Response

Abstract

We thank Dr Sharp et al for their comments. Mounting evidence suggests that transbronchial cryobiopsy (TBC) could represent a paradigm shift in our management of patients with lung disease, promising a high diagnostic yield with a safety profile similar to that of conventional bronchoscopic forceps biopsy. This evidence, however, remains limited overall, and, practically, techniques for TBC seem to vary considerably across centers, as illustrated by the broad range of diagnostic yields and procedural complications. Sheath cryoprobe biopsy offers a potentially safer and more convenient approach for TBC and, if found to be as clinically useful as regular cryobiopsy, could indeed satisfactorily mitigate many problems associated with cryobiopsy and reduce cost substantially. It is unclear, however, whether this novel approach could in fact replace conventional cryoprobes. For example, the histologic diagnosis of diffuse parenchymal lung disease relies primarily on the assessment of microscopic features such as temporal and geographic heterogeneity in the case of usual interstitial pneumonia, which can be assessed at low magnification only when sufficient material is available. Ideal TBC size remains to be defined, but experts suggest that 5 × 5 mm (25 mm2) should be appropriate in most cases (T. Colby, MD, personal communication, November 2016), a size that is consistently attained with the 1.9- and 2.4-mm probes but exceeds the sheath cryobiopsy size reported in this study.1Yarmus L.B. Semaan R.W. Arias S.A. et al.A randomized controlled trial of a novel sheath cryoprobe for bronchoscopic lung biopsy in a porcine model.Chest. 2016; 150: 329-336Abstract Full Text Full Text PDF PubMed Scopus (40) Google Scholar Clearly, more research will be needed to determine their clinical utility in the diagnosis of diffuse parenchymal lung disease. As discussed in the accompanying editorial to our manuscript,2Pastis N.J. Silvestri G.A. Could cryo-biopsies lead bronchoscopy into the Ice Age?.Chest. 2016; 150: 270-272Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar there is a significant potential benefit for the sheath cryoprobe approach toward improving diagnostic yield in lung cancer as well as other disease entities lacking sufficient bronchoscopic diagnostic yields, such as early rejection in lung transplantation. We agree in full with Dr Sharp's call for additional research and randomized controlled trials to assess the efficacy of this novel technique. The current variability in techniques for TBC, diagnostic yields, and complication rates highlights the need for critical appraisal of this new technique. Multicenter multidisciplinary prospective studies to clarify the utility of the procedure are urgently needed. Ultimately, it is only with the demonstration that patient outcomes can be improved that cryobiopsy will find legitimacy within the diagnostic algorithm of pulmonary diseases. Developments in Cryobiopsy for Interstitial Lung Disease May Be Cost SavingCHESTVol. 151Issue 2PreviewThere has been increasing interest in transbronchial cryobiopsy for diagnosis in interstitial lung disease. As we highlighted in our systematic review and cost analysis, this has the potential to be cost saving in the setting of a payment by results system.1 Recently, it has been demonstrated in a porcine model that a new sheath cryoprobe gives equivalent biopsy quality without the need for en bloc bronchoscope removal or an endotracheal tube. This has the potential to shorten procedure times by 34.8% and reduce bleeding by 81.8% and the incidence of pneumothorax by 66.7%. Full-Text PDF A Randomized Controlled Trial of a Novel Sheath Cryoprobe for Bronchoscopic Lung Biopsy in a Porcine ModelCHESTVol. 150Issue 2PreviewTransbronchial forceps biopsy (FBx) has been the preferred method for obtaining bronchoscopic lung biopsy specimens. Cryoprobe biopsy (CBx) has been shown to obtain larger and higher quality samples, but is limited by its inability to retrieve the sample through the working channel of the bronchoscope, requiring the bronchoscope to leave the airway for sample retrieval. Full-Text PDF