Resistin Pathway as Novel Mechanism of Post-lung Transplantation Bronchial Stenosis.

BACKGROUND: Bronchial stenosis remains a significant source of morbidity among lung transplant recipients. Though infection and anastomotic ischemia have been proposed etiologies of the development of bronchial stenosis, the pathophysiologic mechanism has not been well elucidated. METHODS: In this single-centered prospective study, from January 2013 through September 2015, we prospectively collected bronchoalveolar lavage (BAL) and endobronchial epithelial brushings from the direct anastomotic site of bronchial stenosis of bilateral lung transplant recipients who developed unilateral post-transplant bronchial stenosis. Endobronchial epithelial brushings from the contralateral anastomotic site without bronchial stenosis and BAL from bilateral lung transplant recipients who did not develop post-transplant bronchial stenosis were used as controls. Total RNA was isolated from the endobronchial brushings and real-time polymerase chain reaction reactions were performed. Electrochemiluminescence biomarker assay was used to measure 10 cytokines from the BAL. RESULTS: Out of 60 bilateral lung transplant recipients, 9 were found to have developed bronchial stenosis with 17 samples adequate for analysis. We observed a 1.56 to 70.8 mean-fold increase in human resistin gene expression in the anastomotic bronchial stenosis epithelial cells compared with nonstenotic airways. Furthermore, IL-1ß (21.76±10.96 pg/mL; control 0.86±0.44 pg/mL; P <0.01) and IL-8 levels (990.56±326.60 pg/mL; control 20.33±1.17 pg/mL; P <0.01) were significantly elevated in the BAL of the lung transplant patients who developed anastomotic bronchial stenosis. CONCLUSION: Our data suggest that the development of postlung transplantation bronchial stenosis may be in part mediated through the human resistin pathway by IL-1ß induced transcription factor nuclear factor-κß activation and downstream upregulation of IL-8 in alveolar macrophages. Further study is needed in the larger patient cohorts and to determine its potential therapeutic role in the management of post-transplant bronchial stenosis.

Clinical Factors for Successful Removal of Airway Silicone Stents in Patients With Post-Tuberculosis Tracheobronchial Stenosis.

BACKGROUND: After relieving stenosis with an airway silicone stent in post-tuberculosis bronchial stenosis (PTTS), stent removal is attempted if it is determined that airway patency can be maintained even after stent removal. However, the factors affecting airway stent removal are not well known. We investigate the factors that enable the successful removal of airway silicone stents in patients with PTTS. METHODS: We retrospectively analyzed PTTS patients who underwent bronchoscopic intervention from January 2004 to December 2019. Successful stent removal is defined as airway patency maintained when the stent is removed, so that reinsertion of the stent is not required. A multivariate logistic regression analysis was used to identify independent factors associated with successful stent removal at the first attempt. RESULTS: Total 344 patients were analyzed. Patients were followed up for a median of 47.9 (26.9-85.2) months after airway stent insertion. Approximately 69% of PTTS patients finally maintained airway patency after the stent was removed. Factors related to successful stent removal at the first attempt were older age and male sex. Absence of parenchymal calcification, segmental consolidation & bronchiolitis, and no trachea involved lesion were relevant to the successful stent removal. Stent dwelling for 12-24 months was associated with successful stent removal compared to a duration of less than 12 months. CONCLUSION: For patients whose airway patency is determined to be maintained even without a stent, it is necessary to attempt stent removal in consideration of factors related to successful stent removal.

Infectious complications associated with bronchial anastomotic dehiscence in lung transplant recipients.

