Transbronchial Cryobiopsy in Diffuse Lung Disease: Update for the Pathologist

High Diagnostic Accuracy of Transbronchial Cryobiopsy in Fibrotic Interstitial Lung Diseases Compared to Final Explant Diagnosis

BACKGROUND

A diagnostic lung biopsy may be required in some cases of fibrotic interstitial lung diseases (ILD). Transbronchial cryobiopsy has been suggested as a possible alternative to surgical lung biopsy. However, previous estimates of its diagnostic yield were not validated compared to the definitive diagnosis in explanted lungs.

OBJECTIVES

We aimed to assess the diagnostic accuracy of cryobiopsy in fibrotic ILD patients who subsequently had lung transplantation.

METHODS

All 197 patients who underwent lung transplantation at our Center due to fibrotic ILD from January 2010 to May 2018, were screened for the presence of a pre-transplant cryobiopsy. Fourteen patients who underwent cryobiopsy before transplantation were identified. Two expert lung pathologists blindedto the explant diagnoses, independently examined these cryobiopsy specimens to decide if they match guideline criteria for usual interstitial pneumonia (UIP) pattern or an alternative diagnosis. The primary measure was the diagnostic accuracy of cryobiopsy to detect or refute a UIP pattern, as compared to the final explant diagnosis.

RESULTS

Median time between cryobiopsy and transplantation was 1.4 years. All 14 cryobiopsy samples contained adequate alveolar tissue. The explant diagnosis of 13/14 patients was UIP. The two pathologists correctly diagnosed or refuted UIP in the cryobiopsy specimen in 12/14 cases (85.7%) and 11/14 cases (78.6%), respectively. The level of diagnostic agreement between pathologists was good (kappa 0.59, p = 0.016).

CONCLUSIONS

Compared to the final explant diagnosis, transbronchial cryobiopsy had high diagnostic accuracy and good inter-observer agreement for UIP pattern. These findings support a potential diagnostic role for cryobiopsy in experienced centers.

Lung Cryobiopsy for the Diagnosis of Interstitial Lung Diseases: A Series Contribution to a Debated Procedure

Introduction: Transbronchial cryobiopsy is an alternative to surgical biopsy for the diagnosis of fibrosing interstitial lung diseases, although the role of this relatively new method is rather controversial. Aim of this study is to evaluate the diagnostic performance and the safety of transbronchial cryobiopsy in patients with fibrosing interstitial lung disease. Materials and methods: The population in this study included patients with interstitial lung diseases who underwent cryobiopsy from May 2015 to May 2018 at the Division of Pneumology of San Giuseppe Hospital in Milan and who were retrospectively studied. All cryobiopsy procedures were performed under fluoroscopic guidance using a flexible video bronchoscope and an endobronchial blocking system in the operating room with patients under general anaesthesia. The diagnostic performance and safety of the procedure were assessed. The main complications evaluated were endobronchial bleeding and pneumothorax. All cases were studied with a multidisciplinary approach, before and after cryobiopsy. Results: Seventy-three patients were admitted to this study. A specific diagnosis was reached in 64 cases, with a diagnostic sensitivity of 88%; 5 cases (7%) were considered inadequate, 4 cases (5%) were found to be non-diagnostic. Only one major bleeding event occurred (1.4%), while 14 patients (19%) experienced mild/moderate bleeding events while undergoing bronchoscopy; 8 cases of pneumothorax (10.9%) were reported, of which 2 (2.7%) required surgical drainage. Conclusions: When performed under safe conditions and in an experienced center, cryobiopsy is a procedure with limited complications having a high diagnostic yield in fibrotic interstitial lung disease.

Transbronchial Lung Cryobiopsy in Idiopathic Pulmonary Fibrosis: A State of the Art Review

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease associated with significant morbidity and mortality. The diagnosis of IPF involves a combination of clinical history, radiological imaging and examination of histopathological samples in appropriate cases. Historically, transbronchial biopsy (TBB) has been used to obtain histological samples; however this lacks diagnostic accuracy. At present, surgical lung biopsy (SLB) is the gold standard technique for obtaining specimen samples; however this carries a significant mortality risk. Transbronchial lung cryobiopsy (TBLC) is a new technique that has been pioneered in the management of lung malignancy and offers a potential alternative to SLB. The technique employs a freezing probe, which is used to obtain lung tissue samples that are larger and better quality than traditional TBB samples. This affords TBLC an estimated diagnostic yield of 80% in interstitial lung disease. However, with limited evidence directly comparing TBLC to SLB, the diagnostic accuracy of the procedure has been uncertain. Common complications of TBLC include pneumothorax and bleeding. Mortality in TBLC is low compared with SLB, with exacerbation of IPF frequently reported as the cause. TBLC represents an exciting potential option in the diagnostic pathway in IPF; however its true value has yet to be determined.

