Transbronchial cryobiopsy increases diagnostic confidence in interstitial lung disease: a prospective multicentre trial

The Diagnostic Efficiency and Safety of Transbronchial Lung Cryobiopsy Using 1.1-mm Cryoprobe in Diagnosing Interstitial Lung Disease

INTRODUCTION

Transbronchial lung cryobiopsy (TBLC) is increasingly used to diagnose interstitial lung disease (ILD). The 1.1-mm cryoprobe has recently been available in clinical practice. The diagnostic yield and safety of TBLC using a 1.1-mm cryoprobe need to be confirmed.

METHODS

A prospective, randomized controlled trial was conducted in patients with suspected ILD and randomly assigned to 1.1-mm and 1.9-mm cryoprobe groups. The primary outcome was the diagnostic yield of multidisciplinary discussion. Secondary outcomes were sample quality and incidence of complications. The tension and stress effects during TBLC onto the target lobe caused by 1.1-mm and 1.9-mm cryoprobes were also evaluated using finite element analysis.

RESULTS

A total of 224 patients were enrolled. No significant differences were observed in the diagnostic yield (80.4% vs. 79.5%, p = 0.845) and sample quality scores (5.73 ± 0.64 vs. 5.66 ± 0.77; p = 0.324) between the 1.9-mm cryoprobe group and 1.1-mm cryoprobe group. The average surface areas of samples in 1.1-mm cryoprobe group were smaller, while no difference in sample weights was observed. A decreased incidence of moderate bleeding was found in the 1.1-mm cryoprobe group (17.0% vs. 6.2%, p = 0.027), while there was no difference in the incidence of the pneumothorax, there was a trend to higher rate of pneumothorax in 1.1-mm group. In finite element analysis, the 1.1-mm cryoprobe required the largest tension and produced the largest stress.

CONCLUSION

Compared with a 1.9-mm cryoprobe, there was no difference in specimen quality or diagnostic rate but smaller sample size with a 1.1-mm cryoprobe. There was a decreased risk of moderate bleeding, but a trend towards increased risk for pneumothorax with 1.1-mm cryoprobe.

TRAIL REGISTRATION

Clinicaltrials.gov identifier NCT04047667; registered August 4, 2019.

Cone-Beam Computed Tomography Improves Location of Transbronchial Cryobiopsy in Interstitial Lung Disease with Limited Extent

INTRODUCTION

Transbronchial lung cryobiopsy has been recommended as an acceptable alternative to surgical approach for making a histopathological diagnosis in patients with interstitial lung disease (ILD) of undetermined type. In limited diseases (especially if distributed along the subpleural region), sampling the specific area in which the pathological process is more represented could be challenging. Aim of the study was to determine the potential benefit of utilizing cone-beam computed tomography-guided cryobiopsy in patients with limited extent of ILD on CT scan and determine the single impact of each sequential biopsy progressively increasing the total number of biopsies.

METHODS

This study is a prospective analysis of patients with undetermined ILD and CT scan extent <15% undergoing cone-beam CT-guided cryobiopsy. Each biopsy sample was collected and processed individually and pathologic interpretations were performed sequentially with the pathologist reformulating a new report with the addition of each sample (cumulative yield).

RESULTS

Thirty six patients were enrolled. Pathological diagnostic yield was >90%, with almost 80% of diagnostic samples being the first one; when a second biopsy was performed, mean diagnostic yield increased with only a moderately significant difference. No severe adverse events were observed; pneumothorax was documented in 27.8% of the cases.

CONCLUSION

Sequential individual collection and pathologic interpretation of each biopsy sample has confirmed the possibility of obtaining a diagnostic specimen at the first pass if transbronchial cryobiopsy is performed under cone-beam CT.

Transbronchial cryobiopsy followed by as-needed surgical lung biopsy versus immediate surgical lung biopsy for diagnosing interstitial lung disease (the COLD study): a randomised controlled trial

BACKGROUND

An adequate diagnosis for interstitial lung disease (ILD) is important for clinical decision making and prognosis. In most patients with ILD, an accurate diagnosis can be made by clinical and radiological data assessment, but in a considerable proportion of patients, a lung biopsy is required. Surgical lung biopsy (SLB) is the most common method to obtain tissue, but it is associated with high morbidity and even mortality. More recently, transbronchial cryobiopsy has been introduced, with fewer adverse events but a lower diagnostic yield than SLB. The aim of this study is to compare two diagnostic strategies: a step-up strategy (transbronchial cryobiopsy, followed by SLB if the cryobiopsy is insufficiently informative) versus immediate SLB.

METHODS

The COLD study was a multicentre, randomised controlled trial in six hospitals across the Netherlands. We included patients with ILD with an indication for lung biopsy as assessed by a multidisciplinary team discussion. Patients were randomly assigned in a 1:1 ratio to the step-up or immediate SLB strategy, with follow-up for 12 weeks from the initial procedure. Patients, clinicians, and pathologists were not masked to the study treatment. The primary endpoint was unexpected chest tube drainage, defined as requiring any chest tube after transbronchial cryobiopsy, or prolonged (>24 h) chest tube drainage after SLB. Secondary endpoints were diagnostic yield, in-hospital stay, pain, and serious adverse events. A modified intention-to-treat analysis was performed. This trial is registered with the Dutch Trial Register, NL7634, and is now closed.

FINDINGS

Between April 8, 2019, and Oct 24, 2021, 122 patients with ILD were assessed for study participation; and 55 patients were randomly assigned to the step-up strategy (n=28) or immediate SLB (n=27); three patients from the immediate SLB group were excluded. Unexpected chest tube drainage occurred in three of 28 patients (11%; 95% CI 4-27%) in the step-up group, and the number of patients for whom the chest tube could not be removed within 24 h was 11 of 24 patients (46%; 95% CI 2-65%) in the SLB group, with an absolute risk reduction of 35% (11-56%; p=0·0058). In the step-up strategy, the multidisciplinary team diagnostic yield after transbronchial cryobiopsy alone was 82% (64-92%), which increased to 89% (73-96%) when subsequent SLB was performed after inconclusive transbronchial cryobiopsy. In the immediate surgery strategy, the multidisciplinary team diagnostic yield was 88% (69-97%). Total in-hospital stay was 1 day (IQR 1-1) in the step-up group versus 5 days (IQR 4-6) in the SLB group. One (4%) serious adverse event occurred in step-up strategy versus 12 (50%) in the immediate SLB strategy.

