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

Acute exacerbation of interstitial lung diseases and mortality post-cryobiopsy: a multicenter cohort study

Background

Interstitial lung diseases (ILDs) are a group of pulmonary disorders affecting the lung's structure. Acute exacerbation of ILD (AE-ILD) following medical procedures is a significant clinical concern. Lung cryoprobe transbronchial biopsy (cryobiopsy) is a relatively new diagnostic technique for ILD, but data on AE-ILD post-cryobiopsy is limited. This study aims to fill this gap by examining the prevalence, risk factors, and outcomes of AE-ILD following cryobiopsy.

Methods

This multicenter retrospective study analyzed data from patients who underwent cryobiopsy for ILD diagnosis at three U.S. institutions between January 2014 and August 2022. The study included patients over 18 years with confirmed or suspected ILD, categorized into those who experienced AE-ILD post-cryobiopsy and those who did not.

Results

Out of 111 patients, 3.6% experienced AE-ILD, with a 50% mortality rate in these cases. The study cohort was predominantly white, with a median age of 69.0 years. Common comorbidities included tobacco use and hypertension. Patients who developed AE-ILD had an increased median number of biopsies. The overall 30-day mortality was 1.8%. Overall complication rate was 32%, including pneumonia, pneumothorax, AE-ILD, and bleeding requiring intervention. The study findings suggest that bronchoscopic cryobiopsy may be associated with lower overall mortality, particularly in patients with compromised lung function.

Conclusions

This study provides significant insights into AE-ILD following cryobiopsy, underscoring the need for careful patient selection and procedural assessment. While cryobiopsy may offer a safer alternative to surgical lung biopsy in specific patient cohorts, the elevated risk of AE-ILD necessitates further research to optimize patient outcomes and procedural safety.

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.

Assessment of a randomized controlled trial on the safety of pre-placing bronchial balloons in transbronchial lung cryobiopsy for diagnosing interstitial lung disease

RATIONALE AND OBJECTIVES

Bleeding is a major complication of transbronchial lung cryobiopsy (TBLC), and pre-placing a bronchial balloon is one of the clinical practices used to prevent it, but with very weak evidence, which should be confirmed. This study aimed to conduct whether pre-placing a bronchial balloon in TBLC for diagnosing interstitial lung disease (ILD) is more safety.

MATERIALS AND METHODS

In this prospective, single-center, randomized controlled trial, patients with suspected ILD were enrolled and randomly assigned to pre-placed balloon and none-pre-placed balloon groups. The primary outcome was incidence of moderate bleeding in each group. The secondary endpoints were the incidence of severe bleeding, pneumothorax, and other procedural complications.

RESULTS

Exactly 250 patients were enrolled between August 2019 and March 2022, with 125 in each group. There were no significant differences in severe bleeding between the none-pre-placed balloon group and pre-placed balloon group (1.6% vs. 0.8%; adjusted p = 0.520), while more moderate bleeding occurred in the none-pre-placed balloon group (26.4% vs. 6.4%, adjusted p = 0.001), as well as more use of hemostatic drug (28.0% vs. 6.4%, adjusted p = 0.001). Three patients in the none-pre-placed balloon group used the bronchial balloon. More samples could be acquired in the pre-placed balloon group than in the none-pre-placed balloon group (3.8 ± 0.9 vs. 3.1 ± 0.9, p < 0.001). There were no significant differences in multidisciplinary discussion (MDD) between the two groups (89.6% vs. 91.2%, adjusted p = 0.182).

CONCLUSION

A pre-placed bronchial balloon can reduce the incidence of moderate bleeding and increase the confidence of the bronchoscopists. However, it had no effect on increasing the diagnostic rate of MDD and reducing severe bleeding.

REGISTRATION NUMBER

NCT04047667 ( www.

CLINICALTRIALS

gov identifier).

Radial Endobronchial Ultrasound-guided Transbronchial Cryobiopsy versus Forceps Biopsy for the Diagnosis of Solitary Pulmonary Nodules: A Prospective Randomised Trial

Background

Improvements in pulmonary diagnostic imaging and the development of lung cancer screening are increasing the prevalence of Solitary pulmonary nodules (SPNs). Fluoroscopically guided radial endobronchial ultrasound (EBUS) with transbronchial forceps biopsy (TB-FB) has been the conventional diagnostic method. Transbronchial cryobiopsy (TB-CB) is an alternative biopsy method. We sought to compare transbronchial cryobiopsy to transbronchial forceps biopsy for the diagnosis of SPNs.

Methods

A prospective, single-centre, randomised controlled trial was conducted at the Royal Adelaide Hospital (RAH). Patients with SPNs were randomised to either 5 transbronchial forceps biopsies or one transbronchial cryobiopsy. Complete blinding of investigators and participants was not possible, as transbronchial cryobiopsy required general anaesthesia. The primary outcome was diagnostic yield with secondary outcomes of specimen size, diagnostic yield for subsets challenging to access with forceps and safety.

Results

The overall diagnostic yield for the 28 enrolled subjects was 76.8%(22/28). The diagnostic yield was 91.7% (11/12 patients) for transbronchial cryobiopsy and 68.8% (11/16 patients) for forceps biopsy (p=0.14). Median biopsy sizes were consistently larger for the cryobiopsy arm at 7.0mm compared to 2.5mm(p<0.0001). An eccentric EBUS image signalling the probe was adjacent to the nodule occurred in 4/28 cases, and TB-CB confirmed a diagnosis in 3/3 randomised to this arm. There were no major complications with either technique.

Conclusion

Transbronchial cryobiopsy under the guidance of fluoroscopy and radial EBUS facilitates larger biopsy specimens without a significant increase in major complications. Further research is required to confirm the effect on diagnostic yield; however, our study supports a role for TB-CB in the diagnosis of SPNs and small, nodule-adjacent biopsies.

Clinical Trial Registration Number

Reference number of R20160213(HREC/16/RAH/37).

Diagnosing interstitial lung disease by multidisciplinary discussion: A review

The multidisciplinary meeting (MDM) has been endorsed in current international consensus guidelines as the gold standard method for diagnosis of interstitial lung disease (ILD). In the absence of an accurate and reliable diagnostic test, the agreement between multidisciplinary meetings has been used as a surrogate marker for diagnostic accuracy. Although the ILD MDM has been shown to improve inter-clinician agreement on ILD diagnosis, result in a change in diagnosis in a significant proportion of patients and reduce unclassifiable diagnoses, the ideal form for an ILD MDM remains unclear, with constitution and processes of ILD MDMs varying greatly around the world. It is likely that this variation of practice contributes to the lack of agreement seen between MDMs, as well as suboptimal diagnostic accuracy. A recent Delphi study has confirmed the essential components required for the operation of an ILD MDM. The ILD MDM is a changing entity, as it incorporates new diagnostic tests and genetic markers, while also adapting in its form in response to the obstacles of the COVID-19 pandemic. The aim of this review was to evaluate the current evidence regarding ILD MDM and their role in the diagnosis of ILD, the practice of ILD MDM around the world, approaches to ILD MDM standardization and future directions to improve diagnostic accuracy in ILD.