Prospective multicentre study on the safety and utility of transbronchial lung cryobiopsy with endobronchial balloon

Novel method of attaching a suction tube externally to a tracheal tube as an insertion route for a Fogarty catheter in cryobiopsy: Retrospective comparative study

BACKGROUND

Cryobiopsy use is anticipated to become more common in diagnosing lung diseases. In Japan, inserting a Fogarty catheter through a suction channel above the endotracheal tube's cuff for hemostasis is common practice. However, the rigid nature of the endotracheal tube poses challenges to tracheal intubation using a bronchoscope. The endotracheal tube cuff must be removed to prevent interference during Fogarty catheter insertion. To simplify the procedure and enhance safety, we devised and implemented a method of inserting a hemostatic Fogarty catheter with a suction tube externally attached to a softer endotracheal tube. This study aimed to evaluate the sustainability of this Fogarty catheter insertion method using suction tubes.

METHODS

The hemostatic Fogarty catheter insertion method was retrospectively validated. We compared outcomes between 60 patients who underwent the conventional method with a suction channel above the cuff and 50 patients who underwent the novel approach with an externally attached suction tube.

RESULTS

The physicians performing bronchoscopy and inserting the Fogarty catheter in the group in which the suction tube was externally attached for Fogarty catheter insertion had little experience. However, the overall bronchoscopy time was shorter; the two groups showed no significant differences in complications.

CONCLUSION

Regarding cryobiopsy procedures, using an externally attached suction tube for Fogarty catheter insertion was practical and comparable to the conventional method of using a suction channel above the cuff. This method made the procedure more simple and safe.

Case of stage 0 pulmonary sarcoidosis pathologically diagnosed via transbronchial lung cryobiopsy

A 45-year-old male was diagnosed with arrhythmia during a routine health examination. Findings from different modalities, such as echocardiography and radiography, were consistent with cardiac involvement in sarcoidosis. There was no ocular involvement or superficial lymph node enlargement. A chest computed tomography scan did not reveal any pulmonary lesions or bilateral hilar lymphadenopathy. To pathologically diagnose systemic sarcoidosis, transbronchial lung cryobiopsy was performed. Results showed pathological evidence of noncaseating epithelioid granulomas. Herein, we present a case in which sarcoidosis diagnosis was confirmed via transbronchial lung cryobiopsy despite the absence of respiratory lesions on computed tomography scan.

Can transbronchial lung cryobiopsy benefit adaptive treatment strategies in connective tissue disease-associated interstitial lung disease?

BACKGROUND

Some patients with connective tissue disease (CTD)-associated interstitial lung disease (ILD) progress to pulmonary fibrosis over their disease course despite initial improvement, potentially indicating a poor prognosis. Transbronchial lung cryobiopsy (TBLC) is a new bioptic approach used in diffuse parenchymal lung diseases. This study of CTD-ILD assessed the utility of TBLC in determining therapeutic decision-making strategies.

METHODS

We analyzed medical records of 31 consecutive CTD-ILD patients who underwent TBLC focusing on radio-pathological correlation and disease course. A TBLC-based usual interstitial pneumonia (UIP) score was used that assessed three morphologic descriptors: i) patchy fibrosis, ii) fibroblastic foci, and iii) honeycombing.

RESULTS

Among the patients with CTD-ILD, 3 had rheumatoid arthritis, 2 systemic sclerosis, 5 polymyositis/dermatomyositis, 8 anti-synthetase syndrome, 6 Sjögren's syndrome, and 5 had microscopic polyangiitis. Pulmonary function test results showed a mean %FVC of 82.4% and %DL_CO of 67.7%. Among the 10 CTD patients and TBLC-proven pathological UIP, 3 patients had prominent inflammatory cells in addition to a framework of UIP, and pulmonary function of most patients improved with anti-inflammatory agents. Six (40%) of 15 patients with TBLC-based UIP score ≥ 1 had a progressive disease course during follow-up, of whom 4 patients received anti-fibrotic agents.

CONCLUSIONS

TBLC in patients with CTD-ILD can help determine an appropriate medication strategy, particularly when UIP-like lesions are present. TBLC may be useful when judging which agents to prioritize, anti-inflammatory or anti-fibrotic, is difficult. Moreover, additional information from TBLC may be beneficial when considering early intervention with anti-fibrotic agents in clinical practice.

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.

