Transbronchial Lung Cryobiopsy for Diagnosing Interstitial Lung Diseases and Peripheral Pulmonary Lesions - A Stepwise Approach

Summary

Transbronchial lung cryobiopsy (TBLC) for diagnosing interstitial lung disease and peripheral pulmonary lesions is a high-yield diagnostic and safe procedure. We describe a stepwise approach to conduct TBLC for the different indications mentioned with a flexible bronchoscope, which might be helpful for novice bronchoscopists performing TBLC.

Abstract

Transbronchial lung cryobiopsy (TBLC) is an invasive procedure increasingly implemented during the last decade as an alternative to video-assisted thoracic surgery lung biopsy (SLB) for diagnosing interstitial lung diseases (ILDs). The indication for TBLC has primarily been to sub-classify a specific ILD subtype when this cannot be achieved on the basis of a preceding multidisciplinary team discussion. Although SLB is considered the gold standard for establishing a histological diagnosis, TBLC has been gradually suggested as the first-choice histological diagnostic modality in patients with unclassified ILDs due to a comparable diagnostic yield with SLB, but superior to SLB in terms of complications, including mortality. During recent years, radial endobronchial ultrasound (R-EBUS) and electromagnetic navigation bronchoscopy (ENB)-guided TBLC for peripheral pulmonary lesions have also been described as safe procedures, which may improve the diagnostic yield compared to forceps biopsies. Still, the diagnostic properties of TBLC rely on the quality of the procedure's performance. This article aims to describe the stepwise approach to conducting TBLC with a flexible bronchoscope for the different indications mentioned, which might be helpful for novice bronchoscopists performing TBLC.

Introduction

Interstitial lung diseases (ILDs) constitute a group of both acute and chronic lung diseases that affect one or more of all the lung parenchymal components forming the interstitium such as bronchi, alveoli, connective tissue, and blood- and lymphatic vessels. Despite being rare diseases, the more than 200 different subtypes of ILDs represent a heterogeneous disease category with different clinical, radiological, and cyto-histological characteristics. ILDs typically manifest as inflammation, fibrosis, or a combination of both, which are the underlying causes for the patients' usual perceived symptoms as dry cough, dyspnea on exertion, and fatigue^1....

Protocol

The authors come from two Danish TBLC centers (Odense University Hospital and Aarhus University Hospital) that both conduct research in accordance with the principles of the Declaration of Helsinki. Ethics approval was not necessary as the study was observational in nature. All patients included for research purposes gave written informed consent. It is important to emphasize that the described stepwise approach for TBLC conductance relates to the use of a flexible bronchoscope and is based on a combination of recommendations from international guidelines, expert statements, state-of-art reviews, and experiences from the two TBLC centers^9,....

Results

Based on the observations from the authors from two TBLC centers, the described stepwise procedure for TBLC with a flexible bronchoscope allowed histological sampling in well-selected Danish patients with yet undiagnosed ILD subtypes despite preceding MDD. Detailed observations from these cohorts are reported in two recently published studies^23,25 and for the center of the first author summarized in Table 2.

Discussion

Regardless of the indication for TBLC, its diagnostic properties rely on the quality of the procedure's performance and the selected criteria for undergoing the procedure. This emphasizes the recommendation of implementing a formal and certified training program to acquire the competences required to perform a standardized TBLC procedure. Despite the fact that no official TBLC education is currently obtainable, the recent European Respiratory Society guideline on TBLC for ILD suggests that interventional pulmonologis.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
"Chimney" for tube
CO2 gas bottle adapter
CO2 gas tank	Erbe
Endoscopy column
Endotracheal tube, size 7.5-8.5 mm	Erbe
Erbecryo pedal footswitch	Erbe
Erbecryo2 workstation	Erbe
Flexible bronchoscope
Flexible gas hose	Mediland
Flexible single use cryoprobe, OD 1.1 mm	Erbe
Flexible single use cryoprobe, OD 1.7 mm	Erbe
Flexible single use cryoprobe, OD 2.4 mm
Fluoroscope
Fogarty balloon catheter
Formalin glasses in closed system
NaCl incl. cold NaCl
Pean for fixating Fogarty balloon
Sterile disposable cup
Sterile suction tube
Sterile tweesers
Syringe for Fogarty balloon inflation/deflation
Table bag for flouroscope
Three way tap for Fogarty balloon syringe
Tracheal suction
Ultrasound machine	Erbe
Valve for biopsy chanel
Valve to suction duct