Chinese expert consensus on the standardized procedure and technique of transbronchial cryobiopsy

[EBUS-guided cryobiopsy in the diagnosis of mediastinal lesions - step by step]

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is the gold standard in the diagnosis of mediastinal and hilar lesions. For certain purposes, such as the diagnosis and subtyping of lymphoproliferative disorders or molecular pathology, a larger amount of intact sample material is required. EBUS cryobiopsy is a new and efficient tool for this purpose. As it is a new approach, there is still no standardised workflow. In this review, we present the procedure step by step as it is performed at the Ruhrlandklinik in Essen.

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.

Diagnostic performance of cryobiopsy guided by radial-probe EBUS with a guide sheath for peripheral pulmonary lesions

OBJECTIVE

Transbronchial lung cryobiopsy (TBCB) has developed rapidly and has become one of the research hotspots of lung biopsy technology. The present study sought to evaluate the efficacy of TBCB guided by radial-probe EBUS (RP-EBUS) and a guide sheath (GS) without fluoroscopy for peripheral pulmonary lesions.

METHODS

In this retrospective study, McNemar's test was used in order to compare TBCB and transbronchial forceps biopsy (TBFB) in terms of diagnostic performance. A multivariate logistic regression model was designed to explore the association between predictive variables and the diagnostic yield of TBCB.

RESULTS

A total of 168 patients underwent GS-guided RP-EBUS. Of those, 157 had lesions that were visible and 11 had lesions that were not. Of those 157 patients, 24 were excluded because of missing data or an unclear final diagnosis. Therefore, 133 patients underwent RP-EBUS-GS-guided TBFB and TBCB. The pooled diagnostic yield of RP-EBUS-GS-guided TBCB without fluoroscopy was 71.5% (103/144). In 133 patients, the diagnostic yield of TBCB was significantly higher than that of TBFB (77.4% vs. 59.4%; p < 0.05). Multivariate analysis indicated that lesion size and site were independently associated with the diagnostic yield of TBCB (OR = 2.8, p = 0.03 and OR = 4.1, p = 0.01, respectively), although cryoprobe size was not. There was no significant difference between the 1.1-mm cryoprobe and the 1.9-mm cryoprobe in terms of diagnostic performance (78.4% vs. 76.8%; p > 0.05).

CONCLUSIONS

GS-guided RP-EBUS is regarded as a practical option for guiding cryobiopsy, although it may not be able to replace fluoroscopy. Peripheral pulmonary lesions not located in the upper lobes or larger than 30 mm are significantly associated with a higher diagnostic yield of cryobiopsy.

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

INTRODUCTION

Transbronchial lung cryobiopsy (TBLC) has emerged as a promising alternative to surgical lung biopsy for the diagnosis of interstitial lung disease. However, uncertainty remains regarding its overall complications due to a lack of procedural standardization including the size of cryoprobe utilized.

METHODS

This is a prospective cohort study of a protocolized transbronchial cryobiopsy program utilizing a 2.4 mm cryoprobe. 201 consecutive subjects were enrolled at a single academic center.

RESULTS

The average biopsy size was 106.2 ± 39.3 mm². Complications included a total pneumothorax rate of 4.9% with 3.5% undergoing chest tube placement. Severe bleeding defined by the Nashville Working Group occurred in 0.5% of cases. There were no deaths at 30-days.

DISCUSSION

A protocolized transbronchial cryobiopsy program utilizing a 2.4 mm cryoprobe in can achieve a high diagnostic yield with a favorable safety profile.

Evaluation of Transbronchial Lung Cryobiopsy Freezing Time, Biopsy Size, Histological Quality, and Incidence of Complication: A Prospective Clinical Trial

BACKGROUND

Transbronchial cryobiopsy (TBCB), a novel way of obtaining a specimen of lung tissue using a flexible cryoprobe, can obtain large lung biopsies without crush artifacts. The freezing time of TBCB was empirically selected from 3 to 7 s in the previous studies. However, no consensus has yet been reached regarding the optimal freezing time used in TBCB.

OBJECTIVES

The primary endpoint was biopsy size in different freezing times. The secondary endpoints included sample histological quality, diagnostic confidence, and complications in different freezing times.

METHODS

Patients who were suspected of DPLD requiring histopathological examination for further evaluation were enrolled in this study. Distinct biopsies were obtained by using different freezing times increased from 3 to 6 s sequentially. Samples were reviewed by 2 external expert pathologists.

RESULTS

A total of 33 patients were enrolled, and 143 transbronchial cryobiopsies were taken in this trial. An average of 4.33 samples were taken from each patient. The mean biopsy size of different freezing times from 3 to 6 s was 9.10 ± 4.37, 13.23 ± 5.83, 16.26 ± 5.67, and 18.83 ± 7.50 mm2, respectively. A strong correlation between freezing time and biopsy size was observed (r = 0.99, p < 0.01). Statistically significant difference of biopsy size was detected in the freezing time of 3 s versus 4 s (p < 0.01) and 4 s versus 5 s (p = 0.02), but not in the freezing time of 5 s versus 6 s (p = 0.10). Overall bleeding in different freezing times from 3 to 6 s was 53.33%, 67.50%, 89.47%, and 77.14%, respectively. A significantly higher overall bleeding was observed when the freezing time exceeded 4 s (RR = 1.67, p < 0.01). Pneumothorax occurred in 4 cases (12.12%). One lethal case (3.03%) was noted 25 days after TBCB. Lung parenchyma was preserved well in all cryobiopsy samples. Thirty-one (93.94%) patients' histopathological findings were identified as sufficient to establish a CRP diagnosis. There was no statistical difference in diagnostic confidence between different freezing times.

CONCLUSION

A longer freezing time was associated with a larger size of the biopsy sample but a higher risk of bleeding. The optimal transbronchial cryobiopsy freezing time is 3-4 s, which is easily achievable and provides an adequate biopsy size whilst creating a safety threshold from complications.

A pilot study of the ultrathin cryoprobe in the diagnosis of peripheral pulmonary ground-glass opacity lesions

Background

It is very difficult to obtain samples of peripheral pulmonary ground-glass opacity lesions (GGOs) by traditional transbronchial biopsy. This study was conducted to evaluate the diagnostic efficacy and safety of transbronchial cryobiopsy (TBCB) of GGOs using a newly developed ultrathin cryoprobe with an outer diameter of 1.1 mm.

Methods

We retrospectively analyzed 20 patients with 23 GGOs who underwent TBCB using the ultrathin cryoprobe from October 2018 to November 2019 in the Shanghai Chest Hospital. The TBCB procedure was performed under the guidance of virtual bronchoscopic navigation (VBN), electromagnetic navigation bronchoscopy (ENB), endobronchial ultrasound, and fluoroscopy. We collected the baseline information of participants, reported diagnostic yield and complications, and analyzed factors may have affected the diagnostic yield.

Results

A total of 23 GGOs (12 pure GGOs, 11 mixed GGOs), with an average diameter of 21.58±11.88 mm, underwent TBCB, and the diagnostic yield was 82.61% (19/23). Of the 19 GGOs diagnosed by TBCB, 12 were adenocarcinomas, 5 were inflammation, 1 was occupational interstitial lung disease, and 1 was a pulmonary meningothelial-like nodule. The remaining 4 undiagnosed lesions were confirmed to be adenocarcinomas by further analysis. The diagnostic yield was unchanged by factors including size (GGOs ≥20 mm, GGOs <20 mm), navigation (VBN, ENB), fluoroscopic visibility (visible, invisible), GGO-component (pure GGOs, mixed GGOs), and guide sheath (K-201, K203). There was no presentation of pneumothorax or severe hemorrhage.

Conclusions

The ultrathin cryoprobe is feasible, safe, and has a high diagnostic yield in the diagnosis of pulmonary GGOs. There is vast potential for the ultrathin cryoprobe as a tool for the diagnosis of GGOs, especially for cases suspicious of early-stage lung cancer.

Trial registration

ClinicalTrials.gov. No: NCT03716284. Registered: 20 October, 2018. URL: ClinicalTrials.gov.