Transbronchial Lung Cryobiopsy With 2 Bronchoscopes: New Novum New Magna.

Abstract

In Reply: We read the communication by Dhooria et al1 about our transbronchial lung cryobiopsy (TBLC) publication and our 2-scope technqiue.2 We would like to answer some of their questions/observations. Dhooria et al3 state they described our technique previously in spontaneously breathing subjects without an artificial airway. This publication is a case report, not even a case series. When Dhooria et al4 performed TBLC in their second patient, they encountered significant bleeding with life-threatening hypoxemia. This event prompted to change their technique in a subsequent case series, in which there is no mentioning of the use of a Fogarty balloon. While we suspect their technique evolved based on their institutional experience, their so described 2-scope technique had a complication rate of 50% (significant bleeding in their second case) versus 4.1% of moderate-severe bleeding in our case series (3/74 patients). Also, their case report was published in the second quarter of 2016. Our initial TBLC experience was in the last quarter of 2013, while our 2-scope technique was developed about a year after based on our institutional experience (last quarter of 2014). Dhooria and colleagues state that 25% of our subjects had a final diagnosis of granulomatous inflammation, hence the high diagnostic yield. Careful reading of the last paragraph in our publication2 answers their concern: “[…] these cases did not have the typical time course or laboratory and imaging data that would have suggested these diagnoses (low pre-test probability) before they underwent TBLC.” Even Dhooria et al3 used TBLC to differentiate TB infection versus sarcoidosis in their initial experience. As far as we know, when patients undergo surgical lung biopsy, the thoracic surgeon typically requests a double lumen tube intubation, which a vast majority of our patients would have not tolerated. In our opinion, if a patient is fit for surgical lung biopsy, this is the procedure we would recommend (gold standard), unless they refuse. The question about freezing time is based on our 200+ TBLC experience. The cryoprobes are fragile by nature, and continuing use of them extends the freezing time to achieve an iceball that will provide an acceptable biopsy size. We standardized the freezing time about 2.5 years ago to the time necessary to make a 13-Fr iceball with the 1.9 mm probe and 16-Fr iceball with the 2.4 mm probe, whether it is 3 or 8 seconds. Finally, we would like to establish that in no regards our technique is the same that Dhooria et al3 described in a case report. If their technique would have been successful, they would have continued to use it and have a robust database. The use of a Fogarty balloon is cumbersome and will not be useful if taking TBLC samples from the upper lobes. Furthermore, without direct visualization, there is always uncertainty of the location of the already inflated Fogarty balloon. While the balloon theorically would prevent blood spilling into the contralateral lung airways, in patients with marginal lung function, this could pose grave danger to them. The use of an artificial airway reduces the insertion time of the second bronchoscope significantly (as opposed to try to insert it nasally, as per Dhooria and colleagues), while the use of general anesthesia increases patient’s comfort and reduces patient’s cough, which reduces complications. Lastly, we do recommend TBLC to be performed only in bronchoscopic centers of excellence. Thitiwat Sriprasart, MD* Alejandro Aragaki-Nakahod, MD† Sadia Benzaquen, MD†*Department of Internal Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital Thai Redcross Society†Division of Pulmonary, Critical Care and Sleep Medicine, University of Cincinnati Medical Center Cincinnati, Ohio