INTERPRETATION

In ILD diagnosis, if lung tissue assessment is required, a diagnostic strategy starting with transbronchial cryobiopsy, followed by SLB when transbronchial cryobiopsy is inconclusive, appears to result in a significant reduction of patient burden and in-hospital stay with a similar diagnostic yield versus immediate SLB.

FUNDING

Netherlands Organisation for Health Research and Development (ZonMW) and Amsterdam University Medical Centers.

Utility and Safety of Bronchoscopic Cryotechniques-A Comprehensive Review

Cryosurgical techniques are employed for diagnostic and therapeutic bronchoscopy and serve as important tools for the management of pulmonary diseases. The diagnosis of interstitial lung disease requires multidisciplinary team discussions after a thorough assessment of history, physical exam, computed tomography, and lung-function testing. However, histological diagnosis is required in selected patients. Surgical lung biopsy has been the gold standard but this can be associated with increased morbidity and mortality. Transbronchial lung cryobiopsy is an emerging technique and multiple studies have shown that it has a high diagnostic yield with a good safety profile. There is wide procedural variability and the optimal technique for cryobiopsy is still under investigation. There is emerging data that demonstrate that cryobiopsy is safe and highly accurate in the diagnosis of thoracic malignancies. Furthermore, cryorecanalization procedures are a useful adjunct for the palliation of tumors in patients with central airway obstruction. One should keep in mind that these procedures are not free from complications and should be carried out in a specialized center by a trained and experienced bronchoscopy team. We present a review of the literature on the diagnostic and therapeutic utility of bronchoscopy-guided cryosurgical procedures and their safety profile.

Concordance between transbronchial lung cryobiopsy and surgical lung biopsy for interstitial lung disease in the same patients

BACKGROUND

The diagnostic accuracy and safety of transbronchial lung cryobiopsy (TBLC) via a flexible bronchoscope under sedation compared with that of surgical lung biopsy (SLB) in the same patients is unknown.

METHODS

Retrospectively the data of fifty-two patients with interstitial lung diseases (median age: 63.5 years; 21 auto-antibody positive) who underwent TBLC followed by SLB (median time from TBLC to SLB: 57 days) was collected. The samples from TBLC and SLB were randomly labelled to mask the relationship between the two samples. Diagnosis was made independently by pathologists, radiologists, and pulmonary physicians in a stepwise manner, and a final diagnosis was made at multidisciplinary discussion (MDD). In each diagnostic step the specific diagnosis, the diagnostic confidence level, idiopathic pulmonary fibrosis (IPF) diagnostic guideline criteria, and treatment strategy were recorded.

RESULTS

Without clinical and radiological information, the agreement between the histological diagnoses by TBLC and SLB was 42.3% (kappa [κ] = 0.23, 95% confidence interval [CI]: 0.08-0.39). However, the agreement between the TBLC-MDD and SLB-MDD diagnoses and IPF/non-IPF diagnosis using the two biopsy methods was 65.4% (κ = 0.57, 95% CI: 0.42-0.73) and 90.4% (47/52), respectively. Out of 38 (73.1%) cases diagnosed with high or definite confidence at TBLC-MDD, 29 had concordant SLB-MDD diagnoses (agreement: 76.3%, κ = 0.71, 95% CI: 0.55-0.87), and the agreement for IPF/non-IPF diagnoses was 97.4% (37/38). By adding the pathological diagnosis, the inter-observer agreement of clinical diagnosis improved from κ = 0.22 to κ = 0.42 for TBLC and from κ = 0.27 to κ = 0.38 for SLB, and the prevalence of high or definite diagnostic confidence improved from 23.0% to 73.0% and from 17.3% to 73.0%, respectively. Of all 383 TBLC performed during the same period, pneumothorax occurred in 5.0% of cases, and no severe bleeding, acute exacerbation of interstitial lung disease, or fatal event was observed.

CONCLUSIONS

TBLC via a flexible bronchoscope under deep sedation is safely performed, and the TBLC-MDD diagnosis with a high or definite confidence level is concordant with the SLB-MDD diagnosis in the same patients.

Leukocyte differentiation in bronchoalveolar lavage fluids using higher harmonic generation microscopy and deep learning

BACKGROUND

In diseases such as interstitial lung diseases (ILDs), patient diagnosis relies on diagnostic analysis of bronchoalveolar lavage fluid (BALF) and biopsies. Immunological BALF analysis includes differentiation of leukocytes by standard cytological techniques that are labor-intensive and time-consuming. Studies have shown promising leukocyte identification performance on blood fractions, using third harmonic generation (THG) and multiphoton excited autofluorescence (MPEF) microscopy.

OBJECTIVE

To extend leukocyte differentiation to BALF samples using THG/MPEF microscopy, and to show the potential of a trained deep learning algorithm for automated leukocyte identification and quantification.

METHODS

Leukocytes from blood obtained from three healthy individuals and one asthma patient, and BALF samples from six ILD patients were isolated and imaged using label-free microscopy. The cytological characteristics of leukocytes, including neutrophils, eosinophils, lymphocytes, and macrophages, in terms of cellular and nuclear morphology, and THG and MPEF signal intensity, were determined. A deep learning model was trained on 2D images and used to estimate the leukocyte ratios at the image-level using the differential cell counts obtained using standard cytological techniques as reference.

RESULTS

Different leukocyte populations were identified in BALF samples using label-free microscopy, showing distinctive cytological characteristics. Based on the THG/MPEF images, the deep learning network has learned to identify individual cells and was able to provide a reasonable estimate of the leukocyte percentage, reaching >90% accuracy on BALF samples in the hold-out testing set.

