The role of confocal laser endomicroscopy in pulmonary medicine

Bronchoscopy with and without needle-based confocal laser endomicroscopy for peripheral lung nodule diagnosis: protocol for a multicentre randomised controlled trial (CLEVER trial)

INTRODUCTION

Despite many technological advances, the diagnostic yield of bronchoscopic peripheral lung nodule analysis remains limited due to frequent mispositioning. Needle-based confocal laser endomicroscopy (nCLE) enables real-time microscopic feedback on needle positioning, potentially improving the sampling location and diagnostic yield. Previous studies have defined and validated nCLE criteria for malignancy, airway and lung parenchyma. Larger studies demonstrating the effect of nCLE on diagnostic yield are lacking. We aim to investigate if nCLE-imaging integrated with conventional bronchoscopy results in a higher diagnostic yield compared with conventional bronchoscopy without nCLE.

METHODS AND ANALYSIS

This is a parallel-group randomised controlled trial. Recruitment is performed at pulmonology outpatient clinics in universities and general hospitals in six different European countries and one hospital in the USA. Consecutive patients with a for malignancy suspected peripheral lung nodule (10-30 mm) with an indication for diagnostic bronchoscopy will be screened, and 208 patients will be included. Web-based randomisation (1:1) between the two procedures will be performed. The primary outcome is diagnostic yield. Secondary outcomes include diagnostic sensitivity for malignancy, needle repositionings, procedure and fluoroscopy duration, and complications. Pathologists will be blinded to procedure type; patients and endoscopists will not.

ETHICS AND DISSEMINATION

Primary approval by the Ethics Committee of the Amsterdam University Medical Center. Dissemination involves publication in a peer-reviewed journal.

SUPPORT

Financial and material support from Mauna Kea Technologies.

TRIAL REGISTRATION NUMBER

NCT06079970.

A case of congenital bronchial atresia with tracheobronchial stenosis caused by emphysema: Successful management with thoracoscopic surgery

Introduction

Congenital bronchial atresia (CBA), as a rare developmental abnormality of the lung, is usually asymptomatic and is accidently discovered in most cases. Currently, no standardized guidelines for the treatment or management of CBA have been established.

Case presentation

A 22-year-old male soldier was referred to Shanghai Changhai Hospital, The First Affiliated Hospital of Naval Medical University due to chest tightness and shortness of breath after repeated strenuous activities. Contrast-enhanced computed tomography (CT) revealed an 18mm × 11mm solitary, well-circumscribed, and solid nodule with no enhancement in the right upper lobe (RUL), and emphysematous changes distributed throughout the RUL. A flexible bronchoscopic examination showed extrinsic compression stenosis in the bronchial opening of the right middle lobe (RML). After three-dimensional (3D) reconstruction CT and a multidisciplinary consultation, a diagnosis of CBA in the anterior segment (B3) of RUL was established. Subsequently, thoracoscopic right upper lobectomy was performed and resulted in an improved respiratory capacity 6 months after surgery. To date, the patient has good quality of life without any complication.

Conclusion

This study underscores the role of bronchoscopy, 3D reconstruction CT, and a multidisciplinary consultation in the diagnosis of CBA, and highlights that a thoracoscopic intervention should be considered in such case.

A preclinical animal study to evaluate the operability and safety of domestic one-way endobronchial valves

Purpose

To evaluate the operability and safety of bronchoscopic domestic one-way endobronchial valves (EBV) on animals.

Methods

Nine pigs were randomly assigned (2:1) to receive domestic one-way EBV (the experimental group, n = 6) and Zephyr® EBV (the control group, n = 3). Routine blood tests, arterial blood gases, and CT scans of the lungs were performed 1 day pre-procedure in addition to 1 week and 1 month post-procedure to assess changes in blood markers and lung volumes. At 1 month post-procedure, the animals were sacrificed, followed by removal of all valves via bronchoscopy. Pathological examinations of critical organs were subsequently performed.