INTRODUCTION: Bronchial anastomotic dehiscence (AD) is an uncommon complication following lung transplantation that carries significant morbidity and mortality. The objective of this study was to characterize fungal and bacterial infections in ADs, including whether infections following AD were associated with progression to bronchial stenosis. METHODS: This was a single-center study of 615 lung transplant recipients between 6/1/2015 and 12/31/2021. Airway complications were defined according to ISHLT consensus guidelines. RESULTS: 22 of the 615 recipients (3.6%) developed an AD. Bronchial ischemia or necrosis was common prior to dehiscence (68.1%). Fourteen (63.6%) recipients had bacterial airway infections, most commonly with Gram-negative rods, prior to dehiscence. Thirteen (59.1%) recipients had an associated pleural infection, most commonly with Candida species (30.8%). Post-dehiscence Aspergillus species were isolated in 4 recipients, 3 of which were de novo infections. Eleven had bacterial infections prior to dehiscence resolution, most commonly with Pseudomonas aeruginosa. Eleven recipients developed airway stenosis requiring dilation and/or stenting. Development of secondary infection prior to AD resolution was not associated with progression to stenosis (OR = .41, 95% CI = .05-3.30, p = .41). CONCLUSIONS: Gram-negative bacterial infections are common before and after AD. Pleural infection should be suspected in most cases. Infections prior to healing were not associated with subsequent development of airway stenosis.

Balloon Bronchoplasty for the Treatment of Bronchial Stenosis After Lung Transplantation: A Single-Center 10-Year Experience.

OBJECTIVE: To assess the safety and efficacy of balloon dilatation under dual guidance using fluoroscopy and bronchoscopy for treating bronchial stenosis following lung transplantation (LT), and to elucidate the factors associated with patency after the procedure. MATERIALS AND METHODS: From September, 2012, to April, 2021, 50 patients (mean age ± standard deviation, 54.4 ± 12.2 years) with bronchial stenosis among 361 recipients of LT were retrospectively analyzed. The safety of balloon dilatation was assessed by evaluating procedure-related complications. Efficacy was assessed by evaluating the technical success, primary patency, and secondary patency. Primary and secondary cumulative patency rates were calculated using the Kaplan-Meier method. The factors associated with patency after the procedure were evaluated using multivariable Cox hazard proportional regression analysis. RESULTS: In total, 65 bronchi were treated with balloon dilatation in 50 patients. The total number of treatment sessions was 277 and the technical success rate was 99.3% (275/277 sessions). No major procedure-related complications were noted. During the mean follow-up period of 34.6 ± 30.8 months, primary patency was achieved in 12 of 65 bronchi (18.5%). However, the patency rate improved to 76.9% (50 of 65 bronchi) after repeated balloon dilatation (secondary patency). The 6-month, 1-year, 3-year, and 5-year secondary patency rates were 95.4%, 90.8%, 83.1%, and 78.5%, respectively. The presence of clinical symptoms was a significant prognostic factor associated with reduced primary patency (adjusted hazard ratio [HR], 0.465; 95% confidence interval [CI], 0.220-0.987). Early-stage treatment ≤ 6 months (adjusted HR, 3.588; 95% CI, 1.093-11.780) and prolonged balloon dilatation > 5 min (adjusted HR, 3.285; 95% CI, 1.018-10.598) were associated with significantly higher secondary patency. CONCLUSION: Repeated balloon dilatation was determined to be safe and effective for treating bronchial stenosis following LT. Early-stage treatment and prolonged balloon dilatation could significantly promote long-term patency.

Severe Central Airway Obstruction Secondary to a Giant Endobronchial Hamartoma: A Case Report.

Central airway obstruction refers to the occlusion of more than 50% of the trachea, main stem bronchi, or lobar bronchus. It can potentially become a life-threatening condition. Pulmonary hamartomas (PH) are rare tumors with an incidence of 0.25%, constituting about 8% of all benign lung neoplasms. Only 10% of PH occur endobronchially, while the remaining appear peripherally. We present the case of a women with an endobronchial hamartoma that required emergent resection by bronchoscopy. This is 44-year-old woman, with a history of an endobronchial mass on the right main stem bronchus (RMSB) without histopathological diagnosis or surgical management. She presented with a history of chronic cough and expectoration. Upon admission, a chest X-ray was performed, showing opacities of the right lung and amputations of the RMSB. Bronchoscopy was performed and a tumor-like mass that occludes the RMSB was found, with valve effect causing intermittent occlusion. In anesthetic induction, she presents severe airway obstruction and cardiorespiratory arrest. During resuscitation maneuvers, the lesion that was obstructing the light is seen and resection was performed with electrocautery and cryotherapy probes. Histopathological report described an endobronchial chondromesenchymal hamartoma, with no signs of malignancy. The control X-ray showed adequate re-expansion of the right lung. In conclusion, although endobronchial hamartoma has a low incidence and has a slow growth rate, it can manifest as severe airway obstruction. To achieve a complete resection of an endobronchial lesion, both rigid and/or flexible bronchoscopy plus multimodal interventions are recommended.

