Interventional Pulmonology: Extending the Breadth of Thoracic Care.

Interventional pulmonary medicine has developed as a subspecialty focused on the management of patients with complex thoracic disease. Leveraging minimally invasive techniques, interventional pulmonologists diagnose and treat pathologies that previously required more invasive options such as surgery. By mitigating procedural risk, interventional pulmonologists have extended the reach of care to a wider pool of vulnerable patients who require therapy. Endoscopic innovations, including endobronchial ultrasound and robotic and electromagnetic bronchoscopy, have enhanced the ability to perform diagnostic procedures on an ambulatory basis. Therapeutic procedures for patients with symptomatic airway disease, pleural disease, and severe emphysema have provided the ability to palliate symptoms. The combination of medical and procedural expertise has made interventional pulmonologists an integral part of comprehensive care teams for patients with oncologic, airway, and pleural needs. This review surveys key areas in which interventional pulmonologists have impacted the care of thoracic disease through bronchoscopic intervention.

Novel Robotic-Assisted Cryobiopsy for Peripheral Pulmonary Lesions.

PURPOSE: Tissue acquisition in lung cancer is vital for multiple reasons. Primary reasons reported for molecular testing failure in lung cancer biopsy specimens include insufficient amount of tumor cells provided and inadequate tissue quality. Robotic bronchoscopy is a new tool enabling peripheral pulmonary lesion sampling; however, diagnostic yield remains imperfect possibly due to the location of nodules adjacent to or outside of the airway. The 1.1-mm cryoprobe is a novel diagnostic tool and accesses tissue in a 360-degree manner, thus potentially sampling eccentric/adjacent lesions. This study examines the diagnostic yield of the cryoprobe compared to standard needle aspiration and forceps biopsy. It additionally evaluates yield for molecular markers in cases of lung cancer. METHODS: This is a retrospective analysis of 112 patients with 120 peripheral pulmonary lesions biopsied via robotic bronchoscopy using needle aspirate, forceps, and cryobiopsy. RESULTS: The overall diagnostic yield was 90%. Nearly 18% of diagnoses were made exclusively from the cryobiopsy sample. Molecular analysis was adequate on all cryobiopsy samples sent. Digital imaging software confirmed an increase in quantity and quality of samples taken via cryobiopsy compared to needle aspirate and traditional forceps biopsy. CONCLUSION: Using the 1.1-mm cryoprobe to biopsy PPN combined with the Ion robotic bronchoscopy system is safe, feasible, and provides more diagnostic tissue than needle aspirates or traditional forceps biopsies. The combination of cryobiopsy with robotic-assisted bronchoscopy increased diagnostic yield, likely due to its 360-degree tissue acquisition which is beneficial when targeting extraluminal lesions adjacent to the airway.

Pre-Procedural COVID-19 Nasopharyngeal Swab Has Good Concordance with Bronchoalveolar Lavage in Patients at Low Risk for Viral Infection.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has drastically affected hospital and operating room (OR) workflow around the world as well as trainee education. Many institutions have instituted mandatory preoperative SARS-CoV-2 PCR nasopharyngeal swab (NS) testing in patients who are low risk for COVID-19 prior to elective cases. This method, however, is challenging as the sensitivity, specificity, and overall reliability of testing remains unclear. OBJECTIVES: The objective of this study was to assess the concordance of a negative NS in low risk preoperative patients with lower airway bronchoalveolar lavage (BAL) specimens obtained from the same patients. METHODS: We prospectively sent intraoperative lower airway BAL samples collected within 48 h of a negative mandatory preoperative NS for SARS-CoV-2 PCR testing. All adult patients undergoing a scheduled bronchoscopic procedure for any reason were enrolled, including elective and nonelective cases. RESULTS: One-hundred eighty-nine patients were included. All BAL specimens were negative for SARS-CoV-2 indicative of 100% concordance between testing modalities. CONCLUSIONS: These results are promising and suggest that preoperative nasopharyngeal SARS-CoV-2 testing provides adequate screening to rule out active COVID-19 infection prior to OR cases in a population characterized as low risk by negative symptom screening. This information can be used for both pre-procedural screening and when reintroducing trainees into the workforce.

Benign Central Airway Obstruction.