CONCLUSIONS

Label-free THG/MPEF microscopy in combination with deep learning is a promising technique for instant differentiation and quantification of leukocytes. Immediate feedback on leukocyte ratios has potential to speed-up the diagnostic process and to reduce costs, workload and inter-observer variations.

Diagnostic yield and safety of transbronchial lung cryobiopsy for diffuse parenchymal lung diseases diagnosis: Comparison between 1.7-mm and 1.9-mm probes

PURPOSE OF THE RESEARCH

transbronchial lung cryobiopsy has been recently accepted as a valid and less invasive alternative to surgical lung biopsy. The purpose of this randomized controlled study was to evaluate, for the first time, the quality and safety of biopsy specimens obtained by using the new disposable 1.7-mm cryoprobe compared with the standard re-usable 1.9 mm cryoprobe in the diagnosis of diffuse parenchymal lung diseases.

METHODS

60 consecutive patients were prospectively enrolled and randomly assigned to two different groups: 1.9 mm (group A) and 1.7 mm (group B); primary endpoints were pathological and multidisciplinary diagnostic yield, sample size and complication rate.

PRINCIPAL RESULTS

the pathological diagnostic yield of cryobiopsy was 100% in group A and 93.3% in group B (p = 0.718); cryobiopsy median diameter was 6.8 mm in group A and 6.7 mm in group B (p = 0,5241). Pneumothorax occurred in 9 patients in group A and 10 in group B (p = 0.951); mild-to-moderate bleeding in 7 cases and 9 cases in group A and B respectively (p = 0.559). No death or severe adverse events were observed.

CONCLUSIONS

there was no statistically significant difference between the two groups, regarding diagnostic yield, adverse events and sampling adequacy.

Transbronchial lung cryobiopsy and pulmonary fibrosis: A never-ending story?

Background

The diagnostic process of pulmonary fibrosis (PF) is often challenging, requires a collaborative effort of several experts, and often requires bioptic material, which can be difficult to obtain, both in terms of quality and technique. The main procedures available to obtain such samples are transbronchial lung cryobiopsy (TBLC) and surgical lung biopsy (SLB).

Objective

The purpose of this paper is to review the evidence for the role of TBLC in the diagnostic-therapeutic process of PF.

Methods

A comprehensive review was performed to identify articles to date that addressed the role of TBLC in the diagnostic-therapeutic process of PF using the PubMed® database.

Results

The reasoned search identified 206 papers, including 21 manuscripts (three reviews, one systematic review, two guidelines, two prospective studies, three retrospective studies, one cross-sectional study, one original article, three editorials, three clinical trials, and two unclassifiable studies), which were included in the final review.

Conclusions

TBLC is gaining increasing efficacy and improving safety profile; however, there are currently no clear data demonstrating its superiority over SLB. Therefore, the two techniques should be considered with careful rationalization on a case-by-case basis. Further research is needed to further optimize and standardize the procedure and to thoroughly study the histological and molecular characteristics of PF.

Role of Transbronchial Lung Cryobiopsy in the Diagnosis of Interstitial Lung Disease: A Meta-analysis of 68 Studies and 6300 Patients

BACKGROUND

Diagnosis of interstitial lung disease (ILD) is based on multidisciplinary team discussion (MDD) with the incorporation of clinical, radiographical, and histopathologic information if available. We aim to evaluate the diagnostic yield and safety outcomes of transbronchial lung cryobiopsy (TBLC) in the diagnosis of ILD.

METHODS

We conducted a meta-analysis by comprehensive literature search to include all studies that evaluated the diagnostic yields and/or adverse events with TBLC in patients with ILD. We calculated the pooled event rates and their 95% confidence intervals (CIs) for the diagnostic yield by MDD, histopathologic diagnostic yield, and various clinical adverse events.

RESULTS

We included 68 articles (44 full texts and 24 abstracts) totaling 6386 patients with a mean age of 60.7±14.1 years and 56% men. The overall diagnostic yield of TBLC to achieve a definite or high-confidence diagnosis based on MDD was 82.3% (95% CI: 78.9%-85.2%) and histopathologic diagnosis of 72.5% (95% CI: 67.7%-76.9%). The overall rate of pneumothorax was 9.6% (95% CI: 7.9%-11%), while the rate of pneumothorax requiring drainage by a thoracostomy tube was 5.3% (95% CI: 4.1%-6.9%). The rate of moderate bleeding was 11.7% (95% CI: 9.1%-14.9%), while the rate of severe bleeding was 1.9% (95% CI: 1.4%-2.6%). The risk of mortality attributed to the procedure was 0.9% (95% CI: 0.7%-1.3%).

CONCLUSION

Among patients with undiagnosed or unclassified ILD requiring tissue biopsy for diagnosis, transbronchial cryobiopsy represents a reliable alternative to surgical lung biopsy with decreased incidence of various clinical adverse events.

Idiopathic Pulmonary Fibrosis and Progressive Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF), a common interstitial lung disease (ILD), is a chronic, progressive fibrosing interstitial pneumonia, with an unknown cause. IPF has been linked to several genetic and environmental risk factors. Disease progression is common and associated with worse outcomes. Management often encompasses pharmacotherapy, supportive interventions, addressing comorbidities when present, and treating hypoxia with ambulatory O2. Consideration for antifibrotic therapy and lung transplantation evaluation should occur early. Patients with ILD other than IPF, and who have radiological evidence of pulmonary fibrosis, may have progressive pulmonary fibrosis.