Incidence, risk factors, and clinical characteristics of airway complications after lung transplantation.

Airway complications may occur after lung transplantation and are associated with considerable morbidity and mortality. We investigated the incidence, risk factors, and clinical characteristics of these complications. We retrospectively reviewed the medical records of 137 patients who underwent lung transplantation between 2008 and 2021. The median follow-up period was 20 months. Of the 137 patients, 30 (21.9%) had postoperative airway complications, of which 2 had two different types of airway complications. The most common airway complication was bronchial stenosis, affecting 23 patients (16.8%). Multivariable Cox analysis revealed that a recipient's body mass index ≥ 25 kg/m2 (hazard ratio [HR], 2.663; p = 0.013) was a significant independent risk factor for airway complications, as was postoperative treatment with extracorporeal membrane oxygenation (ECMO; HR, 3.340; p = 0.034). Of the 30 patients who had airway complications, 21 (70.0%) were treated with bronchoscopic intervention. Survival rates did not differ significantly between patients with and without airway complications. Thus, our study revealed that one fifth of patients who underwent lung transplantation experienced airway complications during the follow-up period. Obesity and receiving postoperative ECMO are risk factors for airway complications, and close monitoring is warranted in such cases.

Middle lobe syndrome revealing Broncholithiasis: A Case Report.

Middle lobe syndrome is a rare but important clinical entity worth investigating in local obstructive or inflammatory cause. One of its rare etiologies is broncholithiasis. We report the observation of a young female patient who presented with recurrent hemoptysis. Chest CT scan showed atelectasis of the middle lobe and suggested the diagnosis of broncholithiasis by objectifying, within the collapsed lobe, a calcification located in the bronchial lumen. Bronchial fibroscopy was of little help. Recurrent hemoptysis and doubt about pulmonary neoplasia led to a diagnostic and therapeutic lobectomy. In front of MLS, broncholithiasis should be suspected in the presence of calcifications on imaging. Surgery may be required in case of uncertain cases to not ignore an underlying tumor.

Endobronchial Lipoma: A Rare Cause of Bronchial Stenosis or Obstruction.

Endobronchial lipoma (EL) is a rare benign tumor characterized by tracheobronchial smooth-surfaced mass, often resulting in bronchial obstruction without standard guidelines for management. This study seeks to clarify the clinical features and interventions of EL, aiming to improve its diagnosis and outcomes. A retrospective review was conducted on 28516 outpatients treated between January 2015 and December 2019 at the Department of Respiratory and Critical Care Medicine of the Second Affiliated Hospital of Air Force Medical University to collect patients diagnosed with EL. Their clinical, bronchoscopic, chest imaging, and histopathological features along with management were analyzed. Among the patients reviewed, nine were histopathologically diagnosed with EL, comprising seven males and two females. All EL patients exhibited noticeable symptoms, including cough (in eight patients), dyspnea (in six patients), fever (in three patients), expectoration (in two patients), chest pain (in two patients), hemoptysis (in one patient), and fatigue (in one patient). Chest CT abnormalities included endobronchial mass (in four patients), inflammatory exudation (in three patients), atelectasis (in three patients), and infiltration or consolidation (in two patients). In three patients, imaging showed fat density, directly leading to the diagnosis of EL. The EL lesions were distributed with six in the right lung and three in the left lung, all located within the first three subdivisions of the tracheobronchial tree. Treatment approaches varied, with one patient undergoing combined bronchoscopic resection and surgery. The remaining patients received bronchoscopic intervention such as electrosurgical snare resection, argon plasma coagulation (APC), cryotherapy, and holmium laser. Histopathological analysis confirmed the EL diagnosis. Finally, the mass removal restored bronchus patency. Taken together, EL symptoms lack specificity, necessitating reliance on histopathology for EL accurate diagnosis. Bronchoscopic interventions emerge as the preferred option for EL management, surpassing surgical approaches.

