Advancements in airway stents: a comprehensive update

PURPOSE OF REVIEW

This review provides an overview of the evolving field of airway stenting (AS), highlighting its relevance in the management of central airway obstruction (CAO). It discusses recent advancements, including 3D-printed silicone stents (3DPSS), metallic stents, biodegradable stents (BS), and drug-eluting stents (DES), which are transforming clinical practice. The review underscores the ongoing challenges in patient selection, stent choice, and long-term management in the context of an evolving landscape.

RECENT FINDINGS

Innovations, particularly 3DPSS, have shown promise in providing patient-specific solutions. These stents offer improved symptom relief, enhanced quality of life, and lower complication rates, especially for complex airway diseases. The use of BS and DES is explored, raising prospects for future applications.

SUMMARY

The evolution of AS reflects a deepening understanding of airway obstructions. Recent innovations, such as 3DPSS, BS, and DES, show considerable promise in addressing the limitations of conventional stents. However, challenges related to complications, patient selection, and long-term management persist, demanding further research. Wide practice variations in the management of AS highlight the need for more clinical data and standardized guidelines. The search for the ideal stent continues, driven by the pursuit of better outcomes for patients with CAO.

Patient-specific airway stent using three-dimensional printing: a review

The primary function of an airway stent is to reestablish patency, impeding restenosis, supporting the tracheobronchial wall, or occluding fistulas. But stent-related complications are prevalent and can have devastating consequences. For this reason, stents are considered a last resort when there are no alternatives in treatment. Additionally, commercially available airway stents often poorly fit patients with complex airways, and they can cause various complications. At the end of the 20th century, three-dimensional (3D) printing technology was created. It has been transformative in healthcare and has been used in several applications. One of its first utilizations was the anatomical modeling of body structures that helps preoperative planning. In respiratory medicine, this technology has been essentially used in central airway diseases to produce 3D airway models and to create airway splints and prostheses. In the last decade, it has led to a transformation and allowed progress in personalized medicine, making patient-specific stents for individuals with complex airway problems. A patient-specific stent using 3D printing may minimize complications, improve quality of life, and reduce the need for repeated procedures. This review describes the recent advances in 3D printing technology, its use for developing airway prostheses to treat complex airway diseases, and the current evidence that supports its use.

Innovation in rigid bronchoscopy-past, present, and future

German laryngologist Gustav Killian performed the first "Direkte Bronchoskopie" using a rigid bronchoscope to extract a foreign airway body from the right main bronchus over a hundred years ago, transforming the practice of respiratory medicine. The procedure instantaneously became popular throughout the world. Chevalier Jackson Sr from the United States further advanced the instrument, technique, safety, and application. In the 1960s, Professors Harold H. Hopkins and N.S. Kapany introduced optical rods as well as fiberoptics that led Karl Storz to develop the cold light system improving endoluminal illumination, achievements that ushered in the modern era of flexible endoscopy. Several diagnostic and therapeutic procedures became possible such as transbronchial needle biopsy, transbronchial lung biopsy, airway electrosurgery, or cryotherapy. Dr. Jean-François Dumon from France advanced the use of Nd-YAG laser in the endobronchial tree and created the dedicated Dumon silicone stent introducing the whole new field of interventional pulmonology (IP). This major milestone revitalized interest in rigid bronchoscopy (RB). Now, advancements are being made in stenting, instrumentation, and education. RB robotic technology advancements are currently anticipated and can potentially revolutionize the practice of pulmonary medicine. In this review, we describe some of the most substantial advances related to RB from its beginning to the modern era.