Critical reappraisal of underlying histological patterns in patients with suspected idiopathic pulmonary fibrosis

PURPOSE OF REVIEW

Usual interstitial pneumonia (UIP) pattern is the histologic marker of idiopathic pulmonary fibrosis (IPF), but usefulness of ancillary histologic findings may discriminate idiopathic from secondary UIP.

RECENT FINDINGS

Alternative less invasive procedures may identify UIP pattern preventing conventional surgical lung biopsy, whereas genomic analysis may recognize UIP pattern from otherwise poorly diagnostic samples.

SUMMARY

High-resolution computed tomography identifies a 'definite' UIP pattern in about half of cases, failing to recognize UIP in the absence of honeycombing or in limited disease. Although radiologic criteria for UIP need redefinition to improve their diagnostic yield, histologic features of UIP did not significantly change from the 1960s but continue to represent a major diagnostic tool, particularly in challenging interstitial lung diseases. A careful recognition of some histologic ancillary findings in UIP (e.g., cellular/follicular bronchiolitis with germinal centers, chronic pleuritis, interstitial granulomas/giant cells, bridging fibrosis) may be helpful in supporting secondary forms (e.g., connective tissue disease, chronic hypersensitivity pneumonia) from IPF. Cryobiopsy and awake-biopsy are promising approaches to obtain representative lung tissue preventing conventional surgical lung biopsy. Genomic techniques have recently demonstrated good-to-high sensitivity and specificity to disclose UIP pattern starting from RNA obtained in transbronchial biopsy, possibly replacing and/or flanking soon traditional histology.

A Multidisciplinary Proposal for a Diagnostic Algorithm in Idiopathic Pulmonary Fibrosis: The Role of Transbronchial Cryobiopsy

The diagnosis of idiopathic pulmonary fibrosis (IPF) is a complex process that requires the multidisciplinary integration of clinical, radiological, and histological variables. Due to its diagnostic yield, surgical lung biopsy has been the recommended procedure for obtaining samples of lung parenchyma, when required. However, given the morbidity and mortality of this technique, alternative techniques which carry a lower risk have been explored. The most important of these is transbronchial cryobiopsy -transbronchial biopsy with a cryoprobe- which is useful for obtaining lung tissue with less comorbidity. Yield may be lower than surgical biopsy, but it is higher than with transbronchial biopsy with standard forceps. This option has been discussed in the recent clinical guidelines for the diagnosis of IPF, but the authors do not go so far as recommend it. The aim of this article, the result of a multidisciplinary discussion forum, is to review current evidence and make proposals for the use of transbronchial cryobiopsy in the diagnosis of IPF.

Transbronchial lung cryobiopsy in idiopathic acute fibrinous and organizing pneumonia

A 53-year-old Japanese female was admitted to our hospital with 3-week history of cough and worsening dyspnea. Chest computed tomography revealed unilateral focal consolidation in the right lower lobe. She underwent transbronchial lung cryobiopsy (TBLC) and histology showed acute fibrinous and organizing pneumonia (AFOP). High-dose methylprednisolone treatment improved her respiratory condition and radiological findings. AFOP is a rare histologic interstitial pneumonia pattern and has been diagnosed by surgical lung biopsy or autopsy in most cases. To our knowledge, this is the first detailed report of AFOP diagnosed by TBLC. TBLC can be performed safely with less invasion and be a useful diagnostic technique for rapidly progressive diffuse lung disease such as AFOP.

Introducing transbronchial cryobiopsies in diagnosing diffuse parenchymal lung diseases in Greece: Implementing training into clinical practice

Introduction

Diffuse parenchymal lung diseases (DPLD) constitute a heterogeneous group of disorders, sometimes requiring surgical lung biopsies (SLB) to obtain a definite diagnosis. Transbronchial cryobiopsy (TBCB) is a new promising interventional bronchoscopic method of obtaining lung tissue that is gaining ground against SLB.