Feasibility of transbronchial lung cryobiopsy in patients with veno-venous extracorporeal membrane oxygenation support

Background

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is essential life support in patients with severe acute hypoxaemic respiratory failure. However, biopsies should be considered for some patients with unknown aetiology. This study aims to evaluate the feasibility of transbronchial lung cryobiopsy (TBLC) in such patients.

Methods

All patients with acute hypoxaemic respiratory failure of unknown aetiology who underwent TBLC with VV-ECMO support were retrospectively reviewed. Patients' characteristics, ventilation settings, procedure parameters, complications, pathological diagnosis and survival were summarised and analysed.

Results

Eight female and five male patients with VV-ECMO support underwent TBLC. The median age was 58 (interquartile range (IQR) 38-67) years old. Concurrent diseases were present in 10 of the 13 patients, seven of which were immunosuppressed. The median time between biopsy and VV-ECMO establishment was 2.0 (IQR 0.5-6.5) days. No patient died from the procedure. Neither pneumothorax nor severe bleeding occurred in any of the patients. Five of the 13 patients experienced moderate bleeding, and all bleeding events were successfully controlled with prophylactic balloon blockers. Pathological diagnosis by TBLC was obtained in all patients, and the diagnosis of diffuse alveolar damage was made in nine of them.

Conclusions

In patients with VV-ECMO support, the TBLC procedure is generally safe when standardised bleeding prophylaxis is in place. TBLC contributes to identifying underlying aetiologies in patients with acute hypoxaemic respiratory failure of unknown aetiology.

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.

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.

Transbronchial Lung Cryobiopsy in Patients with Interstitial Lung Disease: A Systematic Review

RATIONALE

In 2018, a systematic review evaluating transbronchial lung cryobiopsy (TBLC) in patients with interstitial lung disease (ILD) was performed to inform American Thoracic Society (ATS), European Respiratory Society (ERS), Japanese Respiratory Society (JRS), and Asociación Latinoamericana del Tórax (ALAT) clinical practice guidelines on the diagnosis of idiopathic pulmonary fibrosis (IPF).

OBJECTIVE

To perform a new systematic review to inform updated guidelines.

METHODS

Medline, EMBASE and the Cochrane Central Register of Controlled Trials (CCTR) were searched through June 2020. Studies that enrolled patients with ILD and reported the diagnostic yield or complication rates of TBLC were selected for inclusion. Data was extracted and then pooled across studies via meta-analysis. The quality of the evidence was appraised using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

Histopathologic diagnostic yield (number of procedures that yielded a histopathologic diagnosis divided by the total number of procedures performed) of TBLC was 80% (95% CI 76-83%) in patients with ILD. TBLC was complicated by bleeding and pneumothorax in 30% (95% CI 20-41%) and 8% (95% CI 6-11%) of patients, respectively. Procedure-related mortality, severe bleeding, prolonged air leak, acute exacerbation, respiratory failure, and respiratory infection were rare. The quality of the evidence was very low due to the uncontrolled study designs, lack of consecutive enrollment, and inconsistent results.

CONCLUSION

Very low-quality evidence indicated that TBLC has a diagnostic yield of approximately 80% in patients with ILD, with manageable complications.

Idiopathic Pulmonary Fibrosis (an Update) and Progressive Pulmonary Fibrosis in Adults: An Official ATS/ERS/JRS/ALAT Clinical Practice Guideline

Background: This American Thoracic Society, European Respiratory Society, Japanese Respiratory Society, and Asociación Latinoamericana de Tórax guideline updates prior idiopathic pulmonary fibrosis (IPF) guidelines and addresses the progression of pulmonary fibrosis in patients with interstitial lung diseases (ILDs) other than IPF. Methods: A committee was composed of multidisciplinary experts in ILD, methodologists, and patient representatives. 1) Update of IPF: Radiological and histopathological criteria for IPF were updated by consensus. Questions about transbronchial lung cryobiopsy, genomic classifier testing, antacid medication, and antireflux surgery were informed by systematic reviews and answered with evidence-based recommendations using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. 2) Progressive pulmonary fibrosis (PPF): PPF was defined, and then radiological and physiological criteria for PPF were determined by consensus. Questions about pirfenidone and nintedanib were informed by systematic reviews and answered with evidence-based recommendations using the GRADE approach. Results:1) Update of IPF: A conditional recommendation was made to regard transbronchial lung cryobiopsy as an acceptable alternative to surgical lung biopsy in centers with appropriate expertise. No recommendation was made for or against genomic classifier testing. Conditional recommendations were made against antacid medication and antireflux surgery for the treatment of IPF. 2) PPF: PPF was defined as at least two of three criteria (worsening symptoms, radiological progression, and physiological progression) occurring within the past year with no alternative explanation in a patient with an ILD other than IPF. A conditional recommendation was made for nintedanib, and additional research into pirfenidone was recommended. Conclusions: The conditional recommendations in this guideline are intended to provide the basis for rational, informed decisions by clinicians.