Tracheal bronchus: a rare cause of recurrent pneumonia in adults.

Tracheal bronchus, also known as bronchus suis, is a rare congenital anomaly of the airway where an accessory bronchus originates directly from the trachea. With an estimated incidence of 0.001%-2.0%, this condition is rarely reported in literature. It is usually discovered as an incidental finding in an otherwise asymptomatic individual. However, it can act as a focus of recurrent infection or present as persistent radiographic infiltrates. Multidetector CT imaging and bronchoscopy play a crucial role in the identification of this entity. We hereby report the case of a middle-aged man who presented with recurrent right upper lobe pneumonia, which was found to be due to an underlying tracheal bronchus.

Post-tuberculosis tracheobronchial stenosis: long-term follow-up after self-expandable metallic stents placement and development of a prediction score-the Restenosis Score.

BACKGROUND: The insertion of self-expandable metallic stents (SEMS) for post-tuberculosis tracheobronchial stenosis (PTTS) was controversial. This study aimed to evaluate the efficacy and safety of SEMS for treating PTTS, and developed a scoring system for predicting the occurrence of restenosis after stenting in PTTS patients. METHODS: We conducted a retrospective review of 87 patients who were diagnosed with PTTS and experienced SEMS insertion between January 2000 and December 2017. All procedures were performed via flexible bronchoscopy under conscious sedation and local anesthesia. RESULTS: A total of 85 SEMS were successfully placed in 77 patients. Comparing with pre-stenting, there were significant improvements in the lumen diameters of the stenotic segment, mMRC scale and lung function after short-term SEMS placement. During the long-term (average 163.32 months) follow-up, 48 patients (62.3%) did not develop restenosis after stenting; the other 29 patients (37.7%) developed and eventually, 12 remained under interventional therapies and 11 had bronchial atresia. Multivariate Cox regression analysis revealed that the difference value between SEMS length and the stenosis-segment length, stenosis type, and the number of pre-stenting thermal ablation were independently related to restenosis occurrence and were subsequently used to establish the Restenosis Score. The model's development group (0.83, 95% CI 0.74-0.92) and external validation set (0.94, 95% CI 0.77-1.00) showed excellent discrimination. CONCLUSION: SEMS placement could serve as a safe and effective treatment option for most patients with PTTS. Further, we built a prediction model depending on the independent predictors of restenosis occurrence, the Restenosis Score. This validated tool might provide a decision support and a better management for PTTS patients who underwent SEMS implantation.

Descending aorta translocation for bronchial stenosis caused by shorter interaortic distance.

BACKGROUND AND AIM OF THE STUDY: Numerous anatomic relationships of arteries could cause extrinsic compression of the trachea or bronchus. We report a rare left bronchial stenosis just caused by shorter inter-aortic distance. METHODS: One patient wih recurrent coughing and wheezing was diagnosed as left emphysema.Cardiac computed tomography (CTA) shows a shorter distance between ascending aorta (AAo) and descending aorta (DAo) caused left bronchial stenosis with extrinsic compression of right pulmonary artery. RESULTS: A translocation of the descending aorta was performed in this patient, and postoperative CTA showed that the DAo was translocated to the AAo and the left main bronchial stenosis was relieved. CONCLUSIONS: Translocation of the DAo was necessary for the rare left bronchial stenosis caused by shorter inter-aortic distance and could bring a good outcome.

[Airway Complications after Lung Transplantation].

Lung transplantation is the only option for patients with end-stage pulmonary diseases. During recent years, satisfactory results in terms of long-term survival and quality of life have been achieved with improvements in perioperative management, surgical technique, and immunosuppression. Airway complications after lung transplantation are associated with significant morbidity and mortality. Common airway complications after lung transplantation include anastomotic granulation, airway stenosis, bronchomalacia, fistulas, and anastomotic infection. These airway complications often result in repeated hospitalisations and interventions. If bronchoscopic interventions are not effective, other alternatives like surgical intervention or re-transplantation become necessary. While numerous strategies for airway complications have been proven effective, there are still some issues that to be solved. Further research is necessary to reduce mortality and improve quality of life of these patients.

Delayed Bronchial Obstruction following Esophageal Stent Implantation: A Case Report.

