Lobulated tumor contour as a predictor of preoperative tumor invasion of the lung or pericardium in thymoma patients.

PURPOSE: Preoperative investigations to detect invasion to neighboring organs are important for deciding on the most appropriate surgical approach for thymoma. We evaluated preoperative computed tomography (CT) findings in thymoma patients to identify the CT features associated with tumor invasion. METHODS: Clinicopathologic information on 193 patients who underwent surgical resection for thymoma at Chiba University Hospital between 2002 and 2016 was collected retrospectively. The surgical pathology identified invasion of thymoma in 35 patients: in the lung (n = 18), pericardium (n = 11), or both (n = 6). Contact lengths between the tumor contour and lung (CLTL) or pericardium (CLTP) were measured at the maximum section of the tumor on axial CT. Univariate and multivariate analyses were performed to analyze the relationship between pathological invasion of the lung or pericardium and the clinicopathologic features. RESULTS: The mean CLTL and CLTP were significantly longer in patients with invasion of the neighboring organs than in those without invasion. A lobulated tumor contour was identified in 95.6% of the patients with invasion of the neighboring organs. A multivariate analysis revealed that a lobulated tumor contour was significantly associated with both lung and pericardial invasion. CONCLUSIONS: A lobulated tumor contour was significantly associated with lung and/or pericardial invasion in thymoma patients.

A simple nomogram for predicting occult lymph node metastasis of non-small cell lung cancer from preoperative computed tomography findings, including the volume-doubling time.

PURPOSE: Latent lymph node metastasis is a clinical concern in the surgical treatment of non-small cell lung cancer (NSCLC). The present study identified a simple tool, including the volume-doubling time (VDT), for evaluating the risk of nodal metastasis. METHODS: We reviewed, retrospectively, 560 patients who underwent radical resection for cN0M0 NSCLC. The whole tumor VDT and solid component VDT (SVDT) for differentiating the histological type and adenocarcinoma subtype were analyzed and a nomogram was constructed using variables selected through a stepwise selection method. The model was assessed through a calibration curve and decision curve analysis (DCA). RESULTS: Lymph node metastases were detected in 89 patients (15.9%). The SVDT tended to be longer in patients with adenocarcinoma (294.5 days, p < 0.0001) than in those with other histological types of NSCLC, but was shorter when the solid/micropapillary component was predominant (127.0 days, p < 0.0001). The selected variables (tumor location, solid component diameter, consolidation tumor ratio, SVDT, and carcinoembryonic antigen) demonstrated significant differences and were used for the nomogram. The calibration curve indicated consistency, and the DCA showed validity across most threshold ranges from 0 to 68%. CONCLUSIONS: The established nomogram is a useful tool for the preoperative prediction of lymph node metastasis, and the SVDT was the most influential factor in the nomogram.

Surgical treatment for chronic pulmonary coccidioidomycosis: a retrospective study from a single institution.

PURPOSE: Coccidioidomycosis, caused by the Coccidioides species, is a well-known disease in the Southwestern United States and North Mexico, with scattered reports in Latin America countries. While this disease is still rare in Japan and other Asian countries, its incidence has been increasing over the last two decades. Coccidioides species are highly infectious and require caution when encountered. This study presents a case series of chronic pulmonary coccidioidomycosis surgically treated at a single institution. METHODS: We conducted a retrospective chart review of six patients who underwent lung resection for pulmonary coccidioidomycosis at Chiba University Hospital between January 2007 and December 2021. RESULTS: All six patients had travelled to the Southwestern United States. Preoperative serology was negative for the anti-Coccidioides antibody in four patients and positive in two. Chest computed tomography revealed a single, well-defined round nodule in all patients. Preoperative biopsy taken from three patients failed to obtain a definitive diagnosis. Histopathological examination of the resected pulmonary nodules revealed granulomas that contained numerous spherules with many endospores, thereby confirming the diagnosis of pulmonary coccidioidomycosis. CONCLUSIONS: Pulmonary coccidioidomycosis should be suspected based on travel history and radiological findings. Meticulous care should be taken during specimen processing to prevent cross infection.

