Bronchoscopic lung cryobiopsy: An Indian association for bronchology position statement

Abstract

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.

Bronchoscopic Cryotherapy for Acute Hypoxemic Respiratory Failure in Three Mechanically Ventilated Patients: A Case Series

“…Cryotherapy employs extremely low temperatures to freeze the tissue for adhesion (cryoadhesion), destruction (cryoablation), or biopsy (cryobiopsy). 6 , 7 The principle of cryotherapy is based on the Joule Thomson effect in which a liquefied gas under pressure when exits through a small orifice undergoes rapid conversion and expansion to the gaseous form. This liquid–gas conversion is accompanied by a dramatic temperature drop that is captured at the tip of the cryoprobe.…”

Diagnostic Yield and Safety of Bronchoscopic Lung Cryobiopsy in Evaluation of Lung Mass

“…Patients with contraindication for performing BLC were excluded. Contraindications for performing BLC [ 1 ] are summarized in Table 3 .…”

“…Bronchoscopic lung cryobiopsy (BLC) is a novel video-assisted flexible bronchoscopic technique for obtaining lung biopsy. It comprises the bronchoscopic placement of a flexible cryoprobe into the lung tissue, freezing the cryoprobe and cropping out the lung tissue around the tip under direct vision in a fresh frozen state [ 1 ]. Forceps, brushes, or needles are presently the standard devices used during bronchoscopy for taking lung tissue biopsy specimens when diagnosing lung mass [ 2 ].…”

Guidelines of the Polish Respiratory Society for Diagnosis and Treatment of Idiopathic Pulmonary Fibrosis

“…Observational studies based on IPF patient registries indicate that material for lung pathomorphological examination is ever-more often collected using the TBLC method [146]. At present, the procedure is not commonly available or practiced, although there are ongoing attempts at its standardisation [147][148][149]. Material collected with this method is usually smaller than in surgical biopsy, with no possibility of choosing the precise biopsy siteit usually comes from the more centrally located areas [122].…”

“…The recognised risk factors for cryobiopsy complications include, among others, forced vital capacity (FVC) < 50% of predicted and carbon monoxide lung transfer (T L,CO ) < 35% of predicted, serious hypoxaemia (PaO 2 < 50-60 mm Hg when breathing atmospheric air at rest), suspected pulmonary hypertension with > 40 mm Hg in echocardiographic examination. These factors are sometimes considered relative contraindications for the procedure [147,148].…”