Esophageal submucosal tumor diagnosed with EBUS-guided transbronchial mediastinal cryobiopsy: A case report

Cryobiopsy is advantageous for collecting larger specimens with minimum crushing compared to forceps biopsy and transbronchial needle aspiration (TBNA), but it has not been widely used for mediastinal tumors. In this report, a leiomyoma of the thoracic esophagus was diagnosed with endobronchial ultrasound-guided transbronchial mediastinal cryobiopsy (EBUS-cryo). An asymptomatic 49-year-old woman had a 2.6-cm sized submucosal tumor (SMT) of the esophagus adjacent to the trachea and left main bronchus. EBUS-TBNA and EBUS-guided intranodal forceps biopsy were performed, followed by EBUS-cryo. The biopsy forceps could not be inserted into the tumor, but the cryoprobe was smoothly inserted. EBUS-TBNA could not obtain enough spindle-shaped tumor cells for immunohistochemical staining, but EBUS-cryo provided sufficient specimens for diagnosing the leiomyoma. Adding EBUS-cryo to EBUS-TBNA has recently been reported to achieve high diagnostic yields for lymphomas, uncommon tumors, and benign diseases. EBUS-cryo seems a valid diagnostic option for esophageal SMTs that are difficult to diagnose with needles and forceps.

Thin bronchoscopic cryobiopsy using a nasobronchial tube

BACKGROUND

Transbronchial lung cryobiopsy is useful when diagnosing lung lesions. However, prevention of associated bleeding complications is essential. This study aimed to evaluate the safety and efficacy of our novel bronchoscopic cryobiopsy technique, which uses a long nasobronchial tube to prevent blood flooding the central airway.

METHODS

Patients with localized or diffuse lung lesions were prospectively enrolled and underwent cryobiopsy using a 1.9 mm diameter cryoprobe and a 4.0 mm diameter thin bronchoscope under conscious sedation. For cryobiopsy, a long silicone tube (inner diameter, 5.0 mm) was advanced through the nose to the target bronchus, then wedged to drain blood under thin-tube bronchoscopic control. The primary endpoint was the frequency of bleeding complications.

RESULTS

Of the 80 patients initially enrolled, 73 that underwent at least one cryobiopsy were ultimately included. Mild bleeding during cryobiopsy occurred in 58 patients (79.5%), but there was no moderate or severe bleeding. Other complications occurred in four patients (two pneumothorax, one pneumomediastinum, and one pneumonia). Tube dislocation was noted in eight patients (11%). Cryobiopsy specimens were significantly larger than forceps biopsy specimens (9.0 mm² vs. 2.7 mm², P < .001) and allowed specific diagnoses in 50 patients (68.5%).

CONCLUSIONS

Thin bronchoscopic cryobiopsy using a nasobronchial tube in consciously sedated patients is safe and effective. Trial registration Date of registration: 24/06/2019. UMIN-Clinical Trials Registry; Identifier: UMIN000037156 https://www.umin.ac.jp/ctr/index.htm.

Incidental discovery of interstitial lung disease: diagnostic approach, surveillance and perspectives

The incidental discovery of pre-clinical interstitial lung disease (ILD) has led to the designation of interstitial lung abnormalities (ILA), a radiological entity defined as the incidental finding of computed tomography (CT) abnormalities affecting more than 5% of any lung zone. Two recent documents have redefined the borders of this entity and made the recommendation to monitor patients with ILA at risk of progression. In this narrative review, we will focus on some of the limits of the current approach, underlying the potential for progression to full-blown ILD of some patients with ILA and the numerous links between subpleural fibrotic ILA and idiopathic pulmonary fibrosis (IPF). Considering the large prevalence of ILA in the general population (7%), restricting monitoring only to cases considered at risk of progression appears a reasonable approach. However, this suggestion should not prevent pulmonary physicians from pursuing an early diagnosis of ILD and timely treatment where appropriate. In cases of suspected ILD, whether found incidentally or not, the pulmonary physician is still required to make a correct ILD diagnosis according to current guidelines, and eventually treat the patient accordingly.

In patients with interstitial lung abnormalities (ILA), monitoring of those at risk of progression is currently recommended, and pulmonary physicians should pursue an early diagnosis when ILA become clinically significant to facilitate timely treatment https://bit.ly/3HKOQc8

Risk factors of clinically significant complications in transbronchial lung cryobiopsy: A prospective multi-center study

BACKGROUND

The use of a transbronchial lung cryobiopsy (TBLC) is increasing as a diagnostic method of interstitial lung diseases (ILD). This study aimed to evaluate risk factors associated with clinically significant complications of TBLC in ILD patients.

METHODS

Patients referred to Kuopio or Tampere university hospitals, in Finland, for a suspected ILD were included. The TBLC was performed in an outpatient setting for 100 patients. Patients were mechanically ventilated in general anesthesia. Fluoroscopy guidance and prophylactic bronchial balloon were used. Complications, such as bleeding, pneumothorax, infections, and mortality were recorded. Moderate or serious bleeding, pneumothorax, or death ≤90 days were defined as clinically significant complications. A multivariable model was created to assess clinically significant complications.

RESULTS

The extent of traction bronchiectasis (Odds ratio [OR] 1.30, Confidence interval [CI] 1.03-1.65, p = 0.027) and young age (OR 7.96, CI 2.32-27.3, p = 0.001) were associated with the risk of clinically significant complications whereas the use of oral corticosteroids ≤30 days before the TBLC (OR 3.65, CI 0.911-14.6, p = 0.068) did not quite reach statistical significance. A history of serious cough was associated with the risk of pneumothorax (OR 4.18, CI 1.10-16.0, p = 0.036). Procedure associated mortality ≤90 days was 1%.

CONCLUSION

The extent of traction bronchiectasis on HRCT and young age were associated with the risk of clinically significant complications whereas oral corticosteroid use did not quite reach statistical significance. A history of serious cough was associated with the risk of clinically significant pneumothorax.

Comparison between Image-Guided Transbronchial Cryobiopsies and Thoracoscopic Lung Biopsies in Canine Cadaver: A Pilot Study

Simple Summary

A definitive diagnosis for most pulmonary diseases is possible only through histopathological examination. The literature describes different methods of lung biopsy sampling depending on the case. However, for the diagnosis of diffuse interstitial pulmonary diseases and some peripheral neoplasms, the gold standard is represented by surgical lung biopsies. Given their invasiveness and the high percentage of risk for the patient, in most cases they are not carried out, resulting in a serious diagnostic gap. In human medicine, transbronchial lung cryobiopsies have been introduced as an alternative, which have shown high efficacy and reduced invasiveness. This study aims to evaluate the feasibility of the new technique in dogs by subjecting dog cadavers to pulmonary cryobiopsy and surgical lung biopsies, and to compare the samples obtained for histopathological quality. In total, 42 tissue samples were compared. Pulmonary cryobiopsies were smaller than surgical biopsies but with high levels of agreement upon histological evaluation. This study demonstrates the feasibility of the technique in dogs and the collection of specimens with size and histological features comparable to those from surgical biopsies.

