Transbronchial lung cryobiopsy and pulmonary fibrosis: A never-ending story?

Background: The diagnostic process of pulmonary fibrosis (PF) is often challenging, requires a collaborative effort of several experts, and often requires bioptic material, which can be difficult to obtain, both in terms of quality and technique. The main procedures available to obtain such samples are transbronchial lung cryobiopsy (TBLC) and surgical lung biopsy (SLB). Objective: The purpose of this paper is to review the evidence for the role of TBLC in the diagnostic-therapeutic process of PF. Methods: A comprehensive review was performed to identify articles to date that addressed the role of TBLC in the diagnostic-therapeutic process of PF using the PubMed® database. Results: The reasoned search identified 206 papers, including 21 manuscripts (three reviews, one systematic review, two guidelines, two prospective studies, three retrospective studies, one cross-sectional study, one original article, three editorials, three clinical trials, and two unclassifiable studies), which were included in the final review. Conclusions: TBLC is gaining increasing efficacy and improving safety profile; however, there are currently no clear data demonstrating its superiority over SLB. Therefore, the two techniques should be considered with careful rationalization on a case-by-case basis. Further research is needed to further optimize and standardize the procedure and to thoroughly study the histological and molecular characteristics of PF.

The efficacy and safety of radial endobronchial ultrasound-guided transbronchial lung cryobiopsy in the diagnosis of lung disease.

Background: Transbronchial lung cryobiopsy (TBLC) is a novel technology in which a cryoprobe is used to obtain large tissue samples from the lungs of patients with interstitial lung diseases (ILDs) and peripheral pulmonary lesions (PPLs). We aimed to determine the efficacy and safety of TBLC in the diagnosis of peripheral lung diseases in the Endoscopy Center of Shanghai Pulmonary Hospital. Further, the application value of radial endobronchial ultrasound (R-EBUS) used to determine the optimal area for cryobiopsy was evaluated in this study. Methods: In this retrospective study, the data of patients with unclarified ILDs or PPLs who underwent TBLC guided by R-EBUS between April 2020 and December 2021 at Shanghai Pulmonary Hospital in China were analyzed. Results: A total of 137 patients [72 men, 65 women; median age, 52 years (range, 24-76 years)] were enrolled in the study. Out of the 137 patients included in the study, 123 (89.8%) were diagnosed after multidisciplinary discussions (MDDs), including 105 (85.4%) with ILD, 10 (8.1%) with tuberculosis, and 8 (6.5%) with a malignant tumor. Sixty-five (47.4%) patients had a definitive pathologic diagnosis through TBLC, including 54 (83.1%) with ILD, 5 (7.7%) with tuberculosis and 6 (9.2%) with malignant tumors. The overall pathological diagnosis rate was 47.4%. In addition to clarifying the blood supply situation of the candidate target, R-EBUS detected lesions in 44 (32.1%) patients. Mild and moderate bleeding occurred in 75.2% and 24.8% of patients, respectively. No cases of severe bleeding were observed. Pneumothorax occurred in 6 (4.4%) patients, of which 2 recovered without additional treatment, and 4 (66.7%) needed closed thoracic drainage. Hydropneumothorax and mediastinal emphysema occurred in one patient each. No patients died due to TBLC. Conclusions: R-EBUS-guided TBLC is safe and effective for the diagnosis of lung diseases, including ILDs and other PPLs. R-EBUS can guide cryobiopsy and avoid the potential risk of severe bleeding as well as radiation exposure. The pathological diagnosis rate of ILDs is relatively low, and MDD plays an important role in the diagnosis of ILDs.

Feasibility and Safety of Transbronchial Lung Cryobiopsy for Diagnosis of Acute Respiratory Failure with Mechanical Ventilation in Intensive Care Unit.

BACKGROUND: Acute hypoxemic respiratory failure is common in intensive care units (ICUs). Lung biopsies may be required to make a definitive diagnosis in patients with unknown etiologies. The feasibility of transbronchial lung cryobiopsy is undetermined in patients with respiratory failure in the ICU. METHODS: Patients who underwent bronchoscopy examinations with transbronchial lung cryobiopsy (TBLC) between July 2018 and December 2019 were retrospectively analyzed through medical chart review. The procedures were performed by well-experienced interventional pulmonologists. RESULTS: Ten patients underwent bronchoscopy examinations with TBLC in the ICU at Chang Gung Memorial Hospital during the study period. In all patients, the diagnosis was made via pathological analysis. One patient developed pneumothorax and required chest tube placement after the procedure. None of the patients had bleeding requiring blood transfusion, and no deaths were directly related to the procedure. CONCLUSIONS: TBLC is a feasible technique to obtain lung pathology in patients with acute respiratory diseases of unknown etiologies. While the complication rate may be acceptable, the procedure should be performed by experienced interventional pulmonologists. However, airway blockers and fluoroscopy are highly recommended when used according to the current guideline. We do not encourage TBLC to be performed without having airway blockers available at the bedside.

Air embolism after transbronchial lung cryobiopsy: A case report.

A 76-year-old woman underwent transbronchial lung cryobiopsy (TBLC) and transbronchial lung biopsy (TBLB) for examination of interstitial infiltrates. After the examination, the patient's consciousness became clouded, and head computed tomography showed an air embolus. She was started on 100% oxygen, and her consciousness improved, but she remained hemiplegic on the left side and dysphagic. Vascular air embolism (VAE) is a rare but serious complication. Although cases of VAE have been reported with conventional transbronchial forceps biopsy, cases of VAE after TBLC are quite rare, and thus this case is reported.

