Background: A diagnosis of interstitial lung diseases (ILDs) may include surgical lung biopsy (SLB), which is associated with significant morbidity and mortality and also appreciable costs. Transbronchial lung cryobiopsy (TBLC) is adopting an important role. Objectives: The aim of this study was to compare the diagnostic yield (DY) and safety of TBLC and SLB in a large cohort of patients and to perform a systematic review of the literature as well as a meta-analysis. Methods: We performed a retrospective analysis of 447 cases with ILD undergoing TBLC and/or SLB and a systematic review of the literature (MEDLINE and Embase for all original articles on the DY and safety of TBLC in ILDs up to July 2015). Results: A total of 150 patients underwent SLB and 297 underwent TBLC. The median time of hospitalization was 6.1 days (SLB) and 2.6 days (TBLC; p < 0.0001). Mortality due to adverse events was observed for 2.7% (SLB) and 0.3% (TBLC) of the patients. Pneumothorax was the most common complication after TBLC (20.2%). No severe bleeding was observed. TBLC was diagnostic for 246 patients (82.8%), SLB for 148 patients (98.7%, p = 0.013). A meta-analysis of 15 investigations including 781 patients revealed an overall DY of 0.81 (0.75-0.87); the overall pooled probability of developing a pneumothorax, as retrieved from 15 studies including 994 patients, was 0.06 (95% CI 0.02-0.11). Conclusion: Cryobiopsy is safe and has lower complication and mortality rates compared to SLB. TBLC might, therefore, be considered the first diagnostic approach for obtaining tissue in ILDs, reserving the surgical approach for cases in which TBLC is not diagnostic.

BackgroundHistology is a key element for the multidisciplinary diagnosis of fibrotic diffuse parenchymal lung diseases (f-DPLD) when the clinical-radiological picture is nondiagnostic. Transbronchial lung cryobiopsy (TBLC) have been shown to be useful for obtaining large and well-preserved biopsies of lung parenchyma, but experience with TBLC in f-DPLD is limited.ObjectivesTo evaluate safety, feasibility and diagnostic yield of TBLC in f-DPLD.MethodProspective study of 69 cases of TBLC using flexible cryoprobe in the clinical-radiological setting of f-DPLD with nondiagnostic high resolution computed tomography (HRCT) features.ResultsSafety: pneumothorax occurred in 19 patients (28%). One patient (1.4%) died of acute exacerbation. Feasibility: adequate cryobiopsies were obtained in 68 cases (99%). The median size of cryobiopsies was 43.11 mm2 (range, 11.94–76.25). Diagnostic yield: among adequate TBLC the pathologists were confident (“high confidence”) that histopathologic criteria sufficient to define a specific pattern in 52 patients (76%), including 36 of 47 with UIP (77%) and 9 nonspecific interstitial pneumonia (6 fibrosing and 3 cellular), 2 desquamative interstitial pneumonia/respiratory bronchiolitis–interstitial lung disease, 1 organizing pneumonia, 1 eosinophilic pneumonia, 1 diffuse alveolar damage, 1 hypersensitivity pneumonitis and 1 follicular bronchiolitis. In 11 diagnoses of UIP the pathologists were less confident (“low confidence”). Agreement between pathologists in the detection of UIP was very good with a Kappa coefficient of 0.83 (95% CI, 0.69–0.97). Using the current consensus guidelines for clinical-radiologic-pathologic correlation 32% (20/63) of cases were classified as Idiopathic Pulmonary Fibrosis (IPF), 30% (19/63) as possible IPF, 25% (16/63) as other f-DPLDs and 13% (8/63) were unclassifiable.ConclusionsTBLC in the diagnosis of f-DPLD appears safe and feasible. TBLC has a good diagnostic yield in the clinical-radiological setting of f-DPLD without diagnostic HRCT features of usual interstitial pneumonia. Future studies should consider TBLC as a potential alternative to SLBx in f-DPLD.

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BLC is a new biopsy method that has a meaningful impact on diagnostic confidence in the multidisciplinary diagnosis of interstitial lung disease and may prove useful in the diagnosis of IPF. This study provides a robust rationale for future studies investigating the diagnostic accuracy of BLC compared with SLB.

Background: Transbronchial lung cryobiopsy is an innovative method of obtaining samples from the parenchyma of patients with diffuse parenchymal lung diseases. However, the technique is not yet standardized, and uncertainty exists about the optimal protocol, including the number of samples, the biopsy size, and the choice of the biopsy site. Objectives: To compare the diagnostic yield and complications of cryobiopsy with different strategies adopted to sample lung tissue (number of samples, biopsy site, and sample size). Methods: We prospectively enrolled 46 patients with suspected diffuse parenchymal lung diseases for the diagnosis of which a biopsy was deemed useful. All patients underwent transbronchial lung cryobiopsy, and they were randomly assigned to group A (4 samples obtained from the same segment) or group B (2 samples obtained from one segment and 2 samples obtained from a different segment of the same lobe). Analysis of the samples was performed sequentially (from the first to the last sample), and pathologists reformulated their histopathologic diagnosis with the addition of each sample. Results: The mean diagnostic yield of the procedure combining the 2 groups and performing only the first sampling was 69%. When a second biopsy was performed as well, the mean diagnostic yield improved, but this increase was significant only when the 2 samples were obtained from 2 different segments (96%, group B). Conclusions: This study suggests that the strategy of performing 2 biopsies with a cryoprobe may be associated with an increased diagnostic yield in diffuse parenchymal lung diseases if these samples are obtained from 2 different segments within the same lobe.

BackgroundUsual interstitial pneumonia (UIP), is a necessary feature pathologically or radiologically for the diagnosis of idiopathic pulmonary fibrosis (IPF). The predictive value of transbronchial biopsy (TBB) in identifying UIP is currently unknown. The objective of this study is to assess the accuracy with which histopathologic criteria of usual interstitial pneumonia (UIP) can be identified in transbronchial biopsy (TBB) and to assess the usefulness of TBBx in predicting a the diagnosis of UIP pattern. We conducted a retrospective blinded and controlled analysis of TBB specimens from 40 established cases of UIP and 24 non-UIP interstitial lung diseases.ResultsAdequate TBB specimens were available in 34 UIP cases (85% of all UIP cases). TBB contained histopathologic criteria to suggest a UIP pattern (ie. at least one of three pathologic features of UIP present; patchy interstitial fibrosis, fibroblast foci, honeycomb changes) in 12 cases (30% of all UIP cases). Sensitivity, specificity, positive and negative predictive values for the two pathologists were 30% (12/40), 100% (24/24), 100% (12/12), 46% (24/52) and 30% (12/40), 92% (22/24), 86% (12/14), 55% (22/40) respectively. Kappa coefficient of agreement between pathologists was good (0.61, 95% CI 0.31-0.91). The likelihood of identifying UIP on TBB increased with the number and size of the TBB specimens.ConclusionAlthough sensitivity is low our data suggest that even modest amount of patchy interstitial fibrosis, fibroblast foci, honeycomb changes detected on TBB can be highly predictive of a UIP pattern. Conversely, the absence of UIP histopathologic criteria on TBB does not rule out UIP.

SBD are associated with a worse prognosis, both in terms of mortality or clinical progression. The presence of SBD should be explored in all IPF patients.

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