Abstract 651: Revealing the role of lung cancer microbiota in the tumor progression

Lung cancer (LC) remains as the leading cause of death by cancer worldwide. In Chile, LC is the second cause of cancer-related deaths. Recently, studies in melanoma and non-small cell lung cancer (NSCLC) patients have highlighted the role of the gut microbiota as an important host factor in mediating the responses/resistance to immunotherapy, suggesting that bacteria present in the gut may modulate the immune response in these tumors. However, the role of extra-intestinal microbiota; bacteria living outside of the gut, in cancer pathogenesis and the response to anti-cancer therapies remains largely undetermined. Here we characterize the composition of intratumoral microbiota of NSCLC and seek to establish a functional relationship between it and the composition of the immune microenvironment and the clinicopathological characteristics of NSCLC patients. From the first 157 FFPE NSCLC samples, we extracted DNA from all collected samples, obtaining adequate material in quality and quantity to later be submitted for analysis to 16S sequencing. Using 16S rRNA gene sequencing, we assessed the general landscape of the NSCLC tumor microbiome, revealing the presence of large number of bacterial communities in the NSCLC tumor samples on the different histological subtypes analyzed. We have detected differences in alpha diversity in the histological subtypes studied. Even more interesting, we have detected significant differences in lung adenocarcinoma depending on the degree of histological differentiation, observing a decrease in proteobacteria and an enrichment of Bacteroidales, as cell differentiation is lost. Additionally, we identified taxonomic differences between differentiated and undifferentiated tumors. Differentiated tumors show enrichment in Akkermansia muciniphila and while undifferentiated tumors show enrichment in Actinobacter Corynebacterium. Suggesting that these taxa could contribute to maintaining a differentiated state or inducing cell dedifferentiation, respectively. Our results reveal the presence of a large number of bacterial communities in lung cancer samples in the different histological subtypes analyzed. Suggesting that these communities could play a key role in tumor differentiation and progression.

Citation Format: Erick M. Riquelme, Ivania Valdes, Carlos Aravena, Ilse Valencia, Barbara Mino, Daniel Carvajal, Alberto Martin. Revealing the role of lung cancer microbiota in the tumor progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 651.

Predicting Lymph Node Metastasis in Non-small Cell Lung Cancer: Prospective External and Temporal Validation of the HAL and HOMER Models

BACKGROUND

Two models, the Help with the Assessment of Adenopathy in Lung cancer (HAL) and Help with Oncologic Mediastinal Evaluation for Radiation (HOMER), were recently developed to estimate the probability of nodal disease in patients with non-small cell lung cancer (NSCLC) as determined by endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA). The objective of this study was to prospectively externally validate both models at multiple centers.

RESEARCH QUESTION

Are the HAL and HOMER models valid across multiple centers?

STUDY DESIGN AND METHODS

This multicenter prospective observational cohort study enrolled consecutive patients with PET-CT clinical-radiographic stages T1-3, N0-3, M0 NSCLC undergoing EBUS-TBNA staging. HOMER was used to predict the probability of N0 vs N1 vs N2 or N3 (N2|3) disease, and HAL was used to predict the probability of N2|3 (vs N0 or N1) disease. Model discrimination was assessed using the area under the receiver operating characteristics curve (ROC-AUC), and calibration was assessed using the Brier score, calibration plots, and the Hosmer-Lemeshow test.

RESULTS

Thirteen centers enrolled 1,799 patients. HAL and HOMER demonstrated good discrimination: HAL ROC-AUC = 0.873 (95%CI, 0.856-0.891) and HOMER ROC-AUC = 0.837 (95%CI, 0.814-0.859) for predicting N1 disease or higher (N1|2|3) and 0.876 (95%CI, 0.855-0.897) for predicting N2|3 disease. Brier scores were 0.117 and 0.349, respectively. Calibration plots demonstrated good calibration for both models. For HAL, the difference between forecast and observed probability of N2|3 disease was +0.012; for HOMER, the difference for N1|2|3 was -0.018 and for N2|3 was +0.002. The Hosmer-Lemeshow test was significant for both models (P = .034 and .002), indicating a small but statistically significant calibration error.

INTERPRETATION

HAL and HOMER demonstrated good discrimination and calibration in multiple centers. Although calibration error was present, the magnitude of the error is small, such that the models are informative.