Benign central airway obstruction (CAO) is responsible for significant morbidity due to dyspnea and impaired quality of life. While iatrogenic causes, including stenosis after endotracheal intubation, tracheostomy tube placement, and surgery, account for the majority of cases of benign CAO, there are a multitude of other causes including infections, inflammatory disorders, extrinsic compression, benign endobronchial tumors, and tracheobronchomalacia. The approach to management depends on the underlying process responsible for the disorder and may include systemic therapy, endoscopic therapy, and surgery. In this review, we aim to provide a general overview of the presentation, evaluation, and management of nonmalignant CAO followed by a more in-depth review of several of the more common causes of this disorder.

Postradiofrequency ablation inflammatory pseudotumor associated with pulmonary venoocclusive disease: case report and review of the literature.

Radiofrequency ablation of pulmonary veins is a common therapeutic intervention for atrial fibrillation. Pulmonary vein stenosis and venoocclusive disease are recognized complications, but the spectrum of pathologies postablation have not been previously reviewed. A recent case at our hospital showed a left hilar soft tissue mass in association with superior pulmonary vein stenosis in a patient 4 years postablation. On resection, this proved to be an inflammatory pseudotumor composed of myofibroblasts in an organizing pneumonia-type pattern with adjacent dendriform ossifications. Pulmonary venoocclusive change was a prominent feature. Literature on the histopathology of postradiofrequency ablation complications is limited. The severity of vascular pathology appears to increase with the postablation interval. Although pulmonary vascular changes are the most common late finding, fibroinflammatory changes including pulmonary pseudotumor formation, attributable to thermal injury, should be considered in the differential diagnosis of these cases.

The safety profile of a protocolized transbronchial cryobiopsy program utilizing a 2.4 mm cryoprobe for interstitial lung disease.

INTRODUCTION: Transbronchial lung cryobiopsy (TBLC) has emerged as a promising alternative to surgical lung biopsy for the diagnosis of interstitial lung disease. However, uncertainty remains regarding its overall complications due to a lack of procedural standardization including the size of cryoprobe utilized. METHODS: This is a prospective cohort study of a protocolized transbronchial cryobiopsy program utilizing a 2.4 mm cryoprobe. 201 consecutive subjects were enrolled at a single academic center. RESULTS: The average biopsy size was 106.2 ± 39.3 mm2. Complications included a total pneumothorax rate of 4.9% with 3.5% undergoing chest tube placement. Severe bleeding defined by the Nashville Working Group occurred in 0.5% of cases. There were no deaths at 30-days. DISCUSSION: A protocolized transbronchial cryobiopsy program utilizing a 2.4 mm cryoprobe in can achieve a high diagnostic yield with a favorable safety profile.

ATS Core Curriculum 2021. Adult Pulmonary Medicine: Thoracic Oncology.

The American Thoracic Society Core Curriculum updates clinicians annually in adult and pediatric pulmonary disease, medical critical care, and sleep medicine at the annual international conference. The 2021 Pulmonary Core Curriculum focuses on lung cancer and include risks and prevention, screening, nodules, therapeutics and associated pulmonary toxicities, and malignant pleural effusions. Although tobacco smoking remains the primary risk factor for developing lung cancer, exposure to other environmental and occupational substances, including asbestos, radon, and burned biomass, contribute to the global burden of disease. Randomized studies have demonstrated that routine screening of high-risk smokers with low-dose chest computed tomography results in detection at an earlier stage and reduction in lung cancer mortality. On the basis of these trials and other lung cancer risk tools, screening recommendations have been developed. When evaluating lung nodules, clinical and radiographic features are used to estimate the probability of cancer. Management guidelines take into account the nodule size and cancer risk estimates to provide recommendations at evaluation. Newer lung cancer therapies, including immune checkpoint inhibitors and molecular therapies, cause pulmonary toxicity more frequently than conventional chemotherapy. Treatment-related toxicity should be suspected in patients receiving these medications who present with respiratory symptoms. Evaluation is aimed at excluding other etiologies, and treatment is based on the severity of symptoms. Malignant pleural effusions can be debilitating. The diagnosis is made by using simple pleural drainage and/or pleural biopsies. Management depends on the clinical scenario and the patient's preferences and includes the use of serial thoracentesis, a tunneled pleural catheter, or pleurodesis.