Airway compression is a rare complication of esophageal stent placement. With the introduction of self-expanding metal stents, the incidence of bronchial obstruction by esophageal stents has decreased. Delayed external airway compression after esophageal stent implantation is rarely reported. We describe a case of left main bronchial obstruction after self-expandable esophageal stent placement. A 70-year-old patient with advanced esophageal cancer visited the emergency room (ER) with worsening cough and dyspnea. He had received palliative concurrent chemoradiotherapy after esophageal self-expanding metal stent (SEMS) insertion three months ago. One month before the ER visit, additional esophageal SEMS placement (stent-in-stent) was performed owing to the development of a tracheoesophageal fistula. After hospitalization, chest radiography revealed a patchy consolidation in the left lower lobe. A diagnosis of pneumonia was made, and the patient was treated with antibiotics. Seven days after antibiotic treatment, the patient developed a fever and severe dyspnea. Auscultation revealed the absence of breath sounds in the left hemithorax. A follow-up chest radiograph showed a white-out of the left hemithorax. Flexible bronchoscopy revealed luminal narrowing of the left main bronchus (LMB) due to external compression. Chest computed tomography further demonstrated compression of the LMB by esophageal stents. This case highlights that esophageal SEMS can present as an emergent and often life-threatening airway obstruction.

Periaortic air in native and post-operative aorta on computed tomography.

Periaortic air can be seen in various conditions which can be a benign imaging finding or harbinger of a catastrophic event. The causes vary in native aorta and post-operative aorta. A radiologist has an important part in the management process of these patients, as the treatment varies from conservative to radical surgery based on the aetiology. The presence of periaortic air seen in the light of various clinical, laboratory and radiological findings can guide the radiologist towards a particular aetiology. Cross-sectional imaging, mainly computed tomography, is an indispensable tool in recognising ectopic periaortic air and to identify the associated findings and eventually make an accurate diagnosis. We present a pictorial review of various causes of the periaortic air in native and postoperative aorta, the salient features and management of the described conditions.

Submucosal Injection of Mitomycin C in a Case of Vanishing Bronchus After Lung Transplant.

Segmental nonanastomotic stenosis, also known as vanishing bronchus intermedius syndrome (or simply, "vanishing bronchus"), is a rare complication that can occur after a lung transplant. It usually occurs in the first posttransplant year and often develops in the intermediate bronchus. Definitive diagnosis is established by bronchoscopy. The treatment management primarily includes bronchoscopic dilatation and stenting. In patients who do not benefit from these applications, lung resection or retransplant may be indicated. Our 58-year-old patient developed vanishing bronchus after lung transplant, and recurrence could not be prevented despite repeated bronchoscopic interventions. We applied submucosal mitomycin C injection to the bronchial wall of the stenotic segment and achieved significant benefit for reduction of recurrence. Our aim was to document the first reported case of a patient with vanishing bronchus who was treated with submucosal administration of mitomycin C, a strong fibroblast inhibitor, and to report the outcomes of submucosal mitomycin C administration with regard to recurrence.

Bronchomalacia in Right Aortic Arch Treated With Descending Aortic Translocation and Airway Splint.

Management of recurrent symptomatic tracheobronchomalacia and tracheobronchial compression after prior aortopexy and tracheobronchopexy is a surgical challenge. In patients with right aortic arch, the course of the aortic arch over the right mainstem bronchus can result in superior and posterior compression of the airway. This report presents 2 cases of recurrent bronchomalacia and bronchial compression treated with descending aortic translocation. The addition of bronchial splinting to aortic translocation effectively relieved airway symptoms.

Novel Designed V-shaped Silicone Stent for the Treatment of Unilateral Main Bronchial Stenosis.

Benign main bronchial stenosis may cause a potentially life-threatening condition. Airway silicone stenting is an important option of bronchoscopic treatments for patients with main bronchial stenosis. However stent migration is 1 of the most frequent complications and requires repeated bronchoscopic interventions. To resolve this issue we therefore describe here a novel designed V-shaped silicone stent for the treatment of unilateral main bronchial stenosis. This method may be widely applied to clinical practice to prevent stent migration.