The utility of endobronchial ultrasound-transbronchial needle aspiration in patients with suspected extra-pulmonary sarcoidosis without thoracic lymphadenopathy

BACKGROUND

Diagnosis of extra-pulmonary sarcoidosis can be difficult, and a biopsy is usually required. We evaluated the utility of endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) in patients with suspected extra-pulmonary sarcoidosis with thoracic lymph nodes ≤10 mm on chest computed tomography (CT) and no or minimal pulmonary infiltrates.

METHODS

The Cleveland Clinic bronchoscopy registry was screened. Patients with thoracic lymph nodes >10 mm on short axis or significant pulmonary infiltrates in the chest CT scan were excluded. Two separate analyses using expert consensus (before and after release of bronchoscopy results) were the reference standard.

RESULTS

15 patients met the inclusion criteria. 40% had suspected ocular, 33% cardiac and 27% neurologic sarcoidosis. Six patients (40%) had EBUS-TBNA compatible with sarcoidosis. When the reference standard was the consensus diagnosis blinded to bronchoscopy results, the sensitivity, specificity, positive predictive value and negative predictive value of EBUS-TBNA were 56%, 83%, 83%, and 56% respectively. The combination of a positive EBUS-TBNA and BAL CD4/CD8 improved the specificity from 83 to 100%, but the difference was not statistically significant (p = 0.074). When the reference standard was the consensus diagnosis with the bronchoscopic results, the sensitivity, specificity, positive predictive value and negative predictive value of EBUS-TBNA were 75%, 100%, 100%, and 78% respectively.

CONCLUSIONS

In patients with suspected extra-pulmonary sarcoidosis, the EBUS-TBNA may be useful in the diagnosis of patients with thoracic lymph nodes ≤10 mm and no or minimal pulmonary infiltrates on chest CT. Larger and prospective studies are needed to validate our findings.

Convex probe endobronchial ultrasound: historical, contemporary, and cutting-edge applications

The use of convex-probe endobronchial ultrasound (CP-EBUS) has revolutionized bronchoscopy. It has provided the option of a relatively safe, minimally invasive approach for the assessment of various intrathoracic diseases. In current practice, its most dramatic impact has been on the diagnosing and staging of lung cancer. It has served as an invaluable tool that has replaced mediastinoscopy in a variety of clinical scenarios. Many pulmonologists and thoracic surgeons consider CP-EBUS the most significant milestone in bronchoscopy after the development of the flexible bronchoscope itself. In this review, we summarize the historical aspects, current indications, technical approach, and future direction of CP-EBUS.

Idiopathic subglottic stenosis: a review

Idiopathic subglottic stenosis (iSGS) is a fibrotic disease of unclear etiology that produces obstruction of the central airway in the anatomic region under the glottis. The diagnosis of this entity is difficult, usually delayed and confounded with other common respiratory diseases. No apparent etiology is identified even after a comprehensive workup that includes a complete history, physical examination, pulmonary function testing, auto-antibodies, imaging studies, and endoscopic procedures. This approach, however, helps to exclude other conditions such as granulomatosis with polyangiitis (GPA). It is also helpful to characterize the lesion and outline management strategies. Therapeutic endoscopic procedures and surgery are the most common management modalities, but medical therapy can also play a significant role in preventing or delaying recurrence. In this review, we describe the morphology, pathophysiology, clinical presentation, evaluation, management, and prognosis of iSGS.

The use of pretest probability increases the value of high-resolution CT in diagnosing usual interstitial pneumonia

BACKGROUND

Recent studies have suggested that non-definitive patterns on high-resolution CT (HRCT) scan provide sufficient diagnostic specificity to forgo surgical lung biopsy in the diagnosis of idiopathic pulmonary fibrosis (IPF). The objective of this study was to determine test characteristics of non-definitive HRCT patterns for identifying histopathological usual interstitial pneumonia (UIP).

METHODS

Patients with biopsy-proven interstitial lung disease (ILD) and non-definitive HRCT scans were identified from two academic ILD centres. Test characteristics for HRCT patterns as predictors of UIP on surgical lung biopsy were derived and validated in independent cohorts.