Pulmonary langerhans cell histiocytosis diagnosed in a cervical lymph node: a case report.

BACKGROUND: Pulmonary Langerhans cell histiocytosis (PLCH) is usually confined to the lungs and is therefore an unexpected finding in a cervical lymph node. CASE: A 52-year-old male with a 40-pack-year smoking history presented to our clinic with cough, fever and cervical lymphadenopathy. Chest computed tomography (CT) showed bilateral pulmonary nodules and enlarged mediastinal lymph nodes, worrisome for an infectious or malignant process. Bronchioloalveolar lavage was nondiagnostic. Fine needle aspiration cytology of the enlarged cervical lymph node revealed atypical histiocytoid cells, suspicious for malignancy. Immunohistochemistry revealed CD1a- and S-100-positive Langerhans cells. These findings, along with the patient's extensive smoking history and characteristic radiographic nodules, favored a diagnosis of PLCH with cervical lymph node involvement. The patient was advised to cease smoking, and no therapy was administered. Months later, follow-up chest CT showed spontaneous resolution of the lung nodules. CONCLUSION: The demonstration of Langerhans cells by immunohistochemical staining of CD1a and S-100 on a fine needle aspiration cell block is a useful diagnostic adjunct. In this case, definitive cytology for Langerhans cells in the appropriate clinical and radiologic setting allowed us to arrive at the correct diagnosis of PLCH in a minimally invasive manner.

ATS Core Curriculum 2020. Adult Pulmonary Medicine.

The American Thoracic Society Core Curriculum updates clinicians annually in adult and pediatric pulmonary disease, medical critical care, and sleep medicine in a 3- to 4-year recurring cycle of topics. The topics of the 2020 Pulmonary Core Curriculum include pulmonary vascular disease (submassive pulmonary embolism, chronic thromboembolic pulmonary hypertension, and pulmonary hypertension) and pulmonary infections (community-acquired pneumonia, pulmonary nontuberculous mycobacteria, opportunistic infections in immunocompromised hosts, and coronavirus disease [COVID-19]).

Assessment of Fissure Integrity in Patients With Intrabronchial Valves for Treatment of Prolonged Air Leak.

BACKGROUND: Intrabronchial valves (IBVs) are a treatment alternative for persistent air leak (PAL). However, there is a paucity of evidence regarding whether the absence of collateral ventilation (CV) can predict successful treatment of PAL with IBV placement. We assessed whether absence of CV measured by fissure integrity could predict successful resolution of PAL with IBV placement. METHODS: A multicenter, retrospective study was performed. Patients who underwent IBV placement for PAL were identified. Chest computed tomography analysis via VIDA Diagnostics was used to assess CV. CV was present if the treated lobe was adjacent to a fissure that was <90% complete. RESULTS: A total of 81 valves were placed in 26 patients (median, 3 per patient). A total of 16 patients without CV underwent IBV placement: 14 patients had complete resolution of PAL with a median time from IBV placement to air leak resolution of 4.5 days and 2 patients required subsequent procedures to manage the PAL. In a subset of patients without CV who underwent complete lobar occlusion with IBV (n = 8), median time to PAL resolution was 3 days, whereas in patients without CV who underwent incomplete lobar occlusion with IBV (n = 6), median time PAL resolution was 6.5 days (p = 0.045). All 10 patients with CV underwent IBV placement and complete lobar occlusion: 4 patients had complete PAL resolution with a median time from IBV placement to PAL resolution of 17.5 days and 6 patients required subsequent procedures to manage their PAL. CONCLUSIONS: PAL treatment with IBV is more successful in patients without CV, especially when complete lobar occlusion with IBV is achieved.

Concurrent Versus Sequential Intrapleural Instillation of Tissue Plasminogen Activator and Deoxyribonuclease for Pleural Infection.