Methods

Fifty consecutive patients with indeterminate DPLD (definite/possible UIP excluded), after expert panel review referral, were retrospectively analyzed from January 2016 to August 2018. Patients underwent TBCB under deep sedation with endotracheal intubation and spontaneous breathing at a single, tertiary-care, reference hospital.

Results

A total of 110 TBCBs (2.7 per patient, range 1 to 4) were performed. Frequent complications included mild pneumothorax in 5 patients (10%), requiring only oxygen supplementation, and bleeding in 31 patients (62%) that was mild in 19 patients and moderate in 12 patients. No serious bleeding was observed. There was zero mortality and no serious adverse events. Adequate samples for diagnostic purposes were obtained in 46 patients (92%) and pathologic histologic diagnosis was reached in 40 patients (80%). The most frequent histopathological patterns were organizing pneumonia (OP) (25%) and non-specific interstitial pneumonia (NSIP) (15%). After an expert panel review of all cases a final diagnosis was achieved in 38 patients, corresponding to a diagnostic yield of 76% for TBCB.

Conclusion

Our single center cohort demonstrates that establishing TBCBs as a new technique is safe and feasible after proper training in specialized centers, resulting in low complication rates and adequate diagnostic yields.

Idiopathic pulmonary fibrosis: prognostic impact of histologic honeycombing in transbronchial lung cryobiopsy

Background

Prognostic evaluation in idiopathic pulmonary fibrosis (IPF) may be important as it can guide management decisions, but the potential role of honeycomb changes in providing information about outcome and survival of patients with IPF, particularly if diagnosed using cryobiopsy, has not been evaluated. Aim of this study was to determinate whether a relationship exists between honeycombing on cryobiopsy and clinical/radiological picture and outcome in patients with IPF and to assess whether the same pathologic criteria that have been used to define the UIP pattern (usual interstitial pneumonia) for surgical biopsy can also be applied to cryobiopsy.

Methods

Sixty-three subjects with a multidisciplinary diagnosis of IPF and a UIP pattern on cryobiopsy were evaluated. Patients were classified into two sub-groups depending on the presence of honeycombing on histology.

Results

The presence of honeycombing on cryobiopsy did not identify a specific phenotype of patients as it did not correlate with radiological and clinical picture and it was not associated neither with the risk of death (p = 0.1192) or with the event-free survival (p = 0.827); a higher number of samples and the presence of pleura on biopsy were instead associated with an increase in the finding of honeycombing.

Conclusions

The same pathologic criteria that have been used to define the UIP pattern in surgical biopsies (with honeycombing changes considered as non-mandatory for the definition of the pattern itself) can be applied to cryobiopsy samples, as the presence of these changes do not define different clinical or radiological phenotypes of patients with IPF.

Diagnostic yield and risk/benefit analysis of trans-bronchial lung cryobiopsy in diffuse parenchymal lung diseases: a large cohort of 699 patients

Background

Standardization of trans-bronchial lung cryobiopsy in diffuse parenchymal lung diseases is imminent; however, the majority of published series on cryobiopsy include a limited number of patients and are characterized by several differences in procedural technical details.

Methods

This is an observational, retrospective cohort study. Aim of the study was to suggest some sampling strategies related to transbronchial cryobiopsy in the diagnostic work-up of patients with diffuse parenchymal lung diseases.

Results

Six hundred ninety-nine patients with suspected diffuse parenchymal lung disease were recruited. A specific pathological diagnosis was achieved in 614/699 cases (87.8%) and a multidisciplinary diagnosis was obtained in 630/699 cases (90.1%). Diagnostic yield was significantly influenced by the number of samples taken (1 vs ≥ 2 biopsies, p < 0.005). In 60.4% of patients, biopsies were taken from one site and in 39.6% from different sites (in the same lobe or in two different lobes), with a significant increase in diagnostic yield, specifically in patients with fibrotic lung diseases (65.5% vs 93.4%, p < 0.0001). The 2.4 mm or 1.9 mm probes were used, with no differences in terms of diagnostic yield. Regarding safety, pneumothorax occurred in 19.2% and was influenced by baseline lung function; in all patients Fogarty balloon has been used and severe haemorrhage occurred in 0.7% of cases. Three patients (0.4% of cases) died within 30 days after the procedure.