Abstract

To date, the only method of sampling lung tissue with a high diagnostic yield is represented by surgical lung biopsies (SLB), which are highly invasive and have a high risk/benefit ratio. In humans, transbronchial lung cryobiopsies (TBLC) have recently been introduced, which are described to be less invasive and able to significantly increase diagnostic confidence in most patients with interstitial lung diseases. The aim of this study was to evaluate the feasibility and diagnostic yield of TBLC compared to SLB in small animals. A total of 21 pulmonary cryobiopsies under fluoroscopic and real-time CT fluoroscopic guidance and 21 video-assisted thoracoscopic surgery (VATS) lung biopsies were collected from three dog cadavers. Upon histological examination, cryobiopsy samples were smaller than VATS biopsies, but were still large enough to reach a specific diagnosis or to allow pattern recognition. Morphological features on TBLC and SLB were concordant in all cases. Cryobiopsy samples showed fewer artifacts and a higher percentage of alveolar tissue than VATS samples. TBLC is a feasible and useful alternative to SLB for lung histopathological examination in dogs. The effectiveness and reduced invasiveness of TBLC compared to SLB could represent many advantages in the diagnosis of diffuse lung diseases in small animals.

Transbronchial lung cryobiopsy for the diagnosis of interstitial lung diseases

PURPOSE OF REVIEW

Transbronchial lung cryobiopsy has shown promise in several studies in providing meaningful histological information in the multidisciplinary team diagnosis of fibrotic interstitial lung diseases. The purpose of this review is to describe recent literature providing support for the formal integration of cryobiopsy into the algorithm for interstitial lung disease diagnosis.

RECENT FINDINGS

Histopathological concordance between cryobiopsy and surgical biopsy and diagnostic agreement at multidisciplinary discussion have been reported good; furthermore, cryobiopsy may provide an increased diagnostic confidence to a level likely to influence management. Finally, although cryobiopsy is more likely to provide a probable usual interstitial pneumonia (UIP) pattern than a definite UIP pattern, given the limited sampling of sub-pleural lung parenchyma in most cases, finding of a probable UIP pattern at cryobiopsy samples is strongly predictive of a definite UIP pattern in the corresponding surgical biopsy and when a UIP pattern is found on cryobiopsy sample, this is associated with higher mortality compared with other histological patterns.

SUMMARY

Cryobiopsy is becoming a valid alternative to surgical lung biopsy for making histopathological diagnosis in patients with interstitial lung diseases of undetermined type in experienced centres, with standardized protocols, in order to have the best risks/diagnostic yields ratio.

Transbronchial lung cryobiopsy: prospective safety evaluation and 90-day mortality after a standardized examination protocol

BACKGROUND

Transbronchial lung cryobiopsy (TBLC) is a new method of bronchoscopic tissue sampling in patients with unclear diffuse parenchymal lung disease (DPLD). While not the gold standard, TBLC has a good diagnostic correlation with surgical lung biopsy, and retrospective analyses of peri-interventional complications and mortality are promising. However, prospective reports on 90-day mortality are lacking.

OBJECTIVES

This study addresses morbidity and 30- and 90-day mortality in TBLC after a standardized protocol.

METHODS

In this prospective study, 75 patients with DPLD requiring tissue sampling were included. A standardized protocol (including prophylactic use of an endobronchial balloon, postinterventional observation, and minimum sampling requirements) was used in all patients. Adverse events (pneumothorax, bronchial bleeding, premature discontinuation, prolonged monitoring at ICU, and fatal outcome) and 30- and 90-day mortality rates were recorded.

RESULTS

A total of 308 cryobiopsies were performed in 75 patients. Peri- and postinterventional pneumothorax were observed in 20% (9.3% mild and 10.7% moderate with the necessity of chest drainage), and bronchial bleeding was found in 29.3% (22.7% moderate and 6.7% severe). Total lung capacity below normal value was associated with the risk of pneumothorax (p = 0.009), and diffusion limitation for carbon monoxide below normal value was associated with the risk of bronchial bleeding (p = 0.044). No fatal events were observed within 30 days, and the 90-day mortality rate was 1.3%, but not related to the procedure itself.

CONCLUSION

As it gradually becomes the invasive procedure of choice in unclear DPLD, TBLC is a safe procedure with a low 30- and 90-day mortality.Trial registration ID: DRKS00026746 (German Clinical Trial Register).

Bronchoalveolar lavage and lung biopsy in connective tissue diseases, to do or not to do?

Bronchoalveolar lavage and lung biopsy (LBx) are helpful in patients with connective tissue diseases (CTD) and interstitial lung diseases (ILD) regardless of cause, including infectious, noninfectious, immunologic, or malignant. The decision whether to perform only bronchoalveolar lavage (BAL), and eventually a subsequent LBx in case of a nondiagnostic lavage, or one single bronchoscopy combining both sampling methods depends on the clinical suspicion, on patient’s characteristics (e.g. increased biopsy risk) and preferences, and on the resources and biopsy techniques available locally (e.g. regular forceps versus cryobiopsy). In CTD-ILD, BAL has major clinical utility in excluding infections and in the diagnosis of specific patterns of acute lung damage (e.g. alveolar hemorrhage, diffuse alveolar damage, and organizing pneumonia). LBx is indicated to exclude neoplasm or diagnose lymphoproliferative lung disorders that in CTD patients are more common than in the general population. Defining BAL cellularity and characterizing the CTD-ILD histopathologic pattern by LBx can be helpful in the differential diagnosis of cases without established CTD [e.g. ILD preceding full-blown CTD, interstitial pneumonia with autoimmune features (IPAF)], but the prognostic and theragnostic role of those findings remains unclear. Few studies in the pretranscriptomics era have investigated the diagnostic and prognostic role of BAL and LBx in CTD-ILD, and it is reasonable to hypothesize that future studies conducted applying innovative techniques on BAL and LBx might open new and unexpected avenues in pathogenesis, diagnosis, and treatment approach to CTD-ILD. This is particularly desirable now that a new drug treatment era is emerging, in which we have more than one therapeutic choice (immunosuppressive agents, antifibrotic drugs, and biological agents). We hope that future research will pave the path toward precision medicine providing data for a more accurate ILD-CTD endotyping that will guide the physicians through targeted therapeutic choices, rather than to the approximative approach ‘one drug fits them all’.