BACKGROUND: Treatment of pleural infection with instillation of sequential intrapleural tissue plasminogen activator (tPA) and human recombinant deoxyribonuclease (DNase) twice daily for a total of 6 doses has been shown to decrease surgical referral and improve radiographic imaging. This labor-intensive regimen was empirically chosen. Thus, it remains unclear whether the 2 drugs can be administered immediately one after the other (concurrent administration) instead of instilling them separately with a 1-hour to 2-hour interval in between (sequential administration). The aim of this study was to compare the efficacy and safety of sequential versus concurrent tPA/DNase therapy in patients with pleural infection. METHODS: This was a prospective observational study. Consecutive patients with pleural infection who received concurrent and sequential tPA/DNase were included. The initiation and number of doses of tPA/DNase therapy were based on the amount of pleural fluid drainage, clinical response and radiographic findings. RESULTS: A total of 38 patients with pleural infection received tPA/DNase treatment: 18 in the sequential group and 20 in the concurrent group. Treatment was successful in 77.7% in the sequential group and 75% in concurrent group (P=0.57). There was no statistically significant difference between the 2 treatment groups (sequential and concurrent) in median pleural fluid drainage (P=0.45), median volume of pleural effusion estimated on chest computed tomography scan (P=0.4) or median hemithorax occupied by effusion on chest radiography (P=0.83) following intrapleural therapy. One patient required a blood transfusion for gradual pleural blood loss in each treatment group. Pain needing escalation of analgesia affected 3 patients in each arm but none required cessation of therapy. CONCLUSION: A simpler regimen of concurrent administration of intrapleural tPA/DNase as compared with sequential intrapleural therapy is safe, effective, and represents a viable option for the management of pleural infection.

The Diagnosis and Management of Airway Complications Following Lung Transplantation.

Airway complications following lung transplantation result in considerable morbidity and are associated with a mortality of 2% to 4%. The incidence of lethal and nonlethal airway complications has decreased since the early experiences with double- and single-lung transplantation. The most common risk factor associated with post-lung transplantation airway complications is anastomotic ischemia. Airway complications include the development of exophytic granulation tissue, bronchial stenosis, bronchomalacia, airway fistula, endobronchial infection, and anastomotic dehiscence. The broadening array of bronchoscopic therapies has enhanced treatment options for lung transplant recipients with airway complications. This article reviews the risk factors, clinical manifestations, and treatments of airway complications following lung transplantation and provides our expert opinion when evidence is lacking.

Dual SMAD Signaling Inhibition Enables Long-Term Expansion of Diverse Epithelial Basal Cells.

Functional modeling of many adult epithelia is limited by the difficulty in maintaining relevant stem cell populations in culture. Here, we show that dual inhibition of SMAD signaling pathways enables robust expansion of primary epithelial basal cell populations. We find that TGFß/BMP/SMAD pathway signaling is strongly activated in luminal and suprabasal cells of several epithelia, but suppressed in p63+ basal cells. In airway epithelium, SMAD signaling promotes differentiation, and its inhibition leads to stem cell hyperplasia. Using dual SMAD signaling inhibition in a feeder-free culture system, we have been able to expand airway basal stem cells from multiple species. Expanded cells can produce functional airway epithelium physiologically responsive to clinically relevant drugs, such as CFTR modulators. This approach is effective for the clonal expansion of single human cells and for basal cell populations from epithelial tissues from all three germ layers and therefore may be broadly applicable for modeling of epithelia.

Molecular Mechanisms of Resistance to First- and Second-Generation ALK Inhibitors in ALK-Rearranged Lung Cancer.

Advanced, anaplastic lymphoma kinase (ALK)-positive lung cancer is currently treated with the first-generation ALK inhibitor crizotinib followed by more potent, second-generation ALK inhibitors (e.g., ceritinib and alectinib) upon progression. Second-generation inhibitors are generally effective even in the absence of crizotinib-resistant ALK mutations, likely reflecting incomplete inhibition of ALK by crizotinib in many cases. Herein, we analyzed 103 repeat biopsies from ALK-positive patients progressing on various ALK inhibitors. We find that each ALK inhibitor is associated with a distinct spectrum of ALK resistance mutations and that the frequency of one mutation, ALKG1202R, increases significantly after treatment with second-generation agents. To investigate strategies to overcome resistance to second-generation ALK inhibitors, we examine the activity of the third-generation ALK inhibitor lorlatinib in a series of ceritinib-resistant, patient-derived cell lines, and observe that the presence of ALK resistance mutations is highly predictive for sensitivity to lorlatinib, whereas those cell lines without ALK mutations are resistant. SIGNIFICANCE: Secondary ALK mutations are a common resistance mechanism to second-generation ALK inhibitors and predict for sensitivity to the third-generation ALK inhibitor lorlatinib. These findings highlight the importance of repeat biopsies and genotyping following disease progression on targeted therapies, particularly second-generation ALK inhibitors. Cancer Discov; 6(10); 1118-33. ©2016 AACRSee related commentary by Qiao and Lovly, p. 1084This article is highlighted in the In This Issue feature, p. 1069.