Conclusions

We propose some sampling strategies of cryobiopsy which seem to be associated with a higher diagnostic yield and a favorable risk/benefit ratio: sampling at least two samples in different sites, using either the 2.4 mm or the 1.9 mm probe, intubating the patients and using bronchial blockers/catheters.

Bronchoscopic lung cryobiopsy: An Indian association for bronchology position statement

BACKGROUND

Bronchoscopic lung cryobiopsy (BLC) is a novel technique for obtaining lung tissue for the diagnosis of diffuse parenchymal lung diseases. The procedure is performed using several different variations of technique, resulting in an inconsistent diagnostic yield and a variable risk of complications. There is an unmet need for standardization of the technical aspects of BLC.

METHODOLOGY

This is a position statement framed by a group comprising experts from the fields of pulmonary medicine, thoracic surgery, pathology, and radiology under the aegis of the Indian Association for Bronchology. Sixteen questions on various technical aspects of BLC were framed. A literature search was conducted using PubMed and EMBASE databases. The expert group discussed the available evidence relevant to each question through e-mail and a face-to-face meeting, and arrived at a consensus.

RESULTS

The experts agreed that patients should be carefully selected for BLC after weighing the risks and benefits of the procedure. Where appropriate, consideration should be given to perform alternate procedures such as conventional transbronchial biopsy or subject the patient directly to a surgical lung biopsy. The procedure is best performed after placement of an artificial airway under sedation/general anesthesia. Fluoroscopic guidance and occlusion balloon should be utilized for positioning the cryoprobe to reduce the risk of pneumothorax and bleeding, respectively. At least four tissue specimens (with at least two of adequate size, i.e., ≥5 mm) should be obtained during the procedure from different lobes or different segments of a lobe. The histopathological findings of BLC should be interpreted by an experienced pulmonary pathologist. The final diagnosis should be made after a multidisciplinary discussion. Finally, there is a need for structured training for performing BLC.

CONCLUSION

This position statement is an attempt to provide practical recommendations for the performance of BLC in DPLDs.

Confocal Laser Endomicroscopy as a Guidance Tool for Transbronchial Lung Cryobiopsies in Interstitial Lung Disorder

BACKGROUND

Transbronchial cryobiopsy (TBCB) of the lung parenchyma is a minimally invasive alternative for surgical lung biopsy in interstitial lung disease (ILD) patients. Drawbacks are the nondiagnostic rate and complication risk of pneumothorax and bleeding. Fluoroscopy is the current guidance tool for TBCB, which is limited by 2D imaging and a radiation dose for the patient. Confocal laser endomicroscopy (CLE) is a high-resolution imaging technique that provides immediate feedback during bronchoscopy about the elastin fiber network of peripheral lung areas. Both the visceral pleura and fibrotic lung areas consist of elastin fibers and are therefore potentially detectable with CLE.

OBJECTIVES

To investigate whether CLE is capable of (1) distinguishing fibrotic from normal alveolar areas and (2) identifying the pleura.

METHODS

In and ex vivo CLE imaging obtained during bronchoscopy was compared with histology of lung biopsies in 14 ILD patients.

RESULTS

CLE imaging of the alveolar compartment was feasible in all patients without adverse events. Based on CLE imaging, key characteristics that influence both diagnostic yield (dense fibrotic areas) and complication rate (pleura and subpleural space) were visualized.

CONCLUSIONS

CLE seems a promising alternative to fluoroscopy as a guidance tool for TBCB procedures.

Tissue and Bronchoalveolar Lavage Biomarkers in Idiopathic Pulmonary Fibrosis Patients on Pirfenidone

BACKGROUND

Pirfenidone is a novel anti-fibrotic agent in idiopathic pulmonary fibrosis with proven clinical benefit. Better human tissue models to demonstrate the immunomodulatory and anti-fibrotic effect of pirfenidone are required.

OBJECTIVES

The purpose of the study was to use transbronchial lung cryobiopsy (TBLC), a novel technique which provides substantial tissue samples, and a large panel of biomarkers to temporally assess disease activity and response to pirfenidone therapy.

METHODS

Thirteen patients with confirmed idiopathic pulmonary fibrosis (IPF) underwent full physiological and radiological assessment at diagnosis and after 6-month pirfenidone therapy. They underwent assessment for a wide range of potential serum and bronchoalveolar lavage biomarkers of disease activity. Finally, they underwent TBLC before and after treatment. Tissue samples were assessed for numbers of fibroblast foci, for Ki-67, a marker of tissue proliferation and caspase-3, a marker of tissue apoptosis.