Diagnostic Yield of Transbronchial Lung Cryobiopsy Compared to Transbronchial Forceps Biopsy in Patients with Sarcoidosis in a Prospective, Randomized, Multicentre Cross-Over Trial

Background: Transbronchial lung forceps biopsy (TBLF) is of limited value for the diagnosis of interstitial lung disease (ILD). However, in cases with predominantly peribronchial pathology, such as sarcoidosis, TBLF is considered to be diagnostic in most cases. The present study examines whether transbronchial lung cryobiopsy (TBLC) is superior to TBLF in terms of diagnostic yield in cases of sarcoidosis. Methods: In this post hoc analysis of a prospective, randomized, controlled, multicentre study, 359 patients with ILD requiring diagnostic bronchoscopic tissue sampling were included. TBLF and TBLC were both used for each patient in a randomized order. Histological assessment was undertaken on each biopsy and determined whether sarcoid was a consideration. Results: A histological diagnosis of sarcoidosis was established in 17 of 272 cases for which histopathology was available. In 6 out of 17 patients, compatible findings were seen with both TBLC and TBLF. In 10 patients, where the diagnosis of sarcoidosis was confirmed by TBLC, TBLF did not provide a diagnosis. In one patient, TBLF but not TBLC confirmed the diagnosis of sarcoidosis. Conclusions: In this post hoc analysis, the histological diagnosis of sarcoidosis was made significantly more often by TBLC than by TBLF. As in other idiopathic interstitial pneumonias (IIPs), the use of TBLC should be considered when sarcoidosis is suspected.

Non-neoplastic respiratory fluid cytology including cell differential counts for interstitial lung disease

Bronchioloalveolar lavage (BAL) is a non-invasive and well-tolerated procedure that plays a key role in the diagnosis of a variety of non-neoplastic pulmonary diseases, including acute respiratory failure, infection, diffuse parenchymal lung disease (DLPD), paediatric and occupational lung disease, and in the evaluation of the lung allograft. A variety of analytic techniques are commonly performed on BAL fluid, including cytology, cell differential count, microbiology and virology, as well as a number of additional techniques in specific circumstances.

Integration of transbronchial cryobiopsy into multidisciplinary board decision: a single center analysis of one hundred consecutive patients with interstitial lung disease

Background

Transbronchial cryobiopsy in the evaluation of patients with interstitial lung diseases (ILD) is expected to reduce the need for surgical lung biopsy (SLB).

Objective

To evaluate the diagnostic value of cryobiopsy in combination with bronchoalveolar lavage (BAL), radiologic and clinical data in patients with ILD.

Methods

Between 08/15 and 01/20 patients with ILD underwent cryobiopsy if they: did not have (i) an usual interstitial pneumonia (UIP)-pattern on CT, (ii) predominant ground-glass opacities suggesting alveolitis, (iii) findings suggestive of sarcoidosis on CT, or if they had (i) a CT showing UIP-pattern, but had findings suggesting alternative diagnosis than idiopathic pulmonary fibrosis (IPF), or (ii) had previous non-diagnostic conventional transbronchial forceps biopsy. Histological findings were integrated into the multidisciplinary team discussion (MDTD) and a diagnostic consensus was sought.

Results

One hundred patients underwent cryobiopsy. In 88/100 patients, cryobiopsy was representative with diagnostic findings in 45/88 and non-specific histological findings in 43/88 patients. In 25/43 with non-specific findings, a consensus diagnosis was reached after MDTD integrating BAL, radiologic and clinical data; eight of the remaining 18 patients with non-specific findings were referred to SLB. In 12/100 patients cryobiopsy was not representative and three of these patients were also referred to SLB. In 7/11 patients (64%) SLB was diagnostic. Complications of cryobiopsy included pneumothorax (14%) and locally controlled bleeding (24%).

Conclusions

The diagnostic yield of cryobiopsy was 70%:45% of cryobiopsies were diagnostic based on histology alone and an additional 25% provided non-specific, but valuable findings allowing a consensus diagnosis after MDTD. Our data demonstrate that the diagnostic value of cryobiopsy is high if combined with BAL, radiologic and clinical data.

Diagnosis and Management of Fibrotic Interstitial Lung Diseases

Nonidiopathic pulmonary fibrosis (non-IPF) progressive fibrotic interstitial lung diseases (PF-ILDs) are a heterogeneous group of ILDs, often challenging to diagnose, although an accurate diagnosis has significant implications for both treatment and prognosis. A subgroup of these patients experiences progressive deterioration in lung function, physical performance, and quality of life after conventional therapy. Risk factors for ILD progression include older age, lower baseline pulmonary function, and a usual interstitial pneumonia pattern. Management of non-IPF P-ILD is both pharmacologic and nonpharmacologic. Antifibrotic drugs, originally approved for IPF, have been considered in patients with other fibrotic ILD subtypes, with favorable results in clinical trials.

Biopsy in interstitial lung disease: specific diagnosis and the identification of the progressive fibrotic phenotype

PURPOSE OF REVIEW

The evaluation of progression in fibrotic interstitial lung diseases (ILDs) may require a multidimensional approach. This review will cover the role and usefulness of lung biopsy in diagnosis and assessment of the progressive fibrotic phenotype.