Results

A total of 15 valves were placed in the experimental group and 6 valves were placed in the control group, without serious complications. Routine blood tests and arterial blood gas examinations at 1 day pre-procedure, 1 week post-procedure, and 1 month post-procedure did not differ significantly in both groups. No EBV displacement was noted under bronchoscopy, and the valve was smoothly removable by bronchoscope at 1 month post-procedure. At 1 week post-procedure, varying degrees of target lung lobe volume reduction were observed on lung CT in both groups. Lung volume reduction was achieved at 1 month post-procedure in both groups, without significant statistical difference. Although 3 cases in the experimental group and 1 case in the control group developed varying degrees of pneumonia, the inflammatory response did not increase over time during the experimental period. Pathological examination revealed no significant abnormal changes in the critical organs for both groups.

Conclusion

Our results demonstrate that domestic EBV is safe and reliable for endobronchial application in general-grade laboratory white pigs. The safety of domestic EBV is similar to that of Zephyr® EBV, with good ease of use and operability. This kind of domestic EBV can meet the safety evaluation requirements for animal testing.

ETV6-NTRK2 Fusion in a Patient With Metastatic Pulmonary Atypical Carcinoid Successfully Treated With Entrectinib: A Case Report and Review of the Literature

Pulmonary atypical carcinoid (AC) is an extremely rare neuroendocrine tumor. The neurotrophic tropomyosin receptor kinase (NTRK) fusions are reported in only 0.5% of nonsmall cell lung cancer, and are more rare in AC with only one previously reported case. Currently, there is little established evidence on the optimal therapeutic strategies and prognosis for advanced cases. We present a female patient with metastatic AC after complete resection. Due to low expression of somatostatin receptor in this case, somatostatin analogs and peptide receptor radionuclide therapy were not available. After pursuing other alternative treatments, including chemotherapy (ie, carboplatin, etoposide, capecitabine, temozolomide, and paclitaxel), everolimus, and atezolizumab, she returned with significant progression, including innumerable subcutaneous nodules, left pleura metastasis, multiple bone metastases, and brain metastases. New biopsy analysis revealed an ETV6-NTRK2 fusion. She was immediately administered the first-generation tropomyosin receptor kinase inhibitor entrectinib at a dose of 600 mg q.d. A subsequent month of treatment resulted in a complete response in all of the metastatic lung lesions. To date, she has maintained sustained benefit for at least 1 year from initiation of entrectinib. Here, we present the first case of a female patient with metastatic AC harboring the ETV6-NTRK2 fusion, and successfully treated with entrectinib, providing evidence for the application of entrectinib in patients with NTRK-positive AC, and underscoring the critical role of molecular profiling for such cases.

Radial endobronchial ultrasound - guided bronchoscopy for the diagnosis of peripheral pulmonary lesions: A systematic review and meta-analysis of prospective trials

Background

The diagnostic yield of radial endobronchial ultrasound (r-EBUS) for the diagnosis of peripheral pulmonary lesions (PPLs) varies between studies and is affected by multiple factors. We aimed to evaluate the efficacy and safety of r-EBUS, and to explore the factors influencing the diagnostic yield of r-EBUS in patients with PPLs.

Methods

The PubMed, Web of Science, and EMBASE databases were searched to identify relevant studies that used r-EBUS for diagnosing PPLs from the date of inception to Dec 2022. Meta-analysis was conducted using Review Manager 5.4 and Stata 15.1.

Results

An analysis of 46 studies with a total of 7252 PPLs was performed. The pooled diagnostic yield of r-EBUS was 73.4 % (95 % CI: 69.9%-76.7 %), with significant heterogeneity detected among studies (I2 = 90 %, P < 0.001). Further analysis demonstrated PPLs located in the middle or lower lobe, >2 cm in size, malignant in type, solid in appearance on computerized tomography (CT), present in bronchus sign, the within probe location, and the addition of rapid on-site evaluation (ROSE) were associated with increased diagnostic yield, whereas use of a guide sheath (GS), bronchoscopy type, and a multimodality approach failed to influence the outcome. The pooled incidence rates of overall complications, pneumothorax and moderate and severe bleeding were 3.1 % (95 % CI: 2.1%-4.3 %), 0.4 % (95 % CI: 0.1%-0.7 %) and 1.1 % (95 % CI: 0.5%-2.0 %), respectively.

Conclusions

r-EBUS has an appreciable diagnostic yield and an excellent safety manifestation when used to deal with PPLs.