RESULTS

In the derivation cohort, 64/385 (17%) had possible UIP pattern on HRCT; 321/385 (83%) had inconsistent with UIP pattern. 113/385 (29%) patients had histopathological UIP pattern in the derivation cohort. Possible UIP pattern had a specificity of 91.2% (95% CI 87.2% to 94.3%) and a positive predictive value (PPV) of 62.5% (95% CI 49.5% to 74.3%) for UIP pattern on surgical lung biopsy. The addition of age, sex and total traction bronchiectasis score improved the PPV. Inconsistent with UIP pattern demonstrated poor PPV (22.7%, 95% CI 18.3% to 27.7%). HRCT pattern specificity was nearly identical in the validation cohort (92.7%, 95% CI 82.4% to 98.0%). The substantially higher prevalence of UIP pattern in the validation cohort improved the PPV of HRCT patterns.

CONCLUSIONS

A possible UIP pattern on HRCT has high specificity for UIP on surgical lung biopsy, but PPV is highly dependent on underlying prevalence. Adding clinical and radiographic features to possible UIP pattern on HRCT may provide sufficient probability of histopathological UIP across prevalence ranges to change clinical decision-making.

Minimally Invasive Methods for Staging in Lung Cancer: Systematic Review and Meta-Analysis

Introduction. Endobronchial ultrasound (EBUS) is a procedure that provides access to the mediastinal staging; however, EBUS cannot be used to stage all of the nodes in the mediastinum. In these cases, endoscopic ultrasound (EUS) is used for complete staging. Objective. To provide a synthesis of the evidence on the diagnostic performance of EBUS + EUS in patients undergoing mediastinal staging. Methods. Systematic review and meta-analysis to evaluate the diagnostic yield of EBUS + EUS compared with surgical staging. Two researchers performed the literature search, quality assessments, data extractions, and analyses. We produced a meta-analysis including sensitivity, specificity, and likelihood ratio analysis. Results. Twelve primary studies (1515 patients) were included; two were randomized controlled trials (RCTs) and ten were prospective trials. The pooled sensitivity for combined EBUS + EUS was 87% (CI 84-89%) and the specificity was 99% (CI 98-100%). For EBUS + EUS performed with a single bronchoscope group, the sensitivity improved to 88% (CI 83.1-91.4%) and specificity improved to 100% (CI 99-100%). Conclusion. EBUS + EUS is a highly accurate and safe procedure. The combined procedure should be considered in selected patients with lymphadenopathy noted at stations that are not traditionally accessible with conventional EBUS.

Telomere-related lung fibrosis is diagnostically heterogeneous but uniformly progressive

Heterozygous mutations in four telomere-related genes have been linked to pulmonary fibrosis, but little is known about similarities or differences of affected individuals.115 patients with mutations in telomerase reverse transcriptase (TERT) (n=75), telomerase RNA component (TERC) (n=7), regulator of telomere elongation helicase 1 (RTEL1) (n=14) and poly(A)-specific ribonuclease (PARN) (n=19) were identified and clinical data were analysed.Approximately one-half (46%) had a multidisciplinary diagnosis of idiopathic pulmonary fibrosis (IPF); others had unclassifiable lung fibrosis (20%), chronic hypersensitivity pneumonitis (12%), pleuroparenchymal fibroelastosis (10%), interstitial pneumonia with autoimmune features (7%), an idiopathic interstitial pneumonia (4%) and connective tissue disease-related interstitial fibrosis (3%). Discordant interstitial lung disease diagnoses were found in affected individuals from 80% of families. Patients with TERC mutations were diagnosed at an earlier age than those with PARN mutations (51±11 years versus 64±8 years; p=0.03) and had a higher incidence of haematological comorbidities. The mean rate of forced vital capacity decline was 300 mL·year^-1 and the median time to death or transplant was 2.87 years. There was no significant difference in time to death or transplant for patients across gene mutation groups or for patients with a diagnosis of IPF versus a non-IPF diagnosis.Genetic mutations in telomere related genes lead to a variety of interstitial lung disease (ILD) diagnoses that are universally progressive.