Simulation for Skills-based Education in Pulmonary and Critical Care Medicine.

The clinical practice of pulmonary and critical care medicine requires procedural competence in many technical domains, including vascular access, airway management, basic and advanced bronchoscopy, pleural procedures, and critical care ultrasonography. Simulation provides opportunities for standardized training and assessment in procedures without placing patients at undue risk. A growing body of literature supports the use and effectiveness of low-fidelity and high-fidelity simulators for procedural training and assessment. In this manuscript by the Skills-based Working Group of the American Thoracic Society Education Committee, we describe the background, available technology, and current evidence related to simulation-based skills training within pulmonary and critical care medicine. We outline working group recommendations for key procedural domains.

Evaluation and management of pill aspiration: case discussion and review of the literature.

Pill aspiration represents a unique type of foreign body aspiration requiring a distinct diagnostic and therapeutic approach. In many cases, the "foreign body" itself may no longer be present, whereas the airway manifestations may persist for months to years. Limited data exist to guide management decisions. We report two cases of severe airway injury secondary to pill aspiration and provide a review of the literature. Endobronchial surveillance may be important to identify impending airway obstruction via secretions, edema, granulation tissue, or fibrotic stricture. In many cases, the airway sequelae of pill aspiration can be effectively managed with bronchoscopy.

Fully biodegradable airway stents using amino alcohol-based poly(ester amide) elastomers.

Airway stents are often used to maintain patency of the tracheal and bronchial passages in patients suffering from central airway obstruction caused by malignant tumors, scarring, and injury. Like most conventional medical implants, they are designed to perform their functions for a limited period of time, after which surgical removal is often required. Two primary types of airway stents are in general use, metal mesh devices and elastomeric tubes; both are constructed using permanent materials, and must be removed when no longer needed, leading to potential complications. This paper describes the development of process technologies for bioresorbable prototype elastomeric airway stents that would dissolve completely after a predetermined period of time or by an enzymatic triggering mechanism. These airway stents are constructed from biodegradable elastomers with high mechanical strength, flexibility and optical transparency. This work combines microfabrication technology with bioresorbable polymers, with the ultimate goal of a fully biodegradable airway stent ultimately capable of improving patient safety and treatment outcomes.

Toward the guidance of transbronchial biopsy: identifying pulmonary nodules with optical coherence tomography.

BACKGROUND: Solitary pulmonary nodules (SPNs) frequently require transbronchial needle aspiration (TBNA) or biopsy to determine malignant potential, but have variable diagnostic yields. Confirming needle placement within SPNs during TBNA could significantly increase diagnostic yield. Optical coherence tomography (OCT) provides nondestructive, high-resolution, microstructural imaging with potential to distinguish SPN from parenchyma. We have developed needle-based OCT probes compatible with TBNA. Before OCT can play any significant role in guiding clinical TBNA, OCT interpretation criteria for differentiating SPN from lung parenchyma must be developed and validated. METHODS: OCT of SPN and parenchyma was performed on 111 ex vivo resection specimens. OCT criteria for parenchyma and SPN were developed and validated in a blinded assessment. Six blinded readers (two pulmonologists, two pathologists, and two OCT experts) were trained on imaging criteria in a 15-min training session prior to interpreting the validation data set. RESULTS: OCT of lung parenchyma displayed evenly spaced signal-void alveolar spaces, signal-intense backreflections at tissue-air interfaces, or both. SPNs lacked both of these imaging features. Independent validation of OCT criteria by the six blinded readers demonstrated sensitivity and specificity of 95.4% and 98.2%, respectively. CONCLUSIONS: We have developed and validated OCT criteria for lung parenchyma and SPN with sensitivity and specificity > 95% in this ex vivo study. We anticipate that OCT could be a useful complementary imaging modality to confirm needle placement during TBNA to potentially increase diagnostic yield.