RESULTS

All patients completed treatment and investigations without significant incident. There was no significant fall in number of fibroblast foci per unit tissue volume after treatment (pre-treatment: 0.14/mm² vs. post-treatment 0.08/mm², p = 0.1). Likewise, there was no significant change in other markers of tissue proliferation, Ki-67 or Caspase-3 with pirfenidone treatment. We found an increase in three bronchoalveolar lavage angiogenesis cytokines, Placental Growth Factor, Vascular Endothelial Growth Factor-A, and basic Fibroblast Growth Factor, two anti-inflammatory cytokines Interleukin-10 and Interleukin-4 and Surfactant Protein-D.

CONCLUSIONS

TBLC offers a unique opportunity to potentially assess the course of disease activity and response to novel anti-fibrotic activity in IPF.

Transbronchial Lung Cryobiopsy in Interstitial Lung Diseases: Best Practice

The lung biopsy in interstitial lung disease (ILD) represents an important diagnostic step when the clinical and radiological data are insufficient for a firm diagnosis. A growing body of evidence suggests the utility of transbronchial lung cryobiopsy (TBLC) in the diagnostic algorithm of ILD as it allows, compared to transbronchial lung biopsy with conventional forceps, a better identification of complex histological patterns - such as usual interstitial pneumonia - and can provide information which has a clinical impact on the multidisciplinary discussion similar to that provided by surgical lung biopsy. Performed correctly, it appears to have a better safety profile than surgery. The decision to perform a lung biopsy should be a multidisciplinary decision process where it is felt that there is sufficient diagnostic doubt after a careful clinical evaluation including review of the computed tomograms of the thorax. The presence of severe pulmonary hypertension (> 50 mm Hg), poor lung function (FVC < 50%), or dismissed gas transfer (DLCO of < 35%) are considered relative contraindications for TBLC. Anticoagulants and antiplatelet drugs should be discontinued for the minimum period required for the specific drugs. The greatest consideration should be given to ensure the biopsy is performed safely and we recommend the use of either an endotracheal tube or rigid bronchoscopy. Deep sedation or general anesthesia allow better control of the procedure and a better patient experience. Prophylactic balloon blockers should be used to tamponade any bleeding and also to prevent overspill of blood from the segment that is being sampled. The procedure should be performed under fluoroscopy to ensure that samples are ideally obtained about 10 mm from the pleural edge. The cryoprobe is activated for about 5 s for the first biopsy and then adjusted according to the sample size obtained. With a careful standardized approach it is possible to obtain good-quality lung specimens for diagnosis in a safe manner.

Learning curve for transbronchial lung cryobiopsy in diffuse lung disease

INTRODUCTION

Transbronchial lung cryobiopsy (TBLC) is increasingly used in the diagnosis of diffuse lung disease (DLD), but no data have yet been published on the learning curve associated with this technique.

AIM

To evaluate diagnostic yield, lung tissue sample length and area, and procedure-related complications in a cohort of TBLC procedures to define the learning curve and threshold for proficiency.

METHODS

Retrospective analysis of the first 100 TBLCs performed in different segments of the same lobe in patients with suspected DLD. We compared diagnostic yield, sample length and area, and complications between consecutive groups of patients.

RESULTS

The overall diagnostic yield for TBLC was 82%. Median sample length was 5.4mm (IQR, 5-6) and median area was 19.5mm2 (IQR, 13.3-25). Pneumothorax was the most common complication (18%). On comparing the two groups of 50 consecutive patients, a significant difference was found for diagnostic yield (74% vs 90%; p=0.04), sample length (5.0mm [2.5-16] vs 6.0mm [4-12;] p<0.01) and area (17.5mm2 [6-42] vs 21.5mm2 [10-49]; p<0.01). Logarithm regression was applied to median diagnostic yield and sample length and area for groups of 10 consecutive patients to define the learning curve, which plateaued after approximately 70 procedures.

CONCLUSIONS

Our findings suggest that proficiency in TBLC is achieved at approximately the 70th procedure; however they need to be validated in more series and cohorts.