An 80-year-old woman with myelofibrosis and diffuse mosaic attenuation on chest computed tomography.

An 80-year-old woman with myelofibrosis sought evaluation for progressive dyspnea. Her past medical history included essential thrombocytosis, which transformed to myelofibrosis. Inspiratory computed tomography of chest showed diffuse mosaic attenuation with lymphadenopathy. Flexible bronchoscopy with lymph node and pulmonary parenchymal cryo biopsy revealed nodular deposits of extramedullary hematopoiesis in lung parenchyma and moderate to severe vascular medial and intimal thickening of pulmonary vasculature consistent with pulmonary parenchymal extramedullary hematopoiesis associated with pulmonary hypertension (a rare compensatory mechanism in myeloproliferative disorders). In this report, we explore the manifestations, pathogenesis, treatment, and prognosis of pulmonary extramedullary hematopoiesis reported in the literature.

Trans-bronchial lung cryobiopsy in patients at high-risk of complications.

BACKGROUND: The surgical lung biopsy (SLB) is the recommended sampling technique when the pathological analysis of the lung is required in the work-up of an interstitial lung disease (ILD) but trans-bronchial lung cryobiopsy (TBLC) is increasingly recognized as an alternative approach. As TBLCs have lower mortality and morbidity risks than SLB, this study aimed to investigate the safety of TBLCs in patients at higher risk of complications and for whom SLB was not considered as an alternative. METHOD: This prospective study was conducted in two hospitals in which TBLCs were performed in patients with body mass index (BMI) > 35, and/or older than 75 years, and/or with severely impaired lung function (FVC < 50% or DLCO < 30%), and/or systolic pulmonary artery pressure > 45 mmHg, and/or a clinically significant cardiac disease. Patients with any of these risk factors constituted the high-risk group. Clinical outcomes were compared with those obtained in patients without these risk factors (low-risk group). RESULTS: Ninety-six patients were included between April 2015 and April 2020, respectively 38 and 58 in the high-risk or the low-risk group. No statistically significant difference was observed between both groups in terms of severity and rate of bleeding, pneumothorax, or duration of hospital stay (p value ranging from 0.419 to 0.914). CONCLUSION: This preliminary study on a limited number of patients suggests that TBLC appears safe in those in whom lung biopsy is at high-risk of complications according to their age, BMI, lung impairment, and cardiac comorbidities.

Diagnosis of miliary nodules as lung adenocarcinoma by cryobiopsy: A case report.

A 62-year-old woman with rheumatoid arthritis and a history of receiving immunosuppressant therapy had a recurrence of lung adenocarcinoma with EGFR L858R mutation. Following 14 months of treatment with erlotinib, computed tomography (CT) findings revealed the presence of small diffuse nodules. Bronchoscopy was performed as metastasis was suspected; however, this was not detected on lung biopsy with forceps. Transbronchial lung cryobiopsy (TBLC) succeeded in detecting metastatic adenocarcinoma, and T790M and L858R gene mutations. Pathological examination revealed a cluster of tumor cells in the intralobular interstitial areas, which was consistent with the CT findings. This report provides important information regarding the role of TBLC in diagnosing metastatic cancer, such as diffuse small miliary nodules, and its genetic mutations.

Transbronchial lung cryobiopsy may be of value for nonresolving acute respiratory distress syndrome: case series and systematic literature review.

BACKGROUND: Identification of pathologic features is helpful for the management of nonresolving acute respiratory distress syndrome (ARDS). Transbronchial lung cryobiopsy (TBLC) is a novel biopsy technique that may have comparable utility to surgical biopsy. The aim of this study was to assess the value of TBLC in patients with nonresolving ARDS. METHODS: All patients with nonresolving ARDS who underwent TBLC from January 2019 to August 2019 in a tertiary medical ICU were included. In addition, a literature search of TBLC for ARDS was performed by searching PubMed, EMBASE, ATS/ERS/APSR meeting abstracts, ClinicalTrials.gov , and Google Scholar. Data on complications, histologic diagnosis, management changes, and outcomes were analysed. RESULTS: Five patients (three women and two men) underwent TBLC. None of the patients developed pneumothorax, although two patients developed massive bleeding, which was controlled by continuous occlusion using bronchial blockers. There were no procedure-related deaths. Diffuse alveolar damage (DAD) and alternative histologic patterns were found in two and three patients, respectively, resulting in management changes in all cases. The literature search yielded four studies, which together with the present study comprised data from 25 cases in which TBLC was used in nonresolving ARDS. The summary diagnostic yield was 92% (23/25). Only 44% (11/25) of cases were proven to be DAD. TBLC contributed to management changes in 80% of patients (20/25). Procedure-related complications consisted of pneumothorax (16%, 4/25), significant bleeding (12%, 3/25), and persistent air leaks (8%, 2/25). There were no procedure-related deaths. The follow-up survival rate was 61.9% (13/21). CONCLUSIONS: The complications of TBLC in selected patients with nonresolving ARDS may be acceptable. The procedure may have a high diagnostic yield and can lead to a re-evaluation of the diagnosis as well as changes in patient management. Further investigations with larger sample sizes are required.