L1 expression using digital image analysis. MATERIALS AND METHODS: Participants comprised 66 patients with TET who underwent surgical resection between 2001 and 2016. We calculated tumor cell-positive ratio as total proportion score (TPS) with immunohistochemistry using SP263 anti-PD-L1 monoclonal antibody. PD-L1 expression was also quantified using digital image analysis of whole-slide images. We evaluated the relationship between conventional visual TPS using optical microscopy (TPS-V) and TPS from digital image analysis (TPS-IA). We further classified all TETs into high or low PD-L1 expression groups and assessed the clinical significance of PD-L1 expression level using TPS-V and TPS-IA. RESULTS: WHO histological types were Type A (n = 8), AB (n = 18), B1 (n = 5), B2 (n = 16), B3 (n = 6), metaplastic thymoma (n = 2), and thymic carcinoma (TC) (n = 11). Median TPS-Vs were 2%, 2%, 10 %, 65 %, 90 %, 1%, and 20 %, respectively. TPS-IAs correlated with TPS-Vs in TETs overall and in thymomas, but not in TCs. PD-L1 expression levels in TETs differed significantly among histological types. Whether TPS-V or TPS-IA were used, the PD-L1high group included more cases of the more aggressive histological types. Recurrence-free survival (RFS) was shorter in the PD-L1high group than in the PD-L1low group in thymoma using TPS-IA, whereas RFS of the PD-L1high group was shorter in all TETs using TPS-V. CONCLUSION: PD-L1 expression levels depended on the histological type of TET. Extensive PD-L1 expression in TETs was associated with poor prognosis. Digital image analysis is feasible for evaluating PD-L1 expression in TETs and might offer clinically relevant features of thymomas.

Prognostic Significance of Perioperative C-Reactive Protein in Resected Non-Small Cell Lung Cancer.

Inflammation is reportedly associated with the development and progression of various malignancies. However, the clinical significance of preoperative and postoperative inflammation in lung cancer patients undergoing surgery is unknown. The relationship between preoperative and postoperative C-reactive protein (CRP), an indicator of inflammation, and survival was retrospectively analyzed in 356 patients who underwent complete resection of pathologic Stage I and II non-small cell lung cancers. Cutoffs for preoperative CRP (CRPpre), postoperative maximum levels of CRP (CRPmax), and postoperative CRP levels 30 days after surgery (CRP30) were determined as 0.2 mg/dL, 6.4 mg/dL, and 0.2 mg/dL, respectively. Patients with CRPprehigh, CRPmaxhigh, or CRP30high status had significantly poorer overall survival (OS) and relapse-free survival (RFS) than those with CRPprelow, CRPmaxlow, or CRP30low. Patients were stratified into 4 groups according to perioperative CRP grades, combining CRPprehigh, CRPmaxhigh, and CRP30high statuses, yielding groups with grades 0, 1, 2, and 3. OS and RFS significantly worsened with increasing grade. After controlling for potential confounders, the multivariate Cox proportional hazard model revealed perioperative CRP grade as an independent poor prognostic factor for OS (grade 3 vs grade 0): adjusted hazard ratio, 5.05; 95% confidence interval, 1.59-19.6; P = 0.005), and RFS (adjusted hazard ratio, 3.62; 95% confidence interval, 1.50-9.33; P = 0.004). Perioperative inflammation was associated with a long-term negative prognostic impact after lobectomy for lung cancer. Further prospective analysis is required to identify whether control of perioperative inflammation may improve prognosis after lung cancer surgery.

High Neutrophil Count as a Negative Prognostic Factor for Relapse in Patients with Thymic Epithelial Tumor.

PURPOSE: Preoperative neutrophil count is reportedly associated with poor prognosis in cancer patients. This study aimed to investigate the clinical significance of pre-treatment peripheral blood cell counts in patients with thymic epithelial tumors (TETs). METHODS: A retrospective review of 71 patients with completely resected TETs [64 thymoma, 6 thymic carcinoma, and 1 thymic neuroendocrine tumor] between 2000 and 2018 was conducted. Associations between tumor recurrence and pre-treatment peripheral blood cell counts of leukocytes (WBC), neutrophils (Neut), lymphocytes (Lymph), monocytes (Mono), and platelets (Plt) were analyzed. Optimal cut-off points were selected using receiver operating characteristic curve analysis to predict tumor recurrence. RESULTS: High WBC (≥ 7000), Neut (≥ 4450), and Plt (≥ 226 × 103) counts had significantly poor relapse-free survival (RFS), but high Lymph (≥ 1950) and Mono (≥ 400) did not. High Neut had the strongest correlation with recurrence (area under curve, 0.800); we focused on the analysis between high-Neut and low-Neut groups. High Neut count significantly correlated with smoking history, pre-treatment C-reactive protein level, and advanced stage; high Neut count and aggressive histology tended to show correlations. RFS was significantly poorer in the high-Neut group than in the low-Neut group (p = 0.003), with 5-year RFS rates of 63.8% and 96.8%, respectively. High Neut count was a significant adverse predictor for RFS and cumulative incidence of recurrence (p = 0.005 and p < 0.001, respectively). The risk scoring system comprising high Neut count, advanced stage, and aggressive histology demonstrated better prognostic ability than any prognostic factors alone. CONCLUSIONS: High Neut count significantly correlated with TET recurrence, suggesting a negative prognostic effect of latent inflammation in TET patients.