Fibre-based fluorescence-lifetime imaging microscopy: a real-time biopsy guidance tool for suspected lung cancer

Lung cancer is the most common cause of cancer-related deaths worldwide. Early detection improves outcomes, however, existing sampling techniques are associated with suboptimal diagnostic yield and procedure-related complications. Autofluorescence-based fluorescence-lifetime imaging microscopy (FLIM), a technique which measures endogenous fluorophore decay rates, may aid identification of optimal biopsy sites in suspected lung cancer. Our fibre-based fluorescence-lifetime imaging system, utilising 488 nm excitation, which is deliverable via existing diagnostic platforms, enables real-time visualisation and lifetime analysis of distal alveolar lung structure. We evaluated the diagnostic accuracy of the fibre-based fluorescence-lifetime imaging system to detect changes in fluorescence lifetime in freshly resected ex vivo lung cancer and adjacent healthy tissue as a first step towards future translation. The study compares paired non-small cell lung cancer (NSCLC) and non-cancerous tissues with gold standard diagnostic pathology to assess the performance of the technique. Paired NSCLC and non-cancerous lung tissues were obtained from thoracic resection patients (N=21). A clinically compatible 488 nm fluorescence-lifetime endomicroscopy platform was used to acquire simultaneous fluorescence intensity and lifetime images. Fluorescence lifetimes were calculated using a computationally-lightweight, rapid lifetime determination method. Fluorescence lifetime was significantly reduced in ex vivo lung cancer, compared with non-cancerous lung tissue [mean ± standard deviation (SD), 1.79±0.40 vs. 2.15±0.26 ns, P<0.0001], and fluorescence intensity images demonstrated distortion of alveolar elastin autofluorescence structure. Fibre-based fluorescence-lifetime imaging demonstrated good performance characteristics for distinguishing lung cancer, from adjacent non-cancerous tissue, with 81.0% sensitivity and 71.4% specificity. Our novel fibre-based fluorescence-lifetime imaging system, which enables label-free imaging and quantitative lifetime analysis, discriminates ex vivo lung cancer from adjacent healthy tissue. This minimally invasive technique has potential to be translated as a real-time biopsy guidance tool, capable of optimising diagnostic accuracy in lung cancer.

Real-time and non-invasive acute lung rejection diagnosis using confocal LASER Endomicroscopy in lung transplant recipients: Results from the CELTICS study

BACKGROUND AND OBJECTIVE

Traditionally, the diagnosis of acute rejection (AR) relies on invasive transbronchial biopsies (TBBs) to obtain histopathological samples. We aimed to evaluate the diagnostic yield of probe-based confocal laser endomicroscopy (pCLE) as a complementary and non-invasive tool for ACR screening, comparing its results with those obtained from TBBs.

METHODS

Between January 2015 and April 2022, we conducted a retrospective study of all lung transplant recipients aged over 18 years at Toulouse University Hospital (France). All patients who underwent bronchoscopies with both TBBs and pCLE imaging were included. Two experienced interpreters (TV and MS) reviewed the pCLE images independently, blinded to all clinical information and pathology results.

RESULTS

From 120 procedures in 85 patients, 34 abnormal histological samples were identified. Probe-based confocal laser endomicroscopy revealed significant associations between both alveolar (ALC) and perivascular (PVC) cellularities and abnormal histological samples (p<0.0001 and 0.003 respectively). Alveolar cellularity demonstrated a sensitivity (Se) of 85.3 %, specificity (Spe) of 43 %, positive predictive value (PPV) of 37.2 % and negative predictive value (NPV) of 88.1 %. For PVC, Se was 70.6 %, Spe 80.2 %, PPV 58.5 % and NPV 87.3 %. Intra-interpreter correlation (TV) was 88.3 % for the number of vessels (+/-1), 98.3 % for ALC and 90 % for PVC. Inter-interpreter correlation (TV and MS) was 80 % for vessels (+/-1), 97.5 % for ALC and 83.3 % for PVC.

CONCLUSION

Our study demonstrates the feasibility of incorporating pCLE into clinical practice, demonstrating good diagnostic yield and reproducible outcomes in the screening of AR in lung transplant recipients.