[Management of Tracheobronchial Injuries due to Brunt Trauma].

BACKGROUND: Tracheobronchial injuries resulting from blunt trauma are relatively rare among chest injuries. However, if these injuries are not managed properly, they can be fatal. The prognosis is intricately linked to the precise diagnosis and treatment. We herein report three cases of tracheobronchial trauma that required surgical intervention. Case 1:A 17-year-old male sustained injuries when his torso became entangled in heavy machinery. The diagnosis revealed a tear in the right main bronchus, which required transportation with left single- lung ventilation. The patient was treated by tracheobronchial reconstruction. Case 2:A 71-year-old male experienced trauma when his car collided with a utility pole. He was transported to the hospital after tracheal intubation due to a laceration of the tracheal membranous area. The site of the injury was closed with sutures. Case 3:A 17-year-old female who had been struck by a train suffered acute respiratory failure and was transported to the hospital after intubation. Veno-venous extracorporeal membrane oxgenation (VV-ECMO) was initiated in response to poor oxygenation. Complete rupture of the right middle bronchial trunk and laceration of the right main bronchial membrane were observed, and bronchoplasty was performed. CONCLUSION: A swift and accurate diagnosis, coupled with timely and judicious therapeutic interventions, play a pivotal role in managing tracheal and bronchial injuries.

Association of frequent hypermethylation with high grade histological subtype in lung adenocarcinoma.

Lung adenocarcinoma is classified morphologically into five histological subtypes according to the WHO classification. While each histological subtype correlates with a distinct prognosis, the molecular basis has not been fully elucidated. Here we conducted DNA methylation analysis of 30 lung adenocarcinoma cases annotated with the predominant histological subtypes and three normal lung cases using the Infinium BeadChip. Unsupervised hierarchical clustering analysis revealed three subgroups with different methylation levels: high-, intermediate-, and low-methylation epigenotypes (HME, IME, and LME). Micropapillary pattern (MPP)-predominant cases and those with MPP components were significantly enriched in HME (p = 0.02 and p = 0.03, respectively). HME cases showed a significantly poor prognosis for recurrence-free survival (p < 0.001) and overall survival (p = 0.006). We identified 365 HME marker genes specifically hypermethylated in HME cases with enrichment of "cell morphogenesis" related genes; 305 IME marker genes hypermethylated in HME and IME, but not in LME, with enrichment "embryonic organ morphogenesis"-related genes; 257 Common marker genes hypermethylated commonly in all cancer cases, with enrichment of "regionalization"-related genes. We extracted surrogate markers for each epigenotype and designed pyrosequencing primers for five HME markers (TCERG1L, CXCL12, FAM181B, HOXA11, GAD2), three IME markers (TBX18, ZNF154, NWD2) and three Common markers (SCT, GJD2, BARHL2). DNA methylation profiling using Infinium data was validated by pyrosequencing, and HME cases defined by pyrosequencing results also showed the worse recurrence-free survival. In conclusion, lung adenocarcinomas are stratified into subtypes with distinct DNA methylation levels, and the high-methylation subtype correlated with MPP-predominant cases and those with MPP components and showed a poor prognosis.

Modified Clagett procedure for acute pleural empyema.

Pleural empyema often requires surgical intervention; however, surgical invasiveness should be minimized. We utilized the modified Claget procedure as an alternative to thoracoplasty for acute pleural empyema with a dead space. The procedure was performed as follows: first, 500 mg of kanamycin and 500,000 units of polymyxin sulfate dissolved in 10-100 ml saline was instilled intrapleurally via tube thoracostomy. The chest tube was clamped overnight and then removed. The modified Clagett procedure might be effective for acute pleural empyema with a dead space without pulmonary or bronchopleural fistula. We report our successful experience of performing modified Clagett procedure for pleural empyema with a dead space, through a detailed case presentation.

[Robot-assisted Thoracic Surgery for Mediastinal Tumor].