Successful thoracoscopic evacuation of an extrapleural hematoma with delayed symptomatic pleural effusion: a case report.

BACKGROUND: Traumatic extrapleural hematoma is a rare condition and is usually managed conservatively until spontaneous resolution unless active bleeding or expansion is found. CASE PRESENTATION: An 80-year-old man taking an anticoagulant medication was referred to our hospital after accidentally falling in a street ditch while riding a bike. Chest X-ray and computed tomography (CT) scan showed multiple fractures on ribs 7-9, hemothorax, and extrapleural hematoma in the posterior chest wall. Though the patient's hemothorax was improved by chest tube drainage, the extrapleural hematoma still remained. He was transferred to another hospital for rehabilitation, but he was readmitted to our hospital because of dyspnea with accumulation of left pleural effusion, including a subpopulation of neutrophils, but without bacterial infection. We performed thoracoscopic evacuation of the hematoma on day 57 after the initial blunt chest trauma. The patient has had no recurrence of pleuritis for 6 months after surgery. CONCLUSION: Since posttraumatic extrapleural hematoma may result in delayed secondary intractable pleural effusion causing dyspnea, careful observation is necessary when considering indications of surgical intervention.

Suppressive Effects of Aspirin for Postthoracotomy Pleural Adhesion in Rats.

BACKGROUND: Postoperative adhesion is one of major concerns at re-thoracotomy. Aspirin has both the anti-platelet and anti-inflammatory effects, and decreases several cytokines production. OBJECTIVE: We investigated that aspirin could reduce postoperative adhesion formation in a rat model. METHODS: We cauterised the lung visceral pleural to make postoperative adhesion in rats. The animals were allocated to a control group and an aspirin administration group (100 mg/kg/day for 14 days). We performed re-thoracotomy and evaluated the adhesion lengths on day 14. We also investigated the cytokine expression in the adhesion region and the peripheral tissue with platelet-derived growth factor (PDGF), platelet-derived growth factor receptor (PDGFR), alpha smooth muscle actin (α-SMA), transforming growth factor beta 1 (TGF-ß1), and vascular endothelial growth factor-A (VEGF-A), sequentially. RESULTS: The adhesion lengths were significantly shorter in the aspirin group than that in the control group (8.7±2.0 mm vs 11.2±1.1 mm, p=0.024). The expressions of PDGF and PDGFR were lower in the aspirin group than that in the control group on day 3. The expression of α-SMA on fibroblasts decreased in the aspirin group on day 3. There was no significant difference in the expressions of TGF-ß1 and VEGF-A with administration of aspirin. CONCLUSIONS: Aspirin could reduce postoperative pleural adhesion by inhibiting the expression of PDGF.

Intractable pneumothorax due to rupture of subpleural rheumatoid nodules: a case report.

BACKGROUND: In rare cases, rheumatoid pleural nodules can rupture into the pleural cavity to cause pneumothorax or empyema. We report successful surgical treatment of a patient with an intractable secondary pneumothorax due to rupture of a subpleural rheumatoid nodule into the pleural cavity. CASE PRESENTATION: A 75-year-old man with a medical history of rheumatoid arthritis, acute coronary syndrome, and diabetes was admitted to our hospital because of left chest pain and dyspnea. A chest X-ray and chest computed tomography (CT) scan showed a left pneumothorax and several small subpleural nodules with cavitation. Repeated pleurodesis via a chest tube failed to improve the pneumothorax, so we decided to perform thoracoscopic surgery. Air leakage was detected in the left upper lobe where the subpleural nodule was visible on chest CT. Resection of the lesion successfully resulted in resolution of the air leakage. The final pathological diagnosis of the subpleural nodule was a pulmonary rheumatoid nodule. The patient has had no evidence of recurrence of pneumothorax after surgery. CONCLUSIONS: We obtained a final pathological diagnosis of a rheumatoid nodule that caused an intractable pneumothorax. Pneumothorax associated with rupture of rheumatoid nodules in the subpleural cavitary is difficult to treat with thoracoscopic surgery as a second-line treatment.