Fibre-optic based exploration of lung cancer autofluorescence using spectral fluorescence lifetime

Fibre-optic based time-resolved fluorescence spectroscopy (TRFS) is an advanced spectroscopy technique that generates sample-specific spectral-temporal signature, characterising variations in fluorescence in real-time. As such, it can be used to interrogate tissue autofluorescence. Recent advancements in TRFS technology, including the development of devices that simultaneously measure high-resolution spectral and temporal fluorescence, paired with novel analysis methods extracting information from these multidimensional measurements effectively, provide additional insight into the underlying autofluorescence features of a sample. This study demonstrates, using both simulated data and endogenous fluorophores measured bench-side, that the shape of the spectral fluorescence lifetime, or fluorescence lifetimes estimated over high-resolution spectral channels across a broad range, is influenced by the relative abundance of underlying fluorophores in mixed systems and their respective environment. This study, furthermore, explores the properties of the spectral fluorescence lifetime in paired lung tissue deemed either abnormal or normal by pathologists. We observe that, on average, the shape of the spectral fluorescence lifetime at multiple locations sampled on 14 abnormal lung tissue, compared to multiple locations sampled on the respective paired normal lung tissue, shows more variability; and, while not statistically significant, the average spectral fluorescence lifetime in abnormal tissue is consistently lower over every wavelength than the normal tissue.

Transbronchial lung cryobiopsy for peripheral pulmonary lesions. A narrative review

An increasing number of peripheral pulmonary lesions (PPLs) requiring tissue verification to establish a definite diagnosis for further individualized management are detected due to the growing adoption of lung cancer screening by chest computed tomography (CT), especially low-dose CT. However, the morphological diagnosis of PPLs remains challenging. Transbronchial lung cryobiopsy (TBLC) that can retrieve larger specimens with more preserved cellular architecture and fewer crush artifacts in comparison with conventional transbronchial forceps biopsy (TBFB), as an emerging technology for diagnosing PPLs, has been demonstrated to have the potential to resolve the clinical dilemma pertaining to currently available sampling devices (e.g., forceps, needle and brush) and become a diagnostic cornerstone for PPLs. Of note, with the introduction of the 1.1 mm cryoprobe that will be more compatible with advanced bronchoscopic navigation techniques, such as radial endobronchial ultrasound (r-EBUS), virtual bronchoscopic navigation (VBN) and electromagnetic navigation bronchoscopy (ENB), the use of TBLC is expected to gain more popularity in the diagnosis of PPLs. While much remains for exploration using the TBLC technique for diagnosing PPLs, it can be envisaged that the emergence of additional studies with larger data accrual will hopefully add to the body of evidence in this field.

Predictive value of the resistance of the probe to pass through the lesion in the diagnosis of peripheral pulmonary lesions using radial probe endobronchial ultrasound with a guide sheath

Background

Transbronchial lung biopsy guided by radial probe endobronchial ultrasonography with a guide sheath (EBUS-GS-TBLB) is becoming a significant approach for diagnosing peripheral pulmonary lesions (PPLs). We aimed to explore the clinical value of the resistance of the probe to pass through the lesion in the diagnosis of PPLs when performing EBUS-GS-TBLB, and to determine the optimum number of EBUS-GS-TBLB.

Methods

We performed a prospective, single-center study of 126 consecutive patients who underwent EBUS-GS-TBLB for solid and positive-bronchus-sign PPLs where the probe was located within the lesion from September 2019 to May 2022. The classification of probe resistance for each lesion was carried out by two bronchoscopists independently, and the final result depended on the bronchoscopist responsible for the procedures. The primary endpoint was the diagnostic yield according with the resistance pattern. The secondary endpoints were the optimum number of EBUS-GS-TBLB and factors affecting diagnostic yield. Procedural complications were also recorded.

Results

The total diagnostic yield of EBUS-GS-TBLB was 77.8%, including 83.8% malignant and 67.4% benign diseases (P=0.033). Probe resistance type II displayed the highest diagnostic yield (87.5%), followed by type III (81.0%) and type I (61.1%). A significant difference between the diagnostic yield of malignant and benign diseases was detected in type II (P = 0.008), whereas others did not. Although most of the malignant PPLs with a definitive diagnosis using EBUS-GS-TBLB in type II or type III could be diagnosed in the first biopsy, the fourth biopsy contributed the most sufficient biopsy samples. In contrast, considerably limited tissue specimens could be obtained for each biopsy in type I. The inter-observer agreement of the two blinded bronchoscopists for the classification of probe resistance was excellent (κ = 0.84).