Pleuroparenchymal Fibroelastosis: A Review of Histopathologic Features and the Relationship Between Histologic Parameters and Survival

Pleuroparenchymal fibroelastosis (PPFE) is now a defined clinicopathologic entity in the updated 2013 ATS/ERS classification of idiopathic interstitial pneumonias (IIPs), which has led to a significant increase in cases being diagnosed at our institution. We have therefore reviewed 43 PPFE cases (58 biopsies in total) to assess whether any clinical or histopathologic features provide prognostic information. A semiquantatitive grading system was used to assess extent of fibroblastic foci, intra-alveolar fibroelastosis, visceral pleural fibrosis, chronic inflammation in areas of fibrosis, vascular fibrointimal thickening, and presence of granulomas. Other patterns of interstitial lung disease were also noted, if present. All biopsies showed intra-alveolar fibroelastosis, fibroblastic foci at the leading edge of fibrosis and chronic inflammation within areas of fibrosis, 91% showed vascular fibrointimal thickening of vessels, 73% showed pleural fibrosis, and 35% showed granulomas. Ten cases showed a coexistent IIP (5 showed usual interstitial pneumonia, 5 showed features of hypersensitivity pneumonitis). There was no significant correlation with mortality and severity of histologic parameters, other than a significant decrease in mortality in PPFE with coexistent granulomas, after adjusting for age and gender (hazard ratio, 0.27; P=0.049). Male gender was also associated with an increased risk of mortality, after adjusting for age (hazard ratio, 4.8; P=0.045). PPFE is more common than previously thought, not infrequently showing coexistent pathology, specifically usual interstitial pneumonia and granulomatous lung disease, our data suggesting the latter may have prognostic significance.

Diagnosis of Idiopathic Pulmonary Fibrosis "Pragmatic Challenges in Clinical Practice"

The past few years have signaled a major breakthrough on the management of idiopathic pulmonary fibrosis (IPF). Finally, we have drugs in our arsenal able to slow down the inexorable disease natural course. On the other hand, the latter evidence has increased the responsibility for a timely and accurate diagnosis. Establishment of IPF diagnosis directly affects the choice of appropriate treatment. The current diagnostic guidelines represent a major step forward providing an evidence-based road map; yet, clinicians are encountering major diagnostic dilemmas that inevitably affect therapeutic decisions. This review article aims to summarize the current state of knowledge on the diagnostic procedure of IPF based on the current guidelines and discuss pragmatic difficulties and challenges encountered by clinicians with regards to their applicability in the everyday clinical practice.

The interstitial lung disease multidisciplinary meeting: A position statement from the Thoracic Society of Australia and New Zealand and the Lung Foundation Australia

Interstitial lung diseases (ILD) are a diverse group of pulmonary diseases for which accurate diagnosis is critical for optimal treatment outcomes. Diagnosis of ILD can be challenging and a multidisciplinary approach is recommended in international guidelines. The purpose of this position paper is to review the evidence for the use of the multidisciplinary meeting (MDM) in ILD and suggest an approach to its governance and constitution, in an attempt to provide a standard methodology that could be applied across Australia and New Zealand. This position paper is endorsed by the Thoracic Society of Australia and New Zealand (TSANZ) and the Lung Foundation Australia (LFA).

Biopsy in idiopathic pulmonary fibrosis: back to the future

INTRODUCTION

Idiopathic Pulmonary Fibrosis (IPF) is a relentlessly progressive, fibrosing interstitial pneumonia characterized by a radiologic and/or histologic pattern of usual interstitial pneumonia (UIP). The availability of two effective anti-fibrotic drugs in IPF has encouraged the identification and treatment of patients in early stages in order to maximize clinical benefit. The ability of high-resolution computed tomography (HRCT) to identify a 'definite' UIP pattern is suboptimal, particularly in the absence of honeycombing. Therefore, radiologic criteria for UIP are currently being redefined. Histology represents the major source of information to define a UIP pattern. Novel and less invasive approaches (particularly cryobiopsy) to sample interstitial lung diseases have demonstrated high sensitivity and specificity. In parallel, researchers are focusing on molecular mechanisms underlying IPF with the aim to identify more specific druggable targets. Lung tissue is therefore essential for diagnostic, pathogenetic and therapeutic purposes. Areas covered: We identified and critically reviewed the most relevant recent literature related to the limitations of current radiologic criteria, new lung sampling procedures, and molecular pathways in support of the need of lung tissue to better understand IPF. Expert commentary: The development of truly effective treatments for IPF requires the identification of key pathogenetic molecules and pathways. To this end, the availability of lung tissue is vital.