RECENT FINDINGS

The identification of specific findings and the balance between inflammation and fibrosis on lung biopsy may help distinguishing different disease entities and may likely determine the effect of treatment and possibly prognosis. The fibrotic morphological patterns potentially associated with a progressive phenotype include usual interstitial pneumonia (UIP), fibrotic nonspecific interstitial pneumonia, pleuroparenchymal fibroelastosis, desquamative interstitial pneumonia, fibrotic hypersensitivity pneumonitis and other less common fibrotic variants, with histopathological findings of UIP at the time of diagnosis being predictive of worse outcome compared with other patterns. The prognostic significance of lung biopsy findings has been assessed after both surgical lung biopsy (SLB) and transbronchial lung cryobiopsy (TBLC), the latter becoming a valid alternative to SLB, if performed in experienced centres, due to significantly lower morbidity and mortality.

SUMMARY

Lung biopsy plays an important role in diagnosis and identification of the progressive fibrotic phenotype. The introduction of less invasive procedures could potentially expand the role of lung sampling, including for example patients with a known diagnosis of ILD or at an earlier stage of the disease.

Antisynthetase Syndrome Masquerading as Hypersensitivity Pneumonitis

Interstitial lung diseases (ILDs) cover a wide heterogeneous group of disorders, both of unknown and known causes. Accurate diagnosis is essential but, at the same time, presents many challenges. Typically, the distinction between idiopathic pulmonary fibrosis and fibrotic hypersensitivity pneumonitis (HP) can prove extremely difficult. However, another major, but underestimated, challenge is the diagnosis of connective tissue disease-associated ILD (CTD-ILD), specifically when ILD is the initial manifestation or when extrapulmonary manifestations are subclinical. Antisynthetase syndrome (ASyS) is a characteristic example where lung involvement can be the predominant feature in the absence of other evidence suggestive of CTD. In ASyS, lung involvement can be the initial manifestation or muscle involvement can be subclinical with normal muscle enzymes. Furthermore, a negative antinuclear antibody test does not indicate autoantibody negativity in the context of ASyS. Imaging and pathology findings in ASyS are not specific and overlap with other ILDs. Finally, bronchoalveolar lavage can exhibit pronounced lymphocytosis (>30-40%). The latter, in combination with a history of exposure to an inciting antigen, can lead to an erroneous diagnosis of HP with obvious negative impact on patients' outcome. Herein, we report 3 female patients aged 61, 65, and 70 years and 1 male patient aged 43 years, with ASyS masquerading as HP and analyze the underlying reasons of misdiagnosis, aiming to raise awareness of the need for close collaboration between pulmonologists and rheumatologists.

The Role of Surgical Lung Biopsy in the Diagnosis of Fibrotic Interstitial Lung Disease: Perspective from the Pulmonary Fibrosis Foundation

Diagnosis of interstitial lung disease (ILD) requires a multidisciplinary diagnosis (MDD) approach that includes clinicians, radiologists, and pathologists. Surgical lung biopsy (SLB) is currently the recommended standard in obtaining pathological specimens for patients with ILD requiring a tissue diagnosis. The increased diagnostic confidence and accuracy provided by microscopic pathology assessment of SLB specimens must be balanced with the associated risks in ILD patients. This document was developed by the Surgical Lung Biopsy Working Group of the Pulmonary Fibrosis Foundation, composed of a multidisciplinary group of ILD physicians including pulmonologists, radiologists, pathologists, and thoracic surgeons. In this document, we present an up-to-date literature review of the indications, contraindications, risks, and alternatives to SLB in the diagnosis of fibrotic ILD, outline an integrated approach to the decision-making around SLB in the diagnosis of fibrotic ILD, and provide practical information to maximize the yield and safety of SLB.

Transbronchial mediastinal cryobiopsy in the diagnosis of mediastinal lesions: a randomised trial

BACKGROUND

Guidelines recommend endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) as an initial investigation technique for mediastinal nodal staging in lung cancer. However, EBUS-TBNA can be limited by the inadequacy of intact tissues, which might restrict its diagnostic yield in mediastinal lesions of certain etiologies. We have previously shown that EBUS-guided transbronchial mediastinal cryobiopsy can provide intact samples with greater volume.

METHODS

This randomised study determined the diagnostic yield and safety of transbronchial mediastinal cryobiopsy monitored by endosonography for the diagnosis of mediastinal lesions. Patients with mediastinal lesion of 1 cm or more in the short axis were recruited. Following identification of the mediastinal lesion by linear EBUS, fine-needle aspiration and cryobiopsy were sequently performed in a randomised order. Primary endpoints were diagnostic yield defined as the percentage of patients for whom mediastinal biopsy provided a definite diagnosis, and procedure-related adverse events.

RESULTS

One hundred and ninety-seven patients were enrolled and randomly allocated. The overall diagnostic yield was 79.9% and 91.8% for TBNA and transbronchial mediastinal cryobiopsy, respectively (p=0.001). Diagnostic yields were similar for metastatic lymphadenopathy (94.1% versus 95.6%, p=0.58), while cryobiopsy was more sensitive than TBNA in uncommon tumors (91.7% versus 25.0%, p=0.001) and benign disorders (80.9% versus 53.2%, p=0.004). No significant differences in diagnostic yield were detected between TBNA first and cryobiopsy first groups. We observed 2 cases of pneumothorax and 1 case of pneumomediastinum.

CONCLUSIONS

Transbronchial cryobiopsy performed under EBUS guidance is a safe and useful approach that offers diagnostic histological samples of mediastinal lesions.

Contemporary Concise Review 2020: Interstitial lung disease

The year 2020 was one like no other, as we witnessed the far-reaching impact of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) global pandemic. Yet despite an unprecedented and challenging year, global research in interstitial lung disease (ILD) continued to break new grounds. Research progress has led to an improved understanding in new diagnostic tools and potential biomarkers for ILD. Studies on the role of antifibrotic therapies, newer therapeutic agents, supportive care strategies and the impact of coronavirus disease 2019 (COVID-19) continue to reshape the management landscape of ILD. In this concise review, we aim to summarize the key studies published in 2020, highlighting their impact on the various aspects of ILD.

Trans-bronchial lung cryobiopsy in patients at high-risk of complications

Background

The surgical lung biopsy (SLB) is the recommended sampling technique when the pathological analysis of the lung is required in the work-up of an interstitial lung disease (ILD) but trans-bronchial lung cryobiopsy (TBLC) is increasingly recognized as an alternative approach. As TBLCs have lower mortality and morbidity risks than SLB, this study aimed to investigate the safety of TBLCs in patients at higher risk of complications and for whom SLB was not considered as an alternative.

Method

This prospective study was conducted in two hospitals in which TBLCs were performed in patients with body mass index (BMI) > 35, and/or older than 75 years, and/or with severely impaired lung function (FVC < 50% or DLCO < 30%), and/or systolic pulmonary artery pressure > 45 mmHg, and/or a clinically significant cardiac disease. Patients with any of these risk factors constituted the high-risk group. Clinical outcomes were compared with those obtained in patients without these risk factors (low-risk group).

Results

Ninety-six patients were included between April 2015 and April 2020, respectively 38 and 58 in the high-risk or the low-risk group. No statistically significant difference was observed between both groups in terms of severity and rate of bleeding, pneumothorax, or duration of hospital stay (p value ranging from 0.419 to 0.914).

Conclusion

This preliminary study on a limited number of patients suggests that TBLC appears safe in those in whom lung biopsy is at high-risk of complications according to their age, BMI, lung impairment, and cardiac comorbidities.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01503-9.

Transbronchial lung cryobiopsy for connective tissue disease-related interstitial lung disease and interstitial pneumonia with autoimmune features: a single center retrospective case series

OBJECTIVE

Transbronchial lung cryobiopsy (TBLC) has been recently introduced for diagnosing interstitial lung diseases. We aimed to assess the effectiveness and safety of TBLC by identifying the specific patterns of histology in the diagnosis of connective tissue disease-related interstitial lung disease (CTD-ILD) and interstitial pneumonia with autoimmune features (IPAF).

METHODS

The clinical-radiological-pathological data from the Affiliated Hospital of Guilin Medical University between July 1, 2017, and October 31, 2020, of patients whose clinical-radiological or clinical-radiological-pathological diagnosis was CTD-ILD or IPAF and who underwent TBLC, transbronchial lung biopsy (TBLB), or surgical lung biopsy were retrospectively analyzed and summarized with review. The size of biopsy samples, complications, and diagnostic yield were compared.

RESULTS

Fourteen patients met the inclusion criteria, of whom 12 underwent TBLC, 1 underwent TBLB, and 1 underwent each procedure at different times. Compared to the size of TBLB specimens (5.625 ± 0.479 mm²), the size of TBLC specimens (12.00 (12.00, 15.00) mm²) was much larger (Z = - 3.262, P = 0.001). The diagnostic yields of TBLC and TBLB were 100.00% (13/13) and 0.00% (2/2), respectively (P = 0.0095). The most frequent complication was mild bleeding. The risk of bleeding between TBLB (1/2, 50.00%) and TBLC (10/13, 76.92%) did not differ significantly (P = 0.469).

CONCLUSION

TBLC can add extra diagnostic value by effectively identifying specific types of histology for patients with suspected CTD-ILD or IPAF, with a procedure that is safe from adverse events. Key Points • Transbronchial lung cryobiopsy has been introduced recently for diagnosing interstitial lung disease. • Transbronchial lung cryobiopsy was found to be effective and safe in the diagnosis for patients with suspected interstitial lung disease. It can be used as a preferred method for biopsy when the clinical-radiological diagnosis is uncertain.

Implementation of transbronchial lung cryobiopsy in a tertiary referral center for interstitial lung diseases: a cohort study on diagnostic yield, complications, and learning curves

Background

Transbronchial lung cryobiopsy (TBLC) has been introduced as an alternative to surgical lung biopsy (SLB) in the diagnostics of interstitial lung diseases (ILD). Despite controversy on safety, TBLC is increasingly implemented in ILD centers with an apparent diagnostic yield comparable to SLB. The aim of this study was to assess TBLC implementation experiences from a tertiary Danish ILD center regarding diagnosis, complications, and learning curves for TBLC performance.

Methods

TBLC was prospectively performed in a cohort of patients with unclassifiable ILD based on a preceding multidisciplinary clinical and radiological revision. TBLC was performed as an outpatient procedure with the patients in general anesthesia using a flexible bronchoscope with 1.9 or 2.4 mm cryoprobes. Learning curves for TBLC performance were calculated using cumulated sum (CUSUM) scores for diagnostic yield, pneumothorax, and bleeding.

Results

From February 2017 to March 2020 141 patients (86 (61%) men, median age 69 years [IQR, 60–74 years]) had TBLC performed. A histological and confirmative diagnosis was made in 101 patients (75.2%) and 124 patients (87.9%, i.e. clinical diagnostic yield), respectively, in whom idiopathic interstitial pneumonias constituted the majority (67.3%) of the clinical diagnoses. We observed 2 deaths (1.4%) within 30 days of TBLC, but no procedure-related mortality or severe bleeding. Moderate bleeding occurred in 23 patients (16.3%), pneumothorax in 21 patients (14.9%) with only 14 patients (9.9%) requiring a pleural drain. Based on the CUSUM score analysis, the diagnostic yield obtained was satisfactory throughout the period.

Conclusion

This study reports experiences of outpatient TBLC implementation in a tertiary referral ILD center from the largest investigated TBLC cohort in Scandinavia The diagnostic yield and prevalence of complications obtained by TBLC from this single center study on unclassifiable ILD support outpatient TBLC as a valuable and safe alternative to SLB to diagnose ILD in well-selected patients. The learning curves for TBLC were acceptable in the hands of experienced bronchoscopists.