Conclusion

The probe resistance is a useful predictive factor for successful EBUS-GS-TBLB diagnosis of solid and positive-bronchus-sign PPLs where the probe was located within the lesion. Four serial biopsies are appropriate for both probe resistance type II and type III, and additional diagnostic procedures are needed for type I.

Application of bronchoscopy in the diagnosis and treatment of peripheral pulmonary lesions in China: a national cross-sectional study

Background: Bronchoscopy has gradually become valuable armamentarium in evaluating and applying endoscopic therapy to peripheral pulmonary lesions (PPLs) around the world. We aimed to make a comprehensive understanding of the application of bronchoscopy in the diagnosis and treatment of PPLs in China. Methods: A cross-sectional survey was carried out in China between January 2022 and March 2022. The survey was in the form of an online questionnaire which was filled in with real-time data by the respondents. Results: A total of 347 doctors from 284 tertiary hospitals (81.8%) and 63 secondary general hospitals (18.2%) were included in the data analysis. More than half of the surveyed doctors (55.0%) had independently performed respiratory endoscopy for 5-15 years. Higher proportions of hospitals with a fixed nursing team, anesthesiologists and rapid on-site evaluation (ROSE) during bronchoscopic procedures were performed in tertiary hospitals than those in secondary general hospitals (P<0.001 each). There were 316 hospitals (91.7%) eligible for performing biopsies of PPLs less than 30mm, while more than 300 PPLs biopsies were performed in only 78 hospitals (24.7%) per year. Radial probe endobronchial ultrasound (r-EBUS) (50.3%) was the commonest type of technique used in the guidance of a bronchoscope to PPLs, followed by navigational bronchoscopy (30.3%) and cone beam CT (CBCT) (17.0%). Although two thirds of the surveyed hospitals had at least one bronchoscopic guidance devices, the actual utilization of these devices was not high due to high capital costs and absence of training. To note, more diagnostic procedures and allocated devices were concentrated in the southeast region and coastal cities. Furthermore, therapeutic bronchoscopic interventions for peripheral lung cancer and/or high-risk PPLs could be performed in 124 (35.7%) of the 347 involved hospitals. Conclusions: Bronchoscopy for the diagnosis of PPLs has been carried out in most hospitals in China and yields in different hospitals and regions varied greatly. To date, only a few hospitals in China can develop therapeutic bronchoscopy for PPLs.

A prediction model for risk of low oxygen saturation in patients with post-tuberculosis tracheobronchial stenosis during bronchoscopy

BACKGROUND

Low oxygen saturation (LOS) is a frequent occurrence for patients with post-tuberculosis tracheobronchial stenosis (PTTS) during bronchoscopic procedures. However, there are currently no systematic assessment tools to predict LOS risk in PTTS patients during bronchoscopy.

OBJECTIVES

This study aimed to develop an effective preoperative predictive model to guide clinical practice.

DESIGN

Retrospective cohort study.

METHODS

Data was retrospectively collected from PTTS patients who underwent bronchoscopic interventions between January 2017 and December 2022. Among all patients included in this study, patients between January 2017 and December 2021 were used as training cohort for the logistic regression model, and patients between January 2022 and December 2022 were utilized as validation cohort for internal validation. We used consistency index (C-index), goodness-of-fit test and calibration plot to evaluate the model performance.

RESULTS

A total of 465 patients who met the inclusion criteria were enrolled in the study. The overall incidence of LOS was 26.0% (121/465). Comorbidity, degree of stenosis, bronchoscopist level, thermal ablation therapy, balloon dilation, and airway stenting, as independent risk factors for the presence of LOS, were used to construct the nomogram prediction model. The C-index of training cohort was 0.827 (95% CI, 0.786-0.869), whereas that of validation cohort was 0.836 (95% CI, 0.757-0.916), combining with the results of the calibration plot and goodness-of-fit test, demonstrating that this model had good predictive ability.

CONCLUSION

The predictive model and derived nomogram with good predictive ability has been developed to preoperatively predict the risk of LOS in PTTS patients during bronchoscopy, allowing for individualized interventions for high-risk patients.