In Japan, robot-assisted thoracic surgery (RATS) was introduced in thoracic surgery in 2001, but it did not become widespread. However, surgery for mediastinal tumors and lobectomy for lung cancer with RATS were covered by insurance in 2018 and are currently becoming popular as a general practice, following video-assisted thoracic surgery(VATS). Forty-six patients with mediastinal tumors were treated by RATS from February 2014 to November 2022 in our institution. Theoretically, the RATS approach is performed from one side in a semi-supine position under CO2 insufflation as with the VATS approach of our institution. In the case of extended thymectomy, a bilateral approach is performed by changing the patient's position. The median surgery time was 88 min, and the median surgery time in unilateral and bilateral approaches were 79 and 208 min, respectively. Blood loss during surgery was quite minimum, and no patients required conversion to VATS or thoracotomy. Regarding adverse events, postoperative bleeding was observed in one patient (2.2%). RATS has been successfully introduced and expanded safely for mediastinal tumors. Considering further expansion of RATS indications while conducting verification by comparison with VATS in the future is necessary.

[The Basic Research of Antigen-antibody Reaction in Lung Transplantation].

Lung transplantation has become popular in Japan, showing better survival rate than other countries. However, the results are still not satisfactory compared with other solid organ transplantation. One of the reasons for this might be that knowledge on donor-specific antibodies or antibody-related rejection, which has been attracting attention these days, is less than that of kidney or liver transplantation. Our laboratory has continued basic research in this field using rodent lung transplantation model. We have previously shown that type V collagen is associated in chronic rejection as an autoimmune, and that oral administration of type V collagen induces tolerance. The murine chronic rejection model of the minor antigen mismatch was developed, and involvement of the humoral immunity and role of the complement activation were shown. We are now studying the effects of immune checkpoint molecules, which play a central role in the field of cancer therapy, on rejection after lung transplantation. We are also working to verify the effects of anti-complement drugs and molecular targeted drugs in the future treatment on rejection.

Alternative approaches for clinical clerkship during the COVID-19 pandemic: online simulated clinical practice for inpatients and outpatients-A mixed method.

BACKGROUND: The COVID-19 pandemic has created a need for educational materials and methods that can replace clinical clerkships (CCs) for online simulated clinical practice (online-sCP). This study evaluates the impact of using simulated electronic health records (sEHR) for inpatients, and electronic problem-based learning (e-PBL) and online virtual medical interviews (online-VMI) for outpatients, for an online-sCP using a learning management system (LMS) and online meeting system facilitated by a supervising physician. METHODS: The sEHR was reviewed by medical students and subsequently discussed with a supervising physician using an online meeting system. In the e-PBL, medical students reviewed the simulated patients and discussed on the LMS. For the online-VMI, a faculty member acted as an outpatient and a student acted as the doctor. Small groups of students discussed the clinical reasoning process using the online meeting system. A mixed-method design was implemented. Medical students self-assessed their clinical competence before and after the online-sCP. They answered questionnaires and participated in semi-structured focus group interviews (FGIs) regarding the advantages and disadvantages of the practice. RESULTS: Forty-three students completed the online-sCP during May and June 2020. All students indicated significant improvement in all aspects of self-evaluation of clinical performance after the online-sCP. Students using sEHR reported significant improvement in writing daily medical records and medical summaries. Students using e-PBL and online-VMI reported significant improvement in medical interviews and counseling. Students also indicated CCs as more useful for learning associated with medical interviews, physical examinations, and humanistic qualities like professionalism than the online-sCP. Eight FGIs were conducted (n = 42). The advantages of online-sCP were segregated into five categories (learning environment, efficiency, accessibility, self-paced learning, and interactivity); meanwhile, the disadvantages of online-sCP were classified into seven categories (clinical practice experience, learning environment, interactivity, motivation, memory retention, accessibility, and extraneous cognitive load). CONCLUSIONS: Online-sCP with sEHR, e-PBL, and online-VMI could be useful in learning some of the clinical skills acquired through CC. These methods can be implemented with limited preparation and resources.

Role of leukotriene B4 12-hydroxydehydrogenase in α-galactosylceramide-pulsed dendritic cell therapy for non-small cell lung cancer.