Transbronchial cryobiopsy for diffuse parenchymal lung disease: a state-of-the-art review of procedural techniques, current evidence, and future challenges

Transbronchial lung biopsy with a cryoprobe, or cryobiopsy, is a promising new bronchoscopic biopsy technique capable of obtaining larger and better-preserved samples than previously possible using traditional biopsy forceps. Over two dozen case series and several small randomized trials are now available describing experiences with this technique, largely for the diagnosis of diffuse parenchymal lung disease (DPLD), in which the reported diagnostic yield is typically 70% to 80%. Cryobiopsy technique varies widely between centers and this predominantly single center-based retrospective literature heterogeneously defines diagnostic yield and complications, limiting the degree to which this technique can be compared between centers or to surgical lung biopsy (SLB). This review explores the broad range of cryobiopsy techniques currently in use, their rationale, the current state of the literature, and suggestions for the direction of future study into this promising but unproven procedure.

Diffuse parenchymal lung disease

Between September 2015 and August 2016 there were >1500 publications in the field of diffuse parenchymal lung diseases (DPLDs). For the Clinical Year in Review session at the European Respiratory Society Congress that was held in London, UK, in September 2016, we selected only five articles. This selection, made from the enormous number of published papers, does not include all the relevant studies that will significantly impact our knowledge in the field of DPLDs in the near future. This review article provides our personal view on the following topics: early diagnosis of idiopathic pulmonary fibrosis, current knowledge on the multidisciplinary team diagnosis of DPLDs and the diagnostic role of transbronchial cryobiopsy in this diagnostic setting, insights on the new entity of interstitial pneumonia with autoimmune features, and new therapeutic approaches for scleroderma-related interstitial lung disease.

Role of Transbronchial Lung Cryobiopsies in Diffuse Parenchymal Lung Diseases: Interest of a Sequential Approach

Background. Transbronchial lung cryobiopsies (TBLCs) are a promising diagnostic tool in the setting of diffuse parenchymal lung diseases (DPLDs). However, no comparison with surgical lung biopsy (SLB) in the same patient is available. Methods. The diagnostic yield and safety data of TBLCs, as well as the result of SLB performed after TBLCs, were analysed in a multicentric Belgian study. A SLB was performed after TBLCs in absence of a definite pathological diagnosis or if a NSIP pattern was observed without related condition identified following multidisciplinary discussion. Results. Between April 2015 and November 2016, 30 patients were included. Frequent complications included pneumothorax (20%) and bleeding (severe 7%, moderate 33%, and mild 53%). There was no mortality. The overall diagnostic yield was 80%. A SLB was performed in six patients (three without definite histological pattern and three with an NSIP). The surgical biopsy changed the pathological diagnosis into a UIP pattern in five patients and confirmed a NSIP pattern in one patient. Conclusion. TBLCs are useful in the diagnostic work-up of DPLDs avoiding a SLB in 80% of the patients. However, surgical biopsies, performed as a second step after TBLCs because of an indefinite diagnosis or a NSIP pattern, provide additional information supporting the interest of a sequential approach in these patients.

Introduction of cryobiopsies in the diagnostics of interstitial lung diseases - experiences in a referral center

Introduction: Transbronchial cryobiopsies (cTBB) has emerged as a new method for obtaining lung tissue biopsies in the diagnosis of interstitial lung diseases (ILDs). Until now, it has been used in a few highly specialized interventional centers and has shown promising results in obtaining a definite diagnosis of ILDs. Method: All patients undergoing a cTBB between November 2015 and June 2016 were included in this case series study. Data on patient demographics, high-resolution computed tomography patterns, size and number of biopsies, histology patterns, the contribution to a confident diagnosis and complications were registered. Results: Thirty-eight patients underwent cTBB in the period. cTBB contributed to the diagnosis in 28 (74%) of the 38 patients. Only few complications were observed; pneumothorax was the most frequent complication (10 patients, 26%). In six patients, local bleeding occurred during the procedure and was easily controlled by a Fogarty catheter balloon and in some cases tranexamic acid. Conclusion: Performing cTBB in the diagnostics of ILDs is a safe and feasible procedure. cTBB resulted in a confident diagnosis in 74% of cases.