[Are residents and interns prepared for teaching? Perceptions of undergraduate and graduate medical students]

BACKGROUND

Every doctor is expected to be competent in teaching. There are few initiatives to prepare medical students for this role.

AIM

To explore residents (graduate students) and interns (final year undergraduate students) perceptions of the importance of acquiring teaching skills and how prepared they feel to meet this role. To determine the importance that undergraduate students give to such teaching.

MATERIAL AND METHODS

Residents and interns participated in focus groups, and completed the Medical Education Readiness Questionnaire (METRQ), 5th year medical students were also invited to complete it.

RESULTS

Three hundred and seventy seven subjects answered the questionnaire. The perceived importance of having teaching skills was 6.1 +/-1.2 among residents and 5.7 +/- 1.6 among interns, in a scale 1 to 7. Their perception of their own preparation for teaching was 4.3 +/- 1.6 for both groups in the same scale. Students evaluated the preparation of the residents for teaching as 5.2 +/- 1.6 and that of the interns as 4.4 +/-1.7. Seventy-eight percent of 5th year medical students reported to learn more than two. 5 hours a week from residents. Fifty-nine percent of residents and 66% of interns reported to teach up to 2.5 hours per week to the same students. Focus groups participants agreed that teaching is an important role for a physician, and that to do it properly requires personal characteristics, along with teaching skills. They also found that the best opportunities to learn how to teach are during practical training. CONCLUSIONS. Our study contributes to the recognition of the teaching role of physicians and the need for teaching training among medical students.

Duration of delayed graft function is an important predictor of 1-year serum creatinine

OBJECTIVE

The purpose of this study was to evaluate the importance of various factors on 1-year serum creatinine (SCr) as a surrogate endpoint for allograft survival among a series of kidney transplantations performed at 2 centers.

PATIENTS AND METHODS

Two hundred sixty consecutive renal transplantations were included with overall mean age of 40 +/- 13 years, including 55% men and 19% living donor grafts. Factors considered for analysis were donor and recipient ages, and sexes, number of transplantations, panel-reactive antibodies, total number of HLA mismatches, cold ischemia time (CIT), acute rejection (AR) rate, and presence/duration of delayed graft function (DGF). Multiple regression analyses were performed for 1-year SCr, AR rate, and DGF duration.

RESULTS

One-year SCr was 1.46 +/- 0.5 mg/dL, 6-month AR rate was 22%, and DGF rate was 29% of mean duration 3 +/- 8 days. Multiple regression analysis for lower 1-year SCr value identified as significant female recipient sex, lower donor age, absence of AR within 6 months, and decreased DGF duration (P < .05). The only significant factor affecting AR rate was DGF duration. Finally, prolonged CIT was associated with a longer DGF duration.

CONCLUSIONS

We confirmed that 1-year SCr was primarily affected by well-known factors, such as AR incidence, donor age, and female recipient sex. However, we identified DGF duration as a significant factor affecting 1-year SCr. AR rate was also associated with DGF duration, which in turn depended upon longer CIT.

[Infanto-juvenile stuttering: a multidisciplinary approach]

The authors have conducted a clinical, psychopathological, exploratory research, with a multidisciplinary approach, applied to a sample of 52 children and adolescents stutterers, whose ages ranged between 3.6 and 19.8 years. They made a comparison of two groups, according to the moment in which they began stuttering and the level of development of their previous language. They emphasized the importance of studying the disorders of psychomotor and perceptive-motor functions; of learning disabilities, and the difficulties of interpersonal relationships in the family group and at school. They concluded that stuttering would be a symptom referred to a disorder in the rhythm of speaking, frequently associated to developmental deviations of different areas of language, psychomotor and/or perceptive-motor functions. Stuttering presents itself in normal as well as abnormal personality structures. Its beginning, persistence, and aggravation is frequently associated with unsatisfactory verbal and non verbal communication patterns.