Invariant natural killer T (iNKT) cells exhibit potent antitumor effects upon activation by recognizing a specific glycolipid antigen. We previously performed phase I-II clinical studies to utilize iNKT cells using α-galactosylceramide-pulsed dendritic cells and identified leukotriene B4 12-hydroxydehydrogenase (LTB4DH) as a biomarker highly expressed in T cells derived from non-small cell lung cancer (NSCLC) patients who showed prolonged survival in respond to the iNKT cell immunotherapy. Because LTB4DH expression correlated with prolonged survival of NSCLC patients, we considered LTB4DH to play a role in iNKT cell immunotherapy. We herein demonstrate that the overexpression of LTB4DH in CD4+ or CD8+ T cells increases interferon-γ production and tumoricidal activity in the presence of prostaglandin E2. Moreover, the expression of granzyme a, granzyme b, and perforin mRNA was increased in LTB4DH-overexpressing cells.

Mini grasping basket forceps for endobronchial foreign body removal in pediatric patients.

BACKGROUND: Appropriate device selection is crucial for endobronchial foreign body removal using a bronchoscope. In pediatric patients, bronchoscopy requires the use of a thin device due to the narrow access to the airway, limiting the range of useful endobronchial devices. We herein review our experience in endobronchial foreign body removal with a focus on the type of bronchoscope and the instruments used in comparison with the literature, and investigate the utility of mini grasping basket forceps (FG-55D, Olympus® ; and Zero Tip™ , Airway Retrieval Basket, Boston Scientific). METHODS: Between April 2008 and April 2016, foreign bodies were removed from the airway of 12 pediatric patients by bronchoscopy. These cases are reviewed in this study. The clinical presentation, location and characteristics of the foreign bodies, and the type of bronchoscope and instruments used were analyzed. RESULTS: A consecutive series of 12 pediatric patients was retrospectively reviewed, and the therapeutic characteristics investigated. Nuts were the most frequently observed foreign body. Seven of the 12 pediatric patients required an ultrathin bronchoscope (diameter, 2.8 mm) for foreign body removal. Only one patient required a rigid scope in addition to flexible bronchoscopy. The most frequently used instrument was a mini grasping basket forceps (n = 7; 58%), which was used with a 1.2 mm instrument channel (n = 4; 33%). CONCLUSIONS: The use of a mini grasping basket forceps in combination with an ultrathin flexible bronchoscope was useful for removing smooth, soft materials such as a nuts or beans in pediatric cases.

[The History and Development of Experimental Rodent Models of Chronic Lung Allograft Dysfunction after Lung Transplantation].

Chronic lung allograft dysfunction (CLAD) is a critical impediment to the long-term survival after lung transplantation. A rat orthotopic lung transplantation model was developed in the early 1970s, and using this model, our laboratory has shown that the immunopathogenesis of CLAD involves both allogeneic immunity and autoimmunity. However, further investigation of CLAD is limited by the scarcity of transgenic and knockout strains. The model most widely used to study CLAD, the mouse model of heterotopic tracheal transplantation, has some incomplete pathophysiologic features of CLAD, which limits the utility of this model. Unlike other solid organ transplants, vascularized and aerated murine lung transplantation has only recently been developed. We have also reported that minor, but not major, histocompatibility antigens mismatch induced the development of CLAD in murine orthotopic lung transplants and that CLAD development was interleukin-17-dependent. This mini-review underscores the history and development of rodent models of CLAD after lung transplant, including the findings from our previous studies. In addition, the future direction of rodent models is also discussed.

Recurrent pneumothorax associated with bronchial atresia: report of a case.

We herein report a case of recurrent pneumothorax associated with congenital bronchial atresia. A 26-year-old male presented with chest pain. Chest roentgenograms showed left pneumothorax, a left apical bulla and an area of hyperlucency in the left upper lung field, and chest computed tomography revealed a discontinuation of the left superior bronchus. Additionally, both ventilation and perfusion scintigraphy showed a defect in the left superior segment. A thoracoscopy-assisted left superior segmentectomy was performed, and a pathological examination indicated left superior segmental bronchial atresia, which might have predisposed the peripheral lung to emphysematous conditions. No relapse was observed 6 months after the operation. Although this entity is rare, congenital bronchial atresia should be considered in the differential diagnosis when a patient has suffered from a recurrent spontaneous pneumothorax.

Surgery for Secondary Spontaneous Pneumothorax with Chronic Lung Diseases.

PURPOSES: Secondary spontaneous pneumothorax (SSP) is occasionally observed in elderly patients suffering from diffuse lung diseases. The purpose of this study was to analyze the outcomes of surgical treatment of SSP patients with chronic lung diseases. METHODS: In total, 242 patients who underwent surgery for spontaneous pneumothorax at Chiba University Hospital from January 2006 to October 2016 were included in this study. The patients' records were reviewed retrospectively for data on their background, surgical treatment, morbidity, mortality, and recurrence. RESULTS: Of the spontaneous pneumothorax cohort, primary spontaneous pneumothorax (PSP) accounted for 144 patients. Among the 98 patients with SSP, 57 cases were caused by chronic obstructive pulmonary disease (COPD) and 21 were caused by interstitial pneumonia (IP). The postoperative complication rate was 19.3% in the COPD group, 42.9% in the IP group, and 11.1% in the PSP group. The recurrence rate was 5.3% in the COPD group, 28.6% in the IP group, and 21.5% in the PSP group. CONCLUSIONS: The morbidity and recurrence were comparable between PSP and SSP cases with COPD, whereas these values were unfavorable in SSP cases with IP compared with PSP ones. Surgical intervention should be carefully considered in SSP patients with IP.

Can modified frailty index predict postoperative complication after lung cancer surgery?

PURPOSE: The impact of the modified frailty index (mFI) on postoperative complications after lung cancer surgery was investigated. METHODS: Patients who underwent lung cancer surgery in 2017 were included. 30-day postoperative mortality and morbidity were evaluated according to their Clavien-Dindo classification. mFI values are presented as the sum of values of 11 included items. Logistic regression was used to assess the effect of mFI on postoperative severe complication incidence. RESULTS: Among 190 patients considered, severe postoperative complications (Grade 3 or more) were observed in 30 (16%). No patients died within 30 days of surgery. The incidence of severe complications was 3.6% in patients with mFI of 0, 16.2% in patients with mFI of 1, 23.4% in patients with mFI of 2, and 31.6% in patients with mFI of 3 or more, and was correlated with the grade of mFI. Univariate and multivariate analyses showed that the high mFI was significantly predictive of postoperative complications. Frail patients of mFI ≥ 2 were at 3.0-fold greater risk of severe complications than non-frail patients of mFI 0 or 1. CONCLUSION: mFI was associated with morbidity after lung cancer surgery. Preoperative frailty assessment and appropriate intervention to frail patients would be required to improve postoperative outcomes.

What are the risk factors for postoperative home oxygen therapy in patients with lung cancer?

Background: Home oxygen therapy (HOT) is used to treat chronic respiratory diseases and is sometimes required in patients with lung cancer after radical surgery. We aimed to identify the risk factors for postoperative home-based oxygen therapy in patients with lung cancer. Methods: Patients who underwent surgery for primary lung cancer at Chiba University Hospital between January 2019 and March 2021 were included. Patients who did not undergo complete resection, died in hospital after surgery, or used oxygen therapy preoperatively were excluded. Eligible patients were divided into HOT and non-HOT groups. They were retrospectively analyzed for risk factors for postoperative HOT using medical records in a multivariate analysis. Results: A total of 410 patients were included in this study, 24 (5.9%) of whom required HOT after surgery. The HOT group comprised significantly more men, heavy smokers, and patients with pulmonary comorbidities, low percent forced expiratory volume, percent forced vital capacity, predicted postoperative forced expiratory volume in 1 s, and postoperative pulmonary complications on univariate analysis. In a multivariate analysis, independent risk factors for postoperative HOT were pulmonary comorbidities [odds ratio (OR): 5.94; 95% confidence interval (CI): 1.64-21.5; P=0.002) and postoperative pulmonary complications (OR: 5.39; 95% CI: 2.14-13.5; P<0.001). The postoperative HOT application rate was calculated according to a formula developed for this purpose. Conclusions: Comorbid pulmonary diseases and postoperative pulmonary complications were significantly associated with postoperative HOT in patients with lung cancer.

Postoperative bronchopleural fistula after induction therapy with bevacizumab.

Bronchopleural fistulas are rare complications of bevacizumab treatment. Herein, we report a case of bronchopleural fistula after bevacizumab therapy. The patient was a 65-year-old man with lung cancer who underwent a right lower lobectomy with systemic lymph node dissection after induction chemotherapy with bevacizumab. Pathological examination revealed no residual tumor cells in the resected specimen. The patient presented with severe dyspnea on postoperative day 26. Bronchoscopy revealed a bronchopleural fistula in the membranous portion of the right intermediate bronchus; the bronchial stump remained intact. The bronchopleural fistula was repaired with muscle flaps, and bronchoscopy 9 months after surgery showed satisfactory healing of the fistula. The patient has been alive for 5 years without evidence of recurrence. Careful attention must be paid to postoperative management when bevacizumab is used for induction therapy.

The effect of chest wall surgery on lung volume: a new evaluation concept.

Background: In the surgical treatment of chest wall tumors requiring large chest wall resection, reconstruction of the chest wall defect is required using various autologous tissues or artificial materials. However, no appropriate method has been reported to evaluate whether each reconstruction is successful or not. Therefore, we performed lung volumetry before and after surgery to evaluate the negative effects of chest wall surgery on lung expansion. Methods: Twenty-three patients with chest wall tumors who underwent surgery were included in this study. Lung volume (LV) before and after surgery was measured using SYNAPSE VINSENT (FUJIFILM, Tokyo, Japan). The rate of change in LV was calculated as the postoperative and preoperative LV of the operative side × preoperative/postoperative LV of the opposite side. The excised chest wall area was calculated as vertical diameter × horizontal diameter of the tissue specimen. Results: Reconstruction methods included rigid reconstruction (a combination of titanium mesh and extended polytetrafluoroethylene sheet) in four patients, non-rigid reconstruction (extended polytetrafluoroethylene sheet only) in 11, no reconstruction in five, and no chest wall resection in three. Changes in LV were generally well preserved, regardless of the resected area. In addition, LVs were well maintained in most patients who underwent chest wall reconstruction. However, in some cases, decreased lung expansion was observed with migration and deflection of the reconstructive material into the thorax due to postoperative lung inflammation and shrinking. Conclusions: Lung volumetry can be used to evaluate the effectiveness of chest wall surgery.

Targeting PD-1/PD-L1 inhibits rejection in a heterotopic tracheal allograft model of lung transplantation.

Immune checkpoint molecules such as programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) have revolutionized the field of lung cancer treatment. As part of our study, we examined the role of these proteins in acute rejection in a mouse model of heterotopic tracheal transplantation. Recipient mice were untreated (Allo group) or treated with anti-PD-L1 (aPDL1 group) or PD-L1 Fc recombinant protein (PD-L1 Fc group). A further group of C57BL/6 mice received isografts (Iso group). The occlusion rate was significantly higher in the Allo group than in the Iso group (p = 0.0075), and also higher in the aPD-L1 group (p = 0.0066) and lower in the PD-L1 Fc group (p = 0.030) than in the Allo group. PD-L1 Fc recombinant protein treatment significantly decreased interleukin-6 and interferon-γ levels and reduced the CD4+/CD8+ T cell ratio, without increasing PD-1 and T-cell immunoglobulin mucin 3 expression in CD4+ T cells. These data suggest that PD-L1 Fc recombinant protein decreases the levels of inflammatory cytokines and the proportion of CD4+ T cells without exhaustion. The PD-L1-mediated immune checkpoint mechanism was associated with rejection in the murine tracheal transplant model, suggesting a potential novel target for immunotherapy in lung transplantation.