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.

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.

Utility of radial endobronchial ultrasonography combined with transbronchial lung cryobiopsy in patients with diffuse parenchymal lung diseases: a multicentre prospective study

Background

Radial endobronchial ultrasonography (R-EBUS) has been used in conjunction with transbronchial lung cryobiopsy (TBLC) to diagnose diffuse parenchymal lung disease (DPLD) and to decrease the risk of bleeding complications. The diagnostic utility of different R-EBUS signs, however, remains unknown.

Objectives

This study aimed to determine whether different R-EBUS signs could be used to more accurately diagnose DPLD and whether bronchial bleeding could be prevented with use of R-EBUS during TBLC.

Method

Eighty-seven patients with DPLD were included in this multicentre prospective study, with 49 patients undergoing R-EBUS. R-EBUS signals were characterised as displaying either dense or blizzard signs. Pathological confidence of specimens obtained from TBLC was compared between patients with dense versus blizzard signs, and severity of bronchial bleeding was determined based on whether R-EBUS was performed or not.

Results

All patients with dense signs on R-EBUS showed consolidation on high-resolution CT (HRCT) imaging. Pathological confidence of lung specimens was significantly higher in patients with dense signs versus those with blizzard signs (p<0.01) and versus those who did not undergo R-EBUS (p<0.05). Patients who underwent TBLC with R-EBUS were more likely to experience no or mild bronchial bleeding than patients who did not undergo R-EBUS (p<0.01), with shorter procedure times (p<0.01).

Conclusions

The dense R-EBUS sign corresponded with consolidation on HRCT. High-quality lung specimens may be obtainable when the dense sign is observed on R-EBUS, and R-EBUS combined with TBLC may reduce risk of bronchial bleeding and shorten procedure times.

Comparison of adequacy between transbronchial lung cryobiopsy samples and endobronchial ultrasound-guided transbronchial needle aspiration samples for next-generation sequencing analysis

Background

Most lung cancer patients present with lesions in both lung fields and lymphadenopathy. Thus, transbronchial lung cryobiopsy (TBLC) and endobronchial ultrasound‐guided transbronchial needle aspiration (EBUS‐TBNA) are commonly performed for diagnosing lung cancer. However, the adequacy of these samples for next‐generation sequencing (NGS) analysis remains unclear. This study aimed to compare the adequacy between TBLC and EBUS‐TBNA samples for NGS analysis.

Methods

This retrospective cohort study included patients whose lung samples were collected via TBLC or EBUS‐TBNA and analyzed using NGS. Out of 46 genes, the number of genes in TBNA and TBLC samples that could not be assessed via NGS analysis was mainly evaluated.

Results

A total of 37 patients were included and classified into two groups (TBLC group, n = 18 and TBNA group, n = 19). The mean number of genes that could not be evaluated via NGS analysis was significantly lower in the TBLC group than in the TBNA group (0.9 vs. 10.3, P = 0.024). The median total area of tumor cells in TBLC samples was significantly greater than that in TBNA samples (6.3 [1.6–4.2] vs. 2.6 [0.2–17.3] mm², P < 0.01). In the TBNA group, there were two fully inadequate samples for NGS analysis with a high degree of cell crush or low tumor content, while there was no fully inadequate sample in the TBLC group.

Conclusions

TBLC is more effective in obtaining adequate samples for NGS analysis than EBUS‐TBNA. TBLC should be performed to obtain adequate samples for NGS analysis in lung cancer patients with target lesions in lung fields, even if they have lymphadenopathy.

Key points

Significant findings of the study

The mean number of genes that could not be evaluated was significantly lower in TBLC samples than in EBUS‐TBNA samples (0.9 vs. 10.3, P = 0.024). TBLC could obtain adequate samples with a high concentration of uncrushed tumor cells for NGS.

What this study adds

To obtain samples for NGS analysis, the use of TBLC should be aggressively considered in lung‐cancer patients with target lesions located in lung fields, even if